Compositions

Abstract

A solid composition comprising at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid compos

Description

Field The present invention relates to solid compositions useful in the preparation of detergent formulations. In particular, the invention relates to solid compositions comprising biosurfactants, for example which may be in free flowing particulate form. Background It is highly desirable to provide detergent formulations in solid form. Solid formulations have a reduced environmental impact compared with liquid (for example aqueous) formulations, as unnecessary transport of solvent (for example water) is avoided. However a difficulty which arises during the manufacture of solid formulations is that many component ingredients are only commonly available as aqueous solutions. Biosurfactants, especially glycolipids like sophorolipids and rhamnolipids, are becoming increasingly important as alternatives to traditional surfactants as they can be produced from sustainable materials whilst having equally good or better performance. Biosurfactants are commonly available as aqueous solutions, typically containing about 40 to 60 wt% of active biosurfactant. Biosurfactants are difficult to dry and may form a hygroscopic product, especially when in the acidic form. As a result, the material can be difficult to incorporate into formulations, especially those in the form of solids, gels or highly concentrated liquid formulations. It would be desirable to provide biosurfactants in a solid form that can readily be incorporated into detergent formulations. For example, it would be desirable to provide biosurfactants that are in the form of free flowing particulate materials, as these are easier to handle and dose than gels or lumpy or cake-like solids. The present inventors have surprisingly found that the inclusion of a specific amount of one or more non-biological surfactants, and optionally of one or more chelating agents, can enable the formation of a solid biosurfactant or improve the physical form of a solid biosurfactant, for example by providing a powder or granular solid form. Summary According to a first aspect of the invention, there is provided a solid composition comprising at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%. According to a second aspect of the invention, there is provided a method of preparing a solid composition according to the first aspect, the method comprising: (i) providing an aqueous composition comprising the one or more biosurfactants and the one or more non-biological surfactants and optionally one or more chelating agents; and (ii) drying the composition obtained in step (i). According to a third aspect of the invention, there is provided a detergent formulation comprising a solid composition according to the first aspect. According to a fourth aspect of the invention, there is provided the use of a solid composition according to the first aspect in household cleaning, manual dishwashing, automatic dishwashing, laundry, fabric care, kitchen care, carpet cleaning, vehicle care, polishing products, machine cleaning and maintenance, agrochemical treatments (for example to treat vegetation with pesticides, such as insecticides, fungicides and / or herbicides), oilfield chemical applications (for example tank cleaning), marine applications, personal care or institutional / industrial cleaning. According to a fifth aspect of the invention, there is provided the use of a detergent formulation according to the third aspect in household cleaning, manual dishwashing, automatic dishwashing, laundry, machine cleaning, personal care or institutional / industrial cleaning. According to a sixth aspect of the invention, there is provided method ofcleaning an article, the method comprising dissolving the detergent formulation of the third aspect to produce a solution and applying the solution to the article. According to a seventh aspect of the invention, there is provided the use of one or more non-biological surfactants, and optionally one or more chelating agents, to provide a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and wherein the total surfactant content of the solid composition is at least 75 wt%. According to an eighth aspect of the invention, there is provided a method of providing a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and wherein the total surfactant content of the solid composition is at least 75 wt%, the method comprising drying the one or more biosurfactants with one or more non-biological surfactants and optionally one or more chelating agents. According to a ninth aspect of the invention, there is provided the use of one or more chelating agents to improve the flowability of a solid composition (preferably a particulate composition), wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%. According to a tenth aspect of the invention, there is provided a method of improving the flowability of a solid composition (preferably a particulate composition), wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%, the method comprising drying the one or more biosurfactants and one or more non-biological surfactants with one or more chelating agents. Detailed Description Unless otherwise stated, the following terms used in the specification and claims have the meanings set out below. The term "hydrocarbyl" is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. The terms “alkyl” and “alkenyl” include both straight and branched chain alkyl and alkenyl groups respectively unless otherwise stated. The term “aryl” as used herein relates to an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, and includes any monocyclic, bicyclic or polycyclic carbon ring of up to 7 members in each ring, wherein at least one ring is aromatic. As used in the specification and the appended claims, the singular forms "a", "an," and "the" include both singular and plural referents unless the context clearly dictates otherwise. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of other components. The term “consisting essentially of’ or “consists essentially of’ means including the components specified but excluding other components except for components added for a purpose other than achieving the technical effect of the invention. The term “consisting of’ or “consists of’ means including the components specified but excluding other components. Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to include the meaning “consists essentially of’ or “consisting essentially of’, and also may also be taken to include the meaning “consists of’ or “consisting of’. As used herein, unless otherwise expressly specified, all numbers such as those expressing values, ranges, amounts of percentages may be read as if prefaced by the word “about”, even if the term does not expressly appear. The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1,2,3,4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.70 and 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein. The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each exemplary aspect of the invention, as set out herein are also applicable to any other aspects or exemplary aspects of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or embodiment of the invention as interchangeable and combinable between different aspects of the invention. As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a list is described as comprising group A, B, and / or C, the list can comprise A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination. The amounts provided herein as a wt% are each a weight percentage based on the total weight of the composition, e.g. of the solid composition or detergent formulation, unless otherwise stated. Additionally, the amounts provided herein as an amount of one or more components are a total amount of those components. References to a solid composition, formulation or component herein refer to compositions, formulations or components which are in the solid state under normal atmospheric conditions (i.e. at a pressure of 1 atmosphere and 298 K). According to a first aspect of the invention, there is provided a solid composition comprising at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%. The solid composition of the first aspect may be in any suitable form, for example in the form of granules, needles, agglomerates, a solid bar, block, puck, stick, powder, or tablet. Suitably the solid composition is in the form of a bar, block, puck, or stick manufactured in a way known to a person skilled in the art, for example by compacting, pouring and moulding, or extruding. The solid composition may be advantageously lighter and more compact than a liquid composition comprising the same amount of surfactant. The solid composition advantageously requires less packaging than liquid compositions, and may even require no packaging at all. The solid composition of the first aspect may be a free flowing composition. The solid composition of the first aspect may be a particulate composition, such as a free flowing particulate composition. The solid composition of the first aspect comprises at least 20 wt% of one or more biosurfactants (i.e. at least 20 wt% based on the total weight of the solid composition). By this we mean that the solid composition comprises at least 20 wt% of the active biosurfactant. The solid composition of the first aspect may comprise any suitable biosurfactant(s). In some embodiments, the solid composition of the first aspect may comprise one biosurfactant. In some embodiments, the solid composition of the first aspect may comprise a mixture of two or more biosurfactants. By the term “biosurfactant” we mean a surfactant that is produced by microorganisms, for example which may be a product of a fermentation process. Typically, a biosurfactant is generated as a metabolic product during bacterial, fungal or algal fermentation, and the metabolic product may be further derivatised. Thus, references herein to a biosurfactant refer to biosurfactants that are direct metabolic products of bacterial, fungal or algal fermentation, as well as derivatives of the direct metabolic products. Similarly, references herein to a specific biosurfactant also referto derivatives of that biosurfactant unless otherwise stated. References herein to one or more biosurfactants include mixtures of different biosurfactants when more than one biosurfactant is used. The use of biosurfactants in the solid composition, formulation, methods and uses of the invention is advantageous, because biosurfactants are natural products, are generated in a sustainable way, are environmentally benign and typically have low toxicity. Biosurfactants are typically classified in four categories as polymeric biosurfactants, lipopeptides (or also called proteo-lipids), phospholipids and glycolipids. The one or more biosurfactants may be a complex mixture of biosurfactants. The one or more biosurfactants may be independently selected from one or more of a glycolipid, a lipopeptide, a phospholipid and a polymeric biosurfactant. Preferably the one or more biosurfactants are one or more glycolipids. Biosurfactants may comprise one or more fatty acid and / or fatty alcohol residues. Suitably biosurfactants useful in the invention comprise one or more fatty acid residues. The one or more fatty acid and / or fatty alcohol residues that may be present in the biosurfactants may be the same or different and may be derived from any suitable fatty acid and / or fatty alcohol, preferably from a naturally occurring fatty acid and / orfatty alcohol. Fatty acid residues are mostly derived from natural plant oils in the form of triglycerides. For example, biocatalysts may hydrolyse lipid esters in natural plant oils forming fatty acids and glycerol. Suitably, the fatty acid and / orfatty alcohol residues may comprise a branched or unbranched, saturated or unsaturated, hydrocarbyl group. The fatty acid and / or fatty alcohol residues that may be present in the biosurfactants may comprise from 4 to 50 carbon atoms, for example from 6 to 30 carbon atoms, preferably from 8 to 24 carbon atoms, more preferably from 12 to 22, or from 14 to 20 or from 16 to 18 carbon atoms. Preferred biosurfactants may therefore comprise residues of fatty acids derived from oleic acid, hydroxy substituted oleic acid (such as ricinoleic acid), palmitic acid and vegetable oils (such as sunflower, corn, soya, safflower oil, olive oil, palm oil, palm kernel, coconut oil and rapeseed oil). Any suitable biosurfactant(s) may be used. For example, the one or more biosurfactants may be independently selected from one or more of a glycolipid, a lipopeptide, a phospholipid and a polymeric biosurfactant (and mixtures thereof). For example, the one or more biosurfactants may be a glycolipid and a lipopeptide, or may be a glycolipid, a lipopeptide and a phospholipid, or may be two different glycolipids and so on. The one or more biosurfactants may each have any suitable molecular weight, such as a molecular weight of from 200 to 3000 g mol-1, for example from 250 to 2000 g mol-1, such as from 500 to 1500 g mol-1. The one or more biosurfactants may preferably be one or more glycolipids. Glycolipids comprise one or more carbohydrate residues in addition to the one or more fatty acid and / or fatty alcohol residues. The carbohydrate and fatty acid / fatty alcohol residues are joined either by means of a linker group or a direct bond, for example via an ester, amide or ether (for example glycosidic) bond. Suitable glycolipids may comprise one or more carbohydrate residues selected from rhamnose, trehalose, sophorose, mannose, galactose, glucose, cellobiose, glucosamine, sulfoquinovose, fructose, xylose, sucrose, lactose, maltose, sorbitol, erythritol and / or mannitol residues. For example, the one or more carbohydrate residues may be selected from rhamnose, trehalose, sophorose, mannose, erythritol, galactose, cellobiose and / or glucose residues. Preferably, the one or more carbohydrate residues may be selected from rhamnose, trehalose, sophorose, mannose and / or erythritol residues. More preferably, the one or more carbohydrate residues may be selected from sophorose and / or rhamnose residues. Most preferably, the one or more carbohydrate residues may be sophorose residues. Suitable glycolipids may be selected from one or more of a rhamnolipid, a trehalolipid, a sophorolipid, a mannosylerythritol lipid, a glycolipid produced by Meyerozama guilliermondii, Saccharomyces cerevisiae, Candida utilis, Candida bombicola and / or Marinobacter hydrocarbonoclasticus (including mixtures thereof). For example, suitable glycolipids may be selected from one or more of a rhamnolipid, a trehalolipid, a sophorolipid and a mannosylerythritol lipid (including mixtures thereof). Suitably, the one or more glycolipids are one or more sophorolipids. For example, the one or more biosurfactants may be selected from one or more of a rhamnolipid, a trehalolipid, a sophorolipid and a mannosylerythritol lipid (including mixtures thereof). The one or more biosurfactants may be selected from one or more of a rhamnolipid and a sophorolipid (including mixtures thereof). Preferably, the one or more biosurfactants are one or more sophorolipids. Rhamnolipids comprise a rhamnose residue. Examples of suitable rhamnolipids may include those produced by species of Pseudomonas, Lysinibacillus and / or Serratia, for example those produced by Pseudomonas aeruginosa, Pseudomonas cepacia, Lysinibacillus sphaericus and / or Serratia rubidaea. Trehalolipids comprise a trehalose residue. Examples of suitable trehalolipids may include those produced by species of Nocardia, Rhodococcus, Starmerella, Arthrobacter, Corynebacterium and / or Candida, for example those produced by Rhodococcus erythropolis, Nocardia farcinica and / or Candida bombicola (also known as Starmerella bombicola). Sophorolipids comprise a sophorose residue. Examples of suitable sophorolipids may include those produced by species of Candida, Starmerella and / or Cutaneotrichosporon, for example those produced by Candida sphaerica, Starmerella bombicola and / or Cutaneotrichosporon mucoides. Suitable sophorolipids may exist in the “lactonic” form wherein a fatty acid residue is bonded separately to each ring of the sophorose residue to form a lactonic macrocycle. When the fatty acid residue is not bonded to a sophorose residue this may be known as the “acidic” form. Suitable sophorolipids may have a molar ratio of acidic to lactonic form in the range 99:1 to 1:99, for example in the range 50:50 to 60:40. Suitable sophorolipids may have a molar ratio of acidic to lactonic form of 70:30. Suitably, greater than 60%, for example greater than 70%, preferably greater than 80%, more preferably greater than 90%, of the sophorolipids may comprise an unsaturated fatty acid and / or fatty alcohol residue. Mannosylerythritol lipids comprise a mannose residue and an erythritol residue, preferably joined by an ether bond. Examples of suitable mannosylerythritol lipids may include those produced by species of Pseudozyma and / or Ustilago, for example Pseudozyma aphidis or Pseudozyma antarctica. The one or more biosurfactants may be lipopeptides. Lipopeptides comprise one or more peptide residues in addition to the one or more fatty acid and / or fatty alcohol residues. The one or more peptide residues may be cyclic peptide residues. Suitable lipopeptides may include surfactins, lichenysins, and / or those produced by Pseudomonas azotoformans, Bacillus velezensis, Bacillus pseudomycoides, Virgibacillus salaries, Bacillus cereus, Bacillus pumilius or Halomonas species. Surfactins may be produced by Bacillus species, such as B. subtillis or B. nealsonii. Lichenysins may be produced by Bacillus species, such as B. licheniformis. For example, the one or more biosurfactants may be independently selected from surfactin and lichenysin (including mixtures thereof). The one or more biosurfactants may be phospholipids. Phospholipids comprise one or more phosphate groups in addition to the one or more fatty acid and / or fatty alcohol residues. Phospholipids may further comprise a linker group joining the one or more phosphate groups and the one or more fatty acid and / or fatty alcohol residues. Suitable linker groups may for example comprise an alcohol residue such as glycerol or sphingosine. Suitable phospholipids include those produced by species of Acinetobacter and / or Acidithiobacillus, for example Acidithiobacillus thiooxidans. The one or more biosurfactants may be polymeric biosurfactants. Polymeric biosurfactants are biopolymers (e.g. polysaccharides, polypeptides) comprising fatty acid and / or fatty alcohol residues. Suitable polymeric biosurfactants include cellulose, guar, diutan, starch, chitin, chitosan, glycogen, xanthan, dextran, dextrin, welan, gellan, pullulan, pectin, scleroglucan, schizophyllan, levan, locust bean gum, peptidoglycan, tara, konjak, tamarind, starch, karaya, tragacanth, carrageenan, glycan, succinoglycan, glucan, scleroglucan, maltodextrin, cyclodextrin, inulin, alginates, amylose, amylopectin, liposan, rufisan, emulsan, lipomanan and / or alasan. Polymeric biosurfactants may include those produced by species of Candida and / or Acinetobacter, for example Candida lipolytica, Acinetobacter Iwoffi and / or Acinetobacter radioresistens. For example, the one or more biosurfactants may be selected from one or more of liposan, rufisan, emulsan and alasan (including mixtures thereof). For example, the one or more biosurfactants may be selected from one or more of a rhamnolipid, a trehalolipid, a sophorolipid, a mannosylerythritol lipid, surfactin, lichenysin, liposan, rufisan, emulsan and alasan (including mixtures thereof). Biosurfactants useful in the invention may be those produced by species of Pseudomonas, Lysinibacillus, Serratia, Nocardia, Rhodococcus, Candida, Starmerella, Cutaneotrichosporon, Pseudozyma, Meyerozyma, Saccharomyces, Marinobacter, Bacillus, Lactobacillus Virgibacillus, Halomonas, Thiobacillus, Acidithiobacillus, Klebsiella, Alcanivorax, Arthrobacter, Rhodotorula, Tsukamurella, Ustilago, Sphingomonas, Mycobacterium, Streptomyces, Gluconobacter, Aspergillus and / or Acinetobacter. The biosurfactants that are produced by a specific micro-organism may vary depending on the feedstock used and other variables in the growth conditions (e.g. temperature, pH, agitation and dissolved oxygen). Preferably, feedstocks comprise carbohydrates and / or lipids. Preferred lipid feedstocks are in the form of triglycerides. The feedstocks may comprise agricultural and / or industrial waste, for example vegetable oils, animal or vegetable fats, cooking oil waste, whey, glycerol, and / or combinations thereof. Biosurfactants suitable for the invention are preferably produced by micro-organisms from feedstock comprising carbohydrate and one or more lipids. More preferably, they are produced from feedstock comprising carbohydrate and one or more of vegetable oils (for example rapeseed, palm, sunflower, corn, soya and / or safflower oils), animal fats and vegetable fats. Biosurfactants useful in the invention may be recovered from the fermentation broth before use by known recovery methods. For example, the biosurfactants may be recovered by precipitation, filtration (including ultrafiltration), adsorption to solid supports, centrifugation, chromatography (e.g. ion-exchange chromatography), foam fractionation, liquid-liquid extraction, and / or gravity separation (decanting). Biosurfactants useful in the invention may be used as crude extracts, or they may undergo further purification and / or derivatisation before use. Where biosurfactants are further purified, this may involve one or more purification techniques available to the skilled person, for example chromatographic techniques, ultrafiltration or washing with a suitable solvent (which solvent may be polar or non-polar). Where biosurfactants are further derivatised, this may comprise derivatisation of the fatty acid and / or fatty alcohol residues. Where the fatty acid or fatty alcohol residue has an unsaturated alkyl group, suitable methods for derivatisation of the fatty acid or fatty alcohol residue include mild reductive, strong reductive or oxidative ozonolysis with sodium periodate (resulting in a dialdehyde, diol or diacid respectively); dihydroxylation, for example with OsO4; epoxidation, for example with m-chloroperoxybenzoic acid; reduction, for example with H2 on a Pd / C catalyst; ring opening metathesis; treatment with HBr; or mono-hydroxylation, for example by hydroboration with an oxidative work-up. Where the biosurfactant is a glycolipid, the carbohydrate may be derivatised at the alcohol groups by esterification (e.g. with an anhydride), carboxymethylation (e.g. with an a-chloro acid), oxidation (to e.g. aldehyde or carboxylic acid), reaction with a non-ionic epoxide (e.g. ethylene oxide, propylene oxide), reaction with a cationic epoxide (e.g. glycidyltrimethyl ammonium chloride). The carbohydrate may be further derivatised by oxidative ring opening (e.g. with a periodate) resulting in a dialdehyde. Derivatives of biosurfactants comprising aldehyde groups may be further derivatised, for example to alcohols, carboxylic acids, esters, amides, imines and / or amines. Derivatives of biosurfactants comprising carboxylic acid groups may be further derivatised, for example to esters and / or amides. Derivatives of biosurfactants comprising 1,2-diol groups may be further derivatised, for example by C-C bond cleavage with periodate or peroxide, or reaction with an aldehyde. The solid composition of the first aspect may comprise at least 25 wt% or at least 30 wt% of the one or more biosurfactants. The solid composition of the first aspect may comprise up to 80 wt%, or preferably up to 60 wt%, of the one or more biosurfactants. The solid composition of the first aspect may comprise the one or more biosurfactants in an amount of from 20 to 80 wt%, preferably from 25 to 80 wt%, more preferably from 30 to 60 wt% or from 30 to 50 wt%. The solid composition of the first aspect comprises at least 20 wt% of one or more non-biological surfactants (i.e. at least 20 wt% based on the total weight of the solid composition). In some embodiments, the solid composition of the first aspect may comprise one non-biological surfactant. In some embodiments, the solid composition of the first aspect may comprise a mixture of two or more non-biological surfactants. The solid composition of the first aspect may comprise any suitable non-biological surfactant(s). The term “non-biological surfactant” is used herein to refer to a surfactant which is not a biosurfactant, suitably a surfactant that is not a product of a fermentation process, and which is not a soap. The term “soap” is used herein to refer to a metal or alkanolamine salt of a fatty acid. Suitable non-biological surfactants may include non-biological anionic, non-ionic, cationic and / or amphoteric surfactants (including mixtures thereof). References herein to one or more non-biological surfactants include mixtures of different non-biological surfactants when more than one non-biological surfactant is used. The one or more non-biological surfactants may be synthetic detergents, also known as “syndets”. For example, the one or more non-biological surfactants may be selected from one or more of a non-biological anionic surfactant, a non-biological non-ionic surfactant, a non-biological cationic surfactant and a non-biological amphoteric surfactant (including mixtures thereof). Preferably, the one or more non-biological surfactants may be selected from one or more of a non-biological anionic surfactant, a non-biological non-ionic surfactant and a non-biological amphoteric surfactant (including mixtures thereof). More preferably, the one or more non-biological surfactants may be selected from one or more of a non-biological anionic surfactant and a non-biological amphoteric surfactant (including mixtures thereof). Even more preferably, the one or more non-biological surfactants may be selected from one or more non-biological anionic surfactants (including mixtures thereof). Any suitable non-biological anionic surfactant(s) may be used. Suitable non-biological anionic surfactants may include one or more of an isethionate, a taurate, a sulfonate, a sulfosuccinate, an amino acid surfactant (such as a glutamate, glycinate and / or alaninate), a sarcosinate, a sulfoacetate, lactylate, a sulfate and a phosphate surfactant. Particularly exemplary salts of the above, where applicable, are the sodium, potassium, ammonium, magnesium and triethanolamine salts. Whilst amino acid surfactants may be made from components derived from fermentation the overall surfactant is not herein considered to be a biosurfactant. Preferred non-biological anionic surfactants may include one or more of a taurate, a sulfonate, a sulfosuccinate, a sarcosinate, a sulfoacetate, lactylate, a sulfate surfactant, a phosphate, a glutamate (such as an acyl glutamate), an isethionate and a lactylate surfactant, for example one or more of a taurate, a sulfonate (such as an alpha-olefin sulfonate), a glutamate (such as an acyl glutamate) and a sulfate surfactant. Preferred non-biological anionic surfactants may include one or more of a taurate, a sulfonate, a sulfosuccinate, a sarcosinate, a sulfoacetate, lactylate, a sulfate, a phosphate, an isethionate and a lactylate surfactant. Further preferred non-biological anionic surfactants may include one or more of a taurate and a sulfate surfactant. References herein to one or more isethionates include mixtures of different isethionates when more than one isethionate is used. The same applies to all other surfactants described herein. Any suitable isethionate surfactant(s) may be used. For example, suitable isethionates may each be of the formula (I): O II h2 h2 Ri---C---O---C --C --SO3'M+ wherein Ri represents an optionally substituted C4-C36 hydrocarbyl group; and M+ represents a cation. Further suitable isethionates are compounds of the formula (II) (also known as acyl alkyl isethionates): O R3 R5 R2---c----0---C---C---SOs’M / R4 Re (||) wherein R2 represents an optionally substituted C4-C36 hydrocarbyl group, R3, R4, R5 and Re each independently represents hydrogen or an optionally substituted C1-C4 alkyl group, provided that at least one of R3, R4, Re and Re is not hydrogen; and Mi+ represents a cation. Preferably in the compounds of formula (II) one of the groups R3, R4, Re and Re represents an optionally substituted C1-C4 alkyl group and the remaining groups represent hydrogen. Compounds of formula (II) may be present as an isomeric mixture. Such a mixture may include, for example, a compound in which R3 is an optionally substituted C1-C4 alkyl group and R4, Re and Re are all hydrogen and a compound in which Re is an optionally substituted C1-C4 alkyl group and R3, R4 and Re are all hydrogen. When any of R3, R4, Re and Re represents an optionally substituted C1-C4 alkyl group, the alkyl group is preferably n-propyl, ethyl or methyl, such as ethyl or methyl, most preferably methyl. Preferably in the compounds of formula (II), R3 represents a methyl group and R4, Re and Re all represent hydrogen. Most preferably, in the compounds of formula (II), Re represents a methyl group and R3, R4 and Re all represent hydrogen. Suitably, in the compounds of formula (I) and (II) respectively, M+ and M? may each represent an optionally substituted ammonium cation or, preferably, a metal cation. Suitable ammonium cations include NH4+ and the ammonium cation of triethanolamine or triethylamine. Suitable metal cations include alkali metal cations, for example sodium, lithium and potassium cations, and alkaline earth metal cations, for example calcium and magnesium cations. Preferably in the compounds of formula (I) and (II) respectively, M+ and M? may each represent a zinc, potassium or sodium cation, most preferably a sodium cation. The skilled person will appreciate that when M+ or M? is a divalent metal cation two moles of anion will be present for each mole of cation. When any of the groups Ri, R2, R3, R4, R5 and / or Re in the compounds of formula (I) and (II) are substituted, examples of suitable substituents include C1-4 alkoxy, cyano, hydroxy, oxo, halo (especially fluoro and chloro), trifluoromethyl and trifluoromethoxy. Any suitable taurate surfactant(s) may be used. For example, suitable taurates may each be of formula (III): 0 R8 R10 R7--C---N---C---C---SO3X R12 R9 R11 (HI) wherein X is hydrogen, a metal ion or an optionally substituted ammonium ion; R7 represents an optionally substituted C3-C35 hydrocarbyl group; and each of R8, R9, R10, R11 and R12 independently represents hydrogen or a C1-C4 alkyl group. Suitably R7 represents an optionally substituted C3-C35 alkyl, C3-C35 alkenyl, C6-C12 aryl, C6-C12 aryl-Cs-C22 alkyl or C8-C22 alkyl-Ce-Ci2 aryl group. Suitably R7 represents an optionally substituted C3-C35 alkyl, C3-C35 alkenyl, C6-C12 aryl or Cs-C22 alkyl-Ce-Ci2 aryl group. More suitably, R7 represents an optionally substituted C3-C35 alkyl or C3-C35 alkenyl group, especially an optionally substituted C3-C35 alkenyl group. Most suitably, R1 represents a C3-C35 alkyl or C3-C35 alkenyl group, especially a C3-C35 alkenyl group. Suitably R7 represents a mixture of optionally substituted C3-C35 alkyl, C3-C35 alkenyl, C6-C12 aryl, C6-C12 aryl-Cs-C22 alkyl or C8-C22 alkyl-Ce-Ci2 aryl groups having differing chain lengths. Suitably R7 represents a mixture of optionally substituted C3-C35 alkyl, C3-C35 alkenyl, C6-C12 aryl or C8-C22 alkyl-Ce-Ci2 aryl groups having differing chain lengths. For example R7 may be derived from the mixture of fatty acids having differing chain lengths found in triglyceride oils for example coconut oil, palm oil, palm kernel oil, sunflower oil or rapeseed oil. Suitably R7 may represent an optionally substituted C3-C35 alkyl or C3-C35 alkenyl group, such as an optionally substituted C8-C24 alkyl or C8-C24 alkenyl group, or an optionally substituted C12-C18 alkyl or C12-C18 alkenyl group. Suitably R7 may represent a C3-C35 alkyl or C3-C35 alkenyl group, such as a C8-C24 alkyl or Cs-C24 alkenyl group, or a C12-C18 alkyl or C12-C18 alkenyl group. Suitably R7 may represent an optionally substituted C4-C29 alkyl group, such as an optionally substituted C7-C23 alkyl group, for example an optionally substituted C11-C23 alkyl group, preferably an optionally substituted C13-C21 alkyl group. Suitably R7 may represent an optionally substituted C4-C29 alkenyl group, such as an optionally substituted C7-C23 alkenyl group, for example an optionally substituted C11-C23 alkenyl group, preferably an optionally substituted C13-C21 alkenyl group. Suitably R7 may represent a C4-C29 alkyl group, such as a C7-C23 alkyl group, for example a C11-C23 alkyl group, preferably a C13-C21 alkyl group. Suitably R7 may represent a C4-C29 alkenyl group, such as a C7-C23 alkenyl group, for example a C11-C23 alkenyl group, preferably a C13-C21 alkenyl group. R7 is suitably provided by one or more fatty acids (i.e. one or more acids of formula R7COOH). Fatty acids obtained from natural oils often include mixtures of fatty acids. For example, the fatty acid obtained from coconut oil contains a mixture of fatty acids including C12 lauric acid, C14 myristic acid, C16 palmitic acid, Cs caprylic acid, C10 capric acid and C18 stearic and oleic acid. R7 may be provided by one or more naturally occurring fatty acids and / or of one or more synthetic fatty acids. For example, R7 may consist essentially of or consist of the residue of a single fatty acid. R7 may be provided by one or more naturally occurring and / or renewable fatty acids. Examples of carboxylic acids from which R7 may be derived include coco acid, hexanoic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, gadoleic acid, arachidonic acid, eicosapentaenoic acid, behenic acid, erucic acid, docosahexaenoic acid, lignoceric acid, naturally occurring fatty acids such as those obtained from coconut oil, tallow, palm kernel oil, butterfat, palm oil, olive oil, corn oil, linseed oil, peanut oil, fish oil and rapeseed oil; synthetic fatty acids made as chains of a single length or a selected distribution of chain lengths; and mixtures thereof. R1 may also be derived from fatty acids obtained via fermentation or general biotechnological processes, or from waste vegetable oils. These may be obtained by chemical or enzymatic routes. Suitably R7 may be provided by oleic acid, mixed fatty acids derived from coconut oil or the mixed fatty acids derived from palm kernel oil. Suitable coconut derived feedstocks include coconut fatty acid, coconut oil, coconut oil methyl esters, virgin coconut oil, refined bleached and deodorised coconut oil, ‘distilled and topped’ hardened coconut fatty acid and methyl esters thereof. Also useful are palm oil, hydrogenated palm kernel oil derived C12-C18 fatty acids (hardened and topped fatty acid) and methyl esters thereof. Preferably, R7 predominantly comprises the residue of an unsaturated fatty acid having 18 carbon atoms. R7 may be derived from the mixture of fatty acids having differing chain lengths found in rapeseed oil. The detergent composition may comprise only a single taurate surfactant of formula (III). Alternatively, the detergent composition may comprise a mixture of two or more taurate surfactants of formula (III). Each of R8, R9, R10, R11 and R12 is independently selected from hydrogen or a Ci to C4 alkyl group. When any of R8, R9, R10, R11 and R12 is a Ci to C4 alkyl group, the alkyl group is suitably n-propyl, ethyl or methyl, such as ethyl or methyl, most preferably methyl. Suitably, R12 may be hydrogen. Preferably, R12 may be a Ci to C4 alkyl group, more preferably methyl. Suitably each of R8, R9, R10, R11 and R12 may be hydrogen, i.e. the compound of formula (III) may be an acyl taurate surfactant. Suitably, R12 may be a Ci to C4 alkyl group, each of R8, R9, R10 and R11 may be hydrogen and the compound of formula (III) may be an acyl N-alkyl taurate surfactant. Where the compound of formula (III) is an acyl N-alkyl taurate surfactant, R12 may preferably be n-propyl, ethyl or methyl. Preferably R12 may be ethyl or methyl, most preferably methyl. Thus the compound of formula (III) may preferably be an acyl N-methyl taurate surfactant. Suitably, R12 may be a Ci to C4 alkyl group and each of R8, R9, R10 and R11 may independently represent hydrogen or a C1-C4 alkyl group wherein at least one of R8, R9, R10 and R11 is not hydrogen. When at least one of R8, R9, R10 and R11 represents an optionally substituted C1-C4 alkyl group, the alkyl group is suitably n-propyl, ethyl or methyl, such as ethyl or methyl, most preferably methyl. Preferably one of the groups R8, R9, R10 and R11 represents an optionally substituted C1-C4 alkyl group and the remaining groups represent hydrogen. For example, R8 may represent an optionally substituted C1-C4 alkyl group and R9, R10 and R11 may all represent hydrogen. For example, R10 may represent an optionally substituted C1-C4 alkyl group and R8, R9 and R11 may all represent hydrogen. Preferably R8 represents a C1-C4 alkyl group and R9, R10 and R11 all represent hydrogen and / or R10 represents a C1-C4 alkyl group and R8, R9 and R11 all represent hydrogen. Thus a mixture of compounds may be present in which either R8 or R10 is a C1-4 alkyl group and the remainder of R8, R9, R10 and R11 are hydrogen. Most preferably R8 may represent a methyl group and R9, R10 and R11 may all represent hydrogen or R10 may represent a methyl group and R8, R9 and R11 may all represent hydrogen. Suitably R12 may be hydrogen and either R8 or R10 may be a C1-4 alkyl group, preferably methyl, and the remainder of R8, R9, R10 and R11 may be hydrogen. Suitably X represents hydrogen, a metal cation or an optionally substituted ammonium cation, preferably a metal cation. By “optionally substituted ammonium cation”, we mean to refer to an ammonium cation wherein the nitrogen atom may be substituted with from 1 to 4 optionally substituted hydrocarbyl groups. Suitable ammonium cations include those derived from alkyl amines and alkanolamines. Preferred ammonium cations include isopropanolamine, isopropylamine, ethanolamine, diethanolamine, triethanolamine and 2-amino-2-methyl-1,3-propanediol (AMPD). Preferred ammonium cations include NH4+ and the ammonium cation of triethanolamine. Suitable metal cations include alkali metal cations, for example sodium, lithium and potassium cations, and alkaline earth metal cations, for example calcium and magnesium cations. Suitably, X represents hydrogen, an alkali metal cation or an optionally substituted ammonium cation. Preferably, X represents a potassium or sodium cation. Most preferably, X represents a sodium cation. The skilled person will appreciate that when X is a divalent metal cation two moles of anion will be present for each mole of cation. Suitably the compound of formula (III) may comprise the reaction product of N-methyl methyl taurine and one or more fatty acids, that is a compound of formula R7CONR12CHR8CHR10SO3X in which R12 is methyl and in which one of R8 and R10 is methyl and the other is hydrogen. Mixtures of these isomers may be present. Compounds of formula (III) may be present as a mixture of more than one taurate surfactant of formula (III). For example, an isomeric mixture of N-alkyl alkyl taurate surfactants may be present. Such a mixture may include, for example an N-alkyl alkyl taurate surfactant in which R8 represents a C1-C4 alkyl group (suitably methyl) and R9, R10 and R11 are all hydrogen and an N-alkyl alkyl taurate surfactant in which R10 represents a C1-C4 alkyl group (suitably methyl) and R8, R9 and R11 are all hydrogen. In particular, the compound of formula (III) may comprise a mixture of isomers, that is a compound of formula R7CONR12CH2CHR10SO3X in which R10 represents a C1-C4 alkyl group (preferably methyl) and a compound of formula R7CONR12CHR8CH2SO3X in which R8 represents a C1-C4 alkyl group (preferably methyl). Suitably such mixtures comprise at least 90% of compounds in which R8 is methyl and R10 is hydrogen and at most 10% of compounds in which R8 is hydrogen and R10is methyl. The one or more taurate surfactants may each be of the formula (III) wherein X is a metal ion; R7 represents an optionally substituted C13-C21 hydrocarbyl group; and each of R8, R9, R10, R11 and R12 independently represents hydrogen or methyl. Preferably, the one or more taurate surfactants are each of the formula (III) wherein X is a metal ion; R7 represents an optionally substituted C13-C21 hydrocarbyl group; R8 and R10 each independently represent hydrogen or methyl, provided that one of R8 and R10 represents hydrogen; R9 and R11 each represent hydrogen; and R12 represents hydrogen or methyl. Most preferably, the detergent composition comprises a taurate of formula (III) wherein X is a metal ion, such as sodium; R7 represents an unsubstituted C17 alkenyl group; R8, R9, R10 and R11 represent hydrogen and R12 represents methyl. For example, this may be sodium N-methyl oleoyl taurate. Preferred taurate surfactants include one or more taurate surfactants of formula (III) selected from sodium lauroyl taurate, sodium cocoyl taurate, sodium oleoyl taurate, sodium myristoyl taurate, sodium N-methyl lauroyl taurate, sodium N-methyl cocoyl taurate, sodium N-methyl oleoyl taurate, sodium N-methyl myristoyl taurate, sodium N-methyl methyl lauroyl taurate, sodium N-methyl methyl cocoyl taurate, sodium N-methyl methyl oleoyl taurate and sodium N- methyl methyl myristoyl taurate. Sodium N-methyl oleoyl taurate and sodium N-methyl cocoyl taurate are especially preferred. Most preferred is sodium N-methyl oleoyl taurate. Any suitable sulfonate surfactant(s) may be used. For example, suitable sulfonates include salts (such as alkali metal salts) of alkyl sulfonates, alkyl aryl sulfonates (such as an alkylbenzene sulfonate, especially a linear alkylbenzene sulfonate), fatty acid alkyl ester sulfonates (such as fatty acid methyl ester sulfonates) and / or alpha-olefin sulfonates. Preferred sulfonates include alpha-olefin sulfonates, such as sodium C14-C16 alpha-olefin sulfonate. Any suitable sulfosuccinate surfactant(s) may be used. For example, suitable sulfosuccinates include alkyl sulfosuccinates and alkyl ether sulfosuccinates, such as C1-C10 alkyl sulfosuccinates and C1-C10 alkyl ether sulfosuccinates (for example disodium lauryl sulfosuccinate). Any suitable glutamate surfactant(s) may be used. Suitable glutamates include acyl glutamates and salts thereof (such as metal or optionally substituted ammonium salts), such as sodium lauroyl glutamate, sodium myristoyl glutamate, sodium oleoyl glutamate and sodium cocoyl glutamate. Sodium lauroyl glutamate is especially preferred. Any suitable glycinate surfactant(s) may be used. Suitable glycinates include acyl glycinates and salts thereof (such as metal or optionally substituted ammonium salts), such as sodium cocoyl glycinate, sodium myristoyl glycinate, sodium oleoyl glycinate and sodium lauroyl glycinate. Any suitable alaninate surfactant(s) may be used. Suitable alaninate surfactants include acyl alaninates and salts thereof (such as metal or optionally substituted ammonium salts), such as sodium cocoyl alaninate and sodium lauroyl alaninate. Any suitable sarcosinate surfactant(s) may be used. Suitable sarcosinates include acyl sarcosinates and salts thereof (such as metal or optionally substituted ammonium salts), such as sodium lauroyl sarcosinate, sodium cocoyl sarcosinate, sodium myristoyl sarcosinate, sodium oleoyl sarcosinate and sodium stearoyl sarcosinate. Any suitable sulfoacetate surfactant(s) may be used. Suitable sulfoacetates include acyl sulfoacetates and salts thereof (such as metal or optionally substituted ammonium salts), particularly sodium alkyl sulfoacetates, for example sodium lauryl sulfoacetate. Any suitable lactylate surfactant(s) may be used. Suitable lactylates include alkali salts of acyl lactylates, such as sodium lauroyl lactylate. Any suitable sulfate surfactant(s) may be used. Suitable sulfate surfactants include alkali metal salts of alkyl sulfates and / or alkyl ether sulfates, such as sodium lauryl sulfate, sodium coco sulfate and / or sodium lauryl ether sulfate (sodium laureth sulfate). Sodium lauryl sulfate is especially preferred. Suitable sulfate surfactants include hydrocarbyl sulfates. The hydrocarbyl sulfate may comprise an alkyl sulfate, an alkenyl sulfate, or a combination thereof. The hydrocarbyl sulfate may comprise a fatty alcohol sulfate. Suitably the hydrocarbyl sulfate may comprise a C5 to C30 alkyl or C5 to C30 alkenyl sulfate, such as a C10 to C20 alkyl or C10 to C20 alkenyl sulfate. The hydrocarbyl sulfate may comprise a C5 to C30 alkyl sulfate, preferably a C10 to C20 alkyl sulfate. The alkyl and / or alkenyl group(s) may be unsubstituted. The hydrocarbyl sulfate may comprise a metallic hydrocarbyl sulfate and / or an amine derivative of a hydrocarbyl sulfate. By metallic hydrocarbyl sulfate we mean a hydrocarbyl sulfate comprising a metal cation. Typically, the hydrocarbyl sulfate comprises a metallic hydrocarbyl sulfate. The metallic hydrocarbyl sulfate may comprise a hydrocarbyl sulfate in which the cation is an alkali metal, such as sodium or potassium, or an alkali earth metal, such as magnesium. Preferably the metallic hydrocarbyl sulfate comprises a sodium hydrocarbyl sulfate. The amine derivative of a hydrocarbyl sulfate may comprise an ammonium hydrocarbyl sulfate, an alkyl amine hydrocarbyl sulfate, an alkanolamine hydrocarbyl sulfate, ora combination thereof. Examples of suitable hydrocarbyl sulfates include sodium C12 to C16 alkyl sulfate (e.g. EMPICOL® LX series), sodium C12 to C18 alkyl sulfate (e.g. EMPICOL® LZ, CZ series), ammonium lauryl sulfate (e.g. EMPICOL® AL series), monoethanolamine lauryl sulfate (e.g. EMPICOL® LQ series), diethanolamine lauryl sulfate, triethanolamine lauryl sulfate (e.g. EMPICOL® TL series), monoisopropanolamine lauryl sulfate, diisopropanolamine lauryl sulfate, triisopropanolamine lauryl sulfate, magnesium lauryl sulfate, potassium lauryl sulfate, ammonium myristyl sulfate, monoethanolamine myristyl sulfate, diethanolamine myristyl sulfate, triethanolamine myristyl sulfate, sodium myristyl sulfate, ammonium cetyl sulfate, diethanolamine cetyl sulfate, sodium cetyl sulfate, sodium cetostearyl sulfate, ammonium coco-sulfate, sodium tallow sulfate, sodium oleyl sulfate, diethanolamine oleyl sulfate, sodium 2-ethylhexylsulfate (e.g. EMPICOL® 0585 series), sodium decyl sulfate (e.g. EMPICOL® 0758 series), sodium C10 to C12 fatty alcohol sulfate (e.g. EMPICOL® 0335 series), sodium Cs to C10 fatty alcohol sulfate, or a combination thereof. Surfactants under the name EMPICOL® are commercially available from Innospec. Suitably, the hydrocarbyl sulfate may comprise sodium C12 to C16 alkyl sulfate (e.g. EMPICOL® LX series), sodium C12 to C18 alkyl sulfate (e.g. EMPICOL® LZ, CZ series), magnesium lauryl sulfate, potassium lauryl sulfate, sodium myristyl sulfate, sodium cetyl sulfate, sodium cetostearyl sulfate, sodium tallow sulfate, sodium oleyl sulfate, sodium decyl sulfate (e.g. EMPICOL®0758 series), sodium C10 to C12 fatty alcohol sulfate (e.g. EMPICOL®0335 series), sodium Cs to C10 fatty alcohol sulfate, or a combination thereof. Preferably, the hydrocarbyl sulfate may comprise sodium C12 to C16 alkyl sulfate (e.g. EMPICOL®LX series), sodium C12 to Cis alkyl sulfate (e.g. EMPICOL®LZ, CZseries), ora combination thereof. Any suitable non-biological amphoteric surfactant(s) may be used. By amphoteric surfactants, we mean to include any surfactants having the ability to exhibit both positive and negative sites. The one or more amphoteric surfactants may be selected from surfactants referred to as betaines, sultaines or zwitterionic surfactants or other amphoteric surfactants, for example those based on fatty nitrogen derivatives or amine oxides. References herein to one or more non-biological amphoteric surfactants includes mixtures of different amphoteric surfactants when more than one amphoteric surfactant is used. Suitable non-biological amphoteric surfactants include betaines (including sultaines or su Ifo betaines), amine oxides, amphoacetates and glycinate-based amphoteric surfactants. Preferred non-biological amphoteric surfactants include betaines (including sultaines or su Ifo betaines), amine oxides and amphoacetates. Preferably, the amphoteric surfactant is a betaine. Any suitable betaine surfactant(s) may be used. For example, suitable betaines may each be a betaine (or amido betaine when n is 1) of the formula (IV): O R14 r 11 H 1 । + R13|c—N—(CH2)m-^N—z—Y R15 (IV) wherein R13 represents a C5-30 alkyl or C5-30 alkenyl group, R14 and R15 are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 6 carbon atoms; m is 2 to 4; n is 0 or 1; Z is alkylene of 1 to 6 carbon atoms optionally substituted with hydroxyl; and Y is -CO2- or -SOs-. Preferably R13 is a C9-C14 alkyl or C9-C14 alkenyl group. R13 may be a mixture of alkyl groups. Suitably at least half, preferably at least three quarters, of the groups R13 by mole have 9 to 14 carbon atoms based on the total moles of betaine present. R13 may be a mixture of alkyl groups derived from coconut or palm kernel oil. R14 and R15 are preferably methyl. A suitable betaine may be an alkyl betaine of the formula (V): R14 r13-N—CH2CO2 R15 (V) wherein R13, R14 and R15 are as defined previously. The one or more betaine surfactants preferably comprise one or more amido betaine surfactants of formula (VI): 0 R14 13ll H l + R13-C—N—(CH2)m—N—CH2CO2 R15 (VI) wherein R13 is a C5-30 alkyl or C5-30 alkenyl group, R14 and R15 are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 6 carbon atoms and m is 2 to 4. The betaine may comprise a sultaine (or sulfobetaine) of the formulae (VII) and / or (VIII): R14 R13-N—(CH2)3SO3 R15 (VII); or O R14 1311 H l + R13-C—N—(CH2)m-N—(CH2)3SO3 R15 (VIII) wherein R13, R14 and R15 are as defined previously; and m is 2 or 3; or variants of these in which -(CH2)3SO3_ is replaced by OH H2 | —c —c—CH2SO3“ Suitable betaine surfactants include alkylamido betaine; alkyl betaine; C12 / 14 alkyldimethyl betaine; cocamidopropylbetaine; tallow bis(hydroxyethyl) betaine; hexadecyldimethylbetaine; cocodimethylbetaine; alkyl amido propyl sulfo betaine; alkyl dimethyl amine betaine; coco amido propyl dimethyl betaine; alkyl amido propyl dimethyl amine betaine; lauryl betaine; laurylamidopropyl betaine; coco amido betaine; lauryl amido betaine; alkyl amino betaine; alkyl amido betaine; coco betaine; lauryl betaine; dimethicone propyl PG-betaine; oleyl betaine; N-alkyldimethyl betaine; coco biguanide derivative, Cs amido betaine; C12 amido betaine; lauryl dimethyl betaine; alkylamide propyl betaine; amido betaine; alkyl betaine; cetyl betaine; oleamidopropyl betaine; isostearamidopropyl betaine; lauramidopropyl betaine; 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine; 2-alkyl-N-carboxyethyl-N-hydroxyethyl imidazolinium betaine; 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine; N-alkyl amidopropyl-N,N-dimethyl-N-(3-sulfopropyl)-ammonium-betaine; N-alkyl-N,N-dimethyl-N-(3-sulfopropyl)-ammonium-betaine; cocodimethyl betaine; apricotamidopropyl betaine; isostearamidopropyl betaine; myristamidopropyl betaine; palmitamidopropyl betaine; cocamidopropyl hydroxy sultaine; undecylenamidopropyl betaine; cocoamidosulfobetaine; alkyl amido betaine; C12 / 18 alkyl amido propyl dimethyl amine betaine; lauryldimethyl betaine; ricinol amidobetaine; tallow amidobetaine. Preferably the non-biological amphoteric surfactant is an amidopropyl betaine, preferably cocamidopropyl betaine. Suitable amine oxide surfactants may comprise one or more alkyl or amidoalkyl dimethyl amine oxides. The one or more amine oxide surfactants may comprise a mixture of compounds, suitably a mixture of homologues. The skilled person will understand that amines obtained from natural sources typically comprise mixtures of compounds. The one or more amine oxide surfactants may be oxides of tertiary amines. Suitable amine oxide surfactants may be represented by formula (IX): O R14 „fll H , l+ . R13{C—N—(CH2)m-^N—O R15 (IX) wherein R13, R14 and R15 are as defined in relation to betaines, m may be 2 or 3 and n may be 1 orO. Suitably the amine oxide is an oxide of a tertiary alkylamine or alkenylamine having 6 to 36, preferably 6 to 30, more preferably 8 to 24, for example 10 to 20 or 12 to 18, carbon atoms. Preferably the amine oxide surfactant comprises a mixture of C12 to C18 amine oxides. Preferred amine oxides are lauramine oxide (N,N-dimethyllaurylamine oxide), lauryl myristyl amidoamine oxide, lauryl amidoamine oxide and cocamidopropylamine oxide (CAPAO). Any suitable amphoacetate surfactant(s) may be used. References herein to amphoacetates include monoamphoacetates and diamphoacetates. Suitably amphoacetates may be represented by the formula (X): r16conhch2ch2—n—ch2ch2oh CH2COO“ M + Suitable diamphoacetates may be represented by the formula (XI): ch2coo-m+ I r16conch2ch2—n—ch2ch2oh I + CH2COO M (XI) where R16 is an aliphatic group of 7 to 22 carbon atoms and M+ is a cation such as sodium, potassium, ammonium, or substituted ammonium. Suitable amphoacetates include lauroamphoacetate; alkyl amphoacetate; cocoampho(di)acetate; cocoamphoacetate; disodium cocoamphodiacetate; sodium cocoamphoacetate; disodium cocoamphodiacetate; disodium capryloamphodiacete; disodium lauroamphoacetate; sodium lauroamphoacetate and disodium wheatgerm amphodiacetate. Suitable glycinate-based amphoteric surfactants include cocoamphocarboxyglycinate; tallowamphocarboxygycinate; capryloamphocarboxyglycinate, oleoamphocarboxyglycinate, bis-2-hydroxyethyl tallow glycinate; lauryl amphoglycinate; tallow polyamphoglycinate; coco amphoglycinate; oleic polyamphoglycinate; / V-C10 / 12 fatty acid amidoethyl- / V-(2-hydroxyethyl)-glycinate; A / -Ci2 / is-fatty acid amidoethyl-N-(2-hydroxyethyl)-glycinate; dihydroxyethyl tallow glycinate. Any suitable non-biological non-ionic surfactant(s) may be used. Suitable non-ionic surfactants include alcohol alkoxylate surfactants (such as alcohol ethoxylates, alcohol propoxylates, and ethylene oxide / propylene oxide copolymer derived surfactants), aliphatic esters, aromatic esters, sugar esters, (especially sorbitan esters), glycerol esters including glycerol partial esters and glycerol triesters, fatty alcohols (such as cetearyl alcohol, lauryl alcohol, stearyl alcohol, behenyl alcohol) and alkanolamides. Preferred non-ionic surfactants for use herein are compounds which are not ethoxylated. Any suitable non-biological cationic surfactant(s) may be used. Suitable cationic surfactants include quaternary ammonium compounds, such as dimethyl(2-hydroxyethyl)laurylammonium chloride and alkyldimethylbenzylammonium chloride. In the solid composition of the first aspect, the one or more non-biological surfactants may be selected from one or more of a taurate, a betaine, a sulfonate, a sulfosuccinate, an amino acid surfactant (such as a glutamate, glycinate and / or alaninate), a sarcosinate, a sulfoacetate, an amine oxide, an amphoacetate, lactylate, a sulfate, a phosphate, an isethionate and a lactylate. In the solid composition of the first aspect, the one or more non-biological surfactants may be selected from one or more of a taurate, a betaine, a sulfonate (such as a linear alkylbenzene sulfonate, an alpha-olefin sulfonate and a fatty acid methyl ester sulfonate), a sulfosuccinate, an amino acid surfactant (such as a glutamate, glycinate and / or alaninate), a sarcosinate, a sulfoacetate, an amine oxide, an amphoacetate, a glycinate and a sulfate surfactant, preferably selected from one or more of a taurate, a betaine and a sulfate surfactant, more preferably selected from one or more of a taurate and a sulfate surfactant. In the solid composition of the first aspect, the one or more non-biological surfactants may preferably be selected from one or more of cocamidopropyl betaine, sodium methyl oleoyl taurate, sodium lauryl sulfate, sodium lauroyl glutamate and Ci4-Ci6-alpha olefin sulfonate. The solid composition of the first aspect may comprise at least 25 wt%, such as at least 30 wt%, at least 40 wt% or at least 50 wt%, of the one or more non-biological surfactants. The solid composition of the first aspect may comprise up to 80 wt% or preferably up to 60 wt%, of the one or more non-biological surfactants. The solid composition of the first aspect may comprise the one or more non-biological surfactants in an amount of from 20 to 80 wt%, preferably from 30 to 80 wt%, more preferably from 40 to 60 wt%. The solid composition of the first aspect has a total surfactant content of at least 75 wt%. References to a total solid content refer to a total content of both biological and non-biological surfactants. In other words, the solid composition of the first aspect comprises at least 75 wt% of surfactants in total, i.e. a total of biological and non-biological surfactants. The solid composition of the first aspect may have a total surfactant content of at least 80 wt% or of at least 83 wt%. The solid composition of the first aspect may have a total surfactant content of from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. The solid composition of the first aspect may further comprise one or more chelating agents. The solid composition of the first aspect may comprise the one or more chelating agents (when present) in any suitable amount. For example the solid composition of the first aspect may comprise the one or more chelating agents in an amount of from 0.1 to 20 wt%, preferably from 0.5 to 15 wt%, more preferably from 1 to 10 wt% or from 1 to 5 wt% (i.e. based on the total weight of the composition). Any suitable chelating agent(s) may be included in the solid composition of the first aspect. For example, the one or more chelating agents may be selected from one or more of a polycarboxylic acid chelating agent, a phosphonic acid-containing chelating agent (such as an amino phosphonic acid-containing chelating agent), an amino carboxylic acid-containing chelating agent and an iminodiacetic acid derivative, and salts and derivatives thereof. Preferred chelating agents include aminocarboxylic acid chelating agents and amino phosphonic acid chelating agents. The active species provided in solution by such chelating agents are typically present in solution as the anionic aminocarboxylates or aminophosphonates. Phosphonic acid containing chelating agents include at least one phosphonic acid functionality, and may optionally contain one or more further functionalities, such as amino functionalities. Suitable phosphonic acid containing chelating agents include tripolyphosphoric acid or a salt thereof, for example sodium tripolyphosphate (STPP). Amino phosphonic acid-containing chelating agents include at least one amino functionality and at least one phosphonic acid functionality. Suitable amino phosphonic acid-containing chelating agents include organic amino phosphonic acids, such as the amino alkylene poly(alkylene phosphonic) acids. Preferred chelating agents of this type include ethylene diaminetetramethylene phosphonic acid and preferably diethylene triamine penta(methylene phosphonic acid), ethylene diamine tri (methylene phosphonic acid) and hexamethylene diaminetetra(methylene phosphonic acid). Such phosphonic acid chelating agents are commercially available under the tradename Dequest®, typically as a sodium salt thereof. A suitable chelating agent can be amino tri (methylene phosphonic acid). Amino carboxylic acid-containing chelating agents include at least one amino functionality and at least one carboxylic acid functionality. Suitable amino carboxylic acid-containing chelating agents include polyaminocarboxylic acids for example ethylenediaminotetraacetic acid (EDTA), ethyenetriamine pentaacectic acid, ethylenediaminediglutaric acid, 2-hydroxypropylenediamine disuccinic acid, diethylene triamine pentaacetic acid (DTPA), N-hydroxyethylethylenediamine triacetic acid, ethylenediamine tetrapropionic acid, triethylenetetraaminehexa-acetic acid, ethanol-diglycines, propylene diamine tetracectic acid (PDTA) and methyl glycine diacectic acid (MGDA). Preferred amino carboxylic acid-containing chelating agents are diethylene triamine penta acetic acid, propylene diamine tetracetic acid (PDTA) and methyl glycine di-acetic acid (MGDA). MGDA is most preferred. Suitable iminodiacetic acid derivatives include 2-hydroxyethyl diacetic acid or glyceryl imino diacetic acid, described in EP-A-317,542 and EP-A-399,133. The iminodiacetic acid N-2-hydroxypropyl sulfonic acid and aspartic acid N-carboxymethyl N-2-hydroxypropyl-3- sulfonic acid chelating agents described in EP-A-516,102 are also suitable herein. The p-alanine-N,N’-diacetic acid, aspartic acid-N,N’-diacetic acid, aspartic acid-N-monoacetic acid and iminodisuccinic acid sequestrants described in EP-A-509,382 are also suitable. EP-A-476,257 describes suitable amino based chelating agents. EP-A-510,331 describes suitable chelating agents derived from collagen, keratin or casein. EP-A-528,859 describes a suitable alkyl iminodiacetic acid chelating agent. Glycinamide-N,N’ disuccinic acid (GADS), ethylenediamine-N,N’-diglutaric acid (EDDG) and 2-hydroxypropylenediamine-N-N’-disuccinic acid (HPDDS) are also suitable. Polycarboxylic acid chelating agents include two or more (for example 3, 4 or 5) carboxylic acid moieties or salts thereof. Suitable polycarboxylic acid chelating agents include polyacrylic acid or a salt thereof. Preferably, the one or more chelating agents may be selected from one or more of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), ethylenediamine disuccinic acid (EDDS), methylglycinediacetic acid (MGDA), glutamic acid, N,N-diacetic acid (GLDA), iminodisuccinic acid (IDS); ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), aspartic acid diethoxysuccinic acid (AES), aspartic acid-N,N-diacetic acid (ASDA), ethylenediamine tetra methylene phosphonic acid (EDTMP), iminodifumaric (IDF), iminoditartaric acid (IDT), iminodimaleic acid (IDMAL), iminodimalic acid (IDM), ethylenediaminedifumaric acid (EDDF), ethylenediaminedimalic acid (EDDM), ethylenediamineditartaric acid (EDDT), ethylenediaminedimaleic acid and (EDDMAL), aminotri(methylenephosphonic acid) (ATMP); diethylenetriamine-penta-methylene phosphonic acid (DETPMP), hydroxyethyliminodiacetic acid (HEIDA), aspartic acid diethoxysuccinic acid (AES), aspartic acid-N,N-diacetic acid (ASDA), diethylenetriaminepentamethylene-phosphonic acid (DTPMPA), hydroxyethylenediaminetetraacetic acid (HEDTA), hydroxyethylethylenediaminetriacetic acid (HEEDTA), glucoheptonic acid, citric acid, poly(acrylic-acid co-hypophosphite), tripolyphosphoric acid, polyacrylic acid, and salts and derivatives thereof. Preferred salts include alkali metal, alkaline earth metal and optionally substituted ammonium salts. Sodium salts of said acids are preferred. More preferably, the one or more chelating agents may be selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. More preferably, the chelating agent is citric acid or a salt thereof. More preferably, the chelating agent is an amino carboxylate chelating agent, preferably MGDA. Methylglycinediacetic acid (MGDA) has the structure shown in figure 1: HOOC---\      COOH HOOC---f      CH3 figure 1 In the solid compositions of the first aspect, MGDA may be present having the structure shown in figure 1 and / or the same structure in which a number of the acidic protons have been replaced i.e. in which 1,2 or 3 of the acid groups have been neutralised or partially neutralised. It may be present as a free acid or a salt or complex thereof. MGDA may be present as either enantiomer or a mixture thereof. Preferably it is present as a racemic mixture. When a salt of MGDA is included, this may be the salt of an alkali metal, an alkaline earth metal, ammonia or a suitable amine. Preferably MGDA is provided as the trisodium salt. MGDA is commercially available as a solution comprising 40 wt% of the trisodium salt and is sold under the trade markTrilon M. Glutamic acid N,N-diacetic acid (GLDA) has the structure shown in figure 2: COOH HOOC COOH figure 2 COOH In the compositions of the present invention GLDA, may be present having the structure shown in figure 2 and / orthe same structure in which a number ofthe acidic protons have been replaced, i.e. in which 1,2, 3 or 4 ofthe acid groups have been neutralised or partially neutralised. It may be present as a free acid or a salt or complex thereof. GLDA may be present as either enantiomer or a mixture thereof. Preferably at least 50% is present as [S]-GLDA, preferably at least 70%, more preferably at least 90%, most preferably at least 95 wt%, for example about 98 wt%. In some preferred embodiments the GLDA consists essentially ofthe S enantiomer. When a salt of GLDA is included, this may be the salt of an alkali metal, an alkaline earth metal, ammonia or a suitable amine. GLDA is commercially available as a solution comprising 38 wt% ofthe tetrasodium salt and is sold under the trade mark Dissolvine GL-38. DTPA has the structure shown in figure 3: figure 3 DTPA may be provided in a form having the structure shown in figure 3 or in a form having the same structure in which a number of the hydrogen atoms have been replaced, i.e. in which 1,2, 3, 4 or 5 of the acid groups have been neutralised or partially neutralised. When a salt of DTPA is included, this may be the salt of an alkali metal, an alkaline earth metal, ammonia or a suitable amine. When a monovalent counterion is used the salt may be the monosalt, the disalt, the trisalt, the tetra salt or the pentasalt. For a divalent cation the monosalt or disalt may be present. Mixed salts may also exist, for example, the disodium magnesium salt or the sodium magnesium salt may be present. Preferably the counterion(s) to the DTPA residue is / are selected from one or more of sodium, magnesium, calcium, potassium, lithium, ammonium, and a quaternary ammonium ion. Preferably DTPA when present is included as the pentasodium salt. EDTA has the structure shown in figure 4: EDTA may be provided in a form having the structure shown in figure 4 or in a form having the same structure in which a number of the hydrogen atoms have been replaced, i.e. in which 1,2, 3 or 4 of the acid groups have been neutralised or partially neutralised. When a salt of EDTA is included, this may be the salt of an alkali metal, an alkaline earth metal, ammonia or a suitable amine. When a monovalent counterion is used the salt may be the monosalt, the disalt, the trisalt or the tetrasalt. For a divalent cation the monosalt or disalt may be present. Mixed salts may also exist, for example, the disodium magnesium salt or the sodium magnesium salt may be present. Preferably the counterion(s) to the EDTA residue is / are selected from one or more of sodium, magnesium, calcium, potassium, lithium, ammonium, and a quaternary ammonium ion. Preferably EDTA when present is present as the tetrasodium salt, the trisodium salt or the disodium salt. DETPMP has the structure shown in figure 5: HO OH figure 5 This compound may also be referred to as DETPMP or DTPMP. It may be present as the free acid or a salt or complex thereof. DTPMPA is commercially available as the heptasodium salt form and is sold under the trade mark Dequest 2060 series. Iminodisuccinic acid (IDS) has the structure shown in figure 6: HOOC^^N^^^COOH HOOC^ ^COOH figure 6 In this specification IDS is used to refer to the structure shown in figure 6 and the same structure in which a number of the acidic protons have been replaced, i.e. in which 1,2, 3 or 4 of the acid groups have been neutralised or partially neutralised. IDS or a salt thereof may be present as either enantiomer or a mixture thereof. Preferably it is present as a racemic mixture. IDS is commercially available as a solution comprising 34 wt% of the tetrasodium salt or a solid comprising at least 75 wt% active of the free acid and is sold under the trade mark Baypure CX100. Hydroxyethyliminodiacetic acid (HEIDA) has the structure shown in figure 7: O In this specification, the term HEIDA is used to refer to the structure shown in figure 7 and the same structure in which a number of the acidic protons have been replaced, i.e. in which 1 or 2 of the acid groups have been neutralised or partially neutralised. ASDA is a structural isomer of IDS and has the structure shown in figure 8: In the compositions of the present invention ASDA may be present having the structure shown in figure 8 and / orthe same structure in which a number ofthe acidic protons have been replaced, i.e. in which 1,2, 3 or 4 ofthe acid groups have been neutralised or partially neutralised. It may be present as a free acid or a salt or complex thereof. Ethylenediamine disuccinic acid (EDDS) which has the structure shown in figure 9: O O figure 9 EDDS includes two stereogenic centres and there are three possible stereoisomers. A particularly preferred configuration is [S,S]-ethylenediamine disuccinic acid which is readily biodegradable. In the compositions of the present invention EDDS may be present having the structure shown in figure 9 and / or the same structure in which a number of the hydrogen atoms have been replaced. Thus EDDS may also contain succinate salts in which 1,2, 3 or 4 of the acid groups have been neutralised or partially neutralised. It may be present as a free acid or a salt or complex thereof. One commercially available material is trisodium ethylenediamine disuccinate. The commercial product (Natrlquest E30 (RTM) or Enviomet C140 (RTM)) is supplied as an aqueous solution comprising 30% by weight EDDS (expressed as free acid), or 37 wt% of the trisodium salt (including the counterion). Another commercially available form of EDDS is the tetra acid, sold under the trade mark Natrlquest E80 (RTM), Enviomet C265 (RTM) or Enviomet 280 (RTM). This is provided as a powder which contains 80 wt% solid [S,S] EDDS as an acid and water of crystallisation. Hydroxyethylethylenediaminetriacetic acid (known as HEEDTA or HEDTA) has the structure shown in figure 10: In the compositions of the present invention HEDTA may be present having the structure shown in figure 10 and / or the same structure in which a number of the acidic protons have been replaced, i.e. in which 1, 2 or 3 of the acid groups have been neutralised or partially neutralised. It may be present as a free acid or a salt or complex thereof. HEDTA is commercially available as the trisodium salt under the trade mark Dissolvine H40. Glucoheptonic acid may in some cases be used to describe a number of isomers. However the glucoheptonic acid used in the present invention suitably has the structure p-glucoheptonic acid shown in figure 11: figure 11 This compound may exist in a number of stereoisomeric forms and any of the enantiomers and diastereomers thereof maybe used in the present invention. Two common commercially available forms are a-glucoheptonic acid and p-glucoheptonic acid. In the compositions of the present invention glucoheptonic acid is preferably present as p-glucoheptonic acid, that is the compound having the structure shown in figure 11. It may alternatively be present as a salt in which the acid group has been neutralised or a complex in which the acid group is complexed with another species. The sodium salt of glucoheptonic acid is commercially available as a sodium salt or a boron complex and is sold under the trade mark Crodaquest. In some embodiments the composition comprises poly(acrylic acid-co-hypophosphite) or a salt or complex thereof. Poly(acrylic-acid co-hypophosphite) has the general structure shown in figure 12: O figure 12 Typically, the molecular weight of the poly(acrylic acid co-hypophosphite) is less than 10,000, preferably less than 5,000, preferably less than 3,000. Preferably m is at least 1 and n may be 0 but is preferably at least 1. Preferably the sum of [m + n] is up to 135 and most preferably up to 40. Poly(acrylic-acid co-hypophosphite) may be present in the form shown, or as the sodium or potassium salt or as a complex. Suitable polymers are available under the brand name Belsperse. In the compositions of the present invention poly(acrylic acid-co-hypophosphite) may be present in the form shown in figure 12 or it may be present as a salt or complex. Poly(acrylic acid-co-hypophosphite) is commercially available and is sold under the trade mark Belsperse. 1-hydroxyethylidene -1,1-diphosphonic acid (HEDP) has the structure shown in figure 13: \ ^0H O figure 13 Commercially available HEDP is sold as a viscous yellow liquid comprising approximately 60 wt% active, and is highly acidic. It may be present in the compositions of the present invention as the free acid or a salt or complex thereof. Preferably it is added as the free acid. Aminotri(methylenephosphonic acid) (ATMP) has the structure shown in figure 14: NH2 figure 14 It may be present in the compositions of the present invention as the free acid or a salt or complex thereof. ATMP is commercially available as the free acid or the sodium salt. It is sold under the trade mark Dequest 2000 series. Ethylenediamine tetra methylene phosphonic acid (EDTMP) has the structure shown in figure 15: figure 15 It may be present in the compositions of the present invention as the free acid or a salt or complex thereof. It is commercially available as the sodium salt under the trade mark Dequest 2040 series. Citric acid has the structure shown in figure 16: figure 16 Citric acid may be included as the free acid or as an alkali metal or optionally substituted ammonium salt. For example citric acid may be present as a sodium, potassium or triethanolamine salt. The solid composition of the first aspect may optionally comprise one or more further components in addition to the one or more biosurfactants, one or more non-biological surfactants and optional one or more chelating agents. For example, the solid composition of the first aspect may further comprise sodium chloride. Sodium chloride (when present) may be present in the solid composition in an amount of from 0.1 to 20 wt%, preferably from 0.1 to 15 wt%, suitably from 0.1 to 10 wt%. For example, the solid composition of the first aspect may further comprise water. Preferably the solid composition of the first aspect may comprises less than 5 wt%, preferably 2 wt% or less, or more preferably less than 2 wt%, of water. The amount of water present is dependent on the drying conditions but is preferably minimised. The solid composition of the first aspect may further comprise one or more fillers and / or binding agents, but preferably the solid composition of the first aspect does not comprise any fillers and / or binding agents. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants and from 40 to 65 wt% of the one or more non-biological surfactants, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants and from 40 to 60 wt% of the one or more non-biological surfactants, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants and from 39 to 69 wt% wt% of the one or more non-biological surfactants, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of the one or more non-biological surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of the one or more non-biological surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of the one or more non-biological surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of the one or more non-biological surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of the one or more non-biological surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of the one or more non-biological surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example one or more sophorolipids) and from 40 to 65 wt% of the one or more non-biological surfactants, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example one or more sophorolipids) and from 40 to 60 wt% of the one or more non-biological surfactants, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example one or more sophorolipids) and from 39 to 69 wt% of the one or more non-biological surfactants, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example one or more sophorolipids), from 40 to 65 wt% of the one or more non-biological surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example one or more sophorolipids), from 40 to 60 wt% of the one or more non-biological surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example one or more sophorolipids), from 39 to 69 wt% of the one or more non-biological surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example one or more sophorolipids), from 40 to 65 wt% of the one or more non-biological surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example one or more sophorolipids), from 40 to 60 wt% of the one or more non-biological surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example one or more sophorolipids), from 39 to 69 wt% of the one or more non-biological surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants and from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants and from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example sophorolipids) and from 40 to 65 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine, an amino acid surfactant, an alpha-olefin sulfonate and a sulfate surfactant (preferably selected from one or more of a taurate, an acyl glutamate, an alpha-olefin sulfonate and a sulfate surfactant), provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids) and from 40 to 60 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine, an amino acid surfactant, an alpha-olefin sulfonate and a sulfate surfactant (preferably selected from one or more of a taurate, an acyl glutamate, an alpha-olefin sulfonate and a sulfate surfactant), provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example sophorolipids) and from 40 to 65 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine and a sulfate surfactant (preferably selected from one or more of a taurate and a sulfate surfactant), provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids) and from 40 to 60 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine and a sulfate surfactant (preferably selected from one or more of a taurate and a sulfate surfactant), provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants and from 39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids) and from 39 to 69 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine, an amino acid surfactant, an alpha-olefin sulfonate and a sulfate surfactant (preferably selected from one or more of a taurate, an acyl glutamate, an alpha-olefin sulfonate and a sulfate surfactant), provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids) and from 39 to 69 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine and a sulfate surfactant (preferably selected from one or more of a taurate and a sulfate surfactant), provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt%. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt%. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are amino carboxylate chelating agent(s), preferably MGDA. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are amino carboxylate chelating agent(s), preferably MGDA. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt% and wherein the one or more chelating agent(s) are amino carboxylate chelating agent(s), preferably MGDA. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example sophorolipids), from 40 to 65 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine, an amino acid surfactant, an alphaolefin sulfonate and a sulfate surfactant (preferably selected from one or more of a taurate, an acyl glutamate, an alpha-olefin sulfonate and a sulfate surfactant) and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids), from 40 to 60 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine, an amino acid surfactant, an alphaolefin sulfonate and a sulfate surfactant (preferably selected from one or more of a taurate, an acyl glutamate, an alpha-olefin sulfonate and a sulfate surfactant) and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of one or more glycolipids (for example sophorolipids), from 40 to 65 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine and a sulfate surfactant (preferably selected from one or more of a taurate and a sulfate surfactant) and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids), from 40 to 60 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine and a sulfate surfactant (preferably selected from one or more of a taurate and a sulfate surfactant) and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids), from 39 to 69 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine, an amino acid surfactant, an alphaolefin sulfonate and a sulfate surfactant (preferably selected from one or more of a taurate, an acyl glutamate, an alpha-olefin sulfonate and a sulfate surfactant) and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of one or more glycolipids (for example sophorolipids), from 39 to 69 wt% of one or more non-biological surfactants selected from one or more of a taurate, a betaine and a sulfate surfactant (preferably selected from one or more of a taurate and a sulfate surfactant) and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt% and wherein the one or more chelating agent(s) are selected from one or more MGDA, GLDA, EDTA, EDDS, citric acid, and salts and derivatives thereof. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) is sodium citrate. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) is sodium citrate. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants and from 1 to 5 wt% of the one or more chelating agents, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt% and wherein the one or more chelating agent(s) is sodium citrate. Suitably, the solid composition of the first aspect may comprise from 20 to 55 wt% of the one or more biosurfactants, from 40 to 65 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are amino carboxylate chelating agent(s), preferably MGDA. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 40 to 60 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is at least 75 wt%, preferably at least 80 wt%, more preferably at least 83 wt% and wherein the one or more chelating agent(s) are amino carboxylate chelating agent(s), preferably MGDA. Suitably, the solid composition of the first aspect may comprise from 30 to 60 wt% of the one or more biosurfactants, from 39 to 69 wt% of one or more non-biological surfactants selected from one or more non-biological anionic or amphoteric surfactants, from 1 to 5 wt% of the one or more chelating agents and less than 5 wt% of water, provided that the total surfactant content of the solid composition is from 75 to 99 wt%, preferably from 80 to 99 wt%, more preferably from 83 to 99 wt% and wherein the one or more chelating agent(s) are amino carboxylate chelating agent(s), preferably MGDA. The solid compositions of the first aspect may be, for example, in the form of powders, agglomerates, granules, needles, or combinations thereof. The particles of the solid composition of the first aspect preferably have an average particle size of from 10 to 5000 |j.m, preferably from 25 to 2000 |j.m, more preferably from 50 to 1500 |j.m, suitably from 75 to 1000 |j.m. Average particle size is preferably measured by sieving techniques. One suitable method for determining average particle size is described in the examples. The inventors have surprisingly found that the addition of suitable amounts of one or more non-biological surfactants and optionally one or more chelating agents can enable the formation of a solid (preferably particulate) composition comprising one or more biosurfactants, and may improve the flowability of the solid composition. Preferably the present invention provides a free flowing composition which maintains its free flowing form on storage for at least one month under ambient conditions. More preferably the present invention provides a free flowing particulate composition which maintains its free flowing form on storage for at least one month under ambient conditions. By ambient conditions we mean to refer to storage at atmospheric pressure (i.e. at a pressure of 1 atmosphere) and a temperature of from 15 to 25°C. Preferably the free flowing particulate composition maintains its free flowing form on storage under ambient conditions for at least 3 months, preferably at least 6 months, for example at least 12 months. Advantageously the free flowing particulate composition of the first aspect has been found to maintain its free flowing form on storage for more than 12 months under conditions of varying temperature and humidity. For example a free flowing particulate composition of the first aspect may maintain its free flowing form on storage for more than 12 months under temperatures of 5 to 40 °C and up to 65% humidity. This is particularly advantageous since the solid (preferably particulate, for example free flowing particulate) composition can be stored and transported without needing any special conditions. Preferably the solid (preferably particulate) composition of the first aspect does not form cakes of material on storing. The flowability of a particulate composition may be measured according to the procedure set out in the examples. By “free flowing” we mean that the composition has a flowability as measured by the method described herein of at least 5 g / s, Preferably the solid composition of the first aspect has a flowability as measured by the method described herein of at least 5 g / s, preferably at least 10 g / s, preferably at least 15 g / s, more preferably at least 20 g / s. Preferably the solid composition of the first aspect maintains a flowability after 6 months of storage as measured by the method described herein of at least 2 g / s, preferably at least 5 g / s, preferably at least 10 g / s. Preferably the solid composition of the first aspect maintains a flowability after 24 months of storage as measured by the method described herein of at least 2 g / s, preferably at least 5 g / s, preferably at least 10 g / s. The flowability measurements of dried products can be obtained according to the following method: o Instruments: ■ Plastic tube, diameter (0) 4 cm, volume 500mL ■ Support apparatus for the plastic tube (with a base containing a 1.5 cm hole and an opening / closing system) ■ Empty container (to be placed under the instrument) ■ Scale ■ Stopwatch 0 Procedure: ■ Insert the tube in the support apparatus and close the hole ■ Fill the tube with the dried product to be analysed (500mL) ■ Weigh the empty container and place it under the apparatus (Wi) ■ Open the hole and after the dried product starts to flow start the stopwatch; If the dried product is not immediately flowing, gently hit the base of the support ■ When the dried product flow stops, stop the watch and record the time (t); if some dried product is still in the tube, after 10 seconds of not flowing, the base of the apparatus can be gently hit to help the flowing. If after 3 attempts the majority of the solid is still in the tube, the dried product is not flowable ■ Weigh the container (Wf) ■ The flowability will be measured using the formula Flowability - t According to a second aspect there is provided a method of preparing a solid composition according to the first aspect the method comprising: (i) providing an aqueous composition comprising the one or more biosurfactants, the one or more non-biological surfactants and optionally one or more chelating agents; and (ii) drying the composition obtained in step (i). Preferred features of the second aspect are as defined in relation to the first aspect. Step (i) involves providing an aqueous composition comprising one or more biosurfactants, one or more non-biological surfactants and optionally one or more chelating agents. The one or more biosurfactants, one or more non-biological surfactants and optionally one or more chelating agents are suitably provided in this composition in relative ratios to provide the desired ratio in the solid composition of the first aspect. Suitable ratios are defined in relation to the first aspect. Step (i) may comprise mixing an aqueous solution of one or more biosurfactants with an aqueous solution of one or more non-biological surfactants, and optionally with an aqueous solution of one or more chelating agents. Step (i) may comprise mixing an aqueous solution of one or more biosurfactants with one or more non-biological surfactants in solid form. Step (i) may comprise mixing an aqueous solution of one or more non-biological surfactants with one or more biosurfactants in solid form. Step (i) may comprise mixing an aqueous solution of one or more biosurfactants and one or more non-biological surfactants with one or more chelating agents in solid form. Step (i) may comprise adding water to one or more biosurfactants and one or more non-biological surfactants, and optionally one or more chelating agents, in solid form. The aqueous solutions used in step (i) are preferably highly concentrated and may be saturated. The method may comprise a step between step (i) and step (ii) of agitating the composition obtained in step (i) and / or heating the composition obtained in step (i). Step (ii) involves drying the composition obtained in step (i). Any suitable drying means may be used in step (ii) and such means are known to the person skilled in the art. Suitable drying methods may include fluid bed drying, spray drying, spray granulation, drum drying, flash drying and the use of wiped film evaporators. Suitable drying temperatures would be known to persons skilled in the art and will depend on the desired particle size. For example, suitable drying temperatures when spray drying may be from 65 to 85°C In preferred embodiments step (ii) involves spray drying the composition obtained in step (i). The solid composition of the first aspect is particularly useful in the preparation of detergent formulations. Because the composition is solid it can be easily dosed into and mixed with other components. This is especially the case when the solid composition of the first aspect is a free flowing particulate composition. The inclusion of a component in free flowing particulate form can be particularly useful in compositions where rapid dissolution is desirable. According to a third aspect there is provided a detergent formulation comprising a solid composition of the first aspect. Preferred features of the third aspect are as defined in relation to the first aspect. The detergent formulation of the third aspect may be in solid form, i.e. may be a solid detergent formulation. Solid detergent formulations are advantageous as they avoid the unnecessary transport of large volumes of water and can be packaged in a more environmentally friendly manner. The solid detergent formulation may itself be free flowing but this is not required. The solid detergent formulation may be in any suitable form, for example in the form of a solid bar, tablet, block, puck, stick, or sphere. The solid detergent formulation may be manufactured in a way known to a person skilled in the art, for example by compacting, pouring, dry mixing and moulding, or extruding. The detergent formulation of the third aspect may be in the form of a liquid, i.e. may be a liquid detergent formulation. The liquid detergent formulation may be an aqueous solution, preferably a concentrated aqueous solution in which the solid composition of the first aspect is added to a minimum possible amount of water. The detergent formulation of the third aspect may be useful in household cleaning, manual dishwashing, automatic dishwashing, laundry, fabric care, kitchen care, carpet cleaning, vehicle care, polishing products, machine cleaning and maintenance, agrochemical treatments (for example to treat vegetation with pesticides, such as insecticides, fungicides and / or herbicides), oilfield chemical applications (for example tank cleaning), marine applications, personal care or institutional / industrial cleaning. According to a fourth aspect of the invention, there is provided the use of a solid composition according to the first aspect in household cleaning, manual dishwashing, automatic dishwashing, laundry, fabric care, kitchen care, carpet cleaning, vehicle care, polishing products, machine cleaning and maintenance, agrochemical treatments (for example to treat vegetation with pesticides, such as insecticides, fungicides and / or herbicides), oilfield chemical applications (for example tank cleaning), marine applications, personal care or institutional / industrial cleaning. According to a fifth aspect of the invention, there is provided the use of a detergent formulation according to the third aspect in household cleaning, laundry, manual dishwashing, automatic dishwashing, machine cleaning, personal care or institutional / industrial cleaning. Preferred features of the fourth and fifth aspects are as defined in relation to the first aspect. References herein to automatic dishwashing include use in the main dish wash cycle and in the rinse cycle. Formulations used in the rinse cycle are commonly referred to as rinse aids. The detergent formulation may comprise additional components. Further components suitable for inclusion in such formulations will be known to the person skilled in the art and will depend on the intended use of the detergent formulation. Suitable further components include additional surfactants, preservatives, pH adjusting agents, fillers, perfumes, polymers, dyes, enzymes, probiotics, (additional) chelating agents, rheology modifiers, solubility controllers and hydrotropes. The solid composition of the first aspect may be present in the detergent formulation in any suitable amount, such as in an amount of from 10 to 95 wt%, such as from 15 to 95 wt%, or from 17 to 39 wt%, based on the total weight of the detergent formulation. According to a sixth aspect of the invention, there is provided method ofcleaning an article, the method comprising dissolving the detergent formulation of the third aspect to produce a solution and applying the solution to the article. Preferred features of the sixth aspect are as defined in relation to the third aspect. According to a seventh aspect of the invention, there is provided the use of one or more non-biological surfactants, and optionally one or more chelating agents, to provide a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and wherein the total surfactant content of the solid composition is at least 75 wt%. According to an eighth aspect of the invention, there is provided a method of providing a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and wherein the total surfactant content of the solid composition is at least 75 wt%, the method comprising drying the one or more biosurfactants with one or more non-biological surfactants and optionally one or more chelating agents. Preferred features of the seventh and eighth aspects are as defined in relation to the first aspect. According to a ninth aspect of the invention, there is provided the use of one or more chelating agents to improve the flowability of a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%. According to a tenth aspect of the invention, there is provided a method of improving the flowability of a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%, the method comprising drying the one or more biosurfactants and one or more non-biological surfactants with one or more chelating agents. Preferred features of the ninth and tenth aspects are as defined in relation to the first aspect. Brief Description of the Drawings Examples of the present disclosure will now be described with reference to the accompanying drawings. Figure 1A shows a model graph used in the determination of the average particle size of the dried products in which the mesh size of each sieve is plotted on the X-axis and the amount of product found (in g) is plotted on the Y-axis. The invention will now be further defined with reference to the following non-limiting examples. Examples The following abbreviations are used in the examples section. SL Sophorolipid (rapeseed oil derived) with an acid:lactone ratio of 70:30 CAPB Cocamidopropyl betaine SMOT Sodium methyl oleoyl taurate SLS Sodium lauryl sulfate MGDA Trisodium salt of methyl glycine di-acetic acid GLT Sodium lauroyl glutamate AOS Ci4-Ci6-alpha olefin sulfonate Example 1 Feedstock solutions 1 to 7 (shown in Table 1 below) were prepared by mixing the components 5 as indicated. Each of the resultant feedstock solutions were then dried (where possible) using a spray drying process (spray granulation) to provide the dried product compositions. The SL, CAPB, SMOT and SLS components of the feedstock solutions were all aqueous solutions and are commercially available. The wt% provided for the feedstock solutions 10 represents the wt% of actives. For example, the feedstock solution for example 2 contained 15 wt% of the (active) sophorolipid, which was added as an aqueous solution. Table 1 Composition 1* 2 3 4 5 6 7 Feedstock solution (wt%) SL 61 15 12 12 12 14 14 SLS - - - - - 21 21 SMOT - 22.5 18 18 - - - CAPB - - - - 19 - - Water 33 55 62.5 62.5 62 62.5 61.5 MGDA powder - - 1.2 1.2 1.2 - 1.1 Sodium citrate - - - - 0.5 - - Other** 6 7.5 6.3 6.3 5.3 2.5 2.4 Drying Conditions Temperature (°C) 68 68 70 73 75 75 75 Time 3h 4h 8h*** 8h*** 8h*** 4h 8h*** Amount of Feedstock solution 1000g 2000g 4000 g 4000 g 3000 g 1500g 4000 g Dried product composition (wt%) SL 83 34 33 33 34 38 36 SLS - - - - - 57 54 SMOT - 51 50 50 - - - CAPB - - - - 51 - - Water 9.8 1.4 0.8 0.8 1.3 1.0 0.9 Sodium chloride - 9 8.5 8.5 9 - - Sodium citrate - - - - 1.3 - - MGDA - - 2.5 2.5 2.5 - 2.5 Other** 7.2 4.6 5.2 5.2 0.9 4.0 6.6 ‘Comparative “Inorganics and unreacted starting materials and impurities present in commercial sources of the components. *** Continued until set particle size achieved Example 2 The dried products were visually assessed fortheir appearance and flowability, and their pH and density were measured. Where a powder or granules were provided after drying, the average particle size of the product was determined. The results are shown in Table 2 below. Flowability was visually assessed by pouring 100 g of dried product from a container. pH was measured on a 2% aqueous solution at 20°C with a pH meter. Density (bulk) was measured by weighing 100 mL of dried product in a graduated glass cylinder at 20°C. The average particle size of the dried products was determined according to the following method which is used to evaluate the granulometry of a solid material in a powder, agglomerate, granular or needle form. Apparatus: Sieves at different mesh size: Plate, 75pm, 125pm, 250pm, 500pm, 1000 pm Vibrating screen with a timer Weight scale Analytical Procedure: Take the sieves and weigh each of them Stack the sieves starting from the one with smallest mesh and increasing the size. Pour approx. 100 g of the dry product on the top sieve. Place the sieves on the vibrating screen, cover with a lid and vibrate for 60 seconds. Weigh each sieve again and record the data. Subtract the weight of each sieve from the final weight of the sieves containing the powder. The results can be normalized and plotted on a chart to illustrate the particle size distribution. In the model graph shown in Figure 1A which relates to composition 3 in Table 1, mesh size of each sieve is plotted on the X-axis and the amount of product found (in g) is plotted on the Y-axis. Table 2 Composition 1* 2 3 4 5 6 7 Appearance at room temperature after drying Failed to dry Sticky agglomerates, ground to a powder** powder powder Sticky solid powder powder / granules PH 7.4 10.2 10.1 10.1 10.5 9.6 9.6 Density (g / mL) - - 0.55 0.65 - 0.61 0.61 Average particle size (pm) 125-250 125-250 125-250 125-250 Flowable? No Partially Yes Yes No Yes Yes *Comparative **Agglomerate was collected and ground into a powder once cool. Example 3 Formulated laundry compositions 8 and 9 were prepared according to Table 3 below. Composition 8 was prepared by dry mixing dried composition 3 in Table 1 above with sodium palm-kernelate (in powder form). Composition 9 was prepared by dry mixing dried composition 7 in Table 1 above with sodium palm-kernelate (in powder form) and SMOT (in powder form). Table 3 Composition 8 9 SL 27 14.6 SMOT 40.6 22.8 SLS - 22.9 Sodium palm- kernelate 13.4 15 MGDA 1.4 1 NaCI 12 6 Water &additives To 100 To 100 Appearance at RT Powder Powder Example 4 Feedstock solutions 10 and 11 (shown in Table 4 below) were prepared by mixing the 5 components as indicated. Each of the resultant feedstock solutions were then dried using a spray drying process (spray granulation) to provide the dried product compositions. The SL, GLT and AOS components of the feedstock solutions were all aqueous solutions and are commercially available. As above, the wt% provided for the feedstock solutions represents 10 the wt% of actives. Table 4 Composition 10 11 Feedstock solution (wt%) SL 9 17 GLT 20 - AOS - 25 Water 66 55 Other* 5 3 Drying Conditions Temperature (°C) 70 70 Time 4h 4h Amount of Feedstock solution 2000g 2000g Dried product composition (wt%) SL 26 38 GLT 60 - AOS - 55 Water 2 1.1 Sodium chloride 11 - Other* 1 5.9 inorganics and unreacted starting materials and impurities present in commercial sources of the components. The dried products were visually assessed fortheir appearance and flowability, and their pH and 5 density were measured. The average particle size of the product was determined according to the method of Example 2. Results are shown in Table 5. Table 5 Composition 10 11 Appearance at room temperature after drying powder / granules powder / granules PH 11.2 12 Density (g / mL) 0.33 0.63 Average particle size (pm) 125-250 125-250 Flowable? Yes Yes 10 These results show that inventive flowable powders of acyl glutamate surfactants or alpha-olefin sulfonate surfactants with sophorolipids can be obtained by co-drying according to the methods of the present invention. The present invention is not restricted to the details of the foregoing embodiment(s). The 15 invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A solid composition comprising at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content of the solid composition is at least 75 wt%.

2. A solid composition according to claim 1, which is a free flowing particulate composition.

3. A solid composition according to claim 1 or 2, further comprising one or more chelatingagents.

4. A solid composition according to claim 3, wherein the solid composition comprises the one or more chelating agents in an amount of from 0.1 to 20 wt%, preferably from 0.5 to 15 wt%, more preferably from 1 to 10 wt%.

5. A solid composition according to any preceding claim, wherein the one or more biosurfactants are selected from one or more of a glycolipid, a lipopeptide, a phospholipid and a polymeric biosurfactant.

6. A solid composition according to claim 5, wherein the one or more biosurfactants are one or more glycolipids.

7. A solid composition according to claim 6, wherein the one or more glycolipids are selected from one or more of a rhamnolipid, a trehalolipid, a sophorolipid and a mannosylerythritol lipid, preferably wherein the one or more glycolipids are one or more sophorolipids.

8. A solid composition according to any preceding claim, wherein the one or more non-biological surfactants are selected from one or more of a non-biological anionic surfactant, a non-biological non-ionic surfactant, a non-biological cationic surfactant and a non-biological amphoteric surfactant, preferably wherein the one or more non-biological surfactants are selected from one or more of a non-biological anionic surfactant and a non-biological amphoteric surfactant.

9. A solid composition according to any preceding claim, wherein the one or more non-biological surfactants are selected from one or more of a taurate, a betaine, a sulfonate (such as a linear alkylbenzene sulfonate, an alpha-olefin sulfonate and a fatty acid methyl ester sulfonate), a sulfosuccinate, an amino acid surfactant (such as a glutamate, glycinate and / or alaninate), a sarcosinate, a sulfoacetate, an amine oxide, an amphoacetate, a glycinate and asulfate surfactant, preferably selected from one or more of a taurate, a betaine and a sulfate surfactant, more preferably selected from one or more of a taurate and a sulfate surfactant.

10. A solid composition according to any preceding claim, wherein the one or more non-biological surfactants are selected from one or more of cocamidopropyl betaine, sodium methyl oleoyl taurate, sodium lauryl sulfate, sodium lauroyl glutamate and Ci4-Ci6-alpha olefin sulfonate.

11. A solid composition according to any preceding claim, wherein the solid composition comprises the one or more biosurfactants in an amount of from 20 to 80 wt%, preferably from 25 to 80 wt%, more preferably from 30 to 60 wt%.

12. A solid composition according to any preceding claim, wherein the solid composition comprises the one or more non-biological surfactants in an amount of from 20 to 80 wt%, preferably from 30 to 80 wt%, more preferably from 40 to 60 wt%.

13. A solid composition according to any of claims 3 to 12, wherein the one or more chelating agents are selected from one or more of a polycarboxylic acid chelating agent, a phosphonic acid-containing chelating agent, an amino carboxylic acid-containing chelating agent and an iminodiacetic acid derivative, and salts and derivatives thereof.

14. A solid composition according to claim 13, wherein the one or more chelating agents are selected from one or more of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), ethylenediamine disuccinic acid (EDDS), methylglycinediacetic acid (MGDA), glutamic acid, N,N-diacetic acid (GLDA), iminodisuccinic acid (IDS); ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), aspartic acid diethoxysuccinic acid (AES), aspartic acid-N,N-diacetic acid (ASDA), ethylenediamine tetra methylene phosphonic acid (EDTMP), iminodifumaric (IDF), iminoditartaric acid (IDT), iminodimaleic acid (IDMAL), iminodimalic acid (IDM), ethylenediaminedifumaric acid (EDDF), ethylenediaminedimalic acid (EDDM), ethylenediamineditartaric acid (EDDT), ethylenediaminedimaleic acid and (EDDMAL), aminotri(methylenephosphonic acid) (ATMP); diethylenetriamine-penta-methylene phosphonic acid (DETPMP), hydroxyethyliminodiacetic acid (HEIDA), aspartic acid diethoxysuccinic acid (AES), aspartic acid-N,N-diacetic acid (ASDA), diethylenetriaminepentamethylene-phosphonic acid (DTPMPA), hydroxyethylenediaminetetraacetic acid (HEDTA), hydroxyethylethylenediaminetriacetic acid (HEEDTA), glucoheptonic acid, citric acid, poly(acrylic-acid co-hypophosphite), tripolyphosphoric acid, polyacrylic acid, and salts and derivatives thereof.

15. A solid composition according to any preceding claim, wherein the chelating agent is an amino carboxylate chelating agent, preferably MGDA.

16. A solid composition according to any preceding claim, wherein the chelating agent is citric acid or a salt thereof.

17. A solid composition according to any preceding claim, which comprises less than 5 wt%, preferably less than 2 wt%, of water.

18. A method of preparing a solid composition as claimed in any of claims 1 to 17, the method comprising:(i) providing an aqueous composition comprising the one or more biosurfactants, the one or more non-biological surfactants and optionally one or more chelating agents; and(ii) drying the composition obtained in step (i).

19. A detergent formulation comprising a solid composition according to any of claims 1 to 17.

20. A detergent formulation according to claim 19 which is a solid detergent formulation.

21. The use of a solid composition according to any of claims 1 to 17 in household cleaning, manual dishwashing, automatic dishwashing, laundry, fabric care, kitchen care, carpet cleaning, vehicle care, polishing products, machine cleaning and maintenance, agrochemical treatments (for example to treat vegetation with pesticides, such as insecticides, fungicides and / or herbicides), oilfield chemical applications, marine applications, personal care or institutional / industrial cleaning.

22. The use of a detergent formulation according to claim 19 or 20 in household cleaning, manual dishwashing, automatic dishwashing, laundry, machine cleaning, personal care or institutional / industrial cleaning.

23. A method of cleaning an article, the method comprising dissolving the detergent formulation of claim 19 or 20 to produce a solution and applying the solution to the article.

24. The use of one or more non-biological surfactants, and optionally one or more chelating agents, to provide a solid composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and wherein the total surfactant content of the solid composition is at least 75 wt%.

25. A method of providing a solid composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and wherein the total surfactant content of the solid composition is at least 75 wt%, the method comprising drying the one or more biosurfactants 5 with one or more non-biological surfactants and optionally one or more chelating agents.

26. The use of one or more chelating agents to improve the flowability of a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the 10 total surfactant content of the solid composition is at least 75 wt%.

27. A method of improving the flowability of a solid, preferably a particulate, composition, wherein the solid composition comprises at least 20 wt% of one or more biosurfactants and at least 20 wt% of one or more non-biological surfactants, and wherein the total surfactant content 15 of the solid composition is at least 75 wt%, the method comprising drying the one or more biosurfactants and one or more non-biological surfactants with one or more chelating agents.A

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