A composition for reducing malodour

Abstract

The present invention relates to a composition for reducing malodour. Particularly, the present invention relates to a hard surface cleaning composition like that used to clean dishes in the kitchen, that ensures that the surface remains fresh and free of malodours. This is ensured by using a composition comprising a surfactant, select polysaccharide and a hydrotrope.

Description

[0001] A COMPOSITION FOR REDUCING MALODOUR

[0002] Field of the Invention

[0003] The present invention relates to a composition for reducing malodour. Particularly, the present invention relates to a hard surface cleaning composition like those for use in the kitchen such that the surface remains fresh and free of malodour.

[0004] Background of the Invention

[0005] Washing fabrics, also known as laundering or simply as laundry, makes up one of the main chores that people undertake routinely. For this, people have been relying on detergent compositions that are widely available. Typically, a fabric is washed by contacting it with a detergent composition either in neat or diluted form, rinsing the fabric one or more times with water; and finally, drying it. In the washing step, a fabric is cleaned by mechanically agitating it using hands and / or by using suitable cleaning means e.g. a brush, in so-called hand-wash method. Alternatively, in so-called machine-wash method, a fabric is cleaned by mechanical agitations carried out by a machine. In either case, a step of soaking a fabric, in a neat or diluted detergent composition, may be carried out for a desired duration e.g. 30 to 60 minutes. The step of drying may also be carried out by using machines; or simply by exposing the fabric to air, and if possible, under the sun.

[0006] During the rinsing steps, which may be with fresh water two or three times, often a fabric conditioning composition is added especially in the final rinse step to provide various benefits like anti yellowing, fabric conditioning, or antimicrobial benefits. Fabric conditioners were generally developed to deliver certain surface treatments to the fabric to ensure they are soft, smooth and free of static. The present invention relates to a composition that could be included in either the wash step or the rinsing step for delivering the benefit of reducing dank odours.

[0007] Drying of the fabric may be carried out in a machine at high temperature (e.g. 50 to 80 °C) with flow of air in which case the step may be carried out for half hour to about two hours. This is considered as fast drying in which case the high temperature ensures quick removal of water and inactivation of residual odour causing microorganisms. Machine drying is energy intensive and is popular only in cold and rainy countries where there is continuous supply of power to run such machines. In hot countries like in the tropical areas with high amount of sunshine the washed fabric is dried in the sun on clotheslines. Such a drying process often taken several hours. Depending on the season e.g. the rainy season or unavailability of outdoor space to dry the fabric in the sun, the drying is much slower and may sometimes take two or three days to dry. Under such drying conditions the clothes acquire a dank odour. Including a fabric treatment composition (containing high amount of perfume) during the rinse step does not seem to solve the problem to an adequate amount. The present inventors are aware that microorganisms like Moraxella osloensis and Staphylococcus hominis are responsible for producing the malodour when fabric are present under these high - moisture conditions.

[0008] The present inventors in seeking to solve the above problem have hit upon a solution which involves formulating a composition comprising a surfactant, select polysaccharide and a hydrotrope. Such compositions were found to deliver the desired benefit of reducing malodour. They found that this composition also reduces malodour when used to clean any hard surface especially those in the kitchen like those on utensils and dishes.

[0009] It is an object of the present invention to provide for a composition that delivers malodour reduction benefit on hard surfaces especially those in the kitchen like utensils and dishes.

[0010] Summary of the Invention

[0011] The first aspect of the present invention relates to a composition for reducing malodour on hard surfaces comprising

[0012] (i) 0.01 to 5 wt% a polysaccharide selected from one or more of algin, pectin, dextrin or resistant dextrin;

[0013] (ii) 0.1 to 5 wt% a hydrotrope selected from one or more of sodium cumene sulphonate, sodium xylene sulphonate, polyethylene glycol and mono propylene glycol; and

[0014] (iii) a surfactant.

[0015] Another aspect of the present invention relates to a method of reducing malodour from a hard surface comprising the step of contacting the surface with a composition of the first aspect preferably diluted with water followed optionally with the step of rinsing the surface with water. Detailed Description of the Invention

[0016] For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of” or "composed of". Thus, the term "comprising" is meant not to be limiting to any subsequently stated elements, but rather to optionally also encompass nonspecified elements of major or minor functional importance. In other words, the listed steps or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word "about". Unless specified otherwise, numerical ranges expressed in the format "x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as “wt%”.

[0017] The composition of the invention comprises a polysaccharide selected from one or more of algin, pectin, dextrin or resistant dextrin.

[0018] Alginic acid, also called algin, is a polysaccharide distributed widely in the cell walls of brown algae that is hydrophilic and forms a viscous gum when hydrated. Alginic acid is a linear copolymer with homopolymeric blocks of (1— >4)-linked p-D-mannuronate (M) and a-L- guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. The monomers may appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks) or alternating M and G-residues (MG-blocks). a-L-guluronate is the C-5 epimer of p-D-mannuronate. Alginates are refined from brown seaweeds. Throughout the world, many of the Phaeophyceae class brown seaweeds are harvested to be processed and converted into sodium alginate and alginic acid.

[0019] Pectin is a structural acidic heteropolysaccharide contained in the primary and middle lamella and cell walls of terrestrial plants. Its main component is galacturonic acid, a sugar acid derived from galactose. It is produced commercially as a white to light brown powder, mainly extracted from citrus fruits, and is used in food as a gelling agent, particularly in jams and jellies. It is also used in dessert fillings, medicines, sweets, as a stabiliser in fruit juices and milk drinks, and as a source of dietary fiber. Pectin also known as pectic polysaccharides, are rich in galacturonic acid. Several distinct polysaccharides have been identified and characterised within the pectic group. Homogalacturonans are linear chains of a-(1-4)-linked D-galacturonic acid. Substituted galacturonans are characterised by the presence of saccharide appendant residues (such as D-xylose or D-apiose in the respective cases of xylogalacturonan and apiogalacturonan) branching from a backbone of D-galacturonic acid residues. Rhamnogalacturonan pectins (RG- I) contain a backbone of the repeating disaccharide: 4)-a-D-galacturonic acid-(1 ,2)-a-L- rhamnose-(1. From many of the rhamnose residues, sidechains of various neutral sugars branch off. The neutral sugars are mainly D-galactose, L-arabinose and D-xylose, with the types and proportions of neutral sugars varying with the origin of pectin. Another structural type of pectin is rhamnogalacturonan II (RG-II), which is a less frequent, complex, highly branched polysaccharide.

[0020] Pectin is the preferred first polysaccharide for inclusion in the composition of the invention. Pectin when included is preferably derived from one or more of a fruit chosen from pear, apple, guava, plum, gooseberry, orange or any other citrus fruit, preferably citrus. It is preferably from apple or citrus fruit.

[0021] Pectin consists predominantly of a-D galacturonic acid units, but also contains some amount of neutral sugars such as rhamnose, xylose, arabinose, galactose and glucose.

[0022] The percentage of galacturonic acid units is therefore the amount of galacturonic acid groups present relative to the total amount of the pectin. The galacturonic acid content of a sample can be determined by methods known in the art, such as for example the Saeman hydrolysis method (Englyst and Cummings (Analyst, 109(7), 937-942 (1984), Filisetti-Cozzi and Carpita (Analytical Biochemistry, 197, 157-162 (1991)).

[0023] Galacturonic acid typically has the following repeat unit structure: It is possible to esterify galacturonic acids on the carboxylic acid group. The percentage of esterified units is called the degree of esterification (DE). The degree of esterification can be determined according to methods known in the art, such as the base titration method (Shultz, 1965) as proposed by the Food Chemical Codex (FCC (1981). 3rd ed., (1981) National Academy of Science, Washington, DC), quantification of methanol released during de-esterification using gas chromatography (GC) (Walter et al. (1983), Journal of Food Science, 48: 1006-10070), colorimetry (Hou et al. (1999), Botanical Bulletin of Academia Sincia, 40:115-119), high performance liquid chromatography (HPLC) (Levigne S., et al. (2002), Food Hydrocolloids 16: 547-550), nuclear magnetic resonance (NMR) (Rosenbohm et al. (2003) Carbohydrate Research, 338: 637-649) and capillary zone electrophoresis (CZE) (Williams et al. (2003), Journal of Agricultural Food and Chemistry, 51 : 1777-1781).

[0024] A method to separate pectin into fractions with different DE is described, for example, by Strom, et al. (2005), Carbohydrate Polymers, Volume 60, Issue 4, 20 June 2005, Pages 467-473.

[0025] In nature, the carboxylic groups are typically methylated to varying degrees to provide pectin methyl esters. The number fraction of carboxylic acid groups methylated is known as the degree of methyl esterification.

[0026] The pectin used in the composition of the present invention preferably has a degree of methyl esterification higher than 50%, more preferably 52.5% or higher, further more preferably 55% or higher, yet more preferably 57.5% or higher and most preferably 60% or higher.

[0027] The pectin used according to the invention preferably has a molecular weight of higher than 50kDa, more preferably higher than 100kDa. Typical upper limits of pectin molecular weights are preferably of the order of 1000kDa, more preferably 800kDa. Thus, the pectin for use in the composition of the invention preferably has a molecular weight of between 50 kDa and 1000kDa.

[0028] Dextrin is preferably prepared by partial hydrolysis of starches from corn, potato, arow root, tapioca starch or wheat. The hydrolysis may be by thermal or enzymatic means. Dextrin is a combination of D-glucose units linked through a(1 - 4) or a(1 - 6) glycosidic bonds. Dextrin generally has the chemical formula (CeH Os A preferred dextrin is one having CAS No. 9004- 53-9. It generally has a pH in the range of 4 to 5 when a 20% solution is measured at 25 °C. It is usually sold as a pale yellow powder which is odourless. The power usually has a particle size in the range of 100 to 200 .m. It is soluble in water at 20 °C. The viscosity is low since a 50% solution in water at 20 °C is measured to have a value in the range of about 50 to 200 mPa.s. A preferred supplier of dextrin is Roquette Freres, France who sell it under the brand name NutrioseRFB 06.

[0029] Resistant dextrin is also known by some as maltodextrin. It is usually prepared by highly controlled partial hydrolysis of corn, potatoes, barley or wheat. It usually contains 3 to 20 D- glucose units that are linked by a(1 -4) glycosidic bond. It usually has the chemical formula C6nH( n+2)O(5n+i). A preferred resistant dextrin has the CAS No. 9050-36-6. It is usually sold as an off-white powder which is odourless. It is soluble in water. A preferred supplier of resistant dextrin is ADM Bio Science & Technology (Tianjin) Co. Ltd., Tianjin, China who sell it under the brand name FbersolR2.

[0030] The preferred polysaccharide for use in the composition is pectin. Another preferred aspect comprises inclusion of pectin and resistant dextrin. Yet another preferred aspect comprises inclusion of pectin and dextrin. The composition preferably comprises the polysaccharide to be included at a concentration of 0.01 to 5%, preferably 0.05 to 4% by weight of the composition.

[0031] The composition of the invention comprises a hydrotrope. Suitable hydrotropes for inclusion in the composition of the invention are one or more of an alkali metal cumene sulphonate, alkali metal xylene sulphonate, polyethylene glycol (PEG) and mono propylene glycol (MPG). The preferred alkali metal cumene sulphonate is sodium cumene sulphone (SOS). The preferred alkali metal xylene sulphonate is sodium xylene sulphonate (SXS). The most preferred hydrotrope for use in the present invention is one or both of SOS and MPG. When the composition is in liquid form it is preferred that the hydrotrope is PEG or MPG, preferably MPG. The hydrotropes PEG and MPG preferably MPG are suitable in liquid dishwash compositions as they are not only very efficacious in providing the desired antimalodour benefit but they also deliver better transparency to the composition. When the composition is in solid form it is preferred that the hydrotrope is SOS. The composition preferably comprises 0.1 to 5 wt%, more preferably 0.2 to 4 wt% hydrotrope. Without wishing to be bound by theory the inventors believe that the inclusion of the hydrotrope in addition to its known property of enhancing solubility of the surfactants, increases the bioavailability of the polysaccharide thereby helping in increasing their efficacy in countering the formation of the malodour molecules from the malodour causing bacteria.

[0032] The composition of the invention may also be delivered in a spray format. The spray may be delivered form a hand held container comprising a pump, the container containing the composition as per the invention Such sprays may be used to deliver reduction of malodour from surfaces like those in the kitchen, bathrooms and other surfaces like those on furniture.

[0033] The composition of the invention may also be delivered as a dish wash composition. Such compositions are used to clean dishes either using the hands or by using a dishwash machine. Use of such a composition ensures low malodour on vessels and dishes, on sponges and scrubs used in the kitchen and from filters used in the dishwash machines.

[0034] Dishwash compositions

[0035] The composition of the invention may be useful for upkeep of kitchen items e.g. utensils and dishes which may be cleaned using a liquid dishwash compositions. The composition is also useful for cleaning and disinfecting filters in dishwashing machines. The various ingredients other than the essential ingredients claimed in the present invention which may be included are anionic surfactants, and non-ionic surfactants.

[0036] Preferred anionic surfactants are of the organic sulfates and sulfonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term “alkyl” being used to include the alkyl portion of higher acyl radicals. Examples of such materials include alkyl sulfates, alkyl ether sulfates, alkaryl sulfonates, alpha-olefin sulfonates and mixtures thereof. The alkyl radicals preferably contain from 10 to 18 carbon atoms and may be unsaturated. The alkyl ether sulfates may contain from one to ten ethylene oxide or propylene oxide units per molecule, and preferably contain one to three ethylene oxide units per molecule. The counterion for anionic surfactants is generally an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or triethanolamine (TEA). Mixtures of such counterions may also be employed. Sodium and potassium are preferred.

[0037] Most preferred surfactants are of the alkylbenzene sulfonates type, particularly linear alkylbenzene sulfonates (LAS) with an alkyl chain length of from 10 to 18 carbon atoms. Some alkyl sulfate surfactant (PAS) may be used, such as non-ethoxylated primary and secondary alkyl sulphates with an alkyl chain length of from 10 to 18.

[0038] Preferably, the composition comprises from 1 to 20%, more preferably 5 to 20 wt% non-ionic surfactant based on the total weight of composition. A preferred class of nonionic surfactant for use in the invention includes aliphatic Cs to Cis, more preferably C12 to C15 primary linear alcohol ethoxylates with an average of from 3 to 20, more preferably from 5 to 10 moles of ethylene oxide per mole of alcohol. A preferred non-ionic surfactant are the C16 / 18 Alcohol ethoxylates.

[0039] Additionally, other ingredients like amphoteric surfactants and organic acids, may be included. A preferred aspect of the invention relates to a dishwash composition comprising 1 to 30% anionic surfactant. It may additionally comprise 5 to 20 wt%, preferably 7 to 15 wt% amphoteric surfactant preferably a betaine.

[0040] Preferably, liquid dishwash composition further comprises water in an amount ranging from 5 to 99 wt%, more preferably from 15 to 80 wt%, further more preferably from 30 to 65 wt%, by weight of the composition. Preferably, liquid dishwash composition further comprises one or more sequestrants which may be included in 0.1 to 5 w% by weight of the composition. A preferred sequestrant is a phosphonic acid or a salt thereof. The most preferred sequestrant is 1 - Hydroxyethylidene-1 ,1 - diphosphonic acid (HEDP). It is preferable that the sequestrant is added to the formulation in acid form. Optionally, liquid dishwash composition further comprises an enzyme with or without a suitable enzyme stabilizer. Preferably, viscosity of the composition may suitably range from about 200 to about 10,000 mPa.s at 25°C at a shear rate of 21 sec1. The liquid dishwash composition preferably has pH in the range from 2.0 to 8.0, more preferably from 3.5 to 7.0. The liquid dishwash composition may further comprise one or more polymers which may be included in 0.001 to 10 wt%, more preferably from 0.1 to 6 wt%, still further more preferably from 1 to 3 wt%.

[0041] Preferably, the composition may be used as is, i.e. neat, or it may be diluted before use. The extent of dilution is generally dependent on market choice. In some markets a more concentrated product is desired while in others a more dilute product is preferred. When the composition is a liquid dishwash compositions it is typically diluted with water in a weight ratio in the range of 1 :1 to 1 :100 preferably 1 :1 to 1 :30 more preferably 1 :1 to 1 :10.

[0042] The liquid dishwash composition may optionally comprise ingredients, such as fragrance, colorant, foam boosting agents, and odor absorbing materials.

[0043] The composition of the invention may also be delivered as a rim block. By a rim block is meant a shaped solid composition that is hung on to the rim of the toilet usually in a plastic cage like container so that every time the toilet is flushed, a quantity of water passes over the solid composition, eroding a part thereof before flushing into the toilet bowl. The toilet rim block preferably additionally includes a perfume to provide a lingering pleasant odour after every toilet flush.

[0044] Another aspect of the present invention relates to a method of reducing malodour from a surface comprising the step of contacting the surface with a composition of the invention preferably diluted with water followed optionally with the step of rinsing the surface with water.

[0045] The invention will now be illustrated with the help of the following non-limiting examples.

[0046] Examples

[0047] Examples A-H, 1-10: Model experiments on various combinations of LAS, pectin, and SCS or SXS on malodour generation:

[0048] Experiments were conducted using the procedure as given below to determine the amount of malodour generated on fabric. The data is summarized in Table -1 below:

[0049] 1 ml of milk + 5% starch (1 :1) was added to desized kitchen cloth (5x5 cm). The cloth was inoculated with Acinetobacter baumanii & Moraxella osloensis 108cfu / ml. Different concentrations of treatment was inoculated into respective bottle. The cups were incubated at 37 °C for 48 h. Malodour was scored by a trained panel.

[0050] Table - 1 :

[0051] The data in Table -1 above indicates that a composition comprising a surfactant, polysaccharide and hydrotrope (Examples 1 -10) provides for vastly improved malodour benefit as compared to individual components. (Examples A-H)

[0052] Example l-J,11-12: Effect of inclusion of polysaccharide and humectant in a hand dishwash bar composition

[0053] A hand dishwash bar composition was taken as shown in Table - 2 below. Various compositions as shown in Table - 3 were prepared by including certain amounts of polysaccharide and / or hydrotrope therein to a 10% solution of the bar. The compositions were tested for malodour generation using the procedure followed for the examples A-H, 1-10.

[0054] The summary of the data is summarized in Table -3 below.

[0055] Table -2:

[0056] Table - 3

[0057] The data in table -3 above indicates that inclusion of two types of polysaccharide and the hydrotrope in a hand dishwash composition (Examples 11, 12) provides for vastly improved reduction in malodour as compared to compositions outside the invention (Examples I, J).

Claims

Claims1. A composition for reducing malodour on hard surfaces comprising(i) 0.01 to 5 wt% a polysaccharide selected from one or more of algin, pectin, dextrin or resistant dextrin;(ii) 0.1 to 5 wt% a hydrotrope selected from one or more of alkali metal cumene sulphonate, alkali metal xylene sulphonate, polyethylene glycol and mono propylene glycol; and(iii) a surfactant.

2. A composition as claimed in claim 1 wherein the polysaccharide is pectin.

3. A composition as claimed in claim 2 wherein the pectin is derived from one or more of a fruit selected from pear, apple, guava, plum, gooseberry, orange and any other citrus fruit, preferably citrus fruit.

4. A composition as claimed in any one of the preceding claims in solid form wherein the hydrotrope is SCS.

5. A composition as claimed in any one of the preceding claims 1 to 3 in liquid form wherein the hydrotrope is MPG.

6. A composition as claimed in any one of the preceding claims which is a dishwash composition comprising 1 to 30% anionic surfactant.

7. A composition as claimed in claim 6 additionally comprising 5 to 20 wt%, preferably 7 to 15 wt% amphoteric surfactant preferably a betaine.

8. A method of reducing malodour from a hard surface comprising the step of contacting the surface with a composition as claimed in any one of the preceding claims preferably diluted with water followed optionally with the step of rinsing the surface with water.

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