Anionic galactomannans from GUAR and its process of production

Abstract

The present invention relates to an anionic galactomannan derived from guar gum and having a mannose / galactose ratio of 2.5:1 and 5:1, a production process thereof and its performance and use in home and personal care or agrochemical formulations.

Description

[0001] ANIONIC GALACTOMANNANS FROM GUAR AND ITS PROCESS OF

[0002] PRODUCTION

[0003] FIELD OF THE INVENTION

[0004] The present invention concerns anionic galactomannans obtained from guar gum, a process of production of such anionic galactomannans and performance properties, such as rheology modifier, for home and personal care or agrochemical applications.

[0005] This application claims priority filed on 03 July 2024 in EUROPE with Nr 24186317.4, the whole content of this application being incorporated herein by reference for all purposes.

[0006] TECHNICAL BACKGROUND

[0007] Galactomannans are polysaccharides consisting of a mannose backbone with galactose side groups which can be obtained from a number of Leguminosae. Anionic galactomannans are commonly used in personal care products like hair or skin. Mention can be made to US2018 / 092814 and EP 1040821.

[0008] Home and personal care compositions are commonly used on a daily basis by customers all over the world.

[0009] The same is true for agrochemical compositions when referring to the work in the field and crops.

[0010] The use of thickeners in home and personal care or agrochemical compositions is required to achieve important physical chemical properties such as viscosity and stability, allowing adequate structure of the desired composition.

[0011] Guar is a polysaccharide composed of galactose and mannose as elementary sugar units. The backbone is a linear chain of P-l,4-linked mannose residues to which galactose residues are a-l,6-linked at every other mannose on average, forming short side units. Differently, tara gum is a natural additive, obtained by grinding the endosperm of the seeds of Caesalpinia spinosa. of the Leguminosae family. Structurally, it is a galactomannan polymer consisting of a main chain of P-l,4-linked mannose units with side chains of a-l,6-linked galactose approximately every third mannose unit.

[0012] In the same way, galactomannans derived from locust bean and cassia consist in a polymer having main chain of P-l,4-linked mannose units with side chains of a- 1,6- linked galactose approximately every fourth mannose unit and every fifth mannose unit, respectively.

[0013] However, the main drawbacks concerning tara gum use is due to the difficulty in obtaining the raw material since the latter comes from tall trees rather than bushes, which limits its wide use due to high cost, with the additional disadvantage of lower annual yields as supply trees also only grow in specific regions.

[0014] The enzymatic degradation of galactomannans is known in the art. Biomacromolecules 2000, 1, 782-788 discloses that galactomannans can be cleaved in mannose linkage by ?- mannanase and in galactose residues by u-galactosidase and describes enzymatic degradation process using / ?-mannanase over a wide range of substrate concentrations by using gel permeation chromatography (GPC) and steady shear viscometry.

[0015] The management of galactose content in galactomannans can be modified to a certain extent by using galactosidase enzymes able to remove inherently linked galactose units from the backbone, as is described in the US patent 5,234,825.

[0016] However, such a process has some disadvantages mainly due to the difficulty in obtaining correct and broad access of the enzyme to all portions of guar, due to its viscosity, which in the end will profoundly affect the mannose / galactose molar ratio. Furthermore, this ratio may also be affected by incomplete removal of residual galactose cleaved during the enzymatic reaction.

[0017] At the end, the residual galactose may be particularly relevant, notably when an anionization is implemented, as any residual galactose may be also anionized, impacting the final performance of anionic galactomannan. In view of the above, there is a need to develop a method able to prepare anionic transformed galactomannans structurally similar to anionic galactomannans derived from other Leguminosae as raw material, notably natural tara gum, having good rheology modifier and viscosity properties to be used in home and personal care or agrochemical compositions, cost effective preparation and thus widespread use.

[0018] SUMMARY OF THE INVENTION

[0019] Pursuing research in this field, the Applicant has now developed a method of preparing an original anionic galactomannan having a precisely controlled mannose / galactose ratio similar to galactomannans from other Leguminosae but derived from guar gum using a cost effective and simple enzymatic process.

[0020] The present invention is thus based on an anionic galactomannan comprising a mannose / galactose ratio from 2.5: 1 to 5: 1, wherein the anionic galactomannan is derived from guar gum.

[0021] Preferably, the anionic galactomannan comprises a mannose / galactose ratio from 2.5: 1 to 3.5: 1.

[0022] Furthermore, the present invention also aims to provide a process for preparing said anionic galactomannans with a precise control of the mannose / galactose ratio.

[0023] In particular, according to the invention, in a first production process step guar gum is submitted to a reaction with at least one enzyme to obtain a modified galactomannan having a controlled ratio of mannose / galactose and in a second step the modified galactomannan reacts with at least one anionic agent.

[0024] It has been demonstrated that by using the process of this invention, it is not only possible to control the mannose / galactose ratio of the anionic galactomannan but also the degree of substitution (DS) and the molecular weight (Mw) of such anionic galactomannans can be controlled. Advantageously, the anionic galactomannans with a controlled mannose / galactose ratio have not only excellent performance in home and personal care or agrochemical compositions but also high biodegradability.

[0025] Then, the present invention also concerns the use of said anionic galactomannans with a controlled mannose / galactose ratio, as thickeners and rheology modifiers.

[0026] Also, the present invention also refers to a composition, preferably a home and personal care or an agrochemical composition, comprising at least one anionic galactomannan according to the invention.

[0027] Finally, the present invention refers to a biodegradable material comprising the anionic galactomannan as defined above wherein the material promotes the reduction of greenhouse gasses and water use.

[0028] DETAILED DESCRIPTION OF THE INVENTION

[0029] Definitions:

[0030] Throughout the description, including the claims, the term "comprising one" or “comprising a" should be understood as being synonymous with the term "comprising at least one", unless otherwise specified, "between" and “from... to...” should be understood as being inclusive of the limits.

[0031] Throughout this application, the term "about" is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value.

[0032] As used herein, the term "average" refers to number average unless indicated otherwise.

[0033] As used herein, “weight percent,” “wt%,” “percent by weight,” “% by weight,” and variations thereof refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100. As used herein, the term viscosity refers to measured properties obtained from the response of a fluid when mechanically deformed. The measurements were taken using rotational rheometer in flow ramp methods varying shear rate or stress.

[0034] The term “rheology modifier” is understood as a substance used to control the rheology profile of a composition, which includes the yield stress and the viscosity at different shear modes and rates.

[0035] Throughout this application, including the claims, the term “average” refers to number average unless indicated otherwise.

[0036] Throughout the description, including the claims, all process terms should be understood as being synonymous with the term method.

[0037] Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

[0038] The present invention refers to anionic galactomannan comprising a mannose / galactose ratio of 2.5: 1 and 5: 1, wherein the anionic galactomannan is derived from guar gum.

[0039] As used herein, the term "anionic groups" refers to negatively charged groups and to partially charged groups. As used herein, the expression "partially charged groups" designates groups which may become negatively charged depending on the pH of the formulation. Such groups may also be named "potentially anionic groups". As used herein, the term "anionic" means at least partially anionic. Thus, the terms "anionizing agents", "anionic groups" and "anionic moieties" include carboxyalkyl groups, such as carboxymethyl groups or acrylamide groups such as 2-acrylamido-2-methylpropane sulfonic acid (AMPS). In a preferred embodiment, the mannose / galactose ratio is of 2.5 : 1 and 3.5: 1. Particularly, the mannose / galactose ratio of the anionic galactomannan of the invention is on average 3: 1.

[0040] As used herein, the ratio mannose / galactose refers to the molar ratio mannose / galactose present in the modified galactomannan or in the anionic galactomannan of the invention.

[0041] The measurement of the ratio mannose / galactose of the modified galactomannan of the invention may be made byJH NMR spectroscopy.

[0042] Once theJH NMR spectrum is obtained, the integration of the multiplet of signals corresponding to the cleaved mannose anomeric proton, calibrated at 5.2 ppm, is normalized to 1 unity. Other 3 integrated signals of interest, the one corresponding to the anomeric proton of cleaved galactose, is usually between 5.30 and 5.29 ppm. Another signal, the one corresponding to the anomeric proton of linked mannose is usually around 4.89 ppm. The last signal of interest is usually around 4.61 and 4.60 ppm and corresponds to the anomeric proton of linked galactose.

[0043] Therefore the ratio mannose / galactose can be calculated as follows:

[0044] . . . .. . . J (G1)+7 (G2)

[0045] Molar ratio galactose : mannose = - - -

[0046] The anionic galactomannan of the invention contains at least one anionic group and has desired viscosity performance whilst maintaining good biodegradability.

[0047] As used herein, the expression "anionic degree of substitution" (DSanionic) means the average number of moles of anionic groups per mole of sugar unit. The DSanionic may be estimated by means of13C NMR.

[0048] Once the13C NMR spectrum is obtained, the integration of the multiplet of signals corresponding to the anomeric carbon of sugars usually between 90-100 ppm, is normalized to unity. Particularly for carboxyalkyl substitution, the signals of interest, corresponding to the carbon of the carboxylic acid group on anionic galactomannan, is usually between 170-180 ppm. These signals are integrated for 1 carbon given that this 1 carbon from the carboxylic acid group. Therefore the calculation of the DSanionic for the case of the anionizing agent sodium monochloroacetate is as follows:

[0049] WTEGML COOT

[0050] D5 = - = -

[0051] / jVTE,OT 3Z,_ nomer.':c_Cm-iioji

[0052] Particularly, when the 2-acrylamido-2-methylpropane sulfonic acid (AMPS) anionizing agent is used, the DSanionic determination may be made byJH NMR.

[0053] According to one embodiment of the invention, the anionic galactomannan has an anionic degree of substitution DSanionic for anionic substituent groups ranging from 0.01 to 1.0.

[0054] In a preferred embodiment, the anionic galactomannan has an anionic degree of substitution DSanionic for anionic substituent groups ranging from 0.01 to 0.4.

[0055] In a more preferred embodiment, the anionic galactomannan has an anionic degree of substitution DSanionic for anionic substituent groups ranging from 0.05 to 0.2.

[0056] The anionicity of the anionic galactomannan may also be expressed in terms of charge density. The anionic degree of substitution may be converted to a charge density through several methods.

[0057] The anionicity, as determined and used herein, is highly pH dependent. Particularly for carboxyalkyl substitution, the pH of the medium might be above at least 6 to appropriately have anionic galactomannans and properly charge density calculation.

[0058] The preferred method for calculating charge density of anionic galactomannan uses a method that specifically quantifies the equivalents of carboxymethyl groups on said galactomannan. For anionic galactomannans obtained by reacting a galactomannan with sodium monochloroacetate (SMC A) or monochloroacetic acid (MCA), the anionic charge density may be calculated from the anionic degree of substitution using the following equation:

[0059] Anionic charge density in mequivalents per gram (meq / g) = DSaniomc

[0060] - * 1000

[0061] 162 + 59 * DStniontc

[0062] In general, the equation above depends on the group which is grafted to the galactomannan.

[0063] As used herein, the term "charge density" refers to the ratio of anionic charges on a monomeric unit of which a polymer is comprised to the molecular weight of said monomeric unit. The charge density multiplied by the polymer molecular weight determines the number of negatively charged sites on a given polymer chain.

[0064] According to the present invention, the anionic galactomannan has a charge density from about 0.06 to about 4.52 meq / g, for example from about 0.06 to about 2.16 meq / g and for example from 0.30 to 1.15 meq / g.

[0065] As for the average molecular weight (Mw) of anionic galactomannans of the present invention, in general the anionic galactomannans can have an average molecular weight (Mw) of at least about 2500 Da. The anionic galactomannans of the present invention can also generally have an average molecular weight (Mw) up to about 5,000,000 Da, preferably up to about 2,500,000 Da.

[0066] In a preferred embodiment, the anionic galactomannans of the invention may have an average molecular weight (Mw) higher than about 200,000 Da and more preferably higher than 600,000 Da.

[0067] In still another preferred embodiment, the average molecular weight of the anionic galactomannan herein is lower than about 2,000,000 Da more preferably lower than 1,500,000 Da.

[0068] According to a particular preferred embodiment, the average molecular weight of said anionic galactomannan is comprised from 2500 Da to about 1,500,000 Da. As used herein, the "average molecular weight" of the anionic galactomannan means the weight average molecular mass of said galactomannan.

[0069] The average molecular weight of the anionic galactomannan may be measured by SEC- MALS (Size Exclusion Chromatography with Multi-Angle Light- Scattering detection). A value of 0.140 for dn / dc is used for the molecular weight measurements. A Wyatt MALS detector is calibrated using a 22.5 kDa polyethylene glycol standard. All calculations of the molecular weight distributions are performed using Wyatt's ASTRA software. For anionic galactomannans, the samples are prepared as 0.05% solutions in the mobile phase (100 mM NaNCE, 100 ppm NaNs) and filtered through 0.45 pm PVDF filters before analysis. 100 pL of the filtered solution is injected and then goes through a pre-column plus 3 columns OH pak SB-806 M HQ at 35°C.

[0070] The galactomannans can be functionalized by chemical modification using anionic reactive agents, also known as anionizing agents. Anionizing agents of the present invention are defined as compounds which, by reaction with the hydroxyl groups of the galactomannan can lead to galactomannan comprising at least one anionic group according to the invention. In particular, depending on the galactomannan and the hydroxyl groups available for chemical modification, the anionizing agents can react with the available hydroxyl groups of the mannose main chain or backbone, the available hydroxyl groups of the galactose units that are substituted along the mannose main chain or backbone, or both. In this respect, the anionic galactomannans can be formed from reacting at least one galactomannan in accordance with the invention with at least one anionizing agent.

[0071] Anionizing agents of the present invention are defined as compounds which contain at least one anionic moiety. Anionizing agents comprise agents which can anionize a galactomannan leading to anionic modified galactomannan.

[0072] According to the invention, suitable anionic agents include carboxyalkyl groups or anionic acrylamide groups.

[0073] According to an embodiment, the anionic galactomannan of the invention is anionized using 2-acrylamido-2 -methylpropane sulfonic acid (AMPS). In a preferred embodiment, the anionic galactomannan of the invention is anionized using carboxymethyl groups.

[0074] According to the invention, the anionic groups may be introduced into a modified galactomannan by reacting the modified galactomannan starting material with a derivatizing agent which comprises a reactive functional group and at least one anionic moiety (or a precursor of anionic moiety).

[0075] A group of suitable derivatizing reagents typically contain a reactive functional group, such as an epoxy group, a halide group, an ester group, an anhydride group or an acrylamide group, and at least one anionic moiety or a precursor of such anionic moiety.

[0076] As used herein, the term "derivatizing agent" means an agent containing at least an anionic moiety which is grafted to a galactomannan. The term "derivatizing agent" encompasses the term "anionizing agent". In one embodiment of the invention, the anionic moieties may be linked to the reactive functional group of the derivatizing agent by a bivalent linking group, such as an alkylene or oxyalkylene group. Suitable anionic moieties include carboxyalkyl groups, for instance carboxymethyl groups or anionic acrylamide group, for instance 2-acrylamido-2 -methylpropane sulfonic acid..

[0077] The derivatizing agent can comprise an anionic moiety, or a precursor of an anionic moiety, that contains a carboxymethyl group or a 2-acrylamido-2-methylpropane sulfonic acid group.

[0078] According to an embodiment of the invention, the anionic galactomannan may optionally contain other derivatizing groups, such as anionic hydrophobic group or hydrophobic group. Suitable hydrophobic groups include hydroxyalkyl groups, preferably hydroxypropyl groups.

[0079] Advantageously, the anionic galactomannan of the invention is biodegradable.

[0080] The term biodegradable means when a compound / product or any article is naturally degraded and returns to nature without having a harmful impact on the environment. As used herein, biodegradability is measured according to the readily biodegradability test OECD 301F, and in particular the compound / product is considered biodegradable under OECD 301F, as discussed. Specifically, OECD 301F provides testing guidelines for determining whether a chemical substance is considered biodegradable, including readily biodegradable.

[0081] In one embodiment, the anionic galactomannan of the invention is obtained by reacting a modified galactomannan derived from guar gum having a controlled ratio mannose / galactose with at least one anionizing agent.

[0082] According to the invention, in the first step guar gum is submitted to a reaction with at least one enzyme to obtain the modified galactomannan as defined above.

[0083] In Figure 1, the enzymatic process of the invention is depicted.

[0084] The obtained modified galactomannans have controlled mannose / galactose ratio as shown for example in Figure 1.

[0085] By the process of the invention, it is possible not only to allow extensive cleavage by the enzyme through its access to all necessary sites of guar, but also by the complete removal of the galactose residue cleaved from guar.

[0086] For enzymatic reactions, guar gum is first swollen with water.

[0087] The swelling of guar gum with water results after grinding in swollen guar in the form of “grated parmesan”. In order to control the swollen state of guar gum, the weight ratio of the total water content to guar is between 1.5: 1 g / g, preferably between 1 : 1 g / g. If the amount of water is too high, a paste or slurry is formed and this should be avoided. The enzymatic contact with guar during enzymatic reaction is thus not favored. If the water content is too low, insufficient swelling of guar is obtained and the resulting enzymatic reaction is deeply affected by the lack of contact between enzyme and guar. In both cases, accessibility of guar is not good enough for the reaction to occur properly.

[0088] Afterwards, the obtained swollen guar gum is contacted with an enzymatic solution comprising at least one enzyme and a buffer and submitted to enzymatic reaction. Particularly, the enzymatic solution is obtained using a mixture of at least one enzyme and a buffer in a molar concentration of between 0.01 to 0.05 M, preferably between 0.01 to 0.03 M, based on the total weight of the enzymatic solution.

[0089] Buffer solutions used in the sense of the invention may be selected in a non limited way by sodium acetate solution, potassium acetate solution, sodium citrate solution and potassium phthalate solution or a combination thereof.

[0090] Through the enzymatic fragmentation, it is possible to cleave galactose moieties of guar gum to obtain the modified galactomannan.

[0091] The inventors found that the addition of swollen guar portion by portion to the enzymatic solution comprising the enzyme and the buffer allows both good wetting of guar gum by the enzymatic solution and impregnation of enzyme on guar gum. Particularly, the mixture of guar and enzymatic solution is submitted to rigorous stirring and a macroscopically homogeneous gel is formed.

[0092] Preferably, the swollen guar is added to the enzymatic solution in a weight ratio of guar over total weight of the mixture between 0.01 to 0.1, preferably between 0.01 to 0.03, based on the total weight of the mixture.

[0093] The enzymatic reaction is conducted at a temperature of 0 to 90°C, preferably of 30 to 80°C.

[0094] The enzymatic reaction is preferably carried out for a duration of at least 5 hours. According to the invention, the enzymatic reaction is carried out preferably for a duration of 5 to 30 hours, more preferably of 5 to 24 hours.

[0095] The enzymatic reacted guar is then washed using a mixture of alcohol: water to obtain the raw fragmented galactomannan. The washing mixture comprises alcohol: water in a volume ratio from 6:4 to 8:2 (v / v), preferably of 7:3 (v / v), based on the total volume of the mixture.

[0096] By the use of a washing solution, it is possible to remove galactose residues from the interface of the reaction mixture and the raw galactomannan is obtained. Afterwards, the raw fragmented galactomannan is completely dried in an oven at 50 °C under atmospheric pressure for 16 hours and ground using a cryogenic grinder into fine powder.

[0097] The inventors have found that the additional washing process allows the complete removal of galactose units cleaved and trapped into the raw fragmented galactomannan mixture.

[0098] In a particular preferred embodiment, the ground powder is then washed at least four times using a mixture of alcohol: water to obtain the modified galactomannan; wherein the modified galactomannan comprises mannose / galactose ratio of 2.5: 1 and 5: 1.

[0099] Particularly, the washing mixture comprises alcohokwater in a volume ratio from 6:4 to 8:2 (v / v), pref erably:of 7:3 (v / v), based on the total volume of the mixture.

[0100] Particularly, extra washings after grinding a raw modified galactomannan are unavoidable to get an accurate control of mannose / galactose ratio.

[0101] Furthermore, by using the process of the invention, it is possible to obtain a modified galactomannan having a controlled average ratio of mannose / galactose, which is essential to obtain a desired anionicity of the anionic galactomannan.

[0102] According to a particular preferred embodiment, the process of obtaining a modified galactomannan as described above from guar gum follows the steps: a. guar gum is swollen with water; b. the obtained swollen guar gum is contacted with an enzyme solution comprising at least one enzyme and a buffer and the obtained mixture is heated at a temperature of 30 to 80°C for a duration of 5 to 30 hours to obtain the enzymatic reacted guar; c. the enzymatic reacted guar is washed at least four times using a mixture of alcohol: water to obtain the raw fragmented galactomannan; d. the raw fragmented galactomannan is ground into fine powder after complete drying and washed at least four times using a mixture of alcohol: water to obtain the modified galactomannan; wherein the modified galactomannan comprises mannose / galactose ratio of 2.5: 1 and 5: 1.

[0103] According to the invention, the alcohol may be selected from, not limited to, isopropanol, methanol and ethanol. According to a preferred embodiment, the selected alcohol is isopropanol.

[0104] In a particular embodiment of the invention, at least one enzyme is selected from galactosidase, preferably alpha-galactosidase, even more preferably alpha-galactosidase of CAZy Family GH27 (glycoside hydrolase 27), which can be obtained from guar seed and Aspergillus niger for example. Typically, GH27 alpha-galactosidases are "endo enzymes" that enable random fragmentation.

[0105] Without being bound to any theory, it is assumed that the nature of alpha-galactosidase (GH27 or GH36) has an impact on the final galactose / mannose distribution of modified guar. Particularly, GH27 alpha-galactosidases may promote random fragmentation while GH36 alpha-galactosidases may only cleave galactose units at the end of the polymeric chain.

[0106] By the process according to the invention, it is possible to accurately control the ratio mannose / galactose in the modified galactomannan and, in the end, to properly target the molecular weight (Mw) and anionic degree of substitution (DSanionic) of the anionic galactomannan as described above.

[0107] Afterwards, in a second step, the modified galactomannan reacts with at least one anionizing agent to produce the anionic galactomannan as described above.

[0108] The anionization of galactomannans can be easily made by a skilled person using methods commonly known in the art. Methods for the preparation of modified / derivative galactomannans of the invention are disclosed in CN101906170, CN101323647, U.S. Pat. Nos. 3,467,647 and 3,740,388, WO 2023 / 099324 all of which are incorporated herein by reference. According to the invention, the modified galactomannan with a controlled mannose / galactose ratio obtained by enzymatic treating of guar gum is derivatized or modified so as to contain an anionic group. The resulting compound is the anionic galactomannan of the invention.

[0109] The anionic galactomannan of the invention can be used in home and personal care or agrochemical applications, for example as thickeners and rheology modifiers.

[0110] The viscosity of a home and personal care or an agrochemical composition may be measured by rotational viscometer, for instance, a rheometer or Brookfield. Measurements may be carried out using Plate-Peltier or Coaxial Cylinder rheometer or Brookfield viscometer, for instance with the conditions detailed in the examples.

[0111] In one embodiment, the viscosity of the compositions using the combination of the invention are within 100 to 2,000 mPa.s. range.

[0112] In a preferred embodiment, the viscosity of the compositions is between 600 and 1,100 mPa.s.

[0113] Home and personal care compositions such as shampoos, shower gel and fabric care compositions or even agrochemical compositions in their concentrate forms such as emulsifiable concentrate, suspension concentrate, soluble concentrate and suspension emulsion containing thickeners to control viscosity have been disclosed before and are well known by the person skilled in the art.

[0114] Personal care compositions mean anything done that is of a personal nature. This may include compositions used for bathing and showering, including bed-baths, lotions and creams notably for skin care, oral hygiene, make-up, and hair care. Specifically composition of the invention may be a skin care composition, such as shower gel, soap, hydrogel, cream, lotion or balm, or a hair care composition, such as shampoo, rinse off conditioner, leave-in conditioner, gel, pomade or cuticle coat.

[0115] Home care composition shall include general household cleaning products for example, toilet bowl cleaners, laundry detergents, dishwashing liquid, bathroom cleaner and surface cleaner. These home and personal care compositions may also comprise aesthetic modifiers, filmformers, chelates, emulsifiers, moisturizers, emollients, surfactants (such as anionic, cationic, nonionic, amphoteric, zwitterionic, surfactants, or combinations thereof), propellants, stabilizers, preservatives, cleansing and suspending / gelling agents, and active ingredients.

[0116] Notably these compositions, preferably personal care compositions of the present invention comprises one or more “benefit agents” that is, materials that provide a care benefit, such as moisturizing or conditioning, such as, for example, emollients, oils, moisturizers, humectants, conditioners, polymers, vitamins, abrasives, UV absorbers, antimicrobial agents, anti-dandruff agents, fragrances, and / or appearance modifying additives, such as, for example, colored particles or reflective particles, which may be in the form of a solid, liquid, or gas and may be insoluble or are only partly soluble in the composition. Mixtures of the benefit agents may be used.

[0117] Agrochemical compositions shall include phytosanitary agents and / or synthetic fertilizers. These compositions may further comprise one or more additive such as a wax, a resin, a solvent, a pigment, an anti-foaming agent, a surfactant, an anti-freeze agent, one or several nutrients, a biostimulant, biologicals, a filler, a biocide, a dye, and / or a second or more binder and / or a combination thereof.

[0118] The following examples are included to illustrate embodiments of the invention, but are not limited to described examples.

[0119] All materials are commercially available.

[0120] Enzyme alpha-galactosidase GH27 (glycoside hydrolase 27) purified from guar seed (product code E-AGLGU) was obtained from MEGAZYME.

[0121] Guar gum: Jaguar® S from Solvay.

[0122] Sodium acetate buffer solution (pH 5.2 ± 0.1 at 25°C, for molecular biology, 3 M, 0.2 pm filtered) was obtained from Sigma-Aldrich (product code S7899-500ML). Test methods:

[0123] Molar ratio galactose / mannose

[0124] Molar ratio galactose:mannose of one modified galactomannan or anionic galactomannan was measured byJH NMR spectroscopy after acidic hydrolysis (solvent:TFA-d + D2O) at 90°C for 2 hours as described above.

[0125] Molecular weight

[0126] The average molecular weight of the modified galactomannan or the anionic galactomannan was measured by SEC-MALS (Size Exclusion Chromatography with Multi-Angle Light- Scattering detection) with 3 columns ShodexOH Pack SB-806 M HQ column, as described above.

[0127] Anionic Degree of Substitution

[0128] The anionic degree of substitution of the anionic galactomannans was estimated by13C NMR after acidic hydrolysis (solvent: TFA-d + D2O) at 90°C for 2 hours, as described above.

[0129] Biodegradability

[0130] The biodegradability of the anionic galactomannans were measured in accordance with OECD 301F (as discussed above), which was modified with respect to the % of biodegradability of the sample tested (i.e., at least 60%) and the sensor used to determine the biodegradation. Biodegradability was assessed based on 28 days, as well as based on 60 days. An OxiTop®-IDS sensor available from Xylem Analytics was used to determine the biodegradation in accordance with OECD 301F.

[0131] A series of enzymatic reactions were performed according to the present invention at the same temperature but varying enzyme loading (U / g of guar, enzymatic activity per gram of guar) and guar concentration in the reaction medium. The modified galactomannans obtained (MG4 to MG7) are summarized at TABLE 1. To perform a comparative enzymatic reaction, comparative examples were performed and the obtained comparative modified galactomannans (CMG1 to CMG3) are summarized at TABLE 1.

[0132] Part I: Synthesis of modified galactomannan

[0133] Comparative Example 1: Synthesis of modified galactomannan

[0134] In step b. In a 500 mL round bottom flask with a magnetic stirrer and a condenser are introduced 150 g of ultrapure water, 0.50 mL of sodium acetate buffer solution (3M, pH 5.2 ± 0.1 at 25 °C) and 29 pL of enzyme a-galactosidase (2.9 U of enzyme / g of guar). 5 g of guar gum are added to the enzymatic solution. The obtained paste is mixed with a spatula for 5 minutes every 2 hours for the first 8 hours. The reaction medium is heated at 40 °C for 24 hours. After 24 hours, the reaction medium is heated at 80 °C for 30 minutes to denature the enzyme. After cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar.

[0135] In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid. The raw fragmented galactomannan solid is ground into a fine powder resulting in a comparative modified galactomannan.

[0136] The resulting comparative modified galactomannan CMG1 showed a mannose / galactose molar ratio equal to 1.88: 1.

[0137] Comparative Example 2: Synthesis of modified galactomannan

[0138] In step a. In a mortar, 5 g of guar gum and 5 g of ultrapure water are introduced. The mixture is mixed with a pestle to obtain a swollen guar powder.

[0139] In step b. In a 500 mL round bottom flask with a magnetic stirrer and a condenser are introduced 145 g of ultrapure water, 0.50 mL of sodium acetate buffer solution (3M, pH 5.2 ± 0.1 at 25 °C) and 29 pL of enzyme a-galactosidase (2.9 U of enzyme / g of guar). The swollen guar is added to the enzymatic solution portion by portion under stirring (200 rpm). After addition, the reaction medium is heated at 40 °C for 24 hours. After 24 hours, the reaction medium is heated at 80 °C for 30 minutes to denature the enzyme. After cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar.

[0140] In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid. The raw fragmented galactomannan solid is ground into a fine powder resulting in a comparative modified galactomannan.

[0141] The resulting comparative modified galactomannan CMG2 showed a mannose / galactose molar ratio equal to 2.3 : 1.

[0142] Comparative Example 3: Synthesis of modified galactomannan

[0143] In step b. In a 500 mL round bottom flask with a magnetic stirrer and a condenser are introduced 150 g of ultrapure water, 0.50 mL of sodium acetate buffer solution (3M, pH 5.2 ± 0.1 at 25 °C) and 29 pL of enzyme a-galactosidase (2.9 U of enzyme / g of guar). 5 g of guar gum are added to the enzymatic solution. The obtained paste is mixed with a spatula for 5 minutes every 2 hours for the first 8 hours. The reaction medium is heated at 40 °C for 24 hours. After 24 hours, the reaction medium is heated at 80°C for 30 minutes to denature the enzyme. After cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar.

[0144] In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid.

[0145] In step d. The raw fragmented galactomannan solid is ground into a fine powder and further washed four times with a solution composed of isopropanol and water (200 mL) to obtain comparative modified galactomannan.

[0146] The resulting comparative modified galactomannan CMG3 showed a mannose / galactose molar ratio equal to 1.95 : 1. Example 4: Synthesis of modified galactomannan

[0147] In step a. In a mortar, 15 g of guar gum and 15 g of ultrapure water are introduced. The mixture is mixed with a pestle to obtain a swollen guar powder.

[0148] In step b. In an 1 L round bottom flask with a magnetic stirrer and a condenser are introduced 435 g of ultrapure water, 1.50 mL of sodium acetate buffer solution (3M, pH 30 5.2 ± 0.1 at 25 °C) and 78 pL of the enzyme a-galactosidase (2.60 U of enzyme / g of guar). The swollen guar is added to the enzymatic solution portion by portion under stirring (200 rpm). After addition, the reaction medium is heated at 40°C for 24 hours. After 24 hours, the reaction medium is heated at 80 °C for 30 minutes to denature the enzyme. After cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar. In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid.

[0149] In step d. The raw fragmented galactomannan solid is ground into a fine powder and further washed four times with a solution composed of isopropanol and water (200 mL) to obtain modified galactomannan.

[0150] The resulting modified galactomannan MG4 showed a mannose / galactose molar ratio equal to 2.82: 1 and the average molar weight of Mw = 1,782,000 Da.

[0151] Example 5: Synthesis of modified galactomannan

[0152] In step a. In a mortar, 15 g of guar gum and 15 g of ultrapure water are introduced. The mixture is mixed with a pestle to obtain a swollen guar powder.

[0153] In step b. In an 1 L round bottom flask with a magnetic stirrer and a condenser are introduced 435 g of ultrapure water, 1.50 mL of sodium acetate buffer solution (3M, pH 5.2 ± 0.1 at 25 °C) and 82 pL of enzyme a-galactosidase (2.70 U of enzyme / g of guar). The swollen guar is added to the enzymatic solution portion by portion under stirring (200 rpm). After addition, the reaction medium is heated at 40 °C for 24 hours. After 24 hours, the reaction medium is heated at 80 °C for 30 minutes to denature the enzyme. After 25 cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar.

[0154] In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid.

[0155] In step d. The raw fragmented galactomannan solid is ground into a fine powder and further washed four times with a solution composed of isopropanol and water (200 mL) to obtain modified galactomannan.

[0156] The resulting modified galactomannan MG5 showed a mannose / galactose molar ratio equal to 2.98: 1 and the average molar weight of Mw = 1,853,000 Da.

[0157] Example 6: Synthesis of modified galactomannan

[0158] In step a. In a mortar, 15 g of guar gum and 15 g of ultrapure water. The mixture is mixed with a pestle to obtain a swollen guar powder.

[0159] In step b. In an 1 L round bottom flask with a magnetic stirrer and a condenser are introduced 435 g of ultrapure water, 1.50 mL of sodium acetate buffer solution (3M, pH 5.2 ± 0.1 at 25 °C) and 87 pL of enzyme a-galactosidase (2.90 U of enzyme / g of guar). The swollen guar is added to the enzymatic solution portion by portion under stirring (200 rpm). After addition, the reaction medium is heated at 40 °C for 24 hours. After 24 hours, the reaction medium is heated at 80 °C for 30 minutes to denature the enzyme. After cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar.

[0160] In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid.

[0161] In step d. The raw fragmented galactomannan is ground into a fine powder and further washed four times with a solution composed of isopropanol and water (200 mL) to obtain modified galactomannan. The resulting modified galactomannan MG6 showed a mannose / galactose molar ratio equal to 3.06: 1 and the average molar weight of Mw = 1,698,000 Da.

[0162] Example 7: Synthesis of modified galactomannan

[0163] In step a. In a mortar, 17 g of guar gum and 17 g of ultrapure water were introduced. The 30 mixture is mixed with a pestle to obtain a swollen guar powder.

[0164] In step b. In an 1 L round bottom flask with a magnetic stirrer and a condenser are introduced 133 g of ultrapure water, 0.50 mL of sodium acetate buffer solution (3M, pH 5.2 ± 0.1 at 25 °C) and 99 pL of enzyme a-galactosidase (2.90 U of enzyme / g of guar). The swollen guar is added to the enzymatic solution portion by portion under stirring (200 rpm). After addition, the reaction medium is heated at 40 °C for 24 hours. After 24 hours, the reaction medium is heated at 80 °C for 30 minutes to denature the enzyme. After cooling to room temperature, 200 mL of isopropanol are added into the flask to reduce the viscosity and obtain the reaction medium with enzymatic reacted guar.

[0165] In step c. The reaction medium is filtered under vacuum and washed four times with a solution composed of isopropanol and water (200 mL). A white gel is obtained and it is dried in an oven at 50 °C under atmospheric pressure for 16 hours to obtain the raw fragmented galactomannan solid.

[0166] In step d. The raw fragmented galactomannan is ground into a fine powder and further washed four times with a solution composed of isopropanol and water (200 mL) to obtain modified galactomannan.

[0167] The resulting modified galactomannan MG7 showed a mannose / galactose molar ratio equal to 2.53: 1 and the average molar weight of Mw = 1,652,000 Da.

[0168] TABLE 1 : modified galactomannan obtained from enzymatic reaction of guar gum.

[0169] As shown in TABLE 1, comparative examples CMG1 to CMG3 demonstrated not only the importance of the correct enzymatic cleavage, but also the complete removal of the galactose residue cleaved from guar. All examples of the invention, MG4 to MG7 showed precise control of mannose / galactose molar ratio similar to average mannose / galactose molar ratio of galactomannans derived from tara gum.

[0170] Part II: Synthesis of anionic galactomannan Example 8. Synthesis of Comparative anionic tara gum.

[0171] In a 1 L stirred reactor, 145.0 g of isopropanol solvent mixed with 35.0 g of deionized water were introduced at room temperature, under a blanket of inert nitrogen gas. 60.5 g of tara gum powder (obtained from Molinos Asociados) was then loaded at room temperature and under vigorous stirring. After a few minutes of stirring to allow for homogenization, 24.0 g of sodium monochloroacetate (SMCA, 40% in water) was added. This reagent was left to mix at room temperature with the tara gum dispersion for 30 minutes, after which 10.0 g of sodium hydroxide (50% in water) was slowly added. This reagent was left to mix at room temperature with the tara gum dispersion and the sodium monochloroacetate for 15 minutes. The dispersion was then heated to 75 °C and held at this temperature for 140 minutes, after which the temperature was lowered to at least 50 °C in order to start the washing procedure.

[0172] A reaction mixture obtained as described in the paragraph above was dispersed under stirring with 64.0 g of isopropanol (99%) and 26.0 g of water. The pH was adjusted to approximately 9-10 using 7.8 g of hydrochloric acid (37% in water). The mixture was then left under stirring for 30 minutes and then discharged from the reactor. This dispersion was then filtered under vacuum through qualitative filter paper. This washing and filtering procedure was repeated one more time for 30 minutes with 144 g of isopropanol (99%) and 96 g of water. The obtained solid was then let dry overnight for 6 hours in an oven at 60 °C. The anionic degree of substitution (DSanionic) was estimated at 0.18 and the average molecular weight (Mw) was 942,000 Da. The comparative anionic tara gum was evaluated according to the OECD 301F procedure and it demonstrated that it was readily biodegradable within 28 days (i.e., passed). The anionic tara gum is considered as readily biodegradable.

[0173] In a 100 mL round flask, 24.0 g of isopropanol solvent mixed with 5.5 g of deionized water were introduced at room temperature, under a blanket of inert nitrogen gas. Then, 5.50 g of modified galactomannan powder with a mannose / galactose ratio of 2.82: 1 were then loaded at room temperature and under vigorous stirring. After a few minutes of stirring to allow for homogenization, 4.00 g of sodium monochloroacetate (SMCA, 40% in water) was added. This reagent was left to mix at room temperature with the modified galactomannan dispersion for 30 minutes, after 15 min which 1.65 g of sodium hydroxide (50% in water) were added slowly. This reagent was left to mix at room temperature with the modified galactomannan dispersion and the sodium monochloroacetate for 15 minutes. The dispersion was then heated to 75 °C and held at this temperature for 140 minutes, after which the temperature was lowered to at least 50 °C in order to start the washing procedure.

[0174] A reaction mixture obtained as described above was dispersed under stirring with 10.5 g of isopropanol (99%) and 4.5 g of water. The pH was adjusted to approximately 9-10 using hydrochloric acid (37% in water). The mixture was then left under stirring for 30 minutes. This dispersion was then filtered under vacuum. This washing and filtering procedure was repeated two more times for 30 minutes with 24 g of isopropanol (99%) and 16 g of water. The obtained solid was then let dry overnight for 6 hours in an oven at 60°C.

[0175] The anionic degree of substitution (DSanionic) was estimated at 0.18 the average molecular weight (Mw) was 1,004,000 Da. The anionic galactomannan was evaluated according to the OECD 301F procedure and it demonstrated that it was readily biodegradable within 28 days (i.e., passed). The anionic galactomannan is considered as readily biodegradable.

[0176] Example 10. Viscosity behavior of anionic galactomannan and comparative anionic tara gum.

[0177] Solution preparation

[0178] Two aqueous solutions were prepared, one for each of the two polymers examined (anionic galactomannan according to the invention and anionic tara gum) and were used for the flow curve and Brookfield viscosity measurements.

[0179] The solutions were made in a plastic beaker wherein each ingredient is added. The mixture is stirred by mechanical agitation using a propeller blade, to obtain a homogeneous formulation. Care was taken to avoid the introduction of air bubbles.

[0180] Each solution was prepared at room temperature (21-25 °C).

[0181] The raw material weighing was carried out using a precision balance. The mass of each solution prepared was for 200 g and produced as follow:

[0182] Step 1. In a plastic beaker 197.6 g of water (with a precision scale of 5%) were introduced. Step 2. A weight of 2 g (1%) of polymer (with a precision balance of 1%) and dispersed while stirring at 400 rpm with a propeller blade. The polymer powders were added continuously and slowly in the water. Step 3. The solutions were allowed to mix for 5 minutes at 400 rpm to ensure full polymer dispersion.

[0183] Step 4. The mixing speed was decreased to 200 rpm and 0.2 g of a 50% citric acid solution (50% of citric acid in weight in water) was added.

[0184] Step 5. Once the solution was homogeneous, 0.2 g of phenoxyethanol (with a precision balance of 1%) was added.

[0185] Step 6. The solutions were further mixed for 20 min at 200 rpm to ensure the polymer hydration (pH is measured by a pH-meter Seven Go pH from Mettler Toledo calibrated with buffer solution 4 and 7 before each formulation).

[0186] Rheological behavior and Viscosity measurement:

[0187] Flow curves were carried out on a Kinexus rheometer using a cup and bob geometry. A volume of solution was introduced into the cup such that the bob was fully immersed. The rheology protocol used is as follows and performed automatically by the instrument software:

[0188] • The device temperature was set at 25 °C

[0189] • Insert geometry,

[0190] • Zero the gap

[0191] • Torque mapping

[0192] • Geometry inertia

[0193] • Sample loading

[0194] • Preconditioning step: acquisition each 3 sec, 40 points at a shear rate of 20 sec'1

[0195] ■ Equilibration step of 40 min

[0196] • Steady step flow: shear rate ramp from 1.1 O'3s'1to 200s'1

[0197] TABLE 2: Comparative results of viscosity of anionic galactomannan (inventive) and comparative anionic tara gum.

[0198] As demonstrated in Table 2, the anionic galactomannan according to the invention (inventive) has similar viscosity results when compared to anionic tara gum.

Claims

1. C L A I M S1. An anionic galactomannan comprising a mannose / galactose ratio of 2.5: 1 and 5: 1, wherein the anionic galactomannan is derived from guar gum.

2. The anionic galactomannan according to claim 1, wherein the mannose / galactose ratio is on average 3: 1.

3. The anionic galactomannan according to claims 1 or 2, wherein the anionic galactomannan exhibits a DSanionic for anionic substituent groups ranging from 0.01 to 1.0, preferably from 0.01 to 0.4, more preferably from 0.05 to 0.2.

4. The anionic galactomannan according to any one of the claims 1 to 3, wherein the anionic galactomannan has a molecular weight distribution ranging from 2500 Da to 1,500,000 Da.

5. The anionic galactomannan according to any one of the preceding claims, wherein the anionic galactomannan is anionized by at least one carboxyalkyl group selected from carboxymethyl groups or at least one anionic acrylamide group selected from 2- acrylamido-2-methylpropane sulfonic acid.

6. The anionic galactomannan according to any one of the preceding claims, wherein the anionic galactomannan optionally further comprises at least one non ionic group selected from hydroxyalkyl group, preferably a hydroxypropyl group.

7. The anionic galactomannan according to any one of the preceding claims, wherein the anionic galactomannan is readily biodegradable in accordance with OECD 301F.

8. A process of preparing an anionic galactomannan as defined in any of the claims 1 to 7, by reacting a modified galactomannan derived from guar gum and comprising a mannose / galactose ratio of 2.5: 1 and 5: 1 with at least one anionizing agent.

9. The process according to claim 8, wherein in a first step guar gum is submitted to a reaction with at least one enzyme to obtain the modified galactomannan comprising mannose / galactose ratio of 2.5 : 1 and 5 : 1 and in a second step the modified galactomannan reacts with at least one anionizing agent.

10. The process according to claim 9, wherein in the first step: a. guar gum is swollen with water; b. the obtained swollen guar gum is contacted with an enzyme solution comprising at least one enzyme and a buffer and the obtained mixture is heated at a temperature of 30 to 80°C for a duration of 5 to 30 hours to obtain the enzymatic reacted guar; c. the enzymatic reacted guar is washed at least four times using a mixture of alcohol: water to obtain the raw fragmented galactomannan; d. the raw fragmented galactomannan is ground into fine powder after complete drying and washed at least four times using a mixture of alcohol: water to obtain the modified galactomannan; wherein the modified galactomannan comprises mannose / galactose ratio of 2.5: 1 and 5: 1.

11. The process according to claim 10, wherein the mixture alcohol: water comprises a volume ratio from 6:4 to 8:2, based on the total volume of the mixture.

12. The process according to claims 10 or 11, wherein the alcohol is selected from isopropanol, methanol and ethanol.

13. The process according to any one of the claims 7 to 10, wherein at least one enzyme is selected from galactosidase, preferably alpha-galactosidase.

14. Use of the anionic galactomannan as defined in any of the claims 1 to 7, as thickeners and rheology modifiers.

15. A composition comprising at least an anionic galactomannan as defined in any of the claims 1 to 7.

16. The composition according to claim 15, wherein it is a home and personal care or an agrochemical composition.

17. A biodegradable material comprising the anionic galactomannan as defined in any of the claims 1 to 7 wherein the material promotes the reduction of greenhouse gasses and water use.

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