This invention relates to a process for extracting polysaccharides substantially free from proteinaceous materials from tamarind seed kernel.
Tamarind seed is a by-product of tamarind pulp industry. The tamarind tree is extensively found and cultivated in tropical countries. The large fast growing tree yields fruits for almost 50-60 years. Though almost every part of this tree finds some use, the fruits are extensively used as a souring agent for curries in Indian subcontinent. Chutneys and sauces Are also made from tamarind pulp. The seeds of the fruits are used as cattle feed and are often used as food supplement by poor people. The seed contains proteins, oils, fibre, and carbohydrates in addition to minerals and trace nutrients. Tamarind seed polysaccharides exhibit excel lent adhesive properties and Br& widely used as a sizing agent in textile industry. Polysaccharides obtained from tamarind seed may also be used in the latex industry.
Conventional process for treating tamarind kernel seeds is by extracting a paste of the seed repeatedly with water And bleaching the extract with sulphur dioxide. Certain amount of degradation takes place during this bleaching step which decreases its gelling properties.

The object of this invention is to develop a simple process for preparing defatted and deproteinated polysaccharide powder from tamarind seed kernels. In order to obtain high sizing strength, the polysaccharide must exhibit high viscosity. Any discolouration of the sizing material would damage the final product. Thus, it is essential to ensure that the powder used for sizing is free of any colouring matter. Furthermore presence of even traces of oils/fats in the sizing composition would adversely affect its properties.
In order to achieve the above objectives, a simple process has been developed by us. Tamarind seed is processed to remove the hard shel1 and the testa that surrounds the kernel by conventional method. This kernel is powdered and suspended in atleast one organic solvent selected from hexane, methanol, ethanol, high boiling point ethers, isopropyl alcohol, chloroform and motor spirit. This suspension may be heated under reflux for a period of i-2 hours and then cooled and allowed to settle. The supernatent liquid may be decanted and the sediment at the bottom of the flask may be repeatedly washed to remove any traces of protein therefrom depending on the desired commercial requirement. The resultant powder is free of any colouring matter and exhibits very high viscosity. Optionally, the kernels may be subjected to conventional solvent extraction step for defattening or removing

oil contents therefrom before subjecting the same to deproteination treatment. Our experiments show that the solvents described hereinbefore effect maximum extraction of proteins when compared to other organic solvents and the viscosity of the final product can be controlled by washing the residual semi-solid with the any one of the solvents as desired.
A comparative study of the viscosity of untreated tamarind kernel powder, deoiled tamarind kernel powder and deproteinated tamarind kernel powder is given below.
Viscosity of 4% by wt solution of TKP in hot water 6500 to 7000 cps. Viscosity of 4"/. by wt solution of deoiled TKP is 6500 to 7500 cps, while a deproteinated solution of TKP of the same strength exhibits a viscosity in the range of 8000 to 18000 cps depending upon it protein contamination.
Yet another advantage of the process is that the product obtained can be used directly by dissolving in water, avoiding decolourisation step of the product. This makes it very cost effective.
The process for extracting polysaccharides from tamarind seed kernel according to this invention comprises treating tamarind seed kernel with atleast one solvent selected from hexane, methanol9 ethanol, isopropyl alcohol, motor spirit,

ethers and chloroform, separating the supernatent liquid therefrom, washing the semisolid residue with any of said solvent and subsequently drying the same to obtain polysaccharides substantially free of proteins.
By repeated washing with the selected solvents it is possible to control the protein content of the polysaccharide to be in the range of 87. to 147.. Lowering of the protein content increases the viscosity and enhances the commercial value of the polysaccharide as a sizing/gelling agent. The extraction may be carried out and reflux by heating it to the boi1ing point of the chosen solvent.
It is also observed that a single step treatment of defattening and deproteination is more effective than subjecting previously deoiled/defattened kernel to the extraction step though defattening and subsequent deproteination is also within the scope of this invention. The kernel may be pulverised before treatment for effective extraction.

WE CLAIM:
1. A process for extracting polysaccharides from tamarind ^~) }
seed kernel comprising treating tamarind seed kernel with at At
least one solvent selected from hexane, methanol, ethanol, /
isopropyl alcohol, motor spirit, ether and chloroform, separating \ f
\ the supernatent liquid therefrom, washing the semisolid residue
with any of said solvents and subsequently drying the same to /
obtain polysaccharides substantially free of proteins. ^ A*r*}
2. The process as claimed in claim 1, wherein the tamarind
seed kernel is pulverised prior to said solvent treatment.
3. The process as claimed in claims 1 and 2 wherein the
tamarind seed kernel is defattened or deoiled prior to said
solvent treatment.
4. The process as claimed in any of the preceding claims
wherein the semisolid residue is washed repeatedly to achieve
protein separation ranging from 0V. to 14V. by wt of the residue.
5. The process as claimed in any of the preceding claims
wherein the polysaccharide is powdered subsequent to drying.
b. The process as c1aimed in c1aim 5 wherein the
polysaccharide powder is dissolved in water to produce a viscous gum.

7. The process as claimed in any of the preceding claims wherein the solvent treatment is carried out by heating under reflux.
3. A process for extracting polysaccharides from tamarind seed kernels substantially as herein described.