Extraction and isolation of acidic galactoxyloglucanases from the germinating seeds of Tamarindus indica

India produces about 300,000 tons of tamarind per year and tamarind seed is the major byproduct, which contains about 70% of the endosperm. The endosperm contains about 55 – 60% polysaccharide, galactoxyloglucan. There is a growing demand for specific, efficient and cheap galactoxyloglucanase for use in the production of tamarind oligosaccharides for its use as nutraceuticals. A large number of hydrolytic enzymes, such as  glucosidases,  galactosidases and galactoxyloglucanases are produced during the germination of tamarind seeds. The technology of bioprocessing tamarind seeds using enzymes is gaining momentum.
Healthy tamarind seeds were germinated and endosperms were collected every 48 hrs from 3rd to 31st day. A 20% extract of the fresh endosperm were prepared in different buffer systems. Maximum galatoxyloglucanase activity was extracted with 0.05 M acetate buffer pH 5.5, containing 0.5 M NaCl. The activity was determined using tamarind xyloglucan ( amyloid, Megazyme, Ireland). The specific activity increased 15 – fold during germination, reaching maximum by 23rd day. Km of the enzyme was 66.7 mg %. The enzyme had optimum pH and temperature of 5.5 and 45 O C, and was stable between pH 4 to 6.5 and 50 O C, respectively. Electrophoretic analysis of the galactoxyloglucanase activity during germination using grams iodine revealed five isozymes. Major band 2 was present on all the days while band numbers 3 and 4 appeared from 17th day onwards and band number 5 from 23rd day onwards.