Analysis on the Nutrient compositions of Two Varieties of Sajna (Moringa Oleifera L.) Leaves and Purification, Characterization and Structure-function Analysis of Sajna Leaves Protein

Abstract

Two types of Sajna leaves, small and large sized were analysed to obtained a comparative date on their chemical composition and nutritive values at different maturity levels. The large sized leaves contained higher amount of TT A, dry matter, total chlorophyll, chlorophyll-a, chlorophyll-b, water soluble protein, lipid, total sugar, sucrose, starch, vitamin-C, vitamin-B2 and iron while the small sized leaves contained higher amount of specific gravity, moisture, ash, total protein, total phenol, reducing sugar, f3-carotene, vitamin-B1, calcium and phosphorus .The nutrient compositions of Sajna leaves were found to be changed at different maturity levels. The specific gravity, dry matter, ash, lipid, total sugar, reducing sugar, sucrose, f3-carotene, vitamin-B2 and phosphorus content increased while TT A, moisture, starch, calcium and iron content decreased with the advancement of maturity in both type of leaves. The total chlorophyll, chlorophyll-a, chlorophyll-b, total protein, water soluble protein, total phenol, vitamin-B 1 and vitamin-C content were increased upto mature stage and then decreased in ripen stage. The activities of protease and peroxidase enzymes increased with the changes of maturity, whereas amylase, cellulase, invertase, ascorbic acid oxidase and Polyphenoloxidase increased upto mature stage and then decreased drastically in ripen stage. Fresh Sajna leaves contained significantly higher amount of oxidative enzymes as compared to the hydrolytic enzymes. Polyphenoloxidase, a highly active enzyme in large sized Sajna leaves at mature stage was purified and characterized. The purification was accomplished by ion-exchange chromatography of crude enzyme extract on DEAE-cellulose followed by CM-cellulose chromatography. The purified enzyme gave single band on polyacrylamide gel indicating its homogeneity. The molecular weight of enzyme, as indicated by gel filtration and SDS­polyacrylamide gel electrophoresis were estimated to be 56,000 and 55,500 respectively and the enzyme contained only one subunit. The enzyme gave maximum activities in the pH range of 6.0-6.4 and at temperature 32°C. ----------