Effect of alkaline hydrolysis on the quantity of extractable protein fractions (prolamin, albumin, globulin and glutelin) in Jatropha curcas seed cake

Jatropha curcas seeds were processed and defatted to obtain the seed cake. 60 g of them were separately moistened in 0.1 – 0.5 M NaOH and Ca(OH)2 solutions and autoclaved. Each of the autoclaved samples was separately divided into three portions. A portion was washed with ethanol, another with water and the third was left unwashed. Prolamin, albumin, globulin and glutelin fractions were extracted from the treated and untreated seed cakes and subsequently quantified. Untreated seed cake sample express 0.11 g/Kg prolamin, 4.06 g/Kg albumin, 4.23 g/Kg globulin and 10.91 g/Kg glutelin of seed proteins. In Ca(OH)2 treated cake, albumin and globulin had their maximum yield in ethanol washed cake samples. The quantities obtained were 3.95 and 5.11 g/Kg of the seed protein, respectively. Prolamin and glutelin had their maximum yield in unwashed and water washed cake samples. The yields were 4.84 and 9.27 g/Kg of the seed protein, respectively. In NaOH treated seed cake, the four fractions had their maximum yield in water washed cake. The quantities were 3.37, and 3.64 g/Kg of seed protein for prolamin and albumin. The quantities of globulin and glutelin were 4.90 and 9.26 g/Kg of seed proteins. Quantity of prolamin increased in all the treated cake while the quantities of albumin, globulin and glutelin were reduced by the treatments. Key words: Prolamin, albumin, globulin, glutelin, alkaline hydrolysis.