FUNCTIONAL-PROPERTIES OF HOMOGENEOUS PROTEIN-FRACTIONS FROM PEANUT (ARACHIS-HYPOGAEA L)

Protein fractions, namely arachin, conarachin I, and conarachin II, from peanut (Arachis hypogaea L.) were isolated to homogeneity and their functional properties studied. I Bulk density and water absorption and fat absorption capacities were measured. Solubility of the fractions varied as a function of pH, and more than 95% bf protein was soluble at pH below 2.5 and above 7.0. The presence of NaCl decreased the solubility at low PH. The total protein of peanut had a value;of 1.11 for emulsifying activity (EA), while arachin, conarachin II, and conarachin I had values of 0.90, 1.05, and 1.11, respectively, and their emulsifying stability (ES) values ranged from 72 to 300 s. The effects of variables such as protein concentration, pH, and NaCl concentration on the emulsifying properties of peanut protein fractions:were studied.;The foaming capacities of the fractions before and after hydrolysis with Lu-chymotrypsin were in the order total protein > arachin greater than or equal to conarachin I > conarachin II and total protein > conarachin I > arachin > conarachin II, respectively. The foam stability of enzyme-hydrolyzed fractions followed the order conarachin I > total protein > arachin > conarachin II.