Alteration of functional properties of peanut (Arachis hypogaea L.) protein fractions by chemical and enzymatic modifications.

Major protein feactions of peanut, namely, arachln, conarachin II and conarachin I. were Isolated, from defatted
Rour to homogeneity, and succinylated to 84, 83 and 85% levels, respectively. The protein fractions were also hydrolyzed
With alpha-chymotrypsin. Succinylated peanut proteins exhibited minimum solubility in the pH range 3.0 - 4.0, away
from the range for unmodified proteiml. Enzyme treatment improved the solubility, except in the pH range 2.0 - 3.0
and above pH B.O. Succlnylation improved the water and fat absorption capacities of all the protein fractions. The
emulsifying capacity and activity of succtnylated peanut protein fractions were higher than the unmodified fractions.
The emulsifying capadty of enzyme-hydrolyzed fractions increased by 30-50%. The emulsifying activity also Increased.
after hydrolysis with alpha-chymotrypsin. Foam stabilities of succinylated peanut protein fractions were found to be
improved. except for conarachln II. After hydrolysis with alpha-chymotrypsin, the foam capacity and stability of peanut
protein fractions Improved In eve!)' instance, Maximum Improvement of functional properties occurred after chemical
and enzymatic modifications of arachin, the major fraction. Thus, either chemical or enzymatic modification improves
the functional attributes of peanut protein fractions.