Studies on Bioactivity of Arginine Rich Peptides from Groundnut.

Groundnuts (Arachis hypogeal, L) have been valued for their high nutritional content
throughout the world for many years. Groundnuts contain 26-33% protein, and have good
bioavailability and relatively low content of anti-nutritional factors. Peanut polypeptides
obtained by enzymatic hydrolysis of peanut protein have important physiological functions.
An increasing amount of data demonstrates a bioactive role of proteins and peptides
beyond their nutritional impact. In this study enzymatic hydrolysate of peanut protein
isolate was prepared by treatment with fungal protease. The hydrolysate was further
fractionated into peptide sizes of >30 kDa, >3kDa, <3kDa using membrane filtration. The
protein hydrolysate and its membrane ultra filtration fractions were used to estimate
arginine. The >3kDa peptide exhibited high arginine content. The peptide fraction and
protein hydrolysate were also assayed for invitro antioxidant activities and ACE-inhibitory
activities. The >3kDa arginine rich peptide exhibits significantly high antioxidant capacity
and ACE-inhibitory activity. The high activity of >3kDa peptide may be related to the high
levels of arginine in it. The result shows the potential of arginine rich peanut peptide in the
management of oxidative stress related metabolic disorders and hypertension.