Dual Enzymatic Production of Bioactive Peptides from Velvet Bean Protein Concentrate

Abstract

Bioactive peptides have a great potential for application for functional foods. Velvet bean (Mucuna pruriens) is a promising source of parent protein for the production of bioactive peptides due to its high protein and hydrophobic amino acid composition. This research aimed to obtain the optimum operating conditions for the continuous production of bioactive peptides from velvet bean protein concentrate using dual enzymatic proteolysis. This research was divided into two main stages: preparation of velvet bean protein concentrate and continuous production of bioactive peptides with emphasis on the influence of the enzyme-to- substrate ratio, pH, and residence time. Due to its high enzyme rejection, a 5-kDa PES membrane was used. The optimum operating conditions obtained were: [E]/[S] = 5%, pH = 7.5, and residence time = 12 h. With these operating conditions, the antioxidant capacities and ACE inhibition of the permeate were 0.1803 mg AEAC/mL (DPPH method), 0.1589 mg AEAC/mL (FRAP method), and 74.29%, respectively. Compared to the substrate, there was a decrease in antioxidant capacity and almost a twofold increase in ACE inhibition. The decrease in the antioxidant capacity was due to phenolic compound rejection by the membrane. Moreover, a long-term continuous production of velvet bean protein concentrate was performed. An increase in antioxidant capacity, ACE inhibition, and TMP was observed during the 72-h filtration. A combination of physical and chemical membrane cleaning was able to recover the flux up to 85.6%.