Functional properties of acetylated and succinylated cowpea protein concentrate and effect of enzymatic hydrolysis on solubility

Abstract

The present study was undertaken to improve functional properties of cowpea protein concentrate by acylation and partial hydrolysis with pepsin. The acylated concentrate showed significant improvement in protein solubility and water solubility index, at neutral pH. In addition, acylation increased fat absorption capacity compared with the untreated concentrate, and the maximum was obtained at 0.75 g succinic anhydride/g concentrate. Acetylation at concentrations of 0.25–0.50 g/g led to the higher emulsifying activity, and a markedly improvement in emulsifying stability was observed at 1.0 g anhydride/g concentrate. Foaming activity increased following acylation, particularly at 0.25 and 1.00 g/g succinic anhydride/g concentrate, while foam stability decreased. At pH 3.5, protein solubility of the acylated concentrates was low ( < 8%). Partial hydrolysis of cowpea protein concentrate with pepsin increased protein solubility at the isoelectric and neutral pH.

Keywords::

• Cowpea
• protein concentrate
• functional properties
• acylation
• enzymatic hydrolysis

Declarations of interest: The present work was performed with the resources of the Food and Nutrition Research Centre (IMPM), Ministry of Scientific Research and Innovation, Yaoundé Cameroon.