Chemical and Functional Properties of Hard-to-Cook Bean (<i>Phaseolus vulgaris</i>) Protein Concentrate

Abstract

The objective of this research was to evaluate the chemical and functional properties of hard-to-cook (HTC) bean ( Phaseolus vulgaris ) protein concentrate to determine their potential practical applications. The respective protein concentrate was obtained from the flour using isoelectric precipitation and the protein content was 73.03%. Proximate composition and in vitro digestibility were measured to evaluate the chemical properties, and nitrogen solubility, emulsifying capacity, emulsion stability, foaming capacity, foam stability and viscosity were measured to evaluate its functional properties. The proximate composition of the HTC bean ( P. vulgaris ) flour and protein concentrate registered values of moisture, ash, protein, fat, fiber and NFE of 8.92, 4.52, 21.71%, 4.41%, 4.11% and 65.25% for flour and of 2.68%, 2.54%, 73.03%, 2.77%, 1.31% and 20.35% for protein concentrate. The in vitro digestibility was of 76.7%. The hard-to-cook bean protein concentrate exhibited good functional properties suggesting its use as additive. This concentrate registered solubility values that are ranging from 2.5% to 71.81%. The emulsifying (EC) and foaming capacity (FC) registered values of 89% - 97% and of 7% - 53% at different pH levels, respectively as well as an emulsion (ES) and foaming stability (FS) pH- and time-dependent. The HTC bean ( P. vulgaris ) protein concentrate registered a viscosity profile dependent of shear rate. The results suggest that HTC bean ( P. vulgaris ) protein concentrate is a valuable food ingredient or additive.