Effect of Dry and Wet Fractionation on Nutritional and Physicochemical Properties of Faba Bean and Yellow Pea Protein

Abstract

Plant-based proteins continue to gain popularity as a sustainable alternative to animal proteins due to their nutritional, functional and health benefits. Dry and wet fractionation methods are increasingly being used for the production of value-added pulse protein ingredients. The objective of this study was to compare the nutritional properties, protein quality, physicochemical properties and secondary structure of Australian faba bean and yellow pea protein concentrates and protein isolates obtained by dry and wet fractionation. Amino acid scores highlighted that faba bean and yellow pea protein isolates and concentrates were deficient in the sulphur-containing amino acids, methionine and cysteine and tryptophan. Faba bean (63.7%) and yellow pea protein (63.0%) isolates had higher in vitro protein digestibility-corrected amino acid scores compared to the protein concentrates, being 50.7% and 54.4%, respectively. Fourier-transform infrared spectroscopy revealed different secondary structures between protein concentrates and isolates, especially for the amide I region. Faba bean and yellow pea protein concentrates had higher protein solubility (46.2% and 50.1%, respectively) and higher foaming capacity (65% and 59%, respectively) compared to the protein isolates. Water-holding capacity was higher for faba bean and yellow pea protein isolates, being 4.3% and 4.0 g/g, respectively. These findings demonstrate that faba bean and yellow pea protein concentrates and isolates have unique functional properties that can be exploited for use in a diverse range of new and existing food applications.