Combined effects of isolation temperature and pH on functionality and beany flavor of pea protein isolates for meat analogue applications

Abstract

The combined effects of isolation temperature (20, 30 and 40 °C) and pH (2.0-12.0) on yield, techno-functional properties, and beany flavor of pea protein isolates were investigated. Increasing pH from 2.0 to 9.5 and 11.0 increased yields from 37 % to 75 % and 79 %, respectively, at 20 °C. At a constant pH, increasing temperature from 20 to 40 °C did not increase protein recovery; rather, negatively affected the techno-functional properties such as protein solubility, foaming and gelation. Protein isolated at pH 11.0 (20 °C) provided a higher fat absorption, gelation capacity, gel hardness, cohesiveness, chewiness, and gumminess than at pH 9.5, due to higher protein denaturation as supported by their higher surface hydrophobicity. Volatile beany flavor marker hexanal was predominant in all isolates than the starting material, irrespective of isolation temperature, probably due to lipid oxidation. The results provide a basis for tuning the isolation process for producing pea protein isolates with desired techno-functional properties for meat analogue applications.