Effects of enzyme treatments on the functionality of commercial pea and pea blended protein ingredients

The effects of enzyme treatments on the functional properties of commercial pea protein, pea:rice protein blend (3:2), pea:oat protein blend (1:1), and pea:hemp protein blend (1:1) were investigated. Treatments were applied through hydrolysis (pepsin or papain), crosslinking (transglutaminase, TG), and their combination (pepsin + TG or papain + TG). The protein content of each protein blend increased slightly or remained unchanged under treatments involving papain but decreased after treating with pepsin or pepsin + TG. Surface hydrophobicity increased for pea, pea:rice, and pea:oat blends after all enzyme treatments. Water holding capacity decreased for all samples compared to the untreated materials. For oil holding capacity, there was only improvement in the pea:rice blend with TG and pea:hemp with papain and papain + TG. Emulsion stability of pea:rice and pea:oat blends increased after all treatments; pepsin treatment specifically improved the emulsion stability to over 90%. Foaming capacity of each protein blend increased under all enzyme treatments whereas the foaming stability improved for the pea:rice blend but decreased for the pea:hemp blend. All treatments increased protein solubility. Specific enzyme treatment can be used to tailor the functionality of commercial plant protein blends.