Effects of Tween 20 and Transglutaminase Modifications on the Functional Properties of Peanut Proteins

The effects of Tween 20 on the emulsification and gelation properties of peanut protein isolates (PPI) were investigated. The functional properties of different peanut protein products, including PPI, Tween 20‐assisted aqueous extraction peanut proteins (TPP), and their transglutaminase‐modified products (TG‐TPP), were then compared. The results indicate that the addition of Tween 20 to the PPI resulted in higher emulsifying activity index (EAI) and emulsion stability index (ESI) values than PPI without Tween 20; however, the emulsions produced by the PPI–Tween 20 mixtures were easier to destabilize during storage. As the amount of Tween 20 was increased, both the surface hydrophobicity and gel strength of the PPI–Tween mixtures significantly decreased. TPP (containing approximately 11% Tween 20) exhibited significantly different functional properties from PPI. Compared with PPI, TPP had higher EAI and ESI values but a weaker heat‐induced gelation ability. The protein solubility of TPP was markedly higher than that of PPI. Modification of TPP with transglutaminase (TGase) significantly enhanced their gelation and oil‐binding properties but reduced the protein solubility and ESI value. The remarkable improvement in the gelation ability of TG‐TPP was mainly attributed to the formation of high‐molecular‐weight protein aggregates and their conformational changes.