Enhanced functional properties of pea protein isolate microgel particles modified with sodium alginate: Mixtures and conjugates.

ABSTRACT

Protein microgels are emerging as versatile soft particles due to their desirable interfacial activities and functional properties. In this study, pea protein isolate microgel particles (PPIMP) were prepared by heat treatment and transglutaminase crosslinking, and PPIMP were non-covalently and covalently modified with sodium alginate (SA). The effects of polymer ratio and pH on the formation of PPIMP-SA mixtures and conjugates were investigated. The optimal ratio of PPIMP and SA was found to be 201, with the optimal pH being 7 and 10, respectively. PPIMP-SA conjugates were prepared by Maillard reaction. It was found that ultrasound (195 W, 40 min) enhanced the degree of glycation of PPIMP, with a highest value of 37.21 ± 0.71 %. SDS-PAGE, browning intensity and FTIR data also confirmed the formation of PPIMP-SA conjugates. Compared with PPIMP and PPIMP-SA mixtures, PPIMP-SA conjugates exhibited better thermal stability, antioxidant, emulsifying and foaming properties, which opens up opportunities for protein microgel in various food applications.