Towards higher-quality low salt surimi gels: Significance of the combinatorial effects of chickpea protein with transglutaminase on their micro-structures
Tong Shi, Yuan Li, Yunfei Kong, Yulong Bao, Hao Zhang, Chenya Lu, Wengang Jin, Abdul Razak Monto, Ruichang Gao
Abstract
The textural properties of low-salt hybrid gel made from silver carp ( Hypophthalmichthys molitrix ) and chickpea protein (CPP) with or without external transglutaminase (TGase) were investigated. A decrease in gel strength ( P ﹤0.01), hardness ( P ﹤0.01), storage modulus (G′) and loss modulus (G″) of the hybrid gel containing CPP appeared regardless of the addition of TGase. Furthermore, the addition of CPP combining with TGase significantly induced a significantly higher resilience (from 43.5% to 50.3%), cohesiveness (from 0.72 to 0.79), proportion of immobilized water (from 95.7% to 97.4%), number of pores (from 3181 to 4868) and apparent porosity (from 30.55% to 40.26%) than those of the group containing TGase alone, which indicated the combining effect of CPP and TGase on the textural properties. The SDS-PAGE profiles showed that the covalent complex between CPP and myofibrillar proteins was not observed. During the gelation of myofibrillar protein filaments, CPP wrapped the fibres shown by the microstructure morphology and increased the friction between fibres, leading to an increase in relaxation time. TGase promoted this effect and induced the formation of a denser microstructure. The present study provided a feasible approach for the preparation of high-quality low salt surimi products with more favorable texture and acceptability. • Low salt hybrid gels were produced with Chickpea protein (CPP) and surimi. • A covalent complex between CPP and myofibrillar proteins was not observed. • CPP and TGase showed a synergistic effect on the micro-structures of gels. • CPP and TGase showed a synergistic effect on the textural properties of gels.