Effect of bambara groundnut protein isolate on autolysis and gel properties of surimi from threadfin bream (Nemipterus bleekeri)

Impact of bambara groundnut protein isolate (BGPI) on autolysis and gel properties of surimi from threadfin bream (Nemipterus bleekeri) was investigated. BGPI with trypsin inhibitory activity of 6356.3 ± 6.02 unit/g markedly increased (P < 0.05) the breaking force and deformation of modori gel as the levels used (0-3 g/100 g) increased. Nevertheless, only 0.25 g/100 g BGPI increased breaking force and deformation of kamaboko gel and increasing BGPI levels showed detrimental effect on gelation. Myosin heavy chain (MHC) was more retained when BGPI concentration increased, especially in modori gel. However, whiteness slightly decreased (P < 0.05) with increasing BGPI levels. Microstructure of kamaboko gel added with 0.25 g/100 g BGPI had finer and more ordered fibrillar structure than that without BGPI addition. Therefore, BGPI at an appropriate level could be an alternative food-grade inhibitor to improve gel properties of surimi.

► BGPI at an appropriate level could lower the degradation of myofibrillar proteins in threadfin bream surimi. ► BGPI could increase gel strength without detrimental effect on sensory property. ► BGPI could be used as an alternative protein additive for surimi industry.