Effects of protein isolates from black bean and mungbean on proteolysis and gel properties of surimi from sardine (Sardinella albella).

摘要

Effects of protein isolates from black bean (BBPI) and mungbean (MBPI) on proteolysis and gelling properties of surimi from sardine (Sardinella albella) were investigated. Both BBPI and MBPI showed inhibitory activity against proteolysis in kamaboko (40/90 degrees C) and modori (65/90 degrees C) gels in a concentration-dependent manner. Myosin heavy chain (MHC) was more retained in both gels when the concentration of both protein isolates increased up to 1 g 100 g-1. This was associated with the increased breaking force and deformation as well as lowered degradation as evidenced by the decrease in trichloroacetic acid-soluble peptide content (p < 0.05). Whiteness of kamaboko and modori gels slightly decreased with increasing BBPI or MBPI levels (p < 0.05). However, water-holding capacity of both gels increased with increasing levels of both protein isolates. Microstructure of kamaboko and modori gels added with 1 g 100 g-1 BBPI or MBPI was finer and denser with more ordered structure than that of the control. Generally, BBPI showed slightly higher gel strengthening effects and inhibition against proteolysis of surimi gels than MBPI. Therefore, proteolysis of sardine surimi, associated with endogenous proteases, could be retarded by the addition of BBPI or MBPI, leading to the increased gel strength