Structure and functional properties of modified threadfin bream sarcoplasmic protein

Surimi wash-water contains up to 30% of protein from fish muscle that is currently underutilized. This paper describes the effect of acetylation, succinylation, trypsin hydrolysis or pre-heating at 55 °C on the emulsification and foaming properties of a threadfin bream sarcoplasmic protein (TBSP) model for wash-water protein. Multiple regression analysis showed that emulsification and foaming characteristics were differentially affected by TBSP surface hydrophobicity (S0), solubility in water (SW) and free amino group (fNH2) concentration. Emulsification activity index (EAI) for TBSP was most enhanced by succinylation, whereas the foaming capacity (FC) was more effectively extended by trypsin hydrolysis. Structure–function relationships for emulsification were different from those associated with foaming or for ensuring the stability of these food dispersions. This study suggests that surimi wash-water protein functionality can be improved by protein modification. Further strategies may be needed to stabilize fish protein stabilized emulsions and foams.