Structure and functional properties bream sarcoplasmic of modified threadfin 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 degrees 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 (S-o), solubility in water (S-w) and free amino group (fNH(2)) 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. (C) 2007 Published by Elsevier Ltd.