Effects of fi lleting methods on composition, gelling properties and aroma profi le of grass carp surimi

Traditionally,fi sh carcass is headed and gutted to prepare a skin-on fi llet in surimi production.In this study,tail and/or belly of grass carp carcass were further cut off in the fi lleting step.Yield,composition,gelling properties and aroma profile of surimi as affected by filleting methods were investigated by SDS-PAGE,ELISA,SEM,magnetic resonance imaging(MRI)and electron nose.Cutting tail off increased surimi yield by 14.0%,whereas cutting belly off decreased it by 11.2%.Cutting tail or belly off signifi cantly decreased fat content,but did not change protein content,ash content,cathepsin(B,H and L)contents,nor protein patterns.Both breaking force and whiteness of surimi gel signifi cantly increased after cutting tail off.Cutting belly off slightly increased whiteness of surimi gel.The microstructure of all the surimi gels was compact and uniform,with fractal dimensions(Df)ranging from 2.81 to 2.85.As for the macrostructure,cutting tail off apparently improved the integrity of surimi gel while cutting belly off did not.Aroma profi les of the surimi prepared under different fi lleting methods could be clearly distinguished by linear discriminant analysis(LDA).Our results indicate that cutting tail off contribute positively to surimi production.