Effects of five thermal processing methods on the physicochemical properties and flavor characteristics of grass carp meat

Abstract

This study investigates the effects of five thermal processing methods on fish nutritional components, oxidation, thermal degradation and flavor characteristics of grass carp meat, including steam (SM), boil (BO), fry (FY), roast (RO) and sous-vide (SV). The results found that heat treatments reduced the moisture content, total sulfhydryl content, redness, hardness and chewiness of fish meat, increased carbonyl content, TBA value, proteins cross-linking and covalent modification, brightness and yellowness, and altered fatty acid composition and flavor. A total of 136 volatile compounds and 28 fatty acids were identified from the grass carp meat. Correlation analysis suggested that 2,4-Di-tert-butylphenol and tetracosane are formed mainly due to the oxidation of fish meat, which in turn caused changes in C18:2n6c, C20:0, C18:3n3, C24:0 and b*. Heat treatments caused oxidation and thermal degradation of lipids in grass carp meat to produce free fatty acids, which further produced volatile compounds. SV and RO had a more suitable fatty acid composition for human body, while FY had better sensory quality but excessive intake unfavorable to health. This work is expected to provide guidance to consumers in selecting thermal processing methods, as well as offering insights for the development of fish pre-prepared dishes.