BACKGROUND The influence of heat‐induced structural modifications of grass carp myofibrillar protein (MP) on its ability to bind to selected aldehydes (hexanal, heptanal, octanal and nonanal) was investigated. The interactions of MP and flavor compounds were investigated using HS‐GC‐MS, intrinsic fluorescence spectra, Raman spectra, SDS‐PAGE, turbidity, total sulfhydryl content and surface hydrophobicity. RESULTS The ability to bind to aldehydes was strongly influenced by changes in the structure and surface of proteins during the heating process (0–30 min). During the first 0–10 min of heating, the flavor‐binding ability increased, which is likely attributable to increased surface hydrophobicity and total sulfhydryl content, and to the unfolding of secondary structures of MP by exposure to reactive amino acids, sulfhydryl groups and hydrophobic bonding sites. Nevertheless, lengthy heating (>10 min) caused protein refolding and accelerated aggregation of protein, thus reducing hydrophobic interactions and weakening the resultant capacity of MP to bind to flavor compounds. CONCLUSION The results suggested that hydrophobic interactions were enhanced upon short‐term heating, whereas long‐term heating weakend them. The results provide information concerning improvement of the flavor profile of freshwater fish surimi products. © 2019 Society of Chemical Industry

BACKGROUND: The present study investigated the effect of two-step heat treatments on the structure of grass carp myofibrillar proteins (MPs) and their binding ability for selected aldehydes (hexanal, heptanal, octanal and nonanal). RESULTS: Within 30 min of the first heating step at 40 ∘ C and 5-10 min of the second heating step at 90 ∘ C, the enhancement of the flavor-binding ability was likely explained by the increases in surface hydrophobicity and total sulfhydryl content due to the unfolding of secondary structures of MPs through exposure of hydrophobic amino acids and sulfhydryl groups. Nevertheless, lengthy heating at 90 ∘ C accelerated the aggregation of unfolded MPs and reduced the hydrophobic bonding sites, thus weakening the hydrophobic interactions and decreasing the resultant binding ability of MPs with aldehydes.CONCLUSION: The binding ability of aldehydes to MPs was found to be strongly influenced by changes in protein structure and surface during the two-step heating process. The results provided insight into improving the flavor characteristics of freshwater fish surimi products.