Yongxia Xu1,2, Jiamei Zhao2, Rui Wang2, Xuepeng Li2, Hongbo Mi2, Jianrong Li1,2. 1. College of Food Science, Southwest University, Chongqing, China. 2. College of Food Science and Engineering, National R&D Branch Center of Surimi and Surimi Products Processing, Bohai University, Jinzhou, China.
Abstract
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.
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.