Metabolites profile and endogenous enzymes changes in pre-dehydrated surimi: Mechanistic insights into gelling properties and flavor characteristics.

The essence of traditional surimi processing is a balance between the loss of food chemical components and the quality of the protein gel. The washing process generates a large amount of wastewater, which urgently requires innovation and upgrading of the processing technology. This study investigated the changes in gel properties, endogenous enzyme activities, flavor characteristics and metabolic profile during mechanical pre-dehydration of minced fish, compared to the traditional washing process, in order to understand the relationship between changes in endogenous components and processing quality. The results showed that the pre-dehydration process preserved some of the TGase activities (65.96 U/mg) but also some of the proteases and some metabolites (e.g. Histamine and Phosphatidylcholine) that are detrimental to the gelling process, and the gel strength of the obtained surimi gels was lower but acceptable than that of the washed surimi gels (390.97 g·cm and 464.51 g·cm). The gel strength of unwashed surimi was unacceptable (284.03 g·cm). Pre-dehydrated surimi preserved higher levels of amino acids, glycerolipids, and glycerophospholipids than washed surimi, leading to enhanced flavor precursor retention and generation of volatile compounds during gelling. Compared to washed surimi gel, pre-dehydrated surimi gels exhibited stronger warm-over and fishy flavor (Heptanal, Octanal, et al), while retaining more desirable aromas (3-Hexanone, 1-hexanol, et al). This study demonstrates that mechanical pre-dehydration balances gel quality and flavor retention while reducing water usage, offering a sustainable strategy for surimi processing.