Pulsed electric field-assisted fermentation of low-salt fish sauce from Nile tilapia skeleton hydrolysate: Physicochemical properties and metabolite profile

Nile tilapia skeletons were used to prepare low-salt fish sauce through enzymatic hydrolysis, and the effects of pulsed electric field (PEF)-assisted fermentation with Pediococcus pentosaceus on its physicochemical properties and metabolite profiles were investigated. The results revealed that PEF pretreatment significantly enhanced proteolysis, increasing total soluble nitrogen (0.61 g/100 mL) and amino acid nitrogen (AAN). Additionally, organic acid content was higher in the PEF-pretreated group compared to the untreated group, whereas the content of biogenic amines was significantly lower (tryptamine decreased by 88 %). Metabolomic analysis of the fish sauce not only identified 427 differentially expressed metabolites but also demonstrated that pulsed electric field (PEF) pretreatment synergized with Pediococcus pentosaceus fermentation to increase the abundance of short-chain fatty acids (SCFAs) and umami-enhancing nucleotides, including inosine monophosphate (IMP) and adenosine monophosphate (AMP). Overall, these findings expanded the applicability of pulsed electric field (PEF) technology and provided novel insights into the production of high-quality low-salt fish sauce. • PEF coupled with P. pentosaceus fermentation enhanced fish sauce quality. • Combined fermentation increased soluble nitrogen and reduced biogenic amines. • Combined fermentation enhanced the intracellular metabolic regulation of P. pentosaceus. • PEF-assisted fermentation is a potential alternative to conventional extraction methods.