Metabolomics, volatolomics, and bioinformatics analyses of the effects of ultra-high pressure pretreatment on taste and flavour parameters of cured Culter alburnus

The effects of ultra-high pressure (UHP) pretreatment (50–250 MPa) on the fish curing were studied. UHP increased the overall volatile compound concentration of cured fish. Among 50–250 MPa five treatment groups, 150 MPa UHP group exhibited the highest total free amino acid content (294.34 mg/100 g) with that of the control group being 92.39 mg/100 g. The activity of cathepsin L was increased under 50–200 MPa UHP treatment (62.28–58.15 U/L), compared with that in the control group (53.80 U/L). UHP treatment resulted in a significant increase in small molecule compounds, especially the amino acid dipeptides and ATP metabolic products. Under UHP treatments, the bacterial phyla Actinobacteriota (1.04–5.25 %), Bacteroidota (0.20–4.47 %), and Deinococcota (0.00–0.05 %) exhibited an increased abundance, and they promoted taste and flavor formation . Our results indicated that UHP is a promising pretreatment method to improve taste and flavour in cured fish by affecting the microorganisms, cathepsin, and proteins.