Changes in Metabolite Concentrations and Bacterial Community of Salted and Fermented Squid Shiokara During Processing

Abstract

The squid shiokara, a typical Japanese traditional salted and fermented seafood, is made with a high-salt concentration of 12% at 25 °C (high-salt shiokara). This method resulted in a significant increase in the concentrations of extractive components, including free amino acids, dipeptides, and organic acids. The bacterial community was dominated by Vibrio, Psychrobacter, and Acinetobacter at the beginning of processing, but as the fermentation progressed, Staphylococcus dominated gradually. The squid shiokara, which is now widely available in the Japanese market, is made with a salt concentration of 5% (low-salt shiokara) under refrigeration and showed much smaller changes in the concentrations of the extractive components and the bacterial community than those with the high-salt shiokara. The high-salt shiokara accumulated many metabolites thought to be related to taste and flavor. The observed differences in the metabolite concentrations likely contribute to the distinct taste and flavor characteristics of high-salt shiokara.