Regional chemical composition and microbial flora of commercial hatahatazushi from Akita Prefecture

Abstract

The regional chemical compositions and microbial flora of commercially-produced hatahatazushi, fermented sushi from Akita Prefecture, have not yet been sufficiently examined. Moisture content, water activity, salt content, pH, organic acid content, free amino acid content, free saccharide content and microbial flora of hatahatazushi were investigated. The results indicate that two types of hatahatazushi are currently being produced. Products from the northern and southern coastal regions of Akita Prefecture were produced without lactic acid fermentation and classified as hayazushi. Products from the central coastal region produced with lactic acid fermentation were classified as namanarezushi, a more traditional form of hatahatazushi. Microbial growth in northern and southern coast products was inhibited by acetic acid during the manufacturing process, and was also by low water activity in southern coast products. This is the first study to scientifically demonstrate that two types of hatahatazushi are being produced in Akita Prefecture.