Physicochemical properties and bacterial community dynamics of hongeo, a Korean traditional fermented skate product, during fermentation at 10 °C

In this study, the physicochemical properties and bacterial community of hongeo (fermented skate) were investigated during fermentation at 10 degrees C. A continuous increase in pH, contents of ammonia nitrogen, amino nitrogen, free fatty acid, and released and expressible water, and total bacterial count was noticed during fermentation. Furthermore, the decrease in lightness (L*) and increase in yellowness (b*) were most likely caused by the Maillard reaction, as well as by lipid oxidation during fermentation, as evidenced by the increase in thiobarbituric acid reactive substances (TSARS) values. The bacterial community in hongeo samples at different fermentation stage was determined using 16S rRNA sequencing. Results of linear discriminate analysis effect size (LEfSe) analysis indicated that skate samples of the final fermentation stage were enriched in Pseudomonadales, Alteromonarlales, and Burkholderiales, which showed a profound impact on the physicochemical properties of skate samples during fermentation. The identification of dominant communities in hongeo samples provides important information for selection of starter cultures consisting of strains that are well adapted to the particular production technology.