Chemical and microbial properties of Chinese traditional low-salt fermented whole fish product Suan yu

This paper reports the first study on the chemical and microbial properties of Suan yu, a sanitary Chinese traditional low-salt fermented whole fish product of high nutrition, unique flavor, and long-storage capability. Six brands of Suan yu from different locations in China were studied. Significant differences were observed in some characteristics of this traditional fermented fish, raw material and other spontaneously fermented fish. The values of Enterobacteria and Pseudomonads were under the detection limits in six different brands. In addition, the products contained higher protein and lower moisture ranging from 17.2% to 22.9% and 52.9%–58.1%, respectively. The pH values ranged between 4.27 and 5.18, and lactic acid was the major organic acid. The proteolysis of the myosin heavy chain and actin chain were observed through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Moreover, low concentrations of biogenic amine (BA) and thiobarturic acid (TBARS) values were found in all samples. The characteristics of the six Suan yu brands were all influenced by raw materials, ingredients, and fermentation processes and conditions.

► No Enterobacteria and Pseudomonads were detected in the different brands.
► Higher protein content and lower moisture were observed during the fermentation.
► Low concentrations of biogenic amines and TBA values were found.
► The degradation of muscle proteins was detected.