Regulation of quality and biogenic amine production during sufu fermentation by pure Mucor strains

Abstract

Natural fermentation of sufu yields large amounts of biogenic amines (BAs) and other risk factor, which pose significant health risks. To improve the safety and quality of sufu, we investigated sufu fermentation by three microbial strains, Actinomucor elegans, Mucor wutunkiao, and Mucor racemosus, and monitored the dynamics change of each risk factor during sufu fermentation. Results showed that the moisture content, pH, NaCl, amino acid nitrogen content, and total acid content of all samples were at normal levels for mature sufu products. The H2S and total volatile base nitrogen (TVB-N) levels in Mucor racemosus fermented sufu (MRFS) were lower than those in other mucor fermented sufu. And pure mucor fermentation significantly reduced the benzoic acid content. Different mucor strains and fermentation processes contributed to different BAs levels in the final sufu products. The levels of common BAs cadaverine, spermidine, spermine, histamine, and tyramine were significantly lower (p < 0.05) in MRFS than in sufu fermented with other mucor strains. Through these results, the main step of risk factor generation during sufu fermentation was identified, which can be useful for producing sufu products with good quality and low levels of BAs through pure-culture fermentation.