Abstract: In this paper, fermented duck thigh was manufactured with a mixed starter culture of Lactobacillus plantarum and Saccharomyces cerevisiae, and its physicochemical indexes and changes in quality characteristics during storage were evaluated. The results showed that the optimum processing conditions were determined as follows: inoculum amount 2%, ratio of L. plantarum to S. cerevisiae 1:2, fermentation time 24 h, and temperature 30 ℃. The pH, Escherichia coli count, nitrite, histamine and peroxide value of the fermented product generated under the optimized conditions were all within the requirements of the national standards. As storage time increased, the sensory score gradually decreased, and the thiobarbituric acid (TBA) value and total volatile basic nitrogen (TVB-N) value gradually increased. The changes in all these parameters in the uninoculated control group were greater than those of the inoculated group. The total number of colonies and the content of nitrite in the inoculated group increased during the first 30 d of storage, and then decreased from day 30 to 50 whereas the two parameters in the control group continued to increase. The contents of all tested biogenic amines in the inoculated group showed an upward trend in the early stage of storage. The contents of tryptamine, cadaverine, tyramine and spermidine decreased after day 30, and the contents of phenylethylamine, putrescine and spermine decreased after day 40. In contrast, the total content of biogenic amines in the control group kept increasing. In summary, inoculation with the mixed starter could improve the taste of the product, and significantly retard the deterioration in the sensory quality, fat oxidation and the production of undesirable biogenic amines during prolonged storage.

Key words: mixed fermentation, fermented duck thigh, process optimization, storage characteristics