Abstract:

The effectiveness of a single treatment with nisin, glycin, natamycin or lysozyme in the preservation of vacuum-packed spiced crisp ducks stored at 37 ℃ was investigated by examining the change of total bacterial count at intervals of 7 d. In order to obtain the optimal preservation for spiced crisp ducks, the combined use of the natural preservatives was adopted and their optimum addition proportions were explored for maximizing weighed score of total volatile basic nitrogen (TVB-N) and total bacterial count of spiced crisp ducks using orthogonal array design. Results showed that each natural preservative could significantly inhibit microbiological contamination and nisin exhibited the highest preservation effect among them. The optimal formula of compound preservatives consisted of nisin 0.05%, glycin 0.50%, natamycin 0.05%, lysozyme 0.04%. This formula had much stronger inhibitory effect against bacteria than a single preservative.

Key words: spiced crisp duck, compound natural preservative, total bacterial count, total volatile basic nitrogen (TVB-N)