| Along with the development of chilled meat in the consumption market, it is significant to study in this field. One of the key point of chilled meat is its shelf-life. How to extend the shelf-life and protect the quality are very important. In this paper we selected several lactic acid bacterias and studied their functions in preservation of chilled mutton, to provide some new ideas about chilled meat preservative technologies .Meanwhile, wishing this idea can guide the productions of chilled meat, hoping it make a better development.The paper is consisted of four parts: In part one, the dominate spoilage bacteria in the chilled mutton were studied; In part two, inhibition lactic acid bacteria(LAB) was selected and identified ;In part three, we inoculated the LAB with the dominant spoilage bacteria in broth and co-cultured at 4℃to demonstrate the restraining interaction between these strains; In part four, two LAB fermented solutions were sprayed on chilled mutton, and we did several tests to demonstrate the usefulness of the LAB to prolong the storage time of chilled mutton.Part one: Main microorganisms of chilled mutton were incubated with different selective medium. The results indicated that Pseudomonas , Lactobacillus, Micrococcus, Enterobacteriaceae and Brochothrix were the main bacteria in the chilled mutton. Pseudomonas was the dominant bacteria , its ratio arrived at 72.86% and was raising slowly under the air packages. But in vacuum packaged chilled mutton, LAB was increasing in the storage time instead of Pseudomonas.Part two: Fifty LAB were selected from the traditional fermented meat products. 9 of these strains showed preferable inhibition effects to the Indicator bacteria by the Agar Diffuse Method. Studied the characteristic of inhibition substants more, it is resulted that S1-1 maybe a bacteriocin-production strain.These strains were indentified by analysis their physiological and biochemical characters. The results showed that: TD3-1 and TD3-7 were Pediococcus.pentosaceus; ZJ3-4 and M-2 were Lactobacillus.rhamnosus; ZJ3-8 was Lactobacillus.sake; S1-1 was Lactobacillus.pentosus; S2-1 was Lactobacillus.plantarum; M-1 and S1-2 were Lactobacillus. Using the special primers to PCR amplification of 16SrRNA sequences of LAB S1-1, TD3-1, and the whole sequences were identified by submission to the nucleotide database of NCBI. The results showed that the homologous of 16SrRNA sequences of S1-1 with Lactobacillus.pentosus were 99%, and so did TD3-1 with Pediococcus.pentosaceus.Part three: This part investigated the usefulness of two selected lactic acid bacteria to extend the shelf-life of chilled mutton meat products. The results showed that the lactic acid bacteria TD3-1 can inhibit the growth of three spoilage organisms which selected from chilled mutton. Co-culture with TD3-1 can inhibit the population density of spoilage organism at a lower value than mono-culture. Otherwise, strain S1-1 can inhibit bacteriaP, E, but S.Part four: The vacuum packaged chilled mutton was treated with LAB fermented solutions, at the same time, comparing with different preservation solutions(lactic acid,Nisin), monitoring the microflora counts, psychochemical value and taste panel scores to make sure the effect of the preservation solutions. It was concluded that, after treated with different preservation solutions, the 107CFU/mL LAB solutions showed the best protective effects. There was no evident difference between S1-1 and TD3-1 at the effect of prolong the sorage life of chilled mutton. Both of the two LAB can make the pH value keeping at a low level all the while; The TVB-N value was lower than 9mg/100g at the last time of the storage. The taste panel scores was high. The preservation time was longer than comparisons.
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