Application Of Biopreservatives To Chilled Meat

The limitod sholf life is one of the main obstacles that hinder theused as experimontal materials, and the major spoilage bacteria of chilled micro organism and changes of micro organism during storage is alsoare compared and the composition of a sort of combined preservative isoptimized. Based on the small seale produetion, the effectiveness andmechanism of the combined preservative on the shelf-life of chilled meat is studied.1. The microflora isolated and identified from chilled pork are three genus of Pseudomonas, Enterbacteriaceace each, two genus of Lactic acid bacteria and the one genus of Brochothrix thermosphacta, Micrococcus, Staphylococcal bacteria and Yeast each. The minimum inhibition concentration for bacteria and the strength of the inhibit effect of chitosan, lysozyme, tea-polyphenol, garlic, propolis, Nisin, and the extraction of clove, cinnamon and rosemary are studied.2. Five factors quadratic general design is applied in the experiment and the optimized composition of a sort of combined preservative is :0. 5% chitosan + 10% (V/V) spice extraction + 0.2% propolis + 0.15% Nisin-lysozyme + 1. 0% tea-polyphenol. The spices used above are clove and cinnamon extraction. To get the best inhibit effect, the clove is extracted using organic solvent while the cinnamon was extracted by water. The optimized extraction condition are : 6% clove powder dissolved in 31.8% ethanol, and 70 C water-bath for 6h; 5.6% cinnamon powder dissolved in water and 70 C water-bath for 7h .3. The combined preservative has good stability and strong inhibition effect for bacteria, the initial number on the surface of chilled pork treated with it can be reduced by 1~3 logarithm unit, and at the end of storage, the value of TVB - N, TEARS, drop loss and bioamine are all lower than the goal requirement. For every 500g chilled pork, the increased cost because of the use of preservatives are 0. 42 yuan. The residue of lead , cadmium and arsenic in the preservative are lower than the detected level.4. If the pork is treated with the combined preservative and then packaged in CO-MAP, the growth of micro flora is greatly inhibited , the logarithm number of total micro flora is 3.11 at the end of the storage. This shows that there is significant sysiergetic effect between the MAP and the combined preservative.