Study On Processing And Shelf Life Of Prepared Duck Products

For the impact of high-temperature sterilization on meat products, this paper studies the antibacterial action of Nisin and potassium sorbate compound in cooked duck meat products. It can resist bacterial spores and expand antibacterial spectrum in prepared duck by adding Nisin, thus reducing sterilization intensity to maintain the flavor components and organizational characteristics of duck. I also research different anti- oxidants in duck which can prevent oxidative rancidity of fat. In addition, we also studied the impacts of absorbents and vacuum microwave drying on the quality of Monochoria. These studies provide us a theoretical basis and guidance for the production.Because Nisin is heat-sensitive, this paper studied the effect of Nisin concentration, added time, potassium sorbate concentration intensity of sterilization on microbiology, according these researches, I optimized the scheme by orthogonal experiment, sterilization conditions were: 110℃for 25min, concentration of Nisin was 0.5g/kg, potassium sorbate 0.05g/kg. Small vacuum-packaged monochoria would get soft and rotten after high temperature sterilization. This paper researched precipitation reagent combined with vacuum microwave drying technology to improve product quality such as texture and appearance. When the concentration of lactose, maltose, maltodextrin, sodium lactate was 5%, 1%, 1%, 3%, liquid ratio 1:15 impregnated for 1h, then the water activity of semi Monochoria was 0.950±0.04. After vacuum microwave drying 13min, water activity and moisture content of balance Monochoria was 0.73,37.6%.Secondly, fat covers up about 7.5% in duck meat most of which is unsaturated fatty acids. Therefore, in order to prevent fat oxidation during the storage time, this paper studied antioxidant effect of TBHQ, BHA, BHT, vitamin E. Based on this, carried on complex experiments to study the impact of complex antioxidants on acid value and peroxide value. The result showed us the optimum scheme is: TBHQ to BHA 3:1, the total is 0.2g/kg. By texture analyzer and HS-SPME-GC-MS, this paper studied effects of two sterilization conditions on prepared duck. From the results we can conclude that products by flexible sterilization is superior to conventional sterilization in texture (hardness, springiness, cohesiveness, chewiness)and types of volatile flavor compounds and also total content.Finally , in order to make sure the shelf life, this paper studied changes of colony count, coliforms, acid value, peroxide value, pH in production at room temperature which processed by experimentally determined parameters. This paper established mathematical models according to correlation coefficient (R2) and residual sum of squares (RSS) with date measured during storage period to study the growth pattern of microorganisms in duck meat, and also established first order chemical reaction kinetic equation which can reflect fat oxidation of duck during storage. This first order chemical reaction kinetic equation was established according to peroxide value. The results showed that: the most important indicator which determines product shelf life is microbial; flexible thermal sterilization can keep products available for 7.5-8 months, it has achieved the request of enterprise for 6 months.