Effects Of Starter Culture On The Quality Of Chinese Sausage And Preparation Of Dry Powder Starter Culture For Fermented Sausage

Fermented sausage, which is also known as raw sausage, is a kind of fermented meat which was made from pork or beef and its fat by adding sugar, salt and spices. The sausage is fermented by adding fermentation agent. It has the stable characteristic of microbial and typical flavor of the fermented sausage. In the process of making the traditional sausage, it is relying on the microorganisms in the environment and the raw meat without adding any special microorganisms. And there are a lot of problems such as long production cycle, unstable, susceptible to bacterial contamination. In order to obtain better products, usually by adding nitrate as color fixative and preservative. But it also has poisoning effect on people. To find a substitute for nitrite is very important.The subject is using Weissella hellenica1501(1501), which is isolated from Dong acid meat can product NO, together with Lactobacillus plantarumL.p)、Lactobacillus sakei(L.s)、Pediococcus pentosaceus(P.p) respectively. During the process there is no nitrite. And the control batch is added nitrite. Research the effect on the quality and flavor of the different sausage, make sure the most suitable combination of fermentation agent. Finally produce dry fermentation agent that can be directly used in the manufacture of the sausage. It makes the theoretical basis and experimental basis for the production of no nitrate sausage. The main results are as follows:1. Using1501alone and together with L.p、P.p and L.s without nitrite to manufacture fermented sausages. Research the effect on the microbial and physical and chemical characteristics of the different sausages. The sausages which were added sodium nitrite as a control. The study found that the lactic acid bacteria is the dominant bacteria in the entire process in both of the experimental group and control group. First increased and then a downward trend in the whole process. The total number of bacteria and lactic acid bacteria showed the same trend. The number of Enterobacterium showed a downward trend. No significant difference between the groups.Determination the physical and chemical indicators showed that pH in the experimental groups can be reduced rapidly. The moisture content decreased during ripening. The groups were no significant differences between them. The content of NPN、 PI、TVB-N、AV、POV、TBA in the groups increased during the ripening. L.p+1501and P.p+1501groups have better proteolysis than others. L.p+1501groups can prevent oxidation and decay much better. The content of residual nitrite in the experiment groups was significantly lower than the control group.Determination the color values show that:the L.p and1501groups had the best color.2. Determination the FAA, FFA and volatile compounds show that:the total content of FAA in L.p+1501groups is as many as the control groups and the content of EAA is the highest. The content of FFA in the groups were no significant difference. The content of UFA in L.p+1501groups is as many as the control groups. The mainly volatile flavor substances in the groups are alcohols、acids、esters、ketones and a small amount of hydrocarbons and furans. Sensory evaluation and comprehensive results show that the optimum cultures for fermented sausages production were L.p and1501.3. By centrifugal condition, the optimum centrifugal rotation and time of inspection was6000rpm/10min, the harvest rate was89.43%and91.00%for L.p and1501respectively.Using the single factor and orthogonal tests, the optimum compositions of freeze-dried protectant for L.p were:15%NFM、5%sucrose and7.5%L-sodium glutamate, the survival rate was98.23%. The optimum compositions of freeze-dried protectant for1501were:15%NFM、10%sucrose and2.5%L-sodium glutamate, the survival rate was98.69%. Freeze-dried powder performance results show that the optimum storage condition was-20℃, vacuum.4. Determination of physical and chemical indicators and the microbiological indicators of fermented sausage, and sensory evaluation show that:there were no difference between the liquid fermentation and dry fermented sausages groups. Comprehensive results show that the dry powder prepared by this experiment can be used as cultures for fermented sausage production.