Strain Optimization And Quality Change During The Process Of Fermented Cantonese Sausage

Fermented sausage is that meat and animal fat mixed with sugar, salt, starter cultures and spice and so on,then pour into the casing. It has a stable microbial properties and typically fermented flavor through microbial fermentation. In this paper, Lactobacillus plant, Pediococcus pentosaceus and Debaryomyces hansenii were used as starter cultures for Cantonese-style sausage making and the impacts of different starter culture combinations on quality of Cantonese-style sausage were investigated. Then the optimal starter culture combination and fermentation time were optimized. Then various physical and chemical indicators of lipid oxidation and their correlation, and flavor ingredients of fermented sausage were further studied using the optimal starter culture combination. It could provide data for understanding the flavor formation mechanism, the traditional process improvement and parameter optimization of Cantonese-style fermented sausage.1. Three kinds of bacteria, i.e. Pediococcus pentosaceus, Declubhouseyomyces hansenii, Lactobacillus plantarum were used to ferment Cantonese-style sausage, their optimal ratio was determined by orthogonal experiment. The results showed that the order of three kinds of bacteria affecting Cantonese sausage fermentation quality was as follows: P. pentosaceus > D. hansenii > L. plantarum. The physicochemical property of Cantonese sausages was best when L. plantarum, P. pentosaceus and D. hansenii(10:5:5,v/v/v) were selected as starter cultures with inoculum size 106 cfu/g.2. The effects of different fermentation time(0 h, 8 h, 16 h, 24 h, 32 h and 40 h) on Cantonese sausages quality were investigated using the optimized starter cultures of L. plantarum, P. pentosaceus and D. hansenii. The result showed that fermentation time could obviously affect the quality of Cantonese sausages, and the best quality was achieved when the fermentation time was 24 h.3. The acid value(AV)and peroxide value(POV), triobarbituric acid value(TBA), carbonyl value, total acidity, moisture content, free fatty acid and fat during the process of fermented Cantonese sausage were determined and their correlations were analyzed. The results shown that the AV, POV, TBA and carbonyl value were increasing during the processing of Cantonese Sausages; the saturated fatty acids and total content of free fatty acids were increasing during the whole baking process while the percentage of unsaturated fatty acids reduce after baking for 8 h. It was concluded that a continuous oxidation and hydrolysis of fat was going on during the manufacturing process of fermented Cantonese sausage. It was found that there was a positive correlation among acid value, peroxide value, TAB, carbonyl value, total acid, moisture, and fat content. There were significant positive correlation between POV and total acidity. It indicated that the trend between rancidity degree and the oxidation degree of fat were consistent.4. Volatile flavor compounds of fermented Cantonese-style sausage were analysed by SPME-GC-MS. Thirty-five volatile flavor compounds were separated and identified, mainly consisting of ethanol and ethyl compounds. The dominant factors forming Cantonese-style sausage flavor were adding of relatively large amount of liquor, lipid degradation and oxidation and fermentation of microorganisms. In addition, maillard reaction also play a role in the formation of Cantonese-style sausage flavor.