Study On Technological Optimization And Physical And Chemical Characteristics Of Mixed Fermentation Sausage

Lactobacillus plantarum b2 and Saprophylaxis staphylococcus sw50 were selected as mixed cultures in the early stage of the laboratory.Through study on characteristics of two strains of bacteria growth found:There was no antagonistic effect between Lactobacillus plantarum b2 and Staphylococcus saprophytes sw50,Lactobacillus plantarum b2 have stronger antibacterial ability,rapid growth,achieve stability after 10 h,and produce acid rapidly,can grow well in the range of 24-40?,the tolerance to NaCl was up to 5%and NaNO₂ was up to 200 mg/kg;Saprophytic staphylococcus sw50 reached a plateau at 8 h,with high temperature,its tolerance to NaCl and NaNO₂ was higher than b2.The results showed that both strains met the requirements of meat starter.Single factor and response surface tests were used to optimize the optimum technological conditions of fermented sausage.The optimal fermentation technology was obtained:fermentation temperature:35?,inoculation ratio:1:3,fermentation time:24 h.Under these conditions,fermented sausage has higher sensory quality.The changes of physicochemical quality and microbial index of fermented sausage ripening were studied when the combined ratio was Lactobacillus plantarum b2:Staphylococcus saprophytes sw50=1:1?group B?and Lactobacillus plantarum b2:Staphylococcus saprophytes sw50=1:3?group C?,and were compared with commercial starter VBM-60?group A?and blank group?CK group?.The experimental results showed that after fermentation?24 h?,the total number of Lactic acid bacteria and Staphylococcus in the experimental group was significantly higher than that in the CK group?P<0.05?,the pH values were all lower than 5.3,significantly lower than CK group?P<0.05?,TBA content did not increase significantly during the fermentation process.After fermentation,the values of group A,B and C were 0.226 mg/100 g,0.123 mg/100 g and 0.133 mg/100 g,the residual amount of nitrite was<30mg/kg,far lower than the national standard.Through the analysis of the bacterial community structure in group C sausage at different fermentation stages,it was found that the bacterial diversity in sausage was rich,Firmicutes are dominant,accounting for87.45%⁹7.40%of the total bacterial community,the dominant bacteria are Lactobacillus and Staphylococcus.The change of flavor substances in fermented sausage of group C at different fermentation stages was determined by gas phase-ion migration chromatography?GC-IMS?.The volatile substances released by sausage increased gradually with the prolonging of fermentation time,mainly aldehydes,esters,alcohols and ketones.The quality of four groups of fermented sausage was analyzed.The results showed that Lactobacillus plantarum b2:Saprophytic staphylococcus sw50=1:3?group C?fermented sausage had better quality,could improve color and texture characteristics,and significantly improved flavor.According to the high-throughput sequencing technology,the fermented sausage has a rich diversity of bacteria,with a total of 11 phylum.The dominant bacteria are Firmicutes and Proteobacteria.Among the 20 genera,the dominant bacteria were Staphylococcus,Lactobacillus and Lactococcus.At the same time,the composition and quantity of microbial community in fermented sausage were changed by the addition of mixed bacteria starter.GC-IMS technology was used to detect a total of 33 volatile substances,mainly esters,aldehydes,alcohols and ketones,and the types of the experimental group were significantly more than the blank group.This article through to the physical and chemical properties of fermented sausage change research showed that the inoculation of mixed bacteria starter cultures could increase the number of Lactic acid bacteria,reduce the pH value,inhibit fat oxidation and promote cut down the content of nitrite and improve the color,quantity and change the composition of the microbial flora,endowed with unique flavor of fermented sausage,in order to promote the quality of fermented sausage and security provides scientific theoretical basis and the reference value.