Study On The Correlation Between Microbial Community Structure Changing And Histamine Production Of Sichuan-flavor Sausage During Fermentation

Sichuan-flavor sausage was a traditional fermented food in China,it was popular with consumers because of its unique taste,simple production process and long storage period.However,under the traditional process,some food safety problems had been found in Sichuan-flavor sausages,such as excessive nitrite residues,biogenic amines,and many spoilage pathogens in spontaneous sausage.It was a close correlation between the generation of harmful substances and microorganisms of in fermentation environment.In this project,histamine of biogenic amines was taken as an example to study bacterial and fungal community diversity and succession during spontaneous fermentation of Sichuan-flavor sausage,and studied on histamine change in Sichuan-flavor sausage fermentation.Establishing of a PLSR correlation model between bacterial and fungal community and histamine production to anchor amine-producing microorganisms during fermentation of Sichuan-flavor sausage.The main results were showed:1.Studied on the bacterial community diversity and succession during spontaneous fermentation of Sichuan-flavor sausage: it was found that the diversity and abundance of bacterial community changed greatly during the fermentation of Sichuan-flavor sausage,and there were 64 OTUs in the entire fermentation process.A total of 18 phylums were detected,and the main phylum were Firmicutes and Proteobacteria.At the genus level,Lactobacillus spp.was found to be the dominant genus,the proportion of Lactobacillus spp.increased and then decreased in the bacterial community followed the fermentation time.On the 20 th day of fermentation,Lactobacillus spp.reached a maximum of 63.14% in the bacterial community,and inhibited the growth of other spoilage pathogens bacteria in the fermentation environment.2.Studied on the fungal community diversity and succession during spontaneous fermentation of Sichuan-flavor sausage: it was found that the diversity and abundance of fungal community changed little during 20 days before fermentation of Sichuan-flavor sausage,and there were 329 OTUs in the entire fermentation process.A total of 11 phylums were detected,and the main phylum was unclassed phylum.Among the classified phylums,the main phylums were Bangiales and Ascomycota.At the genus level,the main genus were Debaryomyces spp.,Saccharomyces spp.and Amylomyces spp..3.During the spontaneous fermentation of Sichuan-flavor sausage,both the pH and water activity of Sichuan-flavor sausages decrease with fermentation time,acid value of Sichuan-flavor sausage increases with fermentation time.Residual nitrite in Sichuan-flavor sausage decreases with fermentation time,residual nitrite in Sichuan-flavor sausage was27.81 mg/kg at the end of fermentation.The histamine content increased and then decreased followed the fermentation time in Sichuan-flavor sausage,the histamine content in Sichuan-flavor sausage was 1.31 mg/kg at end of fermentation.4.PLSR was used to analyze the correlation between bacterial and fungal community composition and histamine production during Sichuan-flavor sausage fermentation.It was found that on the 0th day of fermentation.The most microorganisms related to histamine production in the raw and auxiliary materials,there were mainly Weissella spp.,Psychrobacter spp.,Enterococcus spp.,Kurthia spp.,Paenibacillus spp.,Lysinibacillus spp.,Lactococcus spp.,Bosea spp.,Debaryomyces spp.and Lodderomyces spp.et al.In this paper,the histamine production law and the community diversity and succession of bacteria and fungi during the spontaneous fermentation of Sichuan-flavor sausage were studied,and the correlation analysis was performed.It was aimed to find the histamine-related community during the spontaneous fermentation of Sichuan-flavor sausages,provided theoretical basis for improving traditional sausage craft,promoted the development of the industry,and protected the rights and interests of consumers.