Traceability of bacterial contamination during the processing of ready-to-eat dried soybean curd
The traditional microbiological culture method combined with high-throughput sequencing was used to analyze changes in the microbiological quantity and community composition with each step in the processing of ready-to-eat dried soybean curd,to determine the main contamination sources and microbial compositions during the process,and the spoilage bacteria were identified by 16S rDNA.The results showed that the total number of colo-nies of Hubei soybean(D1)raw materials for ready-to-eat dried soybean curd processing was as high as(3.2±0.1)×106 CFU/g,and the total number of colonies of rot,wire drawing spoilage samples(D18,D19)was as high as(4.4±0.4)×106 CFU/g and(2.6±0.2)×106 CFU/g,respectively,and the dominant bacteria were Bacillus.During the processing,Bacillus with high relative abundance was also detected in D20(semi-finished products after two times of baking and cooling),D9(semi-finished products before one marinating),D21(semi-finished products after one marinating)and D23(mixed paste after three marinating),and their relative abun-dances were 95.67%,70.64%,55.24%and 91.26%,respectively.The bacterial genus composition of D18 and D19 was similar to that of the pre-baking processing unit(D1,D3,D4)and the halogen processing unit(D5,D24,D23),that is,the spoilage bacteria were mainly derived from D1,D3,D4,D5,D24 and D23.The bacteria that caused the spoilage of ready-to-eat dried bean curd D18,D19 were B.methylotrophicus and B.tequilensis,respectively.
国家科技期刊平台
NSTL
万方数据
维普
