Microorganism During Pasteurized Milk Corruption Process And Spoilage Microorganism Origin

The milk pasteurized method was invented by French scientist Pasteur in 1865.With the raw milk as raw material,the pasteurized milk was used as raw material to heat 10-15 seconds under the 75-90 o C condition to kill the harmful microorganisms,and to keep the nutrition and good taste of the fresh milk to the maximum.In the market of developed countries,pasteurized milk has always been the mainstream product of liquid milk.The proportion of drinking PAP milk is more than 85%,and the shelf life of pasteurized milk is 2-7 days.Therefore,the transportation and preservation of pasteurized milk need a complete cold chain logistics system to ensure its nutritional value and fresh taste,which greatly restricts the pasteurized milk.The promotion in the whole country,especially in less developed rural areas is difficult.The development of dairy industry in Yunnan has a long history and has great potential for development.But pasteurized milk is only about 10% in the consumption of dairy products in Yunnan Province,which is lower than the average level of 20% in China.Therefore,it has become the breakthrough of competition in Yunnan's dairy enterprises.However,pasteurization cannot completely kill the raw milk and the microorganism in the process of production.On the one hand,they destroy the nutritional components of raw milk by growth and reproduction,and cause the flavour of milk,and even the food safety problems caused by food borne pathogens.Food borne pathogens are the primary cause and greatest threat to the safety of milk products.When dairy products are contaminated by foodborne pathogens or are not thoroughly germicidal during the process of packaging and transportation,they will grow and propagate rapidly with the aid of special nutrients in dairy products,resulting in the corruption and deterioration of dairy products.This will not only shorten the shelf life of dairy products,but also reduce the quality of dairy products.In severe cases,it will cause food poisoning.Microbes in pasteurized milk are different in the production environment and processing technology of pasteurized milk.The microbial changes in the process of corruption are also different.This study simulated the natural decay process of PAP milk in the laboratory room temperature(25o C),the sensory evaluation in the recording process,and the use of high pass based on Illumina Miseq.The method of quantitative sequencing was used to study the variation of bacterial community results during the process of corruption,and the main causes of corruption were Novosphingobium,Acinetobacter and Enterococcus.By simulating the corruption process of pasteurized milk,the main microorganisms that cause corruption have caused the complex and diverse sources of microorganism in the PAP milk corruption,the pollution of water,soil and air and other agricultural environmental resources,as well as the cleanliness of the dairy cattle and the breasts hygiene and so on.By sampling the collecting environment of raw milk and the growth environment of dairy cows and sequencing the high flux,we found that the main pathogenic microbes in the environment were Achromobacter baumannii,Fusobacteria bacterium clone,Escherichia coli and Acinetobacter lwoffii.In the feeding stage of dairy cattle,we should pay attention to the hygienic conditions of dairy cattle and protect the breasts of lactating cows,enhance the sterilizing intensity of milk production environment,thus improve the quality of raw milk,and provide a theoretical basis for improving the quality of fresh milk and prolonging shelf life.