The Research On The Exposure Of Enterobacter Sakazakii In Dairy Products

Enterobacter sakazakii is considered a great danger of opportunistic pathogen, expeciallly to immunocompromised preterm children and underweight babies can lead to irreeversible fatal injuries, the fatality rates have reached above50%. Enterobacter sakazakii is widely distributed environment and a variety of foods, it is basically confirmed that infant formula is the main source of Enterobacter sakazakii by numbers cases of neonatal infections. The main ways of Enterobacter sakazakii contaminated infant formula were:bring into by raw materials, sencondary contaminated after sterilization and by feeding.In this paper, milk powder, pasteurized milk, ultra high temperature sterilized milk and yogurt for the four main kinds of dairy to be study, we have researched the distribution of Enterobacter sakazakii in dairy production processing by statistics theory, and carried out the contamination of Enterobacter sakazakii in HACCP of dairy production, It is significance for the protection of milk safety and the guidance of production; we have researched the growth tendency and survival of Enterobacter sakazakii in dairy products during the shelf life by simulation test of Enterobacter sakazakii contaminated them, that have a great theoretical guiding significance in storage and scientific feeding of dairy. The results of this paper as follows.1. This thesis carried out the contamination of Enterobacter sakazakii in the HACCP of milk powder, and found that the Enterobacter sakazakii contamination rate in samples which after concentrate, spray drying, fluid bed and the final product respectively0%,9.38%,3.13%and7.81%.2. This thesis carried out the contamination of Enterobacter sakazakii in the HACCP of pasteurized milk, and found that the Enterobacter sakazakii contamination rate in samples of fresh milk, mixing materials, sample of after Pasteurization (88～94℃,300s) and the production after filling respectively41.94%,25.81%,0%and3.23%.3. This thesis carried out the contamination of Enterobacter sakazakii in the HACCP of ultra high temperature sterilized milk, and found that the Enterobacter sakazakii contamination rate in samples of fresh milk, mixing materials, sample of after Pasteurization (88～94℃,15s) and the production after filling respectively50.00%,40.00%,3.33%and0%.4. This thesis carried out the contamination of Enterobacter sakazakii in the HACCP of yogurt and found that the Enterobacter sakazakii contamination rate in samples of fresh milk, mixing materials, sample of after Pasteurization (88~94℃,300s) and the production after filling respectively23.33%,16.67%,3.33%and3.33%.5. Through the simulation test of Enterobacter sakazakii contaminate milk powder which stored at37℃, we found that content of Enterobacter sakazakii in samples of0,1,2and3month respectively2.3cfu/100g,0.92cfu/100g,0.36cfu/100g and less than0.3cfu/100g.6. Through the simulation test of Enterobacter sakazakii contaminate raw materials of pasteurized milk, we have confirmed that Pasteurization (88~94℃,300s) can completely kill all of the Enterobacter sakazakii in milk of different concentrations.7. Through the simulation test of Enterobacter sakazakii contaminate pasteurized milk which stored at4℃, we found that content of Enterobacter sakazakii in samples of0,3,5and7day respectively1.5cfu/100g、4.3cfu/100g、2.3cfu/100g and2.3cfu/100g.8. Through the simulation test of Enterobacter sakazakii contaminate yogurt which stored at4℃, we found that content of Enterobacter sakazakii in sample of0day is1.5cfu/100g, and the content of other samples as7,14,19and21day all less than0.3cfu/100g.