Study On The Deifciency Mechanism Of The Staphylococcus Aureus Food Poisoning In Fermented Beef

Recent researches both at home and abroad showed that the fermented beef exist the phenomenathat the food poisoning missing mechanism of Staphylococcus aureus in Fermented Beef. In the thesis,the mechanism of this phenomenon has been discussed. This made the theoretical study ofstaphylococcal food poisoning prevention richer. This study has great practical and theoreticalsignificance to restrain the food poisoning of Staphylococcus aureus.The research discussed the changing regularity of Staphylococcus aureus and its enterotoxin in thetraditional processing and storage stage of the fermented beef. One group inoculated Staphylococcusaureus and mixed starter cultures (including L. plantarum and P. pentosaceus), compared with anothergroup (uninoculated starter culture and natural growth fermented beef). The main factors affectingStaphylococcus aureus and its enterotoxin have been analyzed. We also discussed the effect of thestarter cultures (including L. plantarum and P. pentosaceus) and some other hurdle factors toStaphylococcus aureus and its enterotoxin. The thesis preliminary study the mechanism of how L.plantarum and P. pentosaceus restrain Staphylococcus aureus. The research results show as follow,(1) In the processing of the fermented beef, In the natural fermented beef there is noStaphylococcus aureus and Staphylococcus enterotoxin; In fermented beef inoculated starter culture andStaphylococcus aureus increased progressively and then decreased rapidly, Staphylococcus enterotoxinis negative. Staphylococcus aureus and its enterotoxin in fermented beef inoculated Staphylococcusaureus is Significantly higher than the fermented beef inoculated starter culture. The starter culture of L.plantarum and P. pentosaceus has high antibacterial effects on Staphylococcus aureus.(2) In the storage stage, in the natural fermented beef there is no Staphylococcus aureus andStaphylococcus enterotoxin is negative. In fermented beef inoculated Staphylococcus aureus, theamount of Staphylococcus aureus and Staphylococcus enterotoxin presented to decreased. In fermentedbeef inoculated starter culture and Staphylococcus aureus, the amount of Staphylococcus aureusdecreased rapidly.(3) In culture condition, low temperature has apparent inhibition to Staphylococcus aureus and itsenterotoxin, but the content of salt, pH value have not obvious effect to the growth of Staphylococcusaureus and its enterotoxin.(4) Pediococcus pentosaceus and lactobacillus plantarum have apparent inhibition toStaphylococcus aureus, and lactobacillus plantarum has higher inhibition. The anti-microbial activitiessubstance in the metabolite of Pediococcus pentosaceus and lactobacillus plantarum are Organic acids,bacteriocins and hydrogen peroxide. They have good thermal stability. The anti-microbial activitiessubstance of Pediococcus pentosaceus are not sensitive to trypsinase and proteinase K, but sensitiveto pepsin. The anti-microbial activities substance of Pediococcus pentosaceus are not sensitive totrypsinase, proteinase K and pepsin.