Thermal Inactivation/growth Model Of Staphylococcus Aureus In Pork

Staphylococcus aureus is a common food-bome pathogen.Meat,eggs,milk and other nutritious foods can be easily contaminated.The events of food poisoning which caused by Staphylococcus aureus enterotoxin accounted for 30 to 50 percent of the entire bacterial food poisoning events.Staphylococcus aureus is a necessary item in the world food detection.The application of rapid detection and microbial forecasting techniques,then timely discover and control Staphylococcus aureus,and predict the extent of food contamination,customize a manufacturing control measures reasonably is important for food production and consumption.In this experiment,we select the fresh longissimus muscle as the materials,use the manner of artificial contamination to inoculate the Staphylococcus aureus into the raw meat,through the experiment of storage and thermal dead under different temperatures,simulate the growth / inactivation situation of the Staphylococcus aureus which is in the pork,establish the first level of the growth / deactivation model and the second level of the thermal inactivation model,provide a scientific basis for the meat industry and theoretical basis for government departments to supervise,experiment contents and results are as follows :1. A set of fluorescence quantitative PCR detection method which had a simple operation and a rapid detection was established.Which all steps included the handling of samples,template DNA’s extraction and PCR assay could be completed within 2h,and could analyze the extent of sample contamination quickly.2.Quantitative PCR is not suitable for quantitative count of bacterial but qualitative detection.3.Establish the first level of the thermal inactivation model and the second level of the thermal inactivation model of the taphylococcus aureus which is based on the modified Gompertz model.At 55℃、75℃、85℃and 100℃,The most appropriate model is modified Gompertz model for the first level of the thermal inactivation mode,at 65℃ is Linear model.4.Established the first level of model for the survival of Staphylococcus aureus in the fersh pork at 4 ℃、10 ℃、15 ℃、20 ℃。At 4 ℃ the most appropriate modelis modified Gompertz model,at 15 ℃ is the Logistic model and at 20 ℃ is Gompertz model.Staphylococcus aureus shows negative growth at 4 ℃ linear growth at 10 ℃and typical S-shaped at 15 ℃ and 20 ℃.