Study On PCR Analysis Methods Of Source Of Spoilage Microorganism In Meat Product

Along with the rapid development of economy and the improvement ofpeople’s living standards, consumption of meat products has also been a growingtrend. When food security has becoming consumers′most concerned day-to-dayissues, the safety of meat products has been put on the agenda. For rich nutrient, meatproducts are easily susceptible to microbial contamination to corruption. In addition todegradation of sensory quality, corruption of meat products could result in loss ofnutritional value, once people eat, even producing food poisoning.More than that,putrid meat products can also have direct impact on the economic efficiency ofenterprises for its return. Therefor, corruption and microbial pollution of meat producthave become one of the important issues for restricting the development of meatindustry.About studying of spoilage microorganisms in meat products, bacteriaspecies, changed microflora, preservation, separation and identification weredomestic and international focus. Owing to unclear source of spoilagemicroorganisms, control measures were also discussed broadly, which were notspecific and not systematic enough. Moreover, a variety of sophisticated traceabilitytechnologies have not been applied into meat products to trace spoilagemicroorganism in meat products. So it is necessary to study on source of spoilagemicroorganism in spoilage meat products, and then enterprise can take targeted safetycontrol measures to ultimately achieve the purpose of reducing the rate of corruptionand improving product safety.This subject adopted the traditional microbe methods to isolate and purify thespoilage microorganisms in meat products, after identification of the spoilage bacteria,strain-specific primers was designed. Then specificity, sensitivity and reproducibilityof the method were found based on PCR method, to analysis the reason of meatproducts corruption. Afterwards, selecting spoilage products, spoilage bacteria weretraced in its raw materials and at its production lines, to determine the source and possible pollution pathway. Combining traditional microbiological methods in theapplication, positive interference of dead bacteria were remove.Research results showed that:(1) PCR analysis method of source of spoilagemicroorganism in meat products was studied. Corn hot dog sausage, spicy crispysausage and sauce duck flavor sausage were selected to be as spoilage products, andfive strains were isolated and identified to be as representative strains that wereBacillus subtilis, Bacillus licheniformis, Staphylococcus epidermidis, Lactobacillusbrevis and Escherichia coli. The primer specificity of five spoilage strains were all100%; sensitivity results were69CFU/100g,10.4CFU/100g,1.57CFU/100g,81CFU/100g and1.06CFU/100g separately, so the sensitivity all were﹙1～100﹚CFU/100g. That is, it can be detected when100g sample contains﹙1～100﹚CFUof spoilage bacteria; the reproducibility test results also showed that thereproducibility of the method was well.(2) PCR analysis method was verified, theresults showed that the PCR analysis method can trace the target spoilage organismsrapidly and accurately.When method was verified, Shineway pork knuckle and bakedgarlic sausage were selected to be as spoilage products, and one strain, Bacillussubtilis, was isolated and identified from the two spoilage products. For Shinewaypork knuckle, Bacillus subtilis was detected in its white sugar and soy protein ofingredients and workers′clothes. For baked garlic sausage, Bacillus subtilis existed inits starch, soybean protein and white sugar using for production, sausage stuffer,cooked product, scissors in cooked area and product with secondary sterilization onits production line, and live Bacillus subtilis was also detected in cooked product,vacuum packing product and product with secondary sterilization of baked garlicsausage.