Study Of Monitoring Bacteria In Foods And Radiation Keeping Fresh Technology In Suzhou City

Objective Through monitoring bacteria in foods in Suzhou city, situation of food contamination and their possible sources was realized, and then the food types which need to pay more attention were known.Through watching the effect of radiation keeping fresh technology which is used to radiate on dehydrated vegetables and their packing materials, find a method to keep food fresh.Method The datum was originated from the 2006 annual report of food bacteria monitoring. Analyze the report results by food types and seasoning. Bacteria test ,including number of total bacteria,coli forms and streptomycin, is accord with standard of the microbiological testing of food hygiene.Using the method of counting live bacterial, Radio resistant bacterial spores were isolated from the bacteria contaminating the dehydrated vegetables and were cultured and purified to prepare the spore suspension of 10⁶-10⁷ cfu/ml. The D₁₀ value of ⁶⁰Co irradiation for killing this spore and the original spore count in the suspension were measured .and according to form of SD=D₁₀Ig(N0/N), the irradiation dosages for maintaining the quality and fresh of dehydrated vegetables were determined.By acute toxicity and cell toxicity test verified safety of dehydrated vegetables with 25kGy high irradiation dosages.Result In 2055 sample food, 1954 samples and 1909 samples were qualified in the number of total bacteria and coli forms, respectively; the eligible rate was 95.09 percentage and 92.90 percentage. According to the analysis, the eligible rates of bread, milk, cold drink is higher than that of drink and candied fruit food; The eligible rate is higher in fist and fourth quarter than in second and third quarter; the eligible rate is higher in china store than in supermarket.With decrease in bacterial count to 1000 cfu/ml as the criterion, it was founded that the irradiation dosages for maintaining the quality and fresh of dehydrated carrot, scallion and chili powder were 5.19, 4.30 and 6.02 kGy respectively. It was showed that the vegetables by irradiation of 25 kGy have no acute toxicity and cell toxicity. Furthermore, the package kept sterile and no leakage was found.Conclusion Food hygiene is important to health. So food enterprise need to pay attention to foods' raw material, production, transportation, sale and store; Consumers need be aware of the knowledge of food safety and preventing unsafe food; Law enforcement departments should be serious to license of permitting food hygiene, and ban food enterprise and food shops which isn't accord with standard of food hygiene, and ensure food safety.Irradiation preservation technology is safe to dehydrated vegetables. It can keep foods' color, smell, taste and nutrition .Radiating with setting dose, the performance of packing material sealing and viscosity is kept well, so that the dehydrated vegetables can keep fresh.