| Iced chicken meat refers to the meat strictly under the relative standards of inspection and quarantine,freeze the poultry meat once butchered for holding temperature at 0-4 ?,and follow-up meat processing,preservation and transportation and on sale.There are obvious advantages in taste,freshness,nutrient content.And eaten quickly and conveniently without thawing.So it has a broad prospects.At the moment,the fall behind and limited technologies about iced chicken meat slaughtering,cutting and transportation has caused putrid deterioration from microbial contamination and differing impacts on safety.So it's crucial for product safety and extend lead time that prevent and control the microbial contamination,take the necessary measures keeping pollution and secondary pollution,promote transformation and application of the research results on preservation technology to the market,to ensure product safety.This paper regarding iced chicken meat carried out volatile base nitrogen(TVB-N)value,PH value,the sensory index,total number of colonies on the iced chicken meat frozen in 4 ?Celsius,study the variations about freshness with the change of storage time.Combining the traditional culture with molecular biology technology,analyzing the change of bacterial flora taken place iced chicken meat in 4 ?Celsius for searching dominant bacteria leading to putrid deterioration.And effects of several keeping freshness chemical bacteriostatic agent to iced chicken meat has been studied infer to the most appropriate antimicrobial agents.The main content is as follows:The test of volatile base nitrogen(TVB-N)value,PH value,the sensory index,total number of colonies are proceeded with the iced chicken meat frozen in 4 once ?collected for 0,2,4,6,8 days.The standard of iced chicken meat: total number of colonies: 106 CFU/g and TVB-N value: 15 mg/100g(industry standard: 25 mg /100 g),PH: 6.7 or less.Comes to the result that the delivery time is 4days through the experiment.Picking representative colony and different form colonies,determine the advantage bacterium through separation,DNA extraction,PCR amplification,gel electrophoresis and sequencing analysis: enterobacteriaceae,pseudomonas bacteria,lactic acid bacteria,Brochothrix thermosphacta,staphylococcus.Datas in colony count experiment on 0-4days by selective medium for each kind of bacteria after determine putrid predominant bacteria.The sequence by number of initial microbacteria in experiment is as follows: pseudomorunas > enterobacteriaceae > Brochothrix thermosphacta > lactic acid bacteria > staphylococcus.Yet at the tipping point of corrupt: enterobacteriaceae > pseudomonas > lactic acid bacteria > Brochothrix thermosphacta > staphylococcus.Five kind of Chemical bacteriostatic agent: lactic acid,acidified sodium chlorite and sodium phosphate,acetic acid,citric acid sodium were used for testing the effect to bacteriostasis.(1)Determine the through the total number of colonies in iced chicken meat frozen and the change of TVB-N value by soaking the meat sample.(2)Oxford cup sticked in Semisolid nutrient agar experiment was used for determine the bacteriostatic effect of the bacteriostatic agent.Chemical bacteriostatic agents were added to the oxford cup,cultured at 37 incubator for 48 h.the bacteriostatic circle ?respect the effect.All the physics and chemistry index shows that glacial acetic acid,lactic acid,acidified sodium chlorite and sodium citrate and sodium phosphate have a positive freshness effect,especially glacial acetic acid,lactic acid,these five bacteriostatic agent can deterrent bacteria' growth and extend the delivery time,improve the nutritional value of products and extend the time for freshness. |
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