| Poultry products is obtained by the use of physical or chemical methods, combined with suitable excipients and additives. Chicken feet with pickled peppers is one of the most important poultry products, it is popular by the consumer because of its low fat content, high protein content, the rich collagen and unique flavor. But due to the high moisture content, the high temperature sterilization can not be complete, so chicken feet is easy to spoilage during the storage, transport and so on. The bacterial changes regulation in the chicken feet with pickled peppers was investigated by using PCR-RFLP, then we can find the main advantage of bacteria in chicken feet with pickled peppers spoilage. By analyzing the microbial indicators, sensory indicators, physical and chemical indicators, then the characteristics of quality changes of chicken feet with pickled peppers during storage were determined. The Plasmid pBBRGFP-45with green fluorescent protein gene was tranformed into the dominant spoilage bacteria PJ-9by tri-parents conjugation, so that we got the research materials to trace the Spoilage bacteria and screen antagonistic bacteria of spoilage bacteria.During the storage at20℃, a large number of micro-organisms began to grow, the total number of colonies and TVB-N values were on the rise, the total number of colonies reached7.81×106cfu/g, the TVB-N value reached25.76mg/100g on the sixth day, close to the state provisions of spoilage value. The chicken feet spoilage occured on the sixth day, the color of the feet became yellow, produced rancid smell, texture became soft, surface was sticky, the soup was cloudy, and could not be eating.The results of16S rDNA flora analysis of Chicken feet with pickled peppers showed that community structure consist of Pseudomonas sp., Weissella sp., Lactococcus sp., Lactobacillus sp., Enterococcus sp., Pediococcus sp., Staphylococcus sp., Bacillus sp., Corynebacterium sp., Kocuria sp., Moraxella sp..Separation of26single colonies single colonies obtained from chicken feet with pickled peppers in storage for first days, by dint of the PCR-RFLP in analyzing16S rDNA, we found5OUTs, the Pseudomonas had a total of12clones, reached46.2%, Weissella sp. is second only to Pseudomonas sp., accounted for30.7%. Staphylococcus sp., Lactobacillus sp. and Enterococcus sp. had a lower proportion. After6days, the proportion of Pseudomonas sp. declined, accounting for23.3%. The proportion of Weissella sp. increased, approaching50%. In addition, few Corynebacterium sp., Moraxella sp. and Kocuria sp. were found. Pseudomonas sp. and Weissella sp. occupied a large proportion in the whole storage period, became dominant spoilage bacteria of the chicken feet with pickled peppers.Named one of the Pseudomonas PJ-9, after verification and observation under the fluorescence microscope, we can prove that the green fluorescent protein gene was successfully tranformed into the receptor strain, and could express very well and stably exist. The growth curve of the labeled strain PJ-9gfp and the original strain PJ-9was consistent. By studying the culture conditions and growth characteristics of the two strains, we got that the cultured conditions of the two strains were basically the same, there was no difference. The two kinds of strains grew well at the pH of6.0-8.0, growth was inhibited when the pH value was lower than5or higher than9. The most suitable pH for the growth was7. The most suitable temperature for the growth was30℃. It was very suitable for the growth of PJ-9gfp and PJ-9. The optimum carbon source is glucose when the medium volume was50ml. the optimum nitrogen source was yeast extract, they were easier to use organic nitrogen source beef extract and peptone, but poor utilization of inorganic nitrogen source. |
PDF Full Text Request