Corrlation Between Growth Of Enterococcus Feacalis And Accumulation Of Specific Biogenic Amines In Salted Duck During Storage

Salted duck as a low-temperature characteristics meat are widely spread amongconsumers. Because of its special processing the products are in incompletesterilization. So spoilage corrupted easily in transportation and storage period. Current,on the market basically has two kinds of packaging forms of salted duck appeared,vacuum packaging and palletizing. Along with the market demand，the shelf life ofsalted duck requirement also gradually improve. More effective preservationtechnologies are needed to solve the problem. Reaching salted duck corruptionmechanism provides theoretical foundation for new fresh-keeping technologydevelopment.This topic is about one individual plant mainly produce amine spoilageorganisms obtained from salted duck–Enterococcus feacails R-612-Z1. The researchfocus on growth characteristics and biogenic amine quantity of E. feacails R-612-Z1obtained from salted duck in different storage conditions. This study tends to confirmthe relationship between growth of E. feacails and related biogenic amine quantity.First of all, some related research content were summarized in the first chapterIn the second chapter, pallet packaging of salted duck is the material. Throughspray Enterococcus feacails R-612-Z1bacterial liquid to salted duck in palletpackaging and vacuum packaging conditions, monitoring its growth status andanalyzing the change of total bacterial colony at the same time. The study found that,pallet packaging than vacuum packaging condition,10℃than4℃,0℃more suitablefor Enterococcus feacails growth. The results showed that microbial quantity changetrend is not obvious at0℃. So0℃condition bacteriostatic effect is good.In the third chapter, microbial flora diversity had analyzed by the PCR-DGGEtechnique. Analysis found that microbes are different in different storage conditions. Itwas caused by the microbial aerobic conditions and different low temperatureresistant ability. There is the relationship between growth of bacterial and declineunder different conditions. There is no significant difference between packing types.Enterococcus feacails grew well in the various stages of storage. At the same time, ithas different inhibitions to Psychrobacter sp., P. cryohalolentis and Staphylococcussaprophyticus subsp.The fourth chapter, I detect the growth status of E. feacails under the condition of4℃and10℃by the traditional slab methods. I had found that it growth better at10℃ than at4℃. By using HPLC method only tyramine generation has been detected at4℃and10℃. Accumulation of tyramine is7.554mg/kg on10day at4℃while23.725mg/kg at10℃. This trend is the same to the trend of growth of Enterococcusfeacails at different temperature. RNA obtained from bacteria was extracted fromsample. And take cDNA reversed transcription from RNA as templates, amplificatethe tdc gene. The result showed that it has tdc gene. Description, Enterococcusfeacails produce tyramine while it has tdc gen expression at4℃and10℃.The fifth chapter study on Enterococcus feacails and its tyramine production invacuum packing salted duck storage at4℃and10℃. The results show that onlytyramine generation has been detected at4℃and10℃in vacuum. It has lowertyramine yield at4℃. Comparing with pallet packing condition, result show that traycondition is more suitable for Enterococcus feacails. There is Vacuum condition betterinhibition in growth of Enterococcus feacails while tyramine yield is lower.