Effect Of Slaughter Process And Storage Time On Microbial Diversity Of Beef

Chilled beef, as a representative way of production and consumption, will be the new type of conformation in the fresh beef consumption in the future. However, the growth of contaminated microorganism resulting in the spoilage product has been become the great barrier for plants during slaughter, transportation and preservation, and the meat safety was paid more attention by consumers. Using PCR-DGGE fingerprinting technology and T-RFLP fingerprinting technology as the tool, the microbial diversity during the slaughter and storage was evalued. Analysis of microbial community structure of beef during slaughter and storage,we found out the microflora composition and diversity; the similarity of microbial diversity between slaughter and preservation; we obtained these dominant strains which do the main contribution to the spoilage of chilled beef. The aim was to provide a basic theory and technique for the inspection of quality and safety during the slaughter, transportation and preservation of chilled beef. The results were as follows:1) The microbial diversity index from high to low was, the microbial diversity in abdominal cavity after evisceration equaled to the microbial diversity after splitting, spray, hide removal, the microbial diversity on surface after evisceration,sample stored for 4 days, sample stored for 6 days, sample stored for 2 days, sample stored for 9 days, sample stored for 12 days.2) The microbial diversity of slaughter was higher than the microbial diversity during the storage of chilled beef. The microbial which was detected during the slaughter excepting in the different storage time, included the microbial of the restriction fragment length of 99bp(Bacteroides splanchnicus),199bp(Fusobacterium,str.),209bp(Leuconostoc),453bp(Aeromonas),476bp(Microbacterium),83bp(Eubacteriumtimidum.),586bp(Carnobac-terium) and 675bp(Eubacterium combesii). The microbial diversity was increased during getting away the visceral but decreased by spraying. The microbial diversity rised and then dropped during the storage in different time.3) Acording to the DGGE and T-RFLP diagiam, the bacterial flora diversity of 2d sample and 4d sample had little change and they were the same category, however, the 6d sample and the 9d sample were two different categorys. This mained that the microbial flora: changed between the 4d and 6d during the storage.4) The dominant strains which do the main contribution to the spoilage of chilled beef were mostly coming from the surface, such as the exposed organs of cow and the environment. Another part was coming from enteron, deleave, transportation and so on.5) The dominant strains which do the main contribution to the spoilage of chilled beef detected both by DGGE and T-RFLP fingerprinting technology includeing: Acinetobacter, Pseudomona, Lactobacillus and Carnobacterium.