Microflora Change And Quality Analysis For Different Parts Of Yanbian Beef During Storage

In order to study the microflora and quality changes of different parts of Yanbian beef during storage, we used the traditional microbiological culture method and the PCR-DGGE technique to analyze the patterns in the microbial changes of Yanbian beef during storage. Indicators, such as pH, TVB-N, L*, a*, b*, etc., of silverside, shank, rib eye and rump were detected to provide a theoretical basis for extending the storage period of Yanbian beef and lay a foundation for establishing a quality system of top-grade Yanbian beef. The results showed that:1. Microflora analysis of different parts of Yanbian beef(1) With the extension of storage time, the counts of total colonies, lactic acid bacteria, Brochothrix thermosphacta, Pseudomonas and Enterobacter of different parts of Yanbian beef showed an upward trend. The counts of colonies in order of most to least were as follows:lactic acid bacteria, Pseudomonas, Enterobacter and Brochothrix thermosphacta.(2) The dominant microfloras of silverside in the early stage of storage were Lactobacillus sakei, Obesumbacterium proteus and Serratia proteamaculans. The counts of Lactobacillus sakei and Serratia proteamaculans showed an upward trend during storage, while Obesumbacterium proteus showed a downward trend. The dominant microfloras at the end of storage were Lactobacillus sakei, Obesumbacterium proteus and Serratia proteamaculans.(3) The dominant microfloras of shank in the early stage of storage were Lactobacillus sakei, Obesumbacterium proteus and Serratia proteamaculans. The counts of Lactobacillus sakei, Obesumbacterium proteus, Serratia and Serratia proteamaculans showed an upward trend during storage, and the dominant microfloras at the end of storage were Lactobacillus sakei, Serratia and Serratia proteamaculans.(4) The dominant microfloras of rib eye in the early stage of storage were Carnobacterium divergens and Lactobacillus sakei. The count of Lactobacillus sakei showed an upward trend, and the dominant microfloras at the end of storage were Carnobacterium divergens, Obesumbacterium proteus and Lactobacillus sakei.(5) The dominant microfloras of rump in the early stage of storage were Lactobacillus sakei and Obesumbacterium proteus. The counts of Lactobacillus sakei and Obesumbacterium proteus showed an upward trend during storage, and the dominant microfloras at the end of storage were Lactobacillus sakei and Obesumbacterium proteus.2. Quality analysis of different parts of Yanbian beef(1) The pH value of different parts of Yanbian beef decreased in the beginning and then increased during storage, and there were no differences between various parts in the same storage period (P>0.05). At the end of storage, the pH value of the rump was the highest, that of the rib eye followed, and that of the shank was the lowest.(2) The TVB-N value increased gradually during storage. Four parts of Yanbian beef were in the grade-one fresh state during the first 8 days, and began to corrupt and deteriorate gradually since the 22nd day. The shank had a lower TVB-N value than other parts at the end of storage (P<0.05).(3) The L* value increased in the beginning and then decreased, the a* value decreased gradually and the b* value increased gradually. The L* value of the rib eye was higher than those of other parts (P<0.05), the a* value of the shank was higher than those of other parts (P<0.05), and there was no significant difference between various parts in the b* value. In general, the colors of the shank and rib eye were better than those of the silverside and rump.(4) The sensory scoring showed that the quality of the shank was the best during storage, which was followed by those of the eye rib and the silverside, and that of the rump was the worst.