Abstract: The aerobic plate count(APC) and the diversity of microbial communities on pork carcasses surface of skinning and scalding processes were studied by using denaturing gradient gel electrophoresis and traditional culture-dependent and the changes of APC and coliform (Coli) after lactic acid sprayed were investigated in this paper. The result showed that the microbial species of scalded process after scalding are more than skinning process after being skinned and the level of original contaminated is higher too. The microbial contamination of carcasses surface was mostly due to the initial stages of slaughter. In addition, after spraying 3.5% lactic acid, the APC and Coli of skinning process was significantly decreased to 2.95logCFU/cm2, but it has no effect on scalding process at the end of the slaughter line, therefore different slaughter process should have different control points and HACCP system.

Key words: pork carcass surface, unskinning, scalded, DGGE, APC, diversity