Abstract: This study was designed to identify the microbial contamination source during slaughter by exploring the microbial diversity in the produce of chilled pork using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). In stage of slaughter, the contamination microorganism was sampled from original pork carcasses, chilled pork carcasses and segmental pork carcasses respectively, and also sampled from microbial contamination sources, such as chopping board, knife and water of washing knife respectively. In stage of storage, the contamination microorganism was sampled from pork longissi-mus muscles of 24 h postmortem pork carcasses, which were tray-packaged at 4 ℃ and 10 ℃ for 4 days respectively. The results indicated that the microbial diversities of contamination sources and sample from tray-packaged chilled pork decrease. The similarity index between microbial contamination sources (i.e. surface of knife and water of washing knife) and sample from tray-packaged chilled pork is up to 86%, as 95% between contamination microorganism from surface of knife and that from water of washing knife. The surface of knife and water of washing knife were the major microbial contamination source, and they have a strong cross-contaminated effect on microbial contamination during slaughter.

Key words: microbial contamination source, chilled pork, PCR-DGGE, microbial diversity