| This paper consisted of two parts: the establishment of HACCP plan on the swine slaughter line was studied in part I , and the applications of chitosan and modified atmosphere packaging (MAP) on chilled pork in part 11 The microbial inspection of main procedures, facilities and workers on swine slaughter line was conducted and a large number of references were consulted. Five critical control points were determined, which were hog holding and inspection, stunning, bleeding, chilling and cutting. The completed HACCP plan was established in this paper. The preservative effects of chitosan and MAP on chilled pork were assessed through microbial inspection, pH and TVB-N value examination and sensory evaluation. The results showed that chitosan had a distinct preservative effect. The higher deacetylation rate, the better effect. æ…¬he pork treated with 1% chitosan with a 0.62% NH (dissolved in 2% acetic acid) solution could be preserved for 9 days. The higher concentration, the better effect too. The pork treated with 1.5% chitosan (dissolved in 1% acetic acid) solution had a shelf life of 6 days. 2.5% water-soluble chitosan was less effective than acid-soluble chitosan, which could extended shelf life to 5 days, but the pork had a better sensory quality. MAP could extend the shelf life of chilled pork markedly. The higher ratio of CO2 made a more effective preservation. MAP with the CO2 ratios of 33% and 25% could extend shelf life to 8 days and 7 days respectively. The higher ratio of 02 in MAP, the more fresh red color the pork had, but which benefited the growth of aerobic bacteria and leaded to the decrease of shelf life and the worsening of sensory quality. 50% ~2 ?25%C02 + 25%N2 was the best gas ratio used in this paper, which extended shelf life to 7 days and the pork had a good color. MAP had a better preservative effect and a better influence on sensory quality of chilled pork than chitosan. But the application of chitosan was much cheaper and easier than that of MAP.
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