Abstract: Different treating fluids of 006% nisin， 006% nisin+05% lactic acid， 005% chitosan， 05% chitosan+05% lactic acid， 05% chitosan+1% acetic acid solutions and the control were prepared and used to deal with chilled pork. Then， all the treated pork were stored at 4℃， and the total numbers of colony， total volatile basic nitrogen （TVB\|N）， TBARS value， pH value and a* value of treated pork with different storage periods were determined. The results showed that the chilled pork processed with nisin or chitosan cooperating with 05% lactic acid had good fresh\|keeping effect， as TVB\|N and lipid oxidation increased slower， the variation of pH value was small， and the a* value drop was delayed after treatment. In conclusion， the present study indicated that nisin or chitosan cooperating with lactic acid had potential application value in chilled pork storage.

Key words: nisin, chitosan, lactic acid, chilled pork