Abstract:The synergistic effect on the sterilization and color protection of chilled pork was studied using modified atmosphere packaging containing 2% carbon monoxide（CO）and ultrahigh pressure. The results showed that with the increase of pressure，the value of L*increased，while that of a*gradually decreased and that of b*first decreased，then increased at 0-400 MPa. In addition，a pressure above 200 MPa made the meat white.Thus，treatment with single ultrahigh pressure brings a decline in color，with higher pressure associated with more serious change in color，and pressure above 300 MPa made the meat color unacceptable. However，the synergistic effect of CO could contribute to the restoration of color by improving the value of a*.CO has a bacteriostatic effect，and the synergistic effect of modified atmosphere packaging containing 2% CO combined with ultrahigh pressure could extend the shelf life of chilled meat.In general，this combination could effectively sterilize the meat while ensuring color quality，as long as ultrahigh pressure was below 300 MPa，and the synergistic effect was more significant when ultrahigh pressure was sequentially applied after packaging with modified atmosphere packaging containing 2%CO.