Shelf-Life Studies of Vacuum-Packaged Bacon Treated with Nisin

Abstract

The effect of various concentrations of nisin (250, 500 or 750 IU/g) combined with 50 ppm sodium nitrite on the shelf-life of vacuum-packaged bacon was evaluated. Control packages of bacon containing 50 and 150 ppm nitrite were included. Total numbers of lactic acid bacteria (LAB) (as measured on MRS medium) was used as a criterion for shelf-life. Treated bacon samples were stored at 30 and 5°C for 4 d or 6 wk, respectively. Bacon stored at 30°C showed a 1-d extension of shelf-life at nisin levels of 500 and 750 IU/g. Lowest counts at 6 wk were in bacon treated with 750 IU nisin and stored at 5°C. The LAB count was 1.5-log₁₀ CFU/g lower than the controls. A 1-wk extension of storage life was predicted for nisin-treated (750 IU) bacon.