Effect of protective cultures and packaging film permeability on shelf-life of sliced vacuum-packed cooked ham.

Cooked ham produced with Lactobacillus alimentarius and Staphylococcus xylosus as protective cultures, and control ham were sliced, vacuum-packed in pouches with oxygen transmission rates (OTR) of 360 and 77 cm(3)/m(2)/24 hr/atm, and stored at 4 °C in the dark. The addition of protective cultures increased (p < 0.05) lactic acid bacteria and micrococci and staphylococci counts in the meats. After cooking, the population of lactic acid bacteria was higher (p < 0.05) in hams produced with L. alimentarius than the other treatments. Protective cultures increased (p < 0.05) the shelf-life of cooked ham. The higher the OTR, the lower the shelf-life. Cooked ham with L. alimentarius was acceptable up to 28 days compared to control ham with a shelf-life of 3 weeks. Micrococci and staphylococci were inhibited in hams with L. alimentarius. Hams with S. xylosus had a better red colour than other treatments. Cooked hams with protective cultures had lower total aerobic bacteria, micrococci and staphylococci and Brochothrix thermosphacta counts than control hams which had higher populations of lactic acid bacteria and lower pseudomonads.