Application of Leuconostoc carnosum for biopreservation of cooked meat products

Aims: To optimize the practical use of the bacteriocin producing Leuconostoc carnosum 4010 in order to inhibit the growth of Listeria monocytogenes in sliced meat products. Methods and Results: Four different methods for biopreservation using the partially purified bacteriocin or the living culture of Leuc. carnosum 4010 were evaluated. The methods using the living protective culture added to the sliced gas packed meat product were more effective in preventing growth of L. monocytogenes than the use of the partially purified leucocins 4010 or bacteriocin produced during fermentation before heat treatment of the saveloy. The application method giving the highest reduction in L. monocytogenes used nozzles for sprinkling the protective culture on all surfaces of each slice of the meat product. In the control samples without the protective culture, L. monocytogenes grew to ca. 10(7) CFU g(-1), whereas for the application method using nozzles for distributing the protective culture, counts of L. monocytogenes never exceeded 10 CFU g(-1) during 4 weeks of storage at 10degreesC. Conclusions: The live cells of the bacteriocin producing Leuc. carnosum 4010 was the most efficient method as it inhibited the growth of L. monocytogenes in cooked, sliced and gas packed saveloy stored at 5 and 10degreesC for 4 weeks. Significance and Impact of the Study: The results indicate that biopreservation with lactic acid bacteria is a suitable alternative to chemical preservatives. An even distribution of the protective culture was found to be essential for the efficacy of the protective culture in pilot plant trials.