The efficacy of nisin, sorbic acid and monolaurin as preservatives in pasteurized cured meat products

Nisin, sorbic acid and two proprietary monolaurin products, Lauricidin R and Lauribic II, were studied. Determinations were made of their abilities to prevent Bacillus licheniformis growth in a model product of the cooked luncheon meat type. This product was made from a 3 : 1 mixture of lean beef and beef fat and contained 2.5% salt, 0.3% sodium tripolyphosphate and 200 ppm sodium nitrite. Various concentrations of the test preservatives were added to batches of the raw meat emulsion inoculated with 2 × 104 B. licheniformis spores g−1 before addition of various concentrations of the test preservatives. Emulsions were cooked to a pasteurization value of 36 (reference temperature 70°C), chilled overnight and then stored at 25°C. The minimum concentrations of the test preservatives necessary to prevent product spoilage occurring within 10 days during abusive storage were: nisin 500 international units g−1, sorbic acid 0.125%, Lauricidin 0.5% and Lauribic 0.25%. These concentrations were also effective in controlling the growth of the natural enterococcus spoilage microflora of this mildly cooked product.