Inhibition of Listeria monocytogenes growth in cured ready-to-eat meat products by use of sodium benzoate and sodium diacetate.

The effect of sodium benzoate (0.08 to 0.25%) in combination with different concentrations of sodium diacetate (0.05 to 0.15%) and NaClI (0.8 to 2%) and different finished product moisture (55 to 75%) on the growth of Listeria monocytogenes in ready-to-eat meat products was evaluated using a central composite design over 18 weeks of storage at 4 degrees C. The effects of these factors on time to growth were analyzed using a time-to-failure regression method. All main effects were significant except product moisture, which was significant when included in the two- and three-way interactions (P < 0.05). Sodium benzoate was more effective (lengthening time to growth) when used with increasing concentrations of sodium diacetate and salt and decreasing finished product moisture. The model indicated that low-moisture products, e.g., bologna or wieners, could have time-to-growth values longer than 18 weeks if they were formulated with 0.1% sodium benzoate and 0.1% sodium diacetate. Time to growth in high-moisture products, e.g., ham or cured turkey breast at 75% moisture, was predicted to be much shorter for the same basic formulation (0.1% sodium benzoate and 0.1% sodium diacetate). Consequently, high-moisture ready-to-eat products in which sodium benzoate is limited to 0.1% (current standard for generally recognized as safe) may need additional ingredients to effectively inhibit growth of L. monocytogenes.

Modeling the growth of Listeria monocytogenes in cured ready-to-eat processed meat products by manipulation of sodium chloride, sodium diacetate, potassium lactate, and product moisture content.

A central composite second-order response surface design was employed to determine the influences of added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.2%), potassium lactate syrup (0.25 to 9.25%), and finished-product moisture (45.5 to 83.5%) on the predicted growth rate of Listeria monocytogenes in cured ready-to-eat (RTE) meat products. Increased amounts of both sodium diacetate (P < 0.11) and potassium lactate (P < 0.001) resulted in significant reductions in the growth rate constants of L monocytogenes. Increased finished-product moisture (P < 0.11) significantly increased growth rate constants. The nfluence of sodium chloride was not statistically significant. The second-order statistical factor for lactate was significant (P < 0.01), but all two-way interactions were not. In general, predicted growth rates exceeded actual growth rates obtained from inoculation studies of four cured RTE meat products (wieners, smoked-cooked ham, light bologna, and cotto salami). The final model will be useful to food technologists in determining formulations that will result in finished cured RTE meat products in which L. monocytogenes is not likely to grow.