Minimum Nitrite Levels Required to Control Listeria monocytogenes on Ready-to-Eat Poultry Products Manufactured with Lactate and Diacetate

This project identified the minimum level of sodium nitrite required to suppress growth of L. monocytogenes in ready-to-eat meat and poultry products manufactured with lactate and diacetate.

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Objectives

The objective of this project was to compare the antilisterial effect of various nitrite levels in RTE sliced turkey product manufactured with lactate and diacetate.  Specific objectives were to determine the anti-Listerial effect of various levels of nitrite, lactate and diacetate in a single, model meat system using a turkey bologna-type product and to determine the effect of various antimicrobial combinations including nitrite on cooked color in turkey bologna-type product.

Conclusions

Listerial growth was highly variable for samples formulated with 30 and 60 ppm nitrite.  Formulations with similar lactate-diacetate-NaCl combinations but 120 and 0 ppm nitrite supported growth at 13-15 weeks and 4-6 weeks, respectively. Treatments with other combinations of lactate-diacetate-NaCl and 90 ppm nitrite supported growth similar to that which was predicted by the commercial model. Inhibition of L. monocytogenes was decreased by 3 to 6 weeks in several treatments with 30 ppm nitrite compared with the predictive model, but the addition of low nitrite levels delayed growth by 3 weeks or more compared to the control without nitrite. Addition of nitrite was the overall controlling factor on cooked product color. In general the cured color was not influenced by the addition of the non-nitrite antimicrobial ingredients. Treatments containing 30 to 120 ppm nitrite did not differ in cooked color. The minimum of 30 ppm nitrite was sufficient to produce a pink cured color in contrast to the absence of pink in the no nitrite control.

Deliverable

These results suggest that a minimum 30 ppm nitrite will enhance the antilisterial activity of lactate-diacetate in RTE poultry, but as with other traditional antimicrobials, the effect is concentration dependent with adequate activity estimated at >70 ppm.