Effective use of nisin to control lactic acid bacterial spoilage in sliced cooked ham

Cooked ham is one of the most consumed meat products in Brazil. It is sensitive to the deterioration caused by the growth of lactic acid bacteria (LAB). The objective of this study was to evaluate the antimicrobial activity of nisin over the naturally present LAB on sliced cooked ham stored at 8°C. For this, nisin was added to the cooked ham at two different stages of processing: Injected together with the brine (assay 1) and added during tumbling (assay 2). Results from assay 1 showed LAB inhibition for 2 days, whereas, results from assay 2 showed LAB inhibition for up to 10 days. These results demonstrated that 12.5 mg/kg (dosage approved in Brazil for dairy products) of nisin significantly inhibited LAB growth, suggesting its effectiveness as an appropriate barrier in the control of LAB spoilage in cooked ham. Practical applications When evaluating the antimicrobial activity of nisin for its biopreservation capacity, it is important to consider that meat products are complex systems with several factors influencing the microbial growth and subsequent metabolite production. Therefore, the influence of the medium formulation and technology on the process needs to be tested. Addition of nisin at the tumbling step had a better inhibitory effect against LAB. Thus, it can deliver an important contribution to improve food quality by optimizing the storage management.