Nisin (500 IU per mL) combined with 100 per cent carbon dioxide was effective in reducing Listeria monocytogenes and preventing outgrowth on turkey bologna over 42 days of refrigerated storage.

That is the main conclusion drawn by Hesham Naas of the University of Tripoli in Libya and co-authors from Clemson University in the US in a study published recently in Poultry Science.

The objective of their study was to evaluate the effect of nisin in combination with different types of packaging on the survival of Listeria monocytogenes in ready-to-eat, low-fat turkey bologna.

Bologna was inoculated with L. monocytogenes subjected to one of six treatments: three packaging treatments (100 per cent carbon dioxide, air or vacuum), each with and without nisin.

Bologna was refrigerated and sampled nine times over 42 days.

The researchers found that nisin reduced initial L. monocytogenes populations by 1.5- to 2-log cycles and 100 per cent carbon dioxide packaging prevented outgrowth throughout 42 days of storage, whereas non-carbon dioxide packaging displayed a 2-log increase in population during storage.

Reference

^{Naas H., R. Martinez-Dawson, I. Han and P. Dawson. 2013. Effect of combining nisin with modified atmosphere packaging on inhibition of Listeria monocytogenes in ready-to-eat turkey bologna. Poult. Sci. 92(7):1930-1935. doi: 10.3382/ps.2012-02141}