Application of nisin into slovak fermented salami Púchov

Abstract

Púchov salami is favorite fermented salami among Slovak consumers. Nisin is the only bacteriocin accepted by European Commission for a commercial use as additive for food preservation (although not commonly used in meat products). Because of its possibility to prolonge shelf-life of the products and its antimicrobial activity, its effect in dry fermented Slovak salami Púchov experimentally inoculated with Listeria innocua Li1 strain was checked. The initial number of L. innocua Li1 in the inoculated salami mixtures was 104 CFU/g (log 10; 4.04 ± 0 07). After nisin addition, the count of Li1 strain in the meat samples (inoculated with Li1 and treated by nisin) was 1.36±0.07 CFU/g; difference 2.68 logarithmic cycle was noted between Li and Li/Ni samples. At day 2, the difference 3.23 log cycle was detected between Li1 and Li/Ni samples (Li:5.46±0.08, Li/Ni: 2.14±0.07 CFU/g); at weeks 3, 4, it was 1.69 and 1.80 log cycle. Activity of nisin itself was not recovered from the experimental salamis by the analytical method; however, its inhibitory effect was shown by Li1 count decrease. The pH in salamis during processing was almost at the same level (5.52, 5.53, 5.55). Water activity was not negatively influenced. Water content in Li/Ni salamis reached almost requested levels (maximum percentage of water requested is 34 %).