Starch edible film supporting natamycin and nisin for improving microbiological stability of refrigerated argentinian Port Salut cheese

Abstract

The effectiveness of natamycin and nisin supported in edible films (NANI) was evaluated, at 7±1°C, in relation to the improvement of the microbiological stability of Port Salut cheese. This film inhibited the growth of yeasts and moulds and controlled the growth of psychrotrophic bacteria originally present in the Port Salut cheese stored at refrigeration temperature. It also inhibited the development of a mixed culture (Saccharomyces cerevisiae and Listeria innocua) present in the cheese due to a superficial contamination, throughout the entire storage. With respect to a postprocessing contamination affecting the film present in a covered cheese, control film, commercial film and film containing nisin and natamycin (NANI), acted as barriers precluding the mixed culture growth on the cheese surface. But only NANI inhibited the growth of that culture on the film. These results are demonstrating that the film NANI is an extremely effective method to control the population of microorganisms present in both the cheese and the film, enabling to offer the consumer a safer product.