Study of the performance of nisin supported in edible films

The antimicrobial activity of nisin supported in edible films prepared with suspensions of tapioca starch containing glycerol, was studied. Films were prepared by casting the systems after gelatinization. The effect of the edible film as antimicrobial barrier to external hazard as well as the diffusional characteristics of the nisin and its release characteristics were studied in parallel to antimicrobial inactivation. Studies were performed with L. innocua, after equilibration of edible films at a relative humidity (RH) of 57.5% and at 25 degrees C. Results obtained showed that nisin supported in starch-based films is active and that the film is a useful barrier to further product contamination. Gradual release of the antimicrobial from the edible film can also help to preclude microorganism proliferation better than nisin directly added because it seems to counterbalance, at least partially, the inactivation of nisin. (c) 2006 Elsevier Ltd. All rights reserved.