Antimicrobial plastic film: Physico-chemical characterization and nisin desorption modeling.

摘要

Antimicrobial active films represent an innovative concept in food packaging, developed to answer to consumer's expectation for better microbiological safety. In this study, the growth of pathogenic microorganisms on the surface of food is proposed to be controlled by coating, on the surface of polyethylene/polyamide/polyethylene film (PE/PA/PE), a film-forming solution containing Nisaplin, a commercial form of bacteriocin produced by Lactococcus lactis subsp. lactis: nisin. The bioactivity of these multi-layer films coated with Nisaplin loaded HydroxyPropylMethylCellulose film is based on the release of this antimicrobial molecule towards a food simulant. Nisin mass transfer was studied and modeled, for different operating conditions, generally encountered in food products. pH didn't seem to interfere with nisin release kinetics, while the variation of NaCl concentration between 0.8% and 3.2% decreased the desorption coefficient (kd) by 18% and the temperature increase from 10 degrees C to 28 degrees C resulted in an increase of kd from 1.78 x 10-2 m s-1 to 2.10 x 10-2 m s-1. Coating of PE/PA/PE film with this antimicrobial layer induced little mechanical properties modifications without compromising industrial applications. Water barrier capacity was not altered. Industrial relevance: This paper concerns active packaging, considered as a new approach to preserve food shelf life. Active packaging is a real gain for plastic and Food industrials. Coating was used to obtain antimicrobial packaging. The impact of coating on film characteristics is investigated. Also, antimicrobial agent desorption is determined during storage conditions. All rights reserved, Elsevier.