Potency evaluation of a dermaseptin S4 derivative for antimicrobial food packaging applications

Antimicrobial packaging is part of the broader area of active packaging, in which the package absorbs/releases different compounds during the product's storage and plays a major role in maintaining quality, extending shelf-life and improving the product's safety. Antimicrobial packages are capable of inhibiting the detrimental effects of spoiling microorganisms in food products. There has been very great interest in antimicrobial packaging in recent years and many such packaging materials have been proposed, some of which containing synthetic additives and others natural additives. In the present study, antimicrobial materials containing the antimicrobial peptide (AMP) dermaseptin K4K20-S4, which shows cytolytic activity in vitro against a broad spectrum of pathogenic microorganisms, such as bacteria, protozoa, yeast and filamentous fungi, were investigated. The study was aimed at evaluating the potency of this AMP as an antimicrobial agent for antimicrobial food packaging in two forms: (a) an aqueous solution of AMP was applied onto a polyethylene shrink-wrapping film; (b) the AMP was incorporated in a corn starch-based coating and applied directly onto the foodstuff (fresh cucumbers). Of these two versions, the latter has shown a greater efficiency against moulds and aerobic bacteria, even at lower surface concentrations of AMP (4.5 mu g/dm(2) vs. 3.5-3.8 mu g/dm(2)) in the coating. While in the first version the AMP had slowed down the growth of microorganisms only slightly, incorporation of AMP into the coating caused a reduction in their concentration practically to zero. Copyright (c) 2006 John Wiley & Sons, Ltd.