Bioactive Characterization of Packaging Foils Coated by Chitosan and Polyphenol Colloidal Formulations.

Sanja Potrč,Sonja Smole Možina,Lidija Fras Zemljič,Maša Knez Hrnčič,Meta Sterniša

doi:10.3390/ijms21072610

Sanja Potrč, Sonja Smole Možina + Show 3 more

Open Access

https://doi.org/10.3390/ijms21072610

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Abstract

Polypropylene (PP) and polyethylene (PE) foils, previously activated by ultraviolet (UV)/ozone, were functionalized using chitosan-extract nanoparticle dispersions. A solution of macromolecular chitosan was applied onto foils as a first layer, followed by the deposition of various extracts encapsulated into chitosan nanoparticles, which were attached as an upper layer. Functionalized foils were analyzed from a bioactive point of view, i.e., regarding antimicrobial and antioxidant activity. Desorption kinetics were also studied. Moreover, barrier properties were examined, as the most important parameter influencing antimicrobial and antioxidant activity. Finally, all these properties were correlated with different surface parameters, determined previously, in order to understand if there is any direct correlation between surface elemental composition, surface charge, contact angle, or morphology and a specific bioactive property. It was shown that great bioactive properties were introduced due to the additive effect of antimicrobial chitosan and antioxidative plant extracts. Moreover, oxygen permeability decreased significantly, and the migration of polyphenols and chitosan from the foil surface was below the OML (overall migration limit), which is very important for food industry applications. Furthermore, surface properties of foils influence to some extent the desired bioactivity.

Highlights

Active packaging (AP) is an innovative approach to maintaining or prolonging the shelf-life of food products while ensuring their quality, safety, and integrity
All three extracts showed antimicrobial activity, with lower values obtained for both bacteria, and with the best antimicrobial activity seen in rosemary extract, as noted in previous studies [29]
The final amount of the extract, which was encapsulated into chitosan nanoparticles and further applied onto the foil surface, was 4× its Minimal Inhibitory Concentration (MIC), in order to obtain good antimicrobial activity of functionalized foils

Summary

Introduction

Active packaging (AP) is an innovative approach to maintaining or prolonging the shelf-life of food products while ensuring their quality, safety, and integrity. The use of modern solutions in the field of packaging can contribute to a significant improvement in the sensory characteristics of food products and may ensure their microbiological safety. Their application helps to prevent food spoilage and subsequent waste, and it enables longer transportation and storage times. Active packaging systems can be divided into active scavenging systems (absorbers) and active releasing systems (emitters) Whereas the former remove undesired compounds from the food or its environment, for example, moisture, carbon dioxide, oxygen, ethylene, or odor, the latter add compounds to the packaged food or into the headspace, such as antimicrobial compounds, carbon dioxide, antioxidants, flavors, ethylene, or ethanol. The addition of active substances via active packaging may be more effective than their addition to the bulk of the food [2]

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