13The aim of the present work was the development of antimicrobial films containing garlic 14 extract to be applied as active packaging for preservative-free sliced pan loaf, with the goal of 15 extending its shelf-life. First, the antimicrobial capacity of garlic extract, a compound used as 16 active agent, was tested against Penicillium expansum by the disc diffusion method. The 17 extract showed high antimicrobial activity, 0.1 µL per Petri dish being the minimum inhibitory 18 amount, and 0.25 µL the minimum fungicidal amount. Bread aroma was also used to mask the 19 pungent odour of garlic and it was confirmed to have no antimicrobial activity. Subsequently, 20 polyethylene (PE) aqueous emulsion and ethylene-vinyl alcohol copolymer (EVOH) and zein 21 hydroalcoholic solutions containing 0.25 and 0.5% (w/w per dry polymer) of garlic extract and 22 34 INTRODUCTION 35Bread is an essential food product in the traditional diet in Europe, the Middle East, India, 36America and Oceania. According to the Codex Alimentarius, bread is the product resulting from 37 baking dough obtained by mixing flour and water, with or without addition of edible salt, 38 fermented by baker's yeast, Saccharomyces cerevisiae. Bread slowly deteriorates after baking, 39owing to a combination of chemical and physical processes called staling and owing to 40 microbiological spoilage. 41Pan loaf is a type of bread baked in a pan, with a soft texture and high water activity 42 (0.94

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The design of efficient food contact materials that maintain optimal levels of food safety is of paramount relevance to reduce the increasing number of foodborne illnesses. In this work, we develop a smart composite metal–organic framework (MOF)-based material that fosters a unique prolonged antibacterial activity. The composite is obtained by entrapping a natural food preserving molecule, carvacrol, into a mesoporous MIL-100(Fe) material following a direct and biocompatible impregnation method, and obtaining particularly high payloads. By exploiting the intrinsic redox nature of the MIL-100(Fe) material, it is possible to achieve a prolonged activity against Escherichia coli and Listeria innocua due to a triggered two-step carvacrol release from films containing the carvacrol@MOF composite. Essentially, it was discovered that based on the underlying chemical interaction between MIL-100(Fe) and carvacrol, it is possible to undergo a reversible charge-transfer process between the metallic MOF counterpart and carvacrol upon certain chemical stimuli. During this process, the preferred carvacrol binding site was monitored by infrared, Mössbauer, and electron paramagnetic resonance spectroscopies, and the results are supported by theoretical calculations.

In this work, novel active films based on ethylene vinyl alcohol copolymer (EVOH) and cinnamaldehyde (CIN) were successfully obtained employing a hybrid technique consisting of a two-step protocol involving the preparation of a polymeric EVOH-CIN masterbatch by solvent-casting for its further utilization in the preparation of bioactive EVOH-based films by melt extrusion processing. The influence of CIN over the EVOH matrix was studied in terms of optical, morphological, thermal, and mechanical properties. Optically transparent films were obtained and the incorporation of cinnamaldehyde resulted in yellow-colored films, producing a blocking effect in the UV region. A decrease in the glass transition temperature was observed in the formulations containing cinnamaldehyde, indicating a plasticizing effect. This phenomenon was confirmed by an increase in the elongation at break values of the extruded films. Results from thermogravimetric analysis determined a slight decrease in the thermal stability of EVOH provoked by the vaporization of the bioactive compound. Bioactive properties of the films were also studied; the presence of residual cinnamaldehyde in EVOH after being subjected to an extrusion process conferred some radical scavenging activity determined by the DPPH assay whereas films were able to exert antifungal activity in vapor phase against Penicillium expansum. Therefore, the present work shows the potential of the hybrid technique employed in this study for the preparation of bioactive films by a ready industrial process technology for food packaging applications.

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