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The objective of this work was to evaluate the effectiveness of an antimicrobial packaging system containing active nanoparticles on the quality deterioration of Fior di Latte cheese. To this aim, 3 concentrations of silver montmorillonite embedded in agar were used. The cell loads of spoilage and useful microorganisms were monitored during a refrigerated storage period. Moreover, cheese sensory quality (i.e., odor, color, consistency, and overall quality) was evaluated by means of a panel test. Results showed that the active packaging system markedly increased the shelf life of Fior di Latte cheese, due to the ability of silver cations to control microbial proliferation, without affecting the functional dairy microbiota and the sensory characteristics of the product. The active packaging system developed in this work could be used to prolong the shelf life of Fior di Latte and boost its distribution beyond local market borders.

The aim of the study was to enhance the antioxidant properties of fish burgers with microencapsulated propolis. Spray‐drying process was used to microencapsulate propolis (30 g in 100 mL of ethanol 70% v/v) by means of gum Arabic and Capsul in different ratios (1:6 for gum Arabic and Capsul and then 1:20 just for Capsul). Once defined the optimal microencapsulation conditions, an alcohol‐free powder able to mask the strong odor of propolis was obtained, thus promoting a potential food application as source of phenolics and antioxidants. Specifically, 5% w/w of spray‐dried propolis was incorporated in fish burgers. To improve their sensory properties, new ingredients such as potato flakes (3%, 5%, 7% and 10% w/w) and extra virgin olive oil (9% w/w) were tested and optimized to give a final fish product with good acceptability. Proper tests on burgers also demonstrated an effective increase of both phenolic content and antioxidant activity. Practical Applications Propolis exhibits strong antioxidant properties because of its high content of polyphenols. Thus, it can be potentially used as natural food additive and functional food ingredient, but its application to food products is still limited because of its strong and unpleasant taste and odor that generally compromise food acceptability. The results of this study increase the possibility to embed the propolis as a microencapsulated natural ingredient in various foods to enhance antioxidant properties and phenolic contents.

Silver-montmorillonite (Ag-MMT) antimicrobial nanoparticles were obtained by allowing silver ions from nitrate solutions to replace the Na(+) of natural montmorillonite and to be reduced by thermal treatment. The Ag-MMT nanoparticles were embedded in agar, zein, and poly(ε-caprolactone) polymer matrices. These nanocomposites were tested in vitro with a three-strain cocktail of Pseudomonas spp. to assess antimicrobial effectiveness. The results indicate that Ag-MMT nanoparticles embedded into agar may have antimicrobial activity against selected spoilage microorganisms. No antimicrobial effects were recorded with active zein and poly(ε-caprolactone). The water content of the polymeric matrix was the key parameter associated with antimicrobial effectiveness of this active system intended for food packaging applications.

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This study aimed to assess the potential of pomegranate peel powder as a natural preservative. Its effects were tested on fruit salad quality decay during refrigerated storage. Nectarine and pineapple, equally portioned in polypropylene containers and covered with fructose syrup, were closed using a screw cap in air, with and without the addition of a by-product peel powder. Specifically, amounts of 2.5% and 5% (w/v) of pomegranate peel powder were put into each container. Both the microbiological and sensory qualities of the fruit salad were monitored during storage at 5 °C for 28 days. The results demonstrated that the fruit salad with the by-products showed lower counts of total mesophilic bacteria, total psychrotrophic microorganisms, yeasts, and lactic acid bacteria compared to the control, thus confirming the recognized antimicrobial properties of pomegranate peel. The other interesting finding of this study is that the addition of the investigated by-product in fruit salad did not worsen the main sensory attributes of fresh-cut fruit. Therefore, these preliminary results suggest that pomegranate peel powder has potential applications as a natural preservative in the fresh-cut food sector.