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The search for biodegradable materials motivated the development of new materials for the food industry. Biomaterials (pectin, starch, and chitosan) are considered promising biodegradable polymers for developing or improving materials. This study aimed to develop biodegradable bionanocomposite films with neem oil and carnauba wax nanoemulsion using pectin (high methyl esterification) polymer matrix; and to evaluate the nanoemulsions effects on the water vapor permeability (WVP), mechanical, thermal, and biodegradability properties of the films. Nanoemulsions were characterized by the polydispersity index and mean particle diameter. These results showed an average diameter of 59 to 69 nm. The pectin and 30% of neem oil nanoemulsions showed a 27% reduction in WVP. In addition, the mechanical property was optimized. Young module showed a 66% to 75% reduction for pectin and 30% of carnauba wax film and pectin and 30% of neem oil film. In the biodegradability analysis was presented a very fast degradation in soil. In addition, there was no macroresidue formation in soil with neem oil films during the biodegradation process. This result showed a weight loss after 45 days of testing. Developed bionanocompositie materials have great potential for application in emerging packagings (edible films and coatings) for the food industry and agribusiness area (food and seeds).

Essential oils with antimicrobial properties are widely used in the food industry. This study aimed to evaluate the influence of a blend of garlic (Allium sativum) and thyme (Thymus vulgaris) essential oils on the antimicrobial and mechanical properties of zein films. Four bacteria (Enteropathogenic Escherichia coli (EPEC), Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus) related to food contamination were chosen to evaluate the antimicrobial properties. The results indicated that the oil blend acted as a plasticizer, decreasing the glass transition temperature and the Young’s Modulus of the films. The addition of the oil blend also resulted in lower solubility and water absorption. The addition of the oil blend (0, 2%, 3% and 5% (v/v)) to the zein films showed inhibitory activity against all the bacteria tested, with inhibitory halos of between 6.5 mm and 8.27 mm. The results showed that the coating could be applied as a support to increase the shelf life of food products.

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PurposeThe main purpose of this paper was to evaluate the influence of the zein coating containing essential oils on the sensory characteristics of sodium-reduced mozzarellas.Design/methodology/approachMozzarellas were prepared by dipping in brine containing 5, 10, 15 or 20% of NaCl (w/v) that correspond, respectively, to 25, 50, 75 and 100% of NaCl content used in industry. These salted mozzarellas and another one, unsalted, were coated by an edible zein film added with 3% of a mixture of thyme and garlic essential oils (1:1). They were subjected to sensory analysis in relation to salty taste and overall impression. The mozzarella without salt reduction (20% NaCl w/v), coated or uncoated with the edible film, was also subjected to the analysis of water loss and microbiological quality, in order to evaluate the impact of this film on product quality.FindingsThe zein coating added with oils did not compromise the sensory acceptance of the mozzarella prepared with up to 50% of salt reduction. Water loss and microbial growth were lower in zein-coated mozzarella than in uncoated mozzarella. These results showed that this film could be applied as natural additive, contributing to the microbiological and sensory characteristics of the mozzarella.Originality/valueThis paper contributes to reducing the lack of studies in relation to new technologies for food preservation and sodium reduction. In addition, the zein coating containing essential oils can be tested on other food categories.

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Pseudomonas aeruginosa is an opportunistic pathogen capable of forming biofilms of great relevance to medical microbiology and the food industry. Essential oil (EOs) constituents have been researched as new strategies for the control of biofilms. In the present study cinnamaldehyde was shown to be an effective EO against the planktonic cells of P. aeruginosa strains (p < 0.05). Thus it was used to prepare sanitizing solutions, which were tested against P. aeruginosa biofilms formed on stainless steel surfaces. Cinnamaldehyde showed antibacterial activity against sessile P. aeruginosa cells (p < 0.05). A 100% (5.87 log-reduction) elimination of viable bacterial cells was obtained after treatment with a 6xMIC (0.06% Minimal Inhibitory Concentration) solution for the strain ATCC 9027. Sanitizing cinnamaldehyde solutions can be used as new alternatives to control such microbial sessile communities in food industries.

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