Animal origin foods are widely distributed and consumed around the world due to their high nutrients availability but may also provide a suitable environment for growth of pathogenic and spoilage microorganisms. Nowadays consumers demand high quality food with an extended shelf life without chemical additives. Edible films and coatings (EFC) added with natural antimicrobials are a promising preservation technology for raw and processed meats because they provide good barrier against spoilage and pathogenic microorganisms. This review gathers updated research reported over the last ten years related to antimicrobial EFC applied to meat and meat products. In addition, the films gas barrier properties contribute to extended shelf life because physicochemical changes, such as color, texture, and moisture, may be significantly minimized. The effectiveness showed by different types of antimicrobial EFC depends on meat source, polymer used, film barrier properties, target microorganism, antimicrobial substance properties, and storage conditions. The perspective of this technology includes tailoring of coating procedures to meet industry requirements and shelf life increase of meat and meat products to ensure quality and safety without changes in sensory characteristics.

Edible films (EFs) have gained great interest due to their ability to keep foods safe, maintaining their physical and organoleptic properties for a longer time. The aim of this work was to develop EFs based on a chitosan–zein mixture with three different essential oils (EOs) added: anise, orange, and cinnamon, and to characterize them to establish the relationship between their structural and physical properties. The addition of an EO into an EF significantly affected (p < 0.05) the a* (redness/greenness) and b* (yellowness/blueness) values of the film surface. The EFs presented a refractive index between 1.35 and 1.55, and thus are classified as transparent. The physical properties of EFs with an added EO were improved, and films that incorporated the anise EO showed significantly lower water vapor permeability (1.2 ± 0.1 g mm h⁻¹ m⁻² kPa⁻¹) and high hardness (104.3 ± 3.22 MPa). EFs with an added EO were able to inhibit the growth of Penicillium sp. and Rhizopus sp. to a larger extent than without an EO. Films’ structural changes were the result of chemical interactions among amino acid side chains from zein, glucosamine from chitosan, and cinnamaldehyde, anethole, or limonene from the EOs as detected by a Raman analysis. The incorporation of an EO in the EFs’ formulation could represent an alternative use as coatings to enhance the shelf life of food products.

Cross-linking of magnetic nanoparticles with proteins plays a significant role in the preparation of new materials for biotechnological applications. The aim was the maximization of the magnetic mass attracted and protein loading of magnetic iron oxide nanoparticles coated with chitosan, synthesized in a single step by alkaline precipitation. Chitosan-coated magnetite particles (Fe₃O₄@Chitosan) were cross-linked to a xylanase and a cellulase (Fe₃O₄@Chitosan@Proteins), showing a 93% of the magnetic saturation of the magnetite. X-ray diffraction pattern in composites corresponds to magnetite. Thermogravimetry and differential scanning calorimetry showed that 162 mg of chitosan was coating one gram of composite and 12 mg of protein was cross-linked to each gram of magnetic support. Cross-linking between enzymes and Fe₃O₄@Chitosan was confirmed by infrared spectroscopy with Fourier transform, X-ray energy, and X-ray photoelectron spectroscopy dispersion analysis. From dynamic light scattering, transmission and electron microscopy the average particle size distribution was 230 nm and 430 nm for Fe₃O₄@Chitosan and Fe₃O₄@Chitosan@Proteins, showing agglomerates of individual spherical particles, with an average diameter of 8.5 nm and 10.8 nm, respectively. The preparation method plays a key role in determining the particle size and shape, size distribution, surface chemistry, and, therefore, the applications of the superparamagnetic nanoparticles.

Papaya production plays an important economic role in Mexico’s economy. After harvest, it continues to ripen, leading to softening, skin color changes, development of strong aroma, and microbial spoilage. The objective of this work was to apply an active coating of chitosan–starch to increase papaya shelf life and to evaluate physicochemical and antimicrobial properties of the coating. Papaya surfaces were coated with a chitosan-oxidized starch (1:3 w/w) solution and stored at room temperature (25 ± 1 °C) for 15 days. Variables measured were color, titratable acidity, vitamin C, pH, soluble solids, volatile compounds by gas chromatography, texture, homogeneity by image analysis, and coating antimicrobial activity. At the end of the storage time, there were no significant differences (p > 0.05) between coated and uncoated papayas for pH (4.3 ± 0.2), titratable acidity (0.12% ± 0.01% citric acid), and soluble solids (12 ± 0.2 °Bx). Papaya firmness decreased to 10 N for coated and 0.5 N for uncoated papayas. Volatile compounds identified in uncoated papaya (acetic acid, butyric acid, ethyl acetate, ethyl butanoate) are related to fermentation. Total microbial population of coated papaya decreased after 15 days, whereas population of uncoated papaya increased. This active coating permitted longer shelf life of papaya than that of the uncoated fruit.

Over four billion tons of foods are produced annually on the planet, and about a third is wasted. A minimal part of this waste is incinerated or sent to landfills for treatment, avoiding contamination and diseases; the rest is disposed of elsewhere. The current review was aimed at broadening the panorama on the potential of agroindustrial by-products in applications such as biofuels, biomaterials, biocompounds, pharmaceuticals, and food ingredients. It also exposes the main chemical, physical, and biochemical treatments for converting by-products into raw materials with added value through low environmental impact processes. The value of agroindustrial waste is limited due to the scarce information available. There is a need for further research in unexplored areas to find ways of adding value to these by-products and minimizing their contamination. Instead of throwing away or burning by-products, they can be transformed into useful materials such as polymers, fuels, antioxidants, phenols, and lipids, which will effectively reduce food waste and environmental impact.