Modeling the Lysozyme Release Kinetics from Antimicrobial Films Intended for Food Packaging Applications

Advancements in Biodegradable Active Films for Food Packaging: Effects of Nano/Microcapsule Incorporation

Food packaging plays a fundamental role in the modern food industry as a main process to preserve the quality of food products from manufacture to consumption. New food packaging technologies are being developed that are formulated with natural compounds by substituting synthetic/chemical antimicrobial and antioxidant agents to fulfill consumers’ expectations for healthy food. The strategy of incorporating natural antimicrobial compounds into food packaging structures is a recent and promising technology to reach this goal. Concepts such as “biodegradable packaging”, “active packaging”, and “bioactive packaging” currently guide the research and development of food packaging. However, the use of natural compounds faces some challenges, including weak stability and sensitivity to processing and storage conditions. The nano/microencapsulation of these bioactive compounds enhances their stability and controls their release. In addition, biodegradable packaging materials are gaining great attention in the face of ever-growing environmental concerns about plastic pollution. They are a sustainable, environmentally friendly, and cost-effective alternative to conventional plastic packaging materials. Ultimately, a combined formulation of nano/microencapsulated antimicrobial and antioxidant natural molecules, incorporated into a biodegradable food packaging system, offers many benefits by preventing food spoilage, extending the shelf life of food, reducing plastic and food waste, and preserving the freshness and quality of food. The main objective of this review is to illustrate the latest advances in the principal biodegradable materials used in the development of active antimicrobial and antioxidant packaging systems, as well as the most common nano/microencapsulated active natural agents incorporated into these food-packaging materials.

Formulation of a Bio-Packaging Based on Pure Cellulose Coupled with Cellulose Acetate Treated with Active Coating: Evaluation of Shelf Life of Pasta Ready to Eat

An active packaging based on pure cellulose coupled with cellulose acetate coated with layered double hydroxide (LDH), hosting 4-hydroxybenzoate (listed in EC-Directive 10/2011) as an antimicrobial agent, was formulated and realized. The release of 4-hydroxybenzoate ionically bonded to the LDH layers was much slower than the molecule freely dispersed into the coating. The capability of the active packaging to inhibit Pseudomonas, Escherichia coli, Salmonella and Lactic Bacteria was evaluated, as well as the global migration with three different food simulant (i.e., acetic acid at 3% (v/v), ethanol at 50% (v/v) and vegetable oil) that demonstrated, in compliance with the migration limits of the EU regulation, the suitability of the prepared packaging to be employed as food contact material. Ready to east cooked tomato pasta was packaged into the active trays and in uncoated, as control, up to 30 days at 4 °C. Organoleptic characteristics, mold evolution, total mesophilic aerobic counts (TBC), Enterobacteriaceae, Lactic Bacteria and Pseudomonas, and in colony forming unit per gram (CFU/g), showed a significant activity of 4-hydroxybenzoate in increasing the shelf life of the pasta ready to eat.

Study on the Influence of Bio-Based Packaging System on Sodium Benzoate Release Kinetics

The influence of film structure on the release kinetics of sodium benzoate (SB) from polymeric films is addressed in this study. In particular, four film structures were investigated, two monolayer and two multilayer systems. In particular, in one case, the active substance was uniformly distributed into a chitosan-based matrix, and in the other one, it was previously incorporated into alginate beads before dispersion in the chitosan film, thus realizing two types of monolayer films; on the other hand, the same chitosan film with SB encapsulated in alginate beads was used as the inner layer of a multilayer system constituted by two side films of alginate. The two alginate-based layers were made with two different thicknesses, thus producing a total of two multilayer systems. The release of SB from the above-mentioned films in water was studied by means of a UV/VIS spectrophotometer at 227 nm. A first-order kinetics-type equation was used to quantitatively describe the release data. Results suggest that the film structure strongly affected the release kinetics. In fact, monolayer films showed single-stage release kinetics, whereas the two investigated multilayer systems showed two-stage release kinetics. Further, the presence of alginate beads strongly affected the SB release, thus suggesting the potential of encapsulation to control the release mechanism of active compounds.

Antimicrobial activity of carboxymethyl cellulose-gelatin film containing Dianthus barbatus essential oil against aflatoxin-producing molds

Edible films, as novel degradable materials in food packaging, play an important role in removing consumers' concerns about environmental pollution and food contaminations. Carboxymethyl cellulose (CMC)-gelatin (G) edible films with the ratio 4 to 1 was selected as the optimal film based on physical, mechanical, and physicochemical findings. Then, the effects of 0, 300, 450, and 600 ppm Dianthus barbatus essential oil (DbE) on water vapor permeability, tensile strength, elongation at break, water solubility, glass transition temperature, color, oxygen permeability, and antimicrobial activities on the optimal film were investigated. CMC: G (4:1) containing 600 ppm DbE as the antibacterial-antioxidant film was the best formulae (p < .05) for preventing three types of aflatoxin-producing mold including A. flavus (PTCC-5004), A. parasiticus (PTCC-5286), and A. parasiticus (PTCC-5018) on pistachios for 6 months.

Antimicrobial activity of carboxymethyl cellulose-gelatin film containing Dianthus barbatus essential oil against aflatoxin-producing molds

Edible films, as novel degradable materials in food packaging, play an important role in removing consumers' concerns about environmental pollution and food contaminations. Carboxymethyl cellulose (CMC)-gelatin (G) edible films with the ratio 4 to 1 was selected as the optimal film based on physical, mechanical, and physicochemical findings. Then, the effects of 0, 300, 450, and 600 ppm Dianthus barbatus essential oil (DbE) on water vapor permeability, tensile strength, elongation at break, water solubility, glass transition temperature, color, oxygen permeability, and antimicrobial activities on the optimal film were investigated. CMC: G (4:1) containing 600 ppm DbE as the antibacterial-antioxidant film was the best formulae (p < .05) for preventing three types of aflatoxin-producing mold including A. flavus (PTCC-5004), A. parasiticus (PTCC-5286), and A. parasiticus (PTCC-5018) on pistachios for 6 months.

Development of New Multilayer Active Packaging Films with Controlled Release Property Based on Polypropylene/Poly(Vinyl Alcohol)/Polypropylene Incorporated with Tea Polyphenols

The polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films with controlled release property were developed, of which the intermediate PVA layer was incorporated with 4% (w/w) tea polyphenols (TP) and the microporous PP films with different pore size were used as the internal controlled release layer. The SEM results showed that each layer of these films was agglutinated tightly. With increasing pore size from 171.05 to 684.03 µm, there were little effect on the films' color and opacity, the tensile strength (TS) and elongation at break (EAB) decreased slightly, the gas barrier (O₂ and water vapor) property of the film reduced faintly, the time of achieving the release equilibrium in 50% ethanol decreased from 75 hours to 30 hours. The diffusion coefficient for the films increased with the increase of pore size, from 2.06 × 10^-11 cm² /s to 8.06 × 10^-11 cm² /s, suggesting that the release rate of TP increased as the pore size increased. The results were indicated that its release rate could be controlled by adjusting the size of pore. The films also exhibited different antioxidant activities due to their different release profiles of TP. It showed promise for developing the controlled release active packaging film based on this concept. PRACTICAL APPLICATION: Controlled release packaging is propitious to extension of food shelf life. The microporous polypropylene films with different pore size used as the internal layer of polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films was proved that the release rate of tea polyphenols in the intermediate PVA layer released from the films into the food simulant can be controlled by adjusting the size of pore in this study. It showed a good prospect for using microporous or perforation-mediated film as the internal layer of multilayer film to develop the controlled release active packaging film for food packaging.

Protein-Based Nanostructures for Food Applications

Proteins are receiving significant attention for the production of structures for the encapsulation of active compounds, aimed at their use in food products. Proteins are one of the most used biomaterials in the food industry due to their nutritional value, non-toxicity, biodegradability, and ability to create new textures, in particular, their ability to form gel particles that can go from macro- to nanoscale. This review points out the different techniques to obtain protein-based nanostructures and their use to encapsulate and release bioactive compounds, while also presenting some examples of food grade proteins, the mechanism of formation of the nanostructures, and the behavior under different conditions, such as in the gastrointestinal tract.

Bio-Based Polymers with Antimicrobial Properties towards Sustainable Development

This article concisely reviews the most recent contributions to the development of sustainable bio-based polymers with antimicrobial properties. This is because some of the main problems that humanity faces, nowadays and in the future, are climate change and bacterial multi-resistance. Therefore, scientists are trying to provide solutions to these problems. In an attempt to organize these antimicrobial sustainable materials, we have classified them into the main families; i.e., polysaccharides, proteins/polypeptides, polyesters, and polyurethanes. The review then summarizes the most recent antimicrobial aspects of these sustainable materials with antimicrobial performance considering their main potential applications in the biomedical field and in the food industry. Furthermore, their use in other fields, such as water purification and coating technology, is also described. Finally, some concluding remarks will point out the promise of this theme.

Novel food packaging systems with natural antimicrobial agents

A new type of packaging that combines food packaging materials with antimicrobial substances to control microbial surface contamination of foods to enhance product microbial safety and to extend shelf-life is attracting interest in the packaging industry. Several antimicrobial compounds can be combined with different types of packaging materials. But in recent years, since consumer demand for natural food ingredients has increased because of safety and availability, these natural compounds are beginning to replace the chemical additives in foods and are perceived to be safer and claimed to alleviate safety concerns. Recent research studies are mainly focused on the application of natural antimicrobials in food packaging system. Biologically derived compounds like bacteriocins, phytochemicals, enzymes can be used in antimicrobial food packaging. The aim of this review is to give an overview of most important knowledge about application of natural antimicrobial packagings with model food systems and their antimicrobial effects on food products.

Edible Polymers: Challenges and Opportunities

Edible polymers have established substantial deliberation in modern eons because of their benefits comprising use as edible materials over synthetic polymers. This could contribute to the reduction of environmental contamination. Edible polymers can practically diminish the complexity and thus improve the recyclability of materials, compared to the more traditional non-environmentally friendly materials and may be able to substitute such synthetic polymers. A synthetic hydrogel polymer unlocked a new possibility for development of films, coatings, extrudable pellets, and synthetic nanopolymers, particularly designed for medical, agricultural, and industrial fields. Edible polymers offer many advantages for delivering drugs and tissue engineering. Edible polymer technology helps food industries to make their products more attractive and safe to use. Novel edible materials have been derived from many natural sources that have conventionally been regarded as discarded materials. The objective of this review is to provide a comprehensive introduction to edible polymers by providing descriptions in terms of their origin, properties, and potential uses.

Fabrication and characterization of novel antimicrobial films derived from thymol-loaded zein-sodium caseinate (SC) nanoparticles

The objective of this research was to fabricate novel antimicrobial films based on zein colloidal nanoparticles coated with sodium caseinate (SC), an emulsifier/stabilizer. Thymol-loaded zein-SC nanoparticles were prepared using an antisolvent technique, with the average particle size and zeta potential about 200 ± 20 nm and -40 mV, respectively. Zein-SC nanoparticle-based films exhibited higher mechanical resistance and water barrier capacity than the SC films and concomitant good extensibility as compared with zein films. Thymol loadings endowed zein-SC nanoparticle-based films with antimicrobial activity against Escherichia coli and Salmonella as well as DPPH radical scavenging activity. Water vapor permeability, microstructure, mechanical, and controlled release properties of the films were evaluated. The possible relationship between some selected physical properties and microstructure were also discussed. Atomic force microscopy (AFM) analysis indicated that thymol loadings resulted in the emergence phenomena of the nanoparticles to form large particles or packed structure, consisting of clusters of nanoparticles, within the film matrix, in a thymol loading dependent manner. The appearance of large particles or an agglomerate of particles may weaken the compactness of protein network of films and thus impair the water barrier capacity, mechanical resistance, and extensibility of the films. The release kinetics of thymol from nanoparticle-based films can be described as a two-step biphasic process, that is, an initial burst effect followed by subsequent slower release, and zein-SC nanoparticles within the films matrices gave them the ability to sustain the release of thymol. In addition, a schematic illustration of the formation pathway of zein-SC nanoparticle-based films with or without thymol was proposed to illuminate the possible relationship between some selected physical properties and the microstructure of the films.