Non-migratory Active Packaging Research Articles

Nanoemulsion-based active packaging for food products

Recently, there has been an increasing trend in the food and pharmaceutical industries towards using nanotechnological approaches to drug delivery and active packaging (edible coatings and films). In the food sector, nanoemulsions are the most promising technology for delivering active components and improving the barrier, mechanical, and biological properties of packaging to ensure the safety and quality of food products, as well as extend their shelf life.
 For this review, we used several databases (Google Scholar, Science Direct, PubMed, Web of Science, Scopus, Research Gate, etc.) to collect information about nanoemulsions and their role in edible packaging. 
 We searched for articles published between 2015 and 2022 and described different scientific approaches to developing active packaging systems based on nanoemulsions, as well as their high-energy and low-energy synthesis methods. We also reviewed the uses of different types of essential oil-based nanoemulsions in the packaging of food products to prolong their shelf life and ensure safety. Non-migratory active packaging and active-release packaging systems were also discussed, as well as their advantages and disadvantages.

Development of cellulose-based migratory and nonmigratory active packaging films

The main aim of this work is to develop a transparent bioactive cellulose acetate (CA) film for food packaging applications. The aim of the study is also to optimize the production methods for development of bulk and surface immobilized bioactive CA films. The vacuum drying method was optimized for the production of transparent CA films. The direct infusion and UV-assisted surface immobilization methods were investigated for the development of bioactive CA films. Reduction in the crystalline nature of CA was observed to be responsible for the production of transparent CA films. Thymol, with high antioxidant and antimicrobial properties, was examined to be the major active compound (>40%) present in the polar fraction of oregano. Retention of active compounds analyzed by High Performance Liquid Chromatography (HPLC), surface morphology analyzed by Atomic Force Microscopy (AFM), and surface chemistry analyzed by X-ray Photoelectron Spectroscopy (XPS) proved the efficiency of UV-assisted surface immobilization method. Acetyl cellulose films treated with UV irradiation at 312 nm were examined to have higher retention of active compounds. The bioactive CA films produced by bulk and surface immobilization methods showed >90% and ∼65% thymol retention, respectively. The UV-assisted surface immobilization method was found to decrease the mechanical and barrier properties of CA film. The bioactive CA films produced by bulk and surface immobilization methods were found to have retained the antioxidant and antimicrobial properties of the thymol.

Polymer surface modification using UV treatment for attachment of natamycin and the potential applications for conventional food cling wrap (LDPE)

The purpose of this study was to develop an active non-migratory antifungal Low Density Polyethylene (LDPE) polymer for use in food packaged applications. The functional acrylic acid monomer was grafted on the LDPE film surface by photo-initiated graft polymerization using Ultra Violet light irradiation (from 0 to 5min). Natamycin, an antifungal agent, was applied to the treated film to bind with the pendent functional groups and were evaluated its performance against mold and yeast. The grafted amounts were determined by gravimetric measurement and dye absorbance. Attenuated Total Reflectance/Fourier Transfer Infrared Spectroscopy, scanning electron microscopy, mechanical strength test was used to characterize film properties. The antifungal efficacy of the film was evaluated with Saccharomyces cerevisiae and Penicillium chrysogenum on growth media and fresh cut cantaloupe. The amounts of the grafted group were increased with the longer ultraviolet exposure time. The amount of the grafted natamycin on the treated film was up to 49.87μg/cm2, and the film inhibited mycelium formation of P. chrysogenum spores by over 60%. Due to the thickness of the film (less than 12.25μm), long time UV exposure decrease the film’s mechanical strength. The application of such non-migratory active packaging film represents a promising approach to maintaining food quality with reduced additive.

Performance of Nonmigratory Iron Chelating Active Packaging Materials in Viscous Model Food Systems.

Many packaged food products undergo quality deterioration due to iron promoted oxidative reactions. Recently, we have developed a nonmigratory iron chelating active packaging material that represents a novel approach to inhibit oxidation of foods while addressing consumer demands for "cleanˮ labels. A challenge to the field of nonmigratory active packaging is ensuring that surface-immobilized active agents retain activity in a true food system despite diffusional limitations. Yet, the relationship between food viscosity and nonmigratory active packaging activity retention has never been characterized. The objective of this study was to investigate the influence of food viscosity on iron chelation by a nonmigratory iron chelating active packaging material. Methyl cellulose was added to aqueous buffered iron solutions to yield model systems with viscosities ranging from ∼1 to ∼10(5) mPa·s, representing viscosities ranging from beverage to mayonnaise. Iron chelation was quantified by material-bound iron content using colorimetry and inductively coupled plasma-optical emission spectrometry (ICP-OES). Maximum iron chelation was reached in solutions up to viscosity ∼10(2) mPa·s. In more viscous solutions (up to ∼10(4) mPa·s), there was a significant decrease in iron chelating capacity (P < 0.05). However, materials still retained at least 76% iron chelating capacity. Additionally, the influence of different food hydrocolloids on the performance of nonmigratory iron chelating active packaging was characterized. Methyl cellulose and carrageenan did not compete with the material for specific iron chelation (P > 0.05). Materials retained 32% to 45% chelating capacity when in contact with competitively chelating hydrocolloids guar gum, locust bean gum, and xanthan gum. This work demonstrates the potential application of nonmigratory iron chelating active packaging in liquid and semi-liquid foodsto allow for the removal of synthetic chelators, while maintaining food quality.

Controlling lipid oxidation of food by active packaging technologies

Active packaging is an innovative strategy in preventing lipid oxidation. Different active substances with different mechanisms of action have been investigated for imparting antioxidant activity to active packaging systems, including free radical scavengers, metal chelators, ultraviolet (UV) absorbers, oxygen scavengers, and singlet oxygen quenchers. Antioxidant agents have been incorporated into active packaging systems in different forms, mainly including independent sachet packages, adhesive-bonded labels, physical adsorption/coating on packaging material surface, being incorporated into packaging polymer matrix, multilayer films, and covalent immobilization onto the food contact packaging surface. In this paper, we review recent advances in antioxidant active packaging with the highlight of the development and application of non-migratory active packaging systems. The potential use of emerging technologies in antioxidant active packaging is also emphasized. We further describe challenges and opportunities towards the commercial application of such antioxidant active packaging systems, with a focus on maintaining safety, quality and nutrition of packaged foods.

Innovative technologies in the control of lipid oxidation

AbstractTransition metal promoted oxidative degradation reactions impact quality, shelf‐life, and nutritional content of many packaged foods. When trace metals are present in packaged foods, they can initiate degradation of nutritional compounds such as unsaturated fatty acids, carotenoids, antioxidants, phytosterols, and many vitamins. These reactions occur at metal concentrations naturally occurring in foods (often in the low parts per billion range) therefore complete metal removal is not a practical solution to inhibit these reactions. Chelators such as EDTA can be added to inhibit metal‐promoted oxidation, however there is significant consumer and industry demand to eliminate EDTA from product formulations. Other natural chelators such as citric acid are ineffective in many foods and in some cases can actually increase oxidation rates by increasing metal solubility. An alternate approached to control transition metal reactivity is to utilize active packaging technologies. However, current approaches to antioxidant active packaging can impact packaging film mechanical properties and often exhibit low antioxidant activity. This review article surveys and critically reviews advances in the control of lipid oxidation, paying particular attention to novel advances in both food product formulation (e. g. additives, food microstructure) as well as food packaging. We introduce a new concept of active packaging in which metal ion chelation by non‐migratory active packaging materials may enable removal of synthetic food additives from product formulations while maintaining product quality and shelf‐life.

Control of Lipid Oxidation by Nonmigratory Active Packaging Films Prepared by Photoinitiated Graft Polymerization

Transition metal-promoted oxidation impacts the quality, shelf life, and nutrition of many packaged foods. Metal-chelating active packaging therefore offers a means to protect foods against oxidation. Herein, we report the development and characterization of nonmigratory metal-chelating active packaging. To prepare the films, carboxylic acids were grafted onto the surfaces of polypropylene films by photoinitiated graft polymerization of acrylic acid. Attenuated total reflectance/Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, and iron-chelating assay were used to characterize film properties. Graft polymerization yielded a carboxylic acid density of 68.67 ± 9.99 nmol per cm(2) film, with ferrous iron-chelating activity of 71.07 ± 12.95 nmol per cm(2). The functionalized films extended the lag phase of lipid oxidation in a soybean oil-in-water emulsion system from 2 to 9 days. The application of such nonmigratory active packaging films represents a promising approach to reduce additive use while maintaining food quality.

Polyethylene Glycol Grafted Polyethylene: A Versatile Platform for Nonmigratory Active Packaging Applications

Nonmigratory active packaging, in which bioactive components are tethered to the package, offers the potential to reduce the need for additives in food products while maintaining safety and quality. A challenge in developing nonmigratory active packaging materials is the loss of biomolecular activity that can occur when biomolecules are immobilized. In this work, we describe a method in which a biocompatible polymer (polyethylene glycol, PEG) is grafted from the surface of ozone-treated low-density polyethylene (LDPE) resulting in a surface functionalized polyethylene to which a range of amine-terminated bioactive molecules can be immobilized. Free radical graft polymerization is used to graft PEG onto the LDPE surface, followed by immobilization of ethylenediamine onto the PEG tether. Ethylenediamine was used to demonstrate that amine-terminated molecules could be covalently attached to the PEG-grafted film. Changes in surface chemistry and topography were measured by attenuated total reflectance Fourier transform infrared spectroscopy, contact angle, atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. We demonstrate the ability to graft PEG onto the surface of polymer packaging films by free radical graft polymerization, and to covalently link an amine-terminated molecule to the PEG tether, demonstrating that amine-terminated bioactive compounds (such as peptides, enzymes, and some antimicrobials) can be immobilized onto PEG-grafted LDPE in the development of nonmigratory active packaging. Nonmigratory active packaging offers the potential for improving food safety and quality while minimizing the migration of the active agent into food. In this paper, we describe a technique to modify polyethylene packaging films such that active agents can be covalently immobilized by a biocompatible tether. Such a technique can be adapted to a number of applications such as antimicrobial, antioxidant, or immobilized enzyme active packaging.

Covalent Attachment of Lactase to Low‐Density Polyethylene Films

Polymer films to which bioactive compounds such as enzymes are covalently attached offer potential for in-package processing of food. Beta-galactosidase (lactase) was covalently attached to surface-functionalized low-density polyethylene films. A two-step wet chemical functionalization introduced 15.7 nmol/cm2 primary amines to the film surface. Contact angle, dye assays, X-ray photoelectron spectroscopy, and appropriate protein assays were used to characterize changes in film surface chemistry after each step in the process of attachment. Glutaraldehyde was used to covalently attach lactase to the surface at a density of 6.0 microg protein per cm2 via reductive amination. The bond between the covalently attached lactase and the functionalized polyethylene withstood heat treatment in the presence of an ionic denaturant with 74% enzyme retention, suggesting that migration of the enzyme into the food product would be unlikely. The resulting polyethylene had an enzyme activity of 0.020 lactase units (LU)/cm2 (approximately 4500 LU/g). These data suggest that enzymes that may have applications in foods can be covalently attached to inert polymer surfaces, retain significant activity, and thus have potential as a nonmigratory active packaging materials.