Food Packaging Materials Research Articles

Biodegradable chitosan hydrogel film incorporated with polyvinyl alcohol, chitooligosaccharides, and gallic acid for potential application in food packaging

The food and beverage industry worldwide is trying to switch to using environment-friendly and bio-degradable materials in food packaging to avoid environmental concerns of using petroleum-derived plastic (synthetic polymers) materials. In this study, chitosan (CH) hydrogel films were fabricated by using its derivative chitooligosaccharides (COS) as an additive, polyvinyl alcohol as a plasticiser, and bioactive gallic acid as a cross-linker. The physical, mechanical, structural, barrier (e.g., moisture, water vapour permeability (WVP), and UV-barrier property), thermal properties, and biodegradation patterns of fabricated films were investigated. The use of bio–composite in CH films exhibited a synergistic effect. A film with a homogenous/smooth surface and excellent mechanical and thermal properties was obtained. Additionally, incorporating COS and gallic acid reduced the moisture content, WVP, and transparency. Moreover, the films exhibited good colour, strong UV-barrier properties, and good biodegradable capacity in soil. The results suggest that eco-friendly CH hydrogel films have promising potential to be used in food packaging.

Nanocellulose@gallic Acid-Based MOFs: A Novel Material for Ecofriendly Food Packaging.

The development of an effective food packaging material is essential for safeguarding against infections and preventing chemical, physical, and biological changes during food storage and transportation. In the present study, we successfully synthesized an innovative food packaging material by combining chitosan (CH), nanocellulose (NC), and a gallic acid-based metal-organic framework (MOF). The CH films were prepared using different concentrations of NC (5 and 10%) and MOFs (1.5, 2.5, and 5%). Various properties of prepared films, including water solubility (WS), moisture content (MC), swelling degree, oxygen permeability, water vapor permeability (WVP), mechanical property, color analysis, and light transmittance, were studied. The chitosan film with a 5% NC and 1.5% MOF (CH-5% NC-1.5% MOF) exhibited the least water solubility, moisture content, and water vapor permeability, indicating the overall stability of the film. Additionally, this film demonstrated low oxygen permeability, as indicated by a peroxide value of 18.911 ± 4.009, ensuring the effective preservation of packaged contents. Notably, this synthesized film exhibited high antioxidant activity, resulting in an extended duration of 52 days. This antioxidant activity was further validated by the preservation of apple slices for 9 days in a CH-5% NC-1.5% MOF film. The findings of the study suggest that the developed films can provide a promising and environmentally friendly solution for active food packaging.

Investigation of physico-mechanical, thermal, morphological, and antibacterial effects of bio-based epoxidized soybean oil plasticizer on PLA-ZnO nanocomposites as flexible food packaging

Polylactic acid (PLA) has attracted considerable attention because of its excellent properties compared to petroleum-based materials. However, improving its toughness, crystallization, and functionalities is challenging. Using a laboratory internal batch mixer, we produced unique blended nanocomposites comprising polylactic acid (PLA) as the host matrix, epoxidized soybean oil (ESO) as the plasticizer, and zinc oxide nanoparticles (ZnO NPs) as the reinforcements. The SEM-EDS test showed that neat PLA had a smooth surface, but the PLA-ZnO nanocomposite had rough micrographs and a uniform dispersion state of the nanoparticles. It was also found that adding ESO to the blend nanocomposites created a matrix droplet structure, and the size of the oil domains decreased as the ZnO content increased. All results derived from FTIR, XRD, and DSC tests were consistent with the morphological features in which ZnO NPs acted as the blend’s compatibilizer and heterogeneous nucleating agent. Our team observed that adding ESO decreased the PLA-ZnO nanocomposites’ glass transition temperature (Tg) by an average of 2 °C and increased the crystallization rate. It was also confirmed that the presence of ESO improved the flexibility and reduced the strength of the PLA. The tensile strength was further enhanced by incorporating ZnO into the blend. Adding 5 wt% of ZnO NPs increased the tensile strength of the PLA containing 10 wt% ESO by approximately 3.5 MPa. Furthermore, the tensile modulus was predicted using theoretical models; for example, the Paul model fitted with experimental findings. The addition of ESO increased the overall surface free energy of the nanocomposites. On the other hand, increasing ZnO content resulted in high contact angles and antibacterial properties of the blended nanocomposites. The favorable characteristics of the resulting films emphasized the potential use of these nanocomposite films as a promising choice for food packaging materials.

Thermal and heat-sealing properties of polyvinyl alcohol/cellulose nanocrystals-based nanocomposites for food packaging

Food packaging materials require advanced properties (UV barrier and antioxidant/antimicrobial) to extend the shelf-life of packaged products. Recently, we have developed biodegradable nanocomposites by incorporating cellulose nanocrystals (CNCs) and active agents (titanium dioxide nanoparticles and apple peel extract) into polyvinyl alcohol (PVA). These nanocomposites exhibited advanced properties and many demonstrable advantages in food packaging. Herein, the thermal stability, melting behaviors, and heat-sealing properties of these nanocomposites are investigated to demonstrate their potential production at the industrial level and practical use. The results showed that the PVA/CNC-based nanocomposites exhibited thermoplastic properties and had sufficient heat-sealability. The PVA/CNC-based nanocomposites presented lower melting temperatures (217.7–224 °C) than pure PVA (226 °C). Furthermore, their seal strengths (15.1–1238.1 N/m) are similar to those of petroleum-based food packaging polymers (polypropylene: 300–1100 N/m, low-density polyethylene: 677.7 N/m) and can be controlled by adjusting the sealing temperature, which is useful for various food packaging applications.

Bacteriophages: Natural antimicrobial bioadditives for food preservation in active packaging

Developing innovative films and coatings is paramount for extending the shelf life of numerous food products and augmenting the barrier and antimicrobial properties of food packaging materials. Many synthetic chemicals used in active packaging and food storage have the potential to leach into food, posing long-term health risks. It is imperative for active packaging materials to inherently possess biological protective properties to ensure food quality and safety throughout its storage. Bacteriophages, or simply phages, are bacteria-eating viruses that serve as promising natural biocontrol agents and antimicrobial bioadditives in food packaging materials, specifically targeting bacterial foodborne pathogens. These phages are generally recognized as safe (GRAS) by regulatory authorities for food safety applications. They exhibit targeted action against various Gram-positive and -negative foodborne pathogens, including Bacillus spp., Campylobacter spp., Escherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., and Vibrio spp., associated with foodborne spoilage and illness without affecting the beneficial microbes. Phage cocktails can be applied directly on food surfaces, incorporated into food packaging materials, or utilized during food processing treatments. Unlike chemical agents, phage activity increases proportionally with the rise in pathogenic bacterial populations. Researchers are exploring various packaging materials to deliver phages with broad host range, stability, and viability ensuring their effectiveness in safeguarding various food systems. The effectiveness of phage immobilization or encapsulation on active food packaging materials depends on various factors, including the characteristics of polymers, the choice of solvents, the type of phage, and its loading efficiency. Factors such as the orientation of phage immobilization on substrates, pH, temperature, exposure to carbohydrates and amino acids, exopolysaccharides, lipopolysaccharides, and metals can also influence phage activity. In this review, we comprehensively discuss the various active packaging systems utilizing bacteriophages as natural biocontrols and antimicrobial bioadditives to reduce the incidence of foodborne illness and enhance consumer confidence in the safety of food products.

Bioinspired starch nanofibrous films with tunable hydrophobicity and water adhesion via tannic acid-interfacial self-assembly for food packaging

To address the limitations in water resistance and functionality of existing starch-based food packaging materials, this study developed a new sustainable food packaging material—starch nanofibrous films (SNFs) enhanced with an acylated tannic acid (ATA) interfacial self-assembly coating. Inspired by the unique hydrophobicity and water adhesion properties of rose petals, which effectively control surface characteristics to maintain microenvironmental humidity during food processing and storage, this approach significantly enhanced the water resistance, stability, and mechanical strength of the material. Specifically, the obtained SNFs/ATA exhibited a maximum water contact angle of ∼ 134.1°, tensile strength of ∼ 0.86 MPa, and Young’s modulus of ∼ 43.48 MPa. Moreover, SNFs/ATA showed excellent antibacterial and antioxidant properties, UV-blocking capabilities, and degradability, making it an environmentally friendly choice for food packaging. In practical food preservation applications, cherry tomatoes packaged with SNFs/ATA showed a significant extension of shelf life to 15 days, with a 62.5 % reduction in spoilage rate, a 25.4 % decrease in weight loss, and good quality including pulp firmness, pH, titratable acidity, and total soluble solids. This work demonstrates structurally regulated polyphenol assembly in the preparation of all-natural green biomimetic surface, creating new opportunities for the development of sustainable bio-based food packaging systems.

Efficient cellulose dissolution and derivatization enabled by oxalic/sulfuric acid for high-performance cellulose films as food packaging

The performance of cellulose-based materials is highly dependent on the choice of solvent systems. Exceptionally, cellulose dissolution and derivatization by efficient solvent have been considered as a key factor for large-scale industrial applications of cellulose. However, cellulose dissolution and derivatization often requires harsh reaction conditions, high energy consumption, and complex solubilizing, resulting in environmental impacts and low practical value. Here we address these limitations by using a low-temperature oxalic acid/sulfuric acid solvent to enable cellulose dissolution and derivatization for high-performance cellulose films. The dissolution and derivatization mechanism of the mixed acid is studied, demonstrating that cellulose is firstly socked by oxalic acid, then more hydrogen bonds ionized by sulfuric acid break cellulose chain, and finally the esterification reaction between oxalic acid and cellulose is catalyzed by sulfuric acid. Solutions containing 8 %–10 % cellulose are obtained and can be stored for a long time at −18 °C without significant degradation. Moreover, the cellulose film exhibits a higher tensile strength of up to 66.1 MPa, thermal stability, and degree of polymerization compared to that fabricated by sulfuric acid. These unique advantages provide new paths to utilize renewable resources for alternative food packaging materials at an industrial scale.

An in-depth investigation correlating lifestyle choices with cognitive well-being: Public health implications of food packaging trends and memory capacity, an intensive research study

This study presents a multifaceted investigation into the interplay between lifestyle choices, cognitive well-being, and potential health risks associated with food packaging materials. Statistical analyses of memory patterns among diverse population groups, including healthy volunteers, addicted individuals, and those consuming roadside food from street vendors or hawkers, reveal intriguing correlations. The study also conducts a rigorous chemical analysis of newspaper packaging, uncovering significant concerns related to lead contamination. The findings emphasise the need for heightened awareness, further research, and interventions to address potential health risks and ensure the safety of packaging materials. Overall, this research contributes valuable, insightful information that has implications for public health initiatives and packaging industry practices. This is a qualitative study correlating lifestyle choices with cognitive well-being and specific food packaging that impacts the memory and health too. Key findings reveal intriguing correlations between lifestyle habits, the type of food packaging used, and memory capacity. The study’s chemical analysis of newspaper packaging uncovered significant lead contamination, raising serious public health concerns. These findings emphasise the necessity for heightened awareness and targeted interventions to mitigate health risks.

An Overview of Advanced Antimicrobial Food Packaging: Emphasizing Antimicrobial Agents and Polymer-Based Films.

The food industry is increasingly focused on maintaining the quality and safety of food products as consumers are becoming more health conscious and seeking fresh, minimally processed foods. However, deterioration and spoilage caused by foodborne pathogens continue to pose significant challenges, leading to decreased shelf life and quality. To overcome this issue, the food industry and researchers are exploring new approaches to prevent microbial growth in food, while preserving its nutritional value and safety. Active packaging, including antimicrobial packaging, has gained considerable attention among current food packaging methods owing to the wide range of materials used, application methods, and their ability to protect various food products. Both direct and indirect methods can be used to improve food safety and quality by incorporating antimicrobial compounds into the food packaging materials. This comprehensive review focuses on natural and synthetic antimicrobial substances and polymer-based films, and their mechanisms and applications in packaging systems. The properties of these materials are compared, and the persistent challenges in the field of active packaging are emphasized. Specifically, there is a need to achieve the controlled release of antimicrobial agents and develop active packaging materials that possess the necessary mechanical and barrier properties, as well as other characteristics essential for ensuring food protection and safety, particularly bio-based packaging materials.

Assessment of chemical risks and circular economy implications of recycled PET in food packaging with functional barriers

In response to regulatory demands for sustainable practices, there has been a significant increase in the use of recycled materials in food packaging, particularly when incorporated behind functional barriers. This study, conducted as part of the “ABA Modeling” project, evaluates the migration of contaminants from the non-decontaminated, recycled polyethylene terephthalate (rPET) B-layer, which is sandwiched between two virgin A-layers in three-layer trays. The study aims to assess the long-term implications for food safety within the context of the European and French circular economy frameworks. Using a migration modeling approach based on “worst-case” scenarios for ten contaminants – similar to methodologies employed for decontaminated direct food contact PET – the levels of chemical residues are analyzed and compared. Findings highlight the significant impact of the co-extrusion process on the suitability of rPET for food contact. Additionally, the study discusses the risks and challenges for the recycling sector, particularly in managing chemical contamination during mechanical recycling. Recommendations are provided to improve industrial practices, emphasizing the importance of ongoing monitoring to ensure the long-term sustainability of these recycling practices.

Insight into the Binding Interaction between PEDCs and hERRγ Utilizing Molecular Docking and Molecular Dynamics Simulations.

Phenolic environmental endocrine-disrupting chemicals (PEDCs) are persistent EDCs that are widely found in food packaging materials and environmental media and seriously threaten human health and ecological security. Human estrogen-related receptor γ (hERRγ) has been proposed as a mediator for the low-dose effects of many environmental PEDCs; however, the atomic-level descriptions of dynamical structural features and interactions of hERRγ and PEDCs are still unclarified. Herein, how three PEDCs, 4-(1-methylpropyl)phenol (4-sec-butylphenol), 5,6,7,8-tetrahydro-2-naphthol (tetrahydro-2-napthol), and 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane (BP(2,2)(Me)), interact with hERRγ to produce its estrogenic disruption effects was studied. Molecular docking and multiple molecular dynamics (MD) simulations were first conducted to distinguish the detailed interaction pattern of hERRγ with PEDCs. These binding structures revealed that residues around Leu271, Leu309, Leu345, and Phe435 are important when binding with PEDCs. Furthermore, the binding energies of PEDCs with hERRγ were also characterized using the molecular mechanics/Poisson Boltzmann surface area (MM-PBSA) and solvated interaction energy (SIE) methods, and the results showed that the interactions of CH-π, π-π, and hydrogen bonds are the major contributors for hERRγ binding to these three PEDCs. What is striking is that the methoxide groups of BP(2,2)(Me), as hydrophobic groups, can help to reduce the binding energy of PEDCs binding with hERRγ. These results provide important guidance for further understanding the influence of PEDCs on human health problems.

Odourless vegetable oils as insect pest repellents for short-term protection of various food packaging materials

The repellent activity of two odourless vegetable oils (sweet almond—SAO and soybean—SO) applied on filter paper and four types of food packaging materials (polyethylene film, plastic gunnysacks, cardboard, and wood) was tested against three species of stored product pests (Sitophilus granarius, Tribolium castaneum, and Oryzaephilus surinamensis). The repellence of three doses was evaluated after 24 h, and after 7, 14, 21, and 28 days. Both oils exhibited a repellent effect when applied to filter paper, but this effect decreased with time and concentration. The most susceptible species was T. castaneum. The maximum repellence was 84% and 76% for SO and SAO, respectively. On packaging materials, the repellent effect diminished after a certain period of time, ranging from 7 to 28 days. Subsequently, the oils even became attractive. Generally, the repellent effects of both SO and SAO were higher on cardboard and wood slab than on polyethylene film and plastic gunnysacks. As such, in the case of SO, the repellence against T. castaneum was 88% 24 h after application on cardboard, whilst 68% on plastic bag. This work demonstrated the repellent potential of vegetable oils in the short term for the protection of packaged food against stored product pests.

Peach Gum Polysaccharide as an Additive for Thermoplastic Starch to Produce Water-Soluble Films

Thermoplastic starch (TPS) has gained considerable attention during the last few years in developing starch-based biodegradable food packaging materials or edible coatings due to its high availability and low cost. TPS is manufactured from starch plasticized with food-grade plasticizers, making it suitable for food contact applications. In addition, TPS is bio-based and biodegradable, which, from an environmental perspective, closes the circle of the circular economy. However, the industrial application of TPS is somewhat limited due to its poor mechanical performance and low water resistance. However, the low water resistance could increase the water sensitivity of TPS, which could be advantageous for coating application or food encapsulation. The present work aims to tailor the water sensitivity of TPS by adding peach gum polysaccharide to obtain water-soluble films. With this aim, peach gum polysaccharide (PGP) was extracted from peach gum (PG) using the thermal hydrolysis method. Films of TPS-PG and TPS-PGP were prepared and characterized by their water sensitivity and mechanical, microstructural, and thermal properties. The results show that PGP allows the obtaining of films with water sensitivities higher than 70% but also improves TPS elongation at break, making the material more suitable for application as film.

Novel nanoemulsion-loaded hydroxyl propyl methyl cellulose films as bioactive food packaging materials containing Satureja khuzestanica essential oil

This study was conducted in response to a gap in the production of hydroxyl propyl methyl cellulose (HPMC) edible films from Satureja khuzestanica essential oil (SKEO) and to survey the preservation effect of natural edible films on the vapor phase. For these purpose varying concentrations of SKEO ranging from 1.25 % (EF1) to 7.5 % (EF5) led to producing different edible films for potential food packaging applications and the physicochemical, mechanical, and antimicrobial properties of edible films were evaluated across solid, liquid, and vapor phases. The incorporation of nanoemulsions into the polymer films led to an increase in thickness and opacity, while the addition of SKEO resulted in reduced water solubility without impacting film density. Notably, the antibacterial efficacy of the films was most pronounced against S. aureus, with a zone of inhibition measuring 41 ± 1 mm for EF5 on solid media. Time killing assays further demonstrated that specific formulations (EF3, EF4, and EF5) were capable of eradicating all microorganisms within 60 min. Moreover, SKEO edible films exhibited significant inhibitory effects against E. coli under refrigeration conditions (4 °C). These results highlighted the effect of herbal edible films in enhancing the functionality of bioactive food packaging technologies.

Application Analysis of Biodegradable Polymer Materials in Food Packaging

With the rapid development of biotechnology, the society pays more attention than in the past to the production and development of environmental protection. Choosing materials has always been a more important part of environmental protection work, among them, the degradable polymer materials are also professional research topics, it can be self-degradation under certain conditions, with far-reaching environmental protection value and social significance. Food packaging is a kind of carrier that plays a protective role in packaging, preservation and sales of food, the application of degradable polymer materials in food packaging can play a positive role in environmental protection, reducing environmental pollution and building an ecological society. In this paper, the active application of biodegradable polymer materials for food packaging is elaborated, hoping to provide theoretical reference.

PBAT/lignin-ZnO composite film for food packaging: Photo-stability, better barrier and antibacterial properties

When PBAT used as film, stability deteriorates under sunlight exposure, the poor barrier and antibacterial properties are also limiting its application. In this work, lignin-ZnO nanoparticles were prepared by hydrothermal method, as additives to fill the PBAT matrix. In addition, PBAT-lignin-ZnO composite films were successfully prepared by melting and hot-pressing method. It is found that lignin could well dispersed the ZnO when its implantation into PBAT films, and lignin-ZnO not only maintaining tensile strength and thermal stability, but also could prompt PBAT's crystallinity. Especially, P-L-ZnO-2 composite films have good photostability. After 60 h aging, it can still maintain good molecular weight, chemical structure and mechanical properties. Besides, these composite films have improved hydrophobicity, barrier and antibacterial properties, could prevent mildew and significantly reduce the weight loss rate, color difference and hardness changes of strawberries during storage. This work provides a potential film material for outdoor applications and food packaging.

Development of Polymeric Films Based on Sunflower Seed Proteins and Locust Bean Gum.

Most polymeric food packaging materials are non-biodegradable and derived from petroleum, thus recent studies have focused on evaluating alternative biodegradable materials from renewable sources, with polysaccharides and proteins as the main types of employed biopolymers. Therefore, this study aimed to develop biopolymeric films based on sunflower proteins and galactomannans from locust bean gum. The influence of the galactomannan amount (0.10%, 0.30%, 0.50%, and 0.75% w/v) on the physicochemical, thermal, and mechanical properties of cast sunflower protein-based films was studied. Sunflower proteins gave rise to yellowish, shining, and translucid films. With the incorporation of locust bean gum-derived galactomannans, the films became more brown and opaque, although they still maintained some translucency. Galactomannans significantly changed the proteins' secondary structures, giving rise to films with increased tensile resistance and stretchability. Nevertheless, the increase in the galactomannan amount did not have a significant effect on the film's thermal stability. The protein/galactomannan-based films showed values of water vapor and oxygen permeability that were slightly higher than those of the pristine materials. Overall, blending locust bean gum galactomannans with sunflower proteins was revealed to be a promising strategy to develop naturally colored and translucid films with enhanced mechanical resistance while maintaining flexibility, fitting the desired properties for biodegradable food packaging materials.

Development and characterisation of agar/silver nanoparticles-based film from Gracilaria canaliculata for food packaging

Gracilaria canaliculata was used as a novel source to extract agar, and for the green synthesis of silver nanoparticles. Silver nanoparticles (0.1 - 0.3%) were incorporated into the agar matrix to develop an environment-friendly food packaging material using the solution casting method. The concentration of nanoparticles affected the physical, thermal, and mechanical properties of the films. Films containing higher concentrations of silver nanoparticles exhibited promising properties, and demonstrated strong antimicrobial activity against both Gram-negative and Gram-positive foodborne pathogens. The film formulation exhibited no cytotoxic effect on HepG2 cells, with cell viability exceeding 94%. These findings suggested that the film possessed favourable characteristics for use as a food packaging material, presenting a potential alternative to plastics.

Cinnamon essential oil induced microbial stress metabolome indicates its active food packaging efficiency when incorporated into poly vinyl alcohol, engineered with zinc oxide nanoparticles and nanocellulose

In the study, Poly Vinyl Alcohol (PVA) films engineered with the nanoparticles and essential oils have been developed as efficient alternative to the currently used food packaging materials. For this, impact of cinnamon essential oil (CEO), on the metabolomic profile of Staphylococcus aureus, Escherichia coli and Aspergillus flavus was analysed. Subsequently, PVA based nanocomposite films CEO, zinc oxide nanoparticles (ZnONPs), and nanocellulose (NC) were synthesised and characterized by FT-IR analysis. By the GC–MS analysis. The presence of ZnONPs enhanced the release of cinnamaldehyde from 31.16 to 44.23 and further enhancement to 71.82 was seen the presence of nanocellulose. The incorporation of NPs was found to enhance the hydrodynamic and mechanical properties of the prepared films. The final developed films, PZNCCEO, showed the least values for WHC and MC which were 56.31 ± 2.12 % and 13.30 ± 0 % respectively. Antimicrobial efficacy could also be demonstrated through the observation on changes in the morphological features of treated S. aureus and E. coli by the FE-SEM. Finally, the developed nanocomposite film was found to have the potential for food packaging as demonstrated through the protection of corn kernals and Vigna unguiculata.

Using interfacial behavior and adsorption kinetics measurements as a predictor of bulk hydrophobic development of paper supercritically impregnated with food-grade waxes

Supercritical Impregnation methods are becoming popular in the development of food packaging materials. Bulk functional improvements of cellulose substrates using this method may be influenced by interfacial interactions between the impregnated solutes and cellulose. Hence, an interfacial adsorption kinetics study of solute molecules onto the substrate can provide insight on bulk property development, leading to an optimized packaging material with improved functionality. Paper substrates were impregnated with two food-grade waxes: Alkyl Ketene Dimer (AKD) and Carnauba Wax (CW). Hydrophobic development was monitored over a 3-week period. A quartz crystal microbalance (QCM-D) was used to determine interfacial characteristics and behavior of each wax with cellulose, and adsorption kinetics were quantified to compare the mass transfer processes of each wax at the interface. AKD significantly contributed to the substrate’s hydrophobic development over time. CW generated mildly hydrophobic substrates only when heated. AKD strongly adhered to the cellulose fibers at the interface, and demonstrated a 3-stage kinetic adsorption process, tentatively assigned (i) diffusion through the solvent; (ii) diffusion through the substrate; and (iii) attachment onto the fibers. CW readily washed off the cellulose surface, demonstrating only the first adsorption process. The different chemical structures also impacted these behaviors, as did concentration and temperature.Graphical