Preparation of antimicrobial active packaging film by capacitively coupled plasma treatment

Nanocomplexes film composed of gallic acid loaded ovalbumin/chitosan nanoparticles and pectin with excellent antibacterial activity: Preparation, characterization and application in coating preservation of salmon fillets

Active packaging has been recognized as an effective approach to extend the shelf life of food, but the rapid release of active substances limits the preservation effect. In this study, gallic acid (GA)-loaded ovalbumin (OVA)/chitosan (CS) nanoparticles with slow-release properties were prepared and embedded into the pectin matrix to refine the rapid release of GA in the pectin and elongate the shelf life of salmon fillets. Our results showed that GA could be released continuously from the OVA/CS nanoparticles. The pectin film incorporated with GA-loaded OVA/CS nanoparticles exhibited good light barrier and mechanical properties. The opacity value of the film reached 1.65 ± 0.06 UA/mm, and the tensile strength and elongation at break were 15.97 ± 1.55 MPa and 7.29 ± 0.42 %, respectively. In addition, the pectin film combined with GA-loaded OVA/CS nanoparticles showed improved antibacterial activity against two common biogenic amine-producing bacteria (Morganella morganii and Escherichia coli). Moreover, the nanocomposite film delayed salmon fillets' biogenic amine generation, and the shelf life was extended by 3 days compared with the control group. These promising properties supported using the GA-loaded OVA/CS nanoparticle-pectin films as preservation materials for fish.

Properties of active packaging of PLA-PCL film integrated with chitosan as an antibacterial agent and syzygium cumini seed extract as an antioxidant agent

Active packaging is becoming increasingly significant in the food industry. The present study aims to explore the use of Syzygium Cumini Seed Extract (SCSE) as an antioxidant and chitosan as an antibacterial agent to produce active packaging based on polylactic acid (PLA), poly ε-caprolactone (PCL), and polyethylene glycol (PEG) blend. Using advanced characterization techniques, active packaging (PLA/PCL/PEG) incorporating with 0.5 g chitosan-0.5 mL SCSE was evaluated for its mechanical, physical, structural, and antibacterial-antioxidant properties. The addition of chitosan-SCSE caused an 18.57 % increase in tensile strength and decreased the Water Vapor Transmission Rate (WVTR) by up to 52 %, whereas smooth surface microscopy indicated good compatibility between polymers and active agents. Active packaging incorporating chitosan-SCSE reduced 96.66 % of Gram-positive bacteria Staphylococcus aureus and 73.98 % of Gram-negative bacteria, Escherichia coli. During 15 days of storage, the active packaging was able to slow the increase in Total Volatile Basic Nitrogen (TVBN) in beef and prevent the decrease in vitamin C contents in pineapple.

Cold Plasma Technology Based Eco-Friendly Food Packaging Biomaterials

Biopolymers have intrinsic drawbacks compared to traditional plastics, such as hydrophilicity, poor thermo-mechanical behaviours, and barrier characteristics. Therefore, biopolymers or their film modifications offer a chance to create packaging materials with specified properties. Cold atmospheric plasma (CAP) or Low temperature plasma (LTP) has a wide range of applications and has recently been used in the food industry as a potent tool for non-thermal food processing. Though its original purpose was to boost polymer surface energy for better adherence and printability, it has since become an effective technique for surface decontamination of food items and food packaging materials. These revolutionary innovative food processing methods enable the balance between the economic constraints and higher quality while ensuring food stability and minimal processing. For CAP to be considered as a viable alternative food processing technology, it must positively affect food quality. Food products may have their desired functional qualities by adjusting the conditions for cold plasma formation. Cold plasma is a non-thermal method that has little effects on the treated materials and is safe for the environment. In this review, we focus on recent cold plasma advances on various food matrices derived from plants and animals with the aim of highlighting potential applications, ongoing research, and market trends.

Advances in the application of functional nanomaterial and cold plasma for the fresh-keeping active packaging of meat

The most recent advancements in food science and technology include cold sterilization of food and fresh-keeping packaging. Active packaging technology has received much interest due to the photocatalytic activity (PCA) of functional nanoparticles, including titanium dioxide (TiO2) and ferric oxide (Fe2O3). However, there are still significant concerns about the toxicity and safety of these functional nanoparticles. This review emphasizes the bacteriostatic and fresh-keeping properties of functional nanoparticles as well as their packaging strategies using the ultraviolet photo-catalysis effect. High-voltage electric field cold plasma (HVEF-CP) is the most innovative method of cold-sterilizing food. HVEF-CP sterilizes by producing photoelectrons, ions, and active free radicals on food media, which come into contact with the bacteria's surface and destroy their cells. Next, this review also assesses the photocatalytic activity and bacteriostasis kinetics of nanosized TiO2 and Fe2O3 in poultry, beef, and lamb. In addition, this review also emphasizes the importance of exploiting the complex interaction processes between TiO2 and Fe2O3, along with dietary components and their utilization in the fresh meat industry.

Effect of alginate-gallic acid coating on freshness and flavor properties of Mackerel (Scomberomorus commerson) fillets under refrigerated storage

This study investigates the effect of sodium alginate-gallic acid (ALG-GAL) coating on mackerel's flavor compounds and quality properties during cold storage at 4 °C for 12 days. To this end, freshness quality indicators, including biogenic amines (BAs), volatile organic compounds (VOCs), ATP-related compounds, K value, total viable counts (TVC), thiobarbituric acid (TBA), and sensory assessment, were measured. During storage, eight BAs, i.e., histamine (HIS), tyramine (TYR), putrescine (PUT), cadaverine (CAD), 2-phenylethylamine (2-PHE), agimation, spermine (SPM), and spermidine (SPD) were identified in control and treated samples. The biogenic amine index (BAI) for control samples was 56.25 at the time of sensory rejection (day 6). BAI for samples coated with ALG-GAL did not exceed 20 mg/100 g at the time of sensory rejection (day 12). The fillets treated with the ALG alone or incorporated with GAL possessed a different trend in the retardation of VOCs, including aldehydes, ketones, alcohols, and hydrocarbons. Seven key flavors VOCs, including 3-methylbutanal, phenylacetaldehyde, E-2-hexanal, 1-hexanol, 1-octen-3-ol, 2,3 pentanedione, and hydroxyl-2-butanone, were identified in control and coated samples. Samples coated with ALG and GAL were of significantly higher quality (p < 0.05) throughout storage, which could result in lower Inosine (HxR) concentrations and K values. The results of TVC showed that use ALG-GAL had lower bacterial counts compared to control (p < 0.05). The ALG-GAL-coated samples retarded the increase in the contents of TBA during storage. In addition, significant differences in sensory scores between ALG and ALG-GAL were observed (p < 0.05). In this study, aldehydes and hypoxanthine (Hx) were the main compounds in the formation of off-flavor. These results revealed that ALG coating combined with GAL improved the quality of refrigerated mackerel fillets by decreasing off-flavor compounds and TVC population.

Cold plasma treatment to prepare active polylactic acid/ethyl cellulose film using wheat germ peptides and chitosan

In this study, the surface of the polylactic acid/ethyl cellulose (PLA/EC) blend film was modified by dielectric barrier discharge (DBD) plasma treatment to facilitate the spin-coating of chitosan (CH) and wheat germ bioactive peptides (PEP) obtained from enzymatic hydrolysis of defatted wheat germ protein isolate on the surface of the film. The suitable plasma treatment condition was 5 min at 20 kV according to ATR-FTIR, AFM, SEM, water angle contact, and water solubility results. Increasing the surface roughness and oxygen-containing functional groups (CO and -OH) improved coating by PEP and CH. The PEP-coated film had better antioxidant activity than CH-PEP and CH-coated films. The results of antimicrobial activity demonstrated that PEP-coated film could reduce the growth of gram-negative bacteria (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). The PEP-coated film had competitive antibacterial properties with CH-coated. Hence, the obtained PEP-coated PLA/EC film could be a promising candidate for antioxidant and antibacterial food packaging.

Applications of atmospheric cold plasma in agricultural, medical, and bioprocessing industries

Abstract

Atmospheric cold plasma (ACP) is a nonthermal technology that is extensively used in several industries. Within the scopes of engineering and biotechnology, some notable applications of ACP include waste management, material modification, medicine, and agriculture. Notwithstanding numerous applications, ACP still encounters a number of challenges such as diverse types of plasma generators and sizes, causing standardization challenges. This review focuses on the uses of ACP in engineering and biotechnology sectors in which the innovation can positively impact the operation process, enhance safety, and reduce cost. Additionally, its limitations are examined. Since ACP is still in its nascent stage, the review will also propose potential research opportunities that can help scientists gain more insights on the technology.

Key points

• ACP technology has been used in agriculture, medical, and bioprocessing industries.

• Chemical study on the reactive species is crucial to produce function-specific ACP.

• Different ACP devices and conditions still pose standardization problems.

Attempt to Extend the Shelf-Life of Fish Products by Means of Innovative Double-Layer Active Biodegradable Films

In this study, we aimed to produce, innovative and, at the same time, environmentally-friendly, biopolymer double-layer films with fish processing waste and active lingonberry extract as additives. These double-layered films were based on furcellaran (FUR) (1st layer) and carboxymethyl cellulose (CMC) with a gelatin hydrolysate (HGEL) (2nd layer). The aim of the study was to assess their impact on the durability of perishable salmon fillets during storage, and to evaluate their degree of biodegradation. The fillets were analyzed for changes in microbiological quality (total microbial count, yeast and molds, and psychrotrophic bacteria), biogenic amine content (HPLC), and lipid oxidation (peroxidase and acid values, TBARS). The degree of biodegradation includes analysis of film and compost chemical composition solubility, respiratory activity, and ecotoxicity testing. The obtained results allow to suggest that active films are not only bacteriostatic, but even bactericidal when they used to coat fish fillets. Concerning the group of samples covered with the double-layer films, a 19.42% lower total bacteria count was noted compared to the control samples. Furthermore, it can be observed that the applied double-layer films have a potentially strong inhibitory effect on the accumulation of biogenic amines in fish, which is correlated with its antimicrobial effect (the total biogenic amine content for control samples totaled 263.51 mg/kg, while for the double-layer samples, their value equaled: 164.90 mg/kg). The achieved results indicate a high biodegradation potential, however, a too low pH of the film results in limiting seed germination and growth. Despite that, of these, double-layer films are a technology that has applicative potential.

Cold Plasma-Based Fabrication and Characterization of Active Films Containing Different Types of Myristica fragrans Essential Oil Emulsion

Myristica fragrans essential oil (MFEO) is a potential active compound for application as an active packaging material. A new approach was developed using a cold plasma treatment to incorporate MFEO to improve the optical, physical, and bacterial inhibition properties of the film. The MFEO was added as coarse emulsion (CE), nanoemulsion (NE), and Pickering emulsion (PE) at different concentrations. The PE significantly affected (p < 0.05) the optical, physical, and chemical properties compared with CE and NE films. The addition of MFEO to low-density polyethylene (LDPE) film significantly reduced water vapor permeability (WVP) and oxygen permeability (OP) and showed marked activity against E. coli and S. aureus (p < 0.05). The release rate of PE films after 30 h was 70% lower than that of CE and NE films. Thus, it can be concluded that the fabrication of active packaging containing MFEO is a potential food packaging material.

Effect of Cold Plasma Treatment on the Packaging Properties of Biopolymer-Based Films: A Review

Biopolymers, like polysaccharides and proteins, are sustainable and green materials with excellent film-forming potential. Bio-based films have gained a lot of attention and are believed to be an alternative to plastics in next-generation food packaging. Compared to conventional plastics, biopolymers inherently have certain limitations like hydrophilicity, poor thermo-mechanical, and barrier properties. Therefore, the modification of biopolymers or their films provide an opportunity to develop packaging materials with desired characteristics. Among different modification approaches, the application of cold plasma has been a very efficient technology to enhance the functionality and interfacial characteristics of biopolymers. Cold plasma is biocompatible, shows uniformity in treatment, and is suitable for heat-sensitive components. This review provides information on different plasma generating equipment used for the modification of films and critically analyses the impact of cold plasma on packaging properties of films prepared from protein, polysaccharides, and their combinations. Most studies to date have shown that plasma treatment effectively enhances surface characteristics, mechanical, and thermal properties, while its impact on the improvement of barrier properties is limited. Plasma treatment increases surface roughness that enables surface adhesion, ink printability, and reduces the contact angle. Plasma-treated films loaded with antimicrobial compounds demonstrate strong antimicrobial efficacy, mainly due to the increase in their diffusion rate and the non-thermal nature of cold plasma that protects the functionality of bioactive compounds. This review also elaborates on the existing challenges and future needs. Overall, it can be concluded that the application of cold plasma is an effective strategy to modify the inherent limitations of biopolymer-based packaging materials for food packaging applications.

Development of Active Packaging to Extend the Shelf Life of Agaricus bisporus by Using Plasma Technology

In this study, a preservation package that can extend the shelf life of Agaricus bisporus was developed using plasma modification combined with low-density polyethylene (LDPE), collagen (COL), and carboxymethyl cellulose (CMC). Out results showed that the selectivity of LDPE to gas can be controlled by plasma modification combined with coating of different concentrations of CMC and COL. Packaging test results applied to A. bisporus showed that 3% and 5% of CMC and COL did not significantly inhibit polyphenol oxidase and β-1,3-glucanase, indicating no significant effect on structural integrity and oxidative browning. The use of 0.5% and 1.0% CMC and COL can effectively inhibit the polyphenol oxidase and β-1,3-glucanase activity of A. bisporus, leading to improved effects in browning inhibition and structural integrity maintenance. P-1.0COL can effectively maintain gas composition in the package (carbon dioxide: 10–15% and oxygen: 8–15%) and catalase activity during storage, thereby reducing the oxidative damage caused by respiration of A. bisporus. The current study confirmed that the use of plasma modification technology combined with 1.0% COL can be used in preservation packaging by regulating the respiration of A. bisporus, thus extending its shelf life from 7 to 21 days.

Progresses in Food Packaging, Food Quality, and Safety-Controlled-Release Antioxidant and/or Antimicrobial Packaging

Food packaging is designed to protect foods, to provide required information about the food, and to make food handling convenient for distribution to consumers. Packaging has a crucial role in the process of food quality, safety, and shelf-life extension. Possible interactions between food and packaging are important in what is concerning food quality and safety. This review tries to offer a picture of the most important types of active packaging emphasizing the controlled/target release antimicrobial and/or antioxidant packaging including system design, different methods of polymer matrix modification, and processing. The testing methods for the appreciation of the performance of active food packaging, as well as mechanisms and kinetics implied in active compounds release, are summarized. During the last years, many fast advancements in packaging technology appeared, including intelligent or smart packaging (IOSP), (i.e., time-temperature indicators (TTIs), gas indicators, radiofrequency identification (RFID), and others). Legislation is also discussed.

A review on techniques utilized for design of controlled release food active packaging

Active packaging (AP) is a new class of innovative food packaging, containing bioactive compounds, is able to maintain the quality of food and extend its shelf life by releasing active agent during storage. The main challenge in designing the AP system is slowing the release rate of active compounds for its prolonged activity. Controlled-release active packaging (CRP) is an innovative technology that provides control in the release of active compounds during storage. Various approaches have been proposed to design CRP. The purpose of this review was to gather and present the strategies utilized for release controlling of active compounds from food AP systems. The chemical modification of polymers, the preparation of multilayer films and the use of cross-linking agents are some methods tried in the last decades. Other approaches use molecular complexes and irradiation treatments. Micro- or nano-encapsulation of active compounds and using nano-structured materials in the AP film matrix are the newest techniques used for the preparation of CRP systems. The action mechanism for each technique was described and an effort was made to highlight representative published papers about each release controlling approach. This review will benefit future prospects of exploring other innovative release controlling methods in food CRP.