Antibacterial LDPE/GSE/Mel/ZnONP composite film-coated wrapping paper for convenience food packaging application

Application of nano-ZnO in the food preservation industry: antibacterial mechanisms, influencing factors, intelligent packaging, preservation film and safety

In recent years, how to improve the functional performance of food packaging materials has received increasing attention. One common inorganic material, nanometer zinc oxide (ZnO-NPs), has garnered significant attention due to its excellent antibacterial properties and sensitivity. Consequently, ZnO-NP-based functional packaging materials are rapidly developing in the food industry. However, there is currently a lack of comprehensive and systematic reviews on the use of ZnO-NPs as functional fillers in food packaging. In this review, we introduced the characteristics and antibacterial mechanism of ZnO-NPs, and paid attention to the factors affecting the antibacterial activity of ZnO-NPs. Furthermore, we systematically analyzed the application of intelligent packaging and antibacterial packaging containing ZnO-NPs in the food industry. At the same time, this paper also thoroughly investigated the impact of ZnO-NPs on various properties including thickness, moisture resistance, water vapor barrier, mechanical properties, optical properties, thermal properties and microstructure of food packaging materials. Finally, we discussed the migration and safety of ZnO-NPs in packaging materials. ZnO-NPs are safe and have negligible migration rates, simultaneously their sensitivity and antibacterial properties can be used to detect the quality changes of food during storage and extend its shelf life.

Paper-based material with hydrophobic and antimicrobial properties: Advanced packaging materials for food applications

The environmental challenges posed by plastic pollution have prompted the exploration of eco-friendly alternatives to disposable plastic packaging and utensils. Paper-based materials, derived from renewable resources such as wood pulp, non-wood pulp (bamboo pulp, straw pulp, reed pulp, etc.), and recycled paper fibers, are distinguished by their recyclability and biodegradability, making them promising substitutes in the field of plastic food packaging. Despite their merits, challenges like porosity, hydrophilicity, limited barrier properties, and a lack of functionality have restricted their packaging potential. To address these constraints, researchers have introduced antimicrobial agents, hydrophobic substances, and other functional components to improve both physical and functional properties. This enhancement has resulted in notable improvements in food preservation outcomes in real-world scenarios. This paper offers a comprehensive review of recent progress in hydrophobic antimicrobial paper-based materials. In addition to outlining the characteristics and functions of commonly used antimicrobial substances in food packaging, it consolidates the current research landscape and preparation techniques for hydrophobic paper. Furthermore, the paper explores the practical applications of hydrophobic antimicrobial paper-based materials in agricultural produce, meat, and seafood, as well as ready-to-eat food packaging. Finally, challenges in production, application, and recycling processes are outlined to ensure safety and efficacy, and prospects for the future development of antimicrobial hydrophobic paper-based materials are discussed. Overall, the emergence of hydrophobic antimicrobial paper-based materials stands out as a robust alternative to plastic food packaging, offering a compelling solution with superior food preservation capabilities. In the future, paper-based materials with antimicrobial and hydrophobic functionalities are expected to further enhance food safety as promising packaging materials.

Hydrophobic, Sustainable, High-Barrier Regenerated Cellulose Film via a Simple One-Step Silylation Reaction

With the increasing importance of environmental protection, high-performance biopolymer films have received considerable attention as effective alternatives to petroleum-based polymer films. In this study, we developed hydrophobic regenerated cellulose (RC) films with good barrier properties through a simple gas-solid reaction via the chemical vapor deposition of alkyltrichlorosilane. RC films were employed to construct a biodegradable, free-standing substrate matrix, and methyltrichlorosilane (MTS) was used as a hydrophobic coating material to control the wettability and improve the barrier properties of the final films. MTS readily coupled with hydroxyl groups on the RC surface through a condensation reaction. We demonstrated that the MTS-modified RC (MTS/RC) films were optically transparent, mechanically strong, and hydrophobic. In particular, the obtained MTS/RC films exhibited a low oxygen transmission rate of 3 cm³/m² per day and a low water vapor transmission rate of 41 g/m² per day, which are superior to those of other hydrophobic biopolymer films.

Recent Advances and Progress on Melanin: From Source to Application

Melanin is a biological pigment formed by indoles and phenolic compounds. It is widely found in living organisms and has a variety of unique properties. Due to its diverse characteristics and good biocompatibility, melanin has become the focus in the fields of biomedicine, agriculture, the food industry, etc. However, due to the wide range of melanin sources, complex polymerization properties, and low solubility of specific solvents, the specific macromolecular structure and polymerization mechanism of melanin remain unclear, which significantly limits the further study and application of melanin. Its synthesis and degradation pathways are also controversial. In addition, new properties and applications of melanin are constantly being discovered. In this review, we focus on the recent advances in the research of melanin in all aspects. Firstly, the classification, source, and degradation of melanin are summarized. Secondly, a detailed description of the structure, characterization, and properties of melanin is followed. The novel biological activity of melanin and its application is described at the end.

Facile fabrication of green synthesized silver-decorated magnetic particles for coating of bioactive packaging

To avoid bacterial and viral infections on food products, the use of antibacterial and antiviral packaging offers great benefit to the food industry. In this study, the coating of paper packaging with silver-decorated magnetic particles (Ag@Fe₃O₄) was developed. The Ag@Fe₃O₄ was prepared by a facile and environmentally friendly method using extracted spent coffee grounds (ex-SCG). The effects of Ag@Fe₃O₄ content on properties of coated paper were investigated. The overall properties of coated paper improved when the Ag@Fe₃O₄ content increased up to 0.15%w/v. An increase in tensile strength of 154.01% and a decrease in water vapor permeability of 48.50% were found in coated paper with 0.15%w/v Ag@Fe₃O₄. Furthermore, the coated paper also exhibited the synergistic effect on antibacterial activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The release of metal ions in food simulants and kinetic release parameters were also studied. The release of silver ions and ferrous ions in food simulants met the requirement of overall migration limit of the European Standard. The paper coated with 0.15%w/v Ag@Fe₃O₄ had better capabilities to maintain quality and extend shelf-life of tomatoes. The obtained Ag@Fe₃O₄ coated paper is promising for bioactive food packaging to retain food freshness.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10570-022-04636-0.

Genipin-Crosslinked Gelatin/Chitosan-Based Functional Films Incorporated with Rosemary Essential Oil and Quercetin

Functional food packaging films were prepared using a binary mixture of chitosan and gelatin through crosslinking with genipin and hybridization with rosemary essential oil and quercetin. The mixture of chitosan and gelatin produced the compatible film, and the added fillers also showed good compatibility. The physical properties of the chitosan/gelatin film were not greatly affected by crosslinking with genipin, and the functionality of the composite film was increased by the addition of rosemary essential oil and quercetin. The bioactive additives did not significantly affect the hydrophobicity and water vapor barrier properties of the chitosan/gelatin film but significantly changed the color, while the mechanical and thermal properties were slightly affected. The addition of these functional fillers significantly improved the UV protection, antioxidant, and antibacterial properties of the chitosan/gelatin film. Therefore, the novel chitosan/gelatin film with genipin crosslinking and the integration of rosemary essential oil and quercetin is considered to have high potential for applications in active food packaging.

A Review of Nonbiodegradable and Biodegradable Composites for Food Packaging Application

The dependency on nonbiodegradable-based food packaging, increase in population growth, and persistent environmental problems are some of the driving forces in considering the development of biodegradable food packaging. This effort of green packaging has the potential to solve issues on plastic wastes through the combination of biodegradable composite-based food packaging with plant extracts, nanomaterials, or other types of polymer. Modified biodegradable materials have provided numerous alternatives for producing green packaging with mechanical strength, thermal stability, and barrier performance that are comparable to the conventional food packaging. To the best of our knowledge, the performance of nonbiodegradable and biodegradable composites as food packaging in terms of the above properties has not yet been reviewed. In this context, the capability of biodegradable polymers to substitute the nonbiodegradable polymers was emphasized to enhance the packaging biodegradation while retaining the mechanical strength, thermal stability, barrier properties, and antioxidant and antimicrobial or antibacterial activity. These are the ultimate goal in the food industry. This review will impart useful information on the properties of food packaging developed from different polymers and future outlook toward the development of green food packaging.

Self-assembled all-polysaccharide hydrogel film for versatile paper-based food packaging

Paper-based packaging generally has poor performances in the gas/oil barriers. This work reports a paper-based packaging material prepared via the modification of conventional papers with TEMPO-oxidized cellulose nanofibers (TOCN)/cationic guar gum (CGG) hydrogel film. Specifically, the hydrogel film modification was realized through a layer-by-layer deposition on paper. The hydrogel film modification significantly improved the mechanical and barrier properties of the paper. Specifically, the 4-layer hydrogel film modified paper showed a tensile strength of 34.03 MPa and a burst strength of 510 kPa, respectively. In contrast, the unmodified paper exhibited a tensile strength of 26.78 MPa and a bursting strength of 388 kPa. The packaging performance of this TOCN/CGG hydrogel film modified paper was demonstrated via the fresh mooncake packaging test. Such hydrogel film not only provided the oil resistance, but also maintained the mooncake's freshness. This material can serve as a green and sustainable food packaging.

Smart and Active Food Packaging: Insights in Novel Food Packaging

The demand for more healthy foods with longer shelf life has been growing. Food packaging as one of the main aspects of food industries plays a vital role in meeting this demand. Integration of nanotechnology with food packaging systems (FPSs) revealed promising promotion in foods’ shelf life by introducing novel FPSs. In this paper, common classification, functionalities, employed nanotechnologies, and the used biomaterials are discussed. According to our survey, FPSs are classified as active food packaging (AFP) and smart food packaging (SFP) systems. The functionality of both systems was manipulated by employing nanotechnologies, such as metal nanoparticles and nanoemulsions, and appropriate biomaterials like synthetic polymers and biomass-derived biomaterials. “Degradability and antibacterial” and “Indicating and scavenging” are the well-known functions for AFP and SFP, respectively. The main purpose is to make a multifunctional FPS to increase foods’ shelf life and produce environmentally friendly and smart packaging without any hazard to human life.

New insight into melanin for food packaging and biotechnology applications

Melanin is a dark brown to black biomacromolecule with biologically active multifunctional properties that do not have a precise chemical structure, but its structure mainly depends on the polymerization conditions during the synthesis process. Natural melanin can be isolated from various animal, plant, and microbial sources, while synthetic melanin-like compounds can be synthesized by simple polymerization of dopamine. Melanin is widely used in various areas due to its functional properties such as photosensitivity, light barrier property, free radical scavenging ability, antioxidant activity, etc. It also has an excellent ability to act as a reducing agent and capping agent to synthesize various metal nanoparticles. Melanin nanoparticles (MNP) or melanin-like nanoparticles (MLNP) have the unique potential to act as functional materials to improve nanocomposite films' physical and functional properties. Various food packaging and biomedical applications have been made alone or by mixing melanin or MLNP. In this review, the general aspects of melanin that highlight biological activity, along with a description of MNP and the use as nanofillers in packaging films as well as reducing and capping agents and biomedical applications, were comprehensively reviewed.

Carboxymethyl cellulose/cellulose nanocrystals immobilized silver nanoparticles as an effective coating to improve barrier and antibacterial properties of paper for food packaging applications

A new natural formulation composed of CMC and various contents of CNC immobilized AgNPs (CNC@AgNPs) was developed for paper coating. The mechanical strength, water vapor and air barrier properties, and antibacterial activities of CMC/CNC@AgNPs coated paper improved with the increasing content of CNC@AgNPs. CMC/CNC@AgNPs7 % coated paper exhibited 1.26 times increase in tensile strength, 45.4 % decrease in WVP, 93.3 % reduction in air permeability as well as the best antibacterial activities against E.coli and S.aureus compared with uncoated paper. Moreover, the cumulative release rate of AgNPs from coated paper significantly reduced due to the immobilization effect of CNC on AgNPs. Furthermore, CMC/CNC@AgNPs coated paper was used to package strawberries under ambient conditions. The results showed that coated paper could maintain better strawberries quality compared with unpackaged strawberries and extend the shelf-life of strawberries to 7 days. Therefore, the prepared CMC/CNC@AgNPs coated paper will have a great application prospect in the food packaging.