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Cellulose-based packaging has received great attention due to its characteristics of biodegradability, sustainability, and recyclability. Natural polymer coatings are usually applied to the paper surface to enhance the barriers to water vapour and improve the mechanical properties. A chitosan-based coating for paper packaging was developed in this work to store specialty roasted coffee beans, evaluating two samples of chitosan (Sigma® and molasses chitosan), and following the physico-chemical and microbiological characteristics of coffee beans along a period of 60 days. Sensory tests (Ranking Descriptive Analysis and Preference Test) were applied to the beverage prepared with the roasted and ground coffee beans stored in each packaging. Thin chitosan films provided good coverage and adhesion on the paper. Improved mechanical properties and lower water permeability were observed in the chitosan-coated papers. The physicochemical and microbiological characteristics of the coffee beans were not influenced by the packaging along 60 days of storage. The molasses chitosan coating resulted in slightly darker roasted beans. In sensory evaluation, there is a clear difference between the chitosan samples, so that molasses chitosan-coated packaging had higher scores compared to Sigma® chitosan treatment for flavor and global impression in the preference analysis of the beverage. The molasses chitosan-coated packaging had three to four more consumers attributing the highest scores for the beverage prepared with the roasted beans stored in this type of packaging., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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., (© 2024 Institute of Food Technologists®.)

The demand for paper-based packaging materials as an alternative to incumbent disposable petroleum-derived polymers for food packaging applications is ever-growing. However, typical paper-based formats are not suitable for use in unconventional applications due to inherent limitations (e.g., excessive hydrophilicity, lack antimicrobial ability), and accordingly, enabling new capabilities is necessity. Herein, a simple and environmentally friendly strategy was proposed to introduce antimicrobial and hydrophobic functions to cellulose paper through successive chemical grafting of 3-aminopropyltriethoxysilane (APS) and cinnamaldehyde (CA). The results revealed that cellulose paper not only showed long-term antibacterial effect on different bacteria, but also inhibited a wide range of fungi. Encouragingly, the modified paper, which is fluorine-free, displays a high contact angle of 119.7°. Thus, even in the wet state, the modified paper can still maintain good mechanical strength. Meanwhile, the multifunctional composite papers have excellent biocompatibility and biodegradability. Compared with ordinary cellulose paper, multifunctional composite paper can effectively prolong the shelf life of strawberries. Therefore, the multifunctional composite paper represents good application potential as a fruit packaging material., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Per- and polyfluoroalkyl substances (PFAS) analysis has become crucial due to their presence in the environment, their persistence and potential health risks. These compounds are commonly used in food contact materials (FCM) as a coating to provide water and grease-repellent properties. One of the pathways for PFAS to enter the human body is either through direct consumption of contaminated food or indirectly through migration from FCM into food. The purpose of this study was to investigate where the initial contamination of paper FCM occurs. We analysed paper material consisting of fresh fibre and secondary materials, intended to produce food packaging for the presence of PFAS. The samples were extracted and analysed for 23 different PFAS substances using the targeted approach with LC tandem mass spectrometry (LC-MS/MS). This analytical technique detects specific, easily ionisable PFAS with high sensitivity. However, one drawback of this approach is that it allows the identification of less than 1% of the PFAS known today. For this reason, we used combustion ion chromatography (CIC) to determine the content of extractable organic fluorine compounds (EOF) and compare it to the total fluorine content. The targeted analysis using LC-MS/MS measured an average sum concentration of PFAS of 0.17 ng g -1 sample. Our research shows that the primary PFAS contamination happens during the recycling process since all of the samples in which the targeted PFAS were measured belonged to the secondary material. The most frequently detected analytes were PFOA and PFOS, detected in 90% and 62% of the samples, respectively, followed by PFBS (in 29% of the samples). CIC showed that measured PFAS via LC-MS/MS amount to an average of 2.7 × 10 -4 % of total fluorine content, whereas the EOF was under the LOD in all of the measured samples. This result highlights the complexity of the accurate determination of PFAS compounds, displaying what kind of information the chosen methods provide.

Nanoplastics (NPs, <1 µm) pose greater risks due to their increased absorption rates in biological systems. In this study, we investigated the release of NPs from paper cups and microwavable food containers coated with low-density polyethylene (LDPE) and polylactic acid (PLA). For disposable paper cups, we found that LDPE-coated cups released up to 26-fold more NPs (maximum 1.9 × 10 7 per cup) than PLA-coated ones. The NPs release from LDPE-coated cups was increased at high temperatures above 80 °C, and further increased by physical agitation. However, negligible NP release was observed when the inner coating thickness exceeded 1 mm. For microwavable food containers, those with PLA coatings were more susceptible to the effects of microwave. Depending on the cooking time, we noticed a significant difference (up to 40000 times) in the number of released NPs between LDPE and PLA coatings. Additionally, higher microwave power level led to an increase of NPs, even with constant total energy input. Considering the release of NP, PLA coatings for disposable paper cups and LDPE coatings for microwavable food containers seem more suitable. Furthermore, our results suggest that multi-use cups significantly reduce NPs release due to their material thickness, making them a safer alternative to disposable ones., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This study evaluated the production of marine biodegradable plastics, specifically polyhydroxyalkanoates (PHAs), using waste paper from food containers as a novel material source. The results showed that adding dilute sulfuric acid as a pretreatment may have a negative impact on enzyme hydrolysis efficiency. Without pretreatment, the highest glucose concentration was observed in the 50-min heating group. In the experimental group with 1% dilute sulfuric acid as a pretreatment, the highest average glucose concentration was observed in the 25-min treatment group. In flask scale experiments, the C/N ratio was controlled at 10, 20, and 30. The results showed that when the C/N ratio was 10, the PHA/CDM ratios were 16.3 and 23.6 at 48 and 72 h, respectively. After 96 h of cultivation using hydrolysis liquid from the waste paper container as the sole carbon source in a 5-L scale experiment, the PHA/CDM ratio was 28.7 and the PHA concentration was 0.95 g/L. The potential bacterial strain in this study was confirmed to be a Bacillus genus bacterium after strain identification. The signal peaks indicated that the PHA obtained from the Bacillus sp. production process was PHB. [ABSTRACT FROM AUTHOR]

In the realm of food waste recycling, industrial suberoligneous by‐products like cork and peels, pose a challenge for value‐added conversion, primarily due to their intricate structures. This study introduces an innovative approach by utilizing recycled cork as a prime example of repurposing food waste to create a reusable and durable packaging paper. Notably, the manufacturing process of this cork‐based paper avoids the generation of waste liquids from lignin removal, effectively alleviating concerns related to liquid waste pollution. The resulting packaging paper demonstrates remarkable printability, readability, and erasability while offering reusability. Its performance can be fine‐tuned through pH value adjustments. Moreover, this packaging paper exhibits outstanding antioxidative properties and barrier properties, seamlessly integrating superb UV‐blocking proficiency and heightened visible transparency, rendering it highly appealing for sustainable food packaging applications. [ABSTRACT FROM AUTHOR]

• The PBAT/PLA coated paper shows high methane yield under AD condition. • Plastic film residues remain after the digestion of PBAT/PLA coated paper. • The decrease of hydrophobicity for PBAT/PLA bags is due to the formation of PLA monomers. • The bacterial community shows difference between PBAT/PLA coated paper and bags. • Methanoculleus is enriched on the plastic surface under mesophilic AD. Poly (lactic acid) (PLA) and Poly(butylene adipate-co-terephthalate) (PBAT) are two of biodegradable plastics with the highest production capacities in 2021. Bioplastic waste management can be easily integrated with organic waste management, especially when bioplastics are used as food packaging material, since they are potentially biodegradable. The aim of this study was to assess the biodegradability of biodegradable polymer-coated paper (BPCP) and bioplastic bags made from PBAT/PLA blend during mesophilic and thermophilic anaerobic digestion (AD) and to reveal the changes in the physicochemical properties of the bioplastics. BPCP obtained 155 NmL-CH 4 /g VS and 307.3 NmL-CH 4 /g VS under mesophilic and thermophilic conditions, respectively, but left bioplastic film residues. The bioplastic bags did not exhibit significant biodegradation during the AD processes. 1H NMR results indicated that the ratio of PLA to PBAT decreased significantly after AD of the BPCP film and that PLA monomers were formed from the bioplastic bags, leading to a decrease in the hydrophobicity on the surfaces of the materials. Methanoculleus was found to be enriched on the bioplastic surface after mesophilic AD. From the perspective of coupling bioplastic waste management with the food waste management, the incorporation of BPCP into the AD reactor not only enhances system stability and methane production to a greater extent than biodegradable plastic bags but also raises concerns regarding the residual biofilm when utilizing the digestate for direct land applications. [ABSTRACT FROM AUTHOR]

Traditional food packaging coated paper is not environmentally friendly, and there have been many studies on oil- and water-resistant paper for food packaging. However, preparing oil- and water-resistant paper that is plastic-free, fluorine-free, and environmentally friendly is still a significant challenge. In this study, oil- and water-resistant paper for food packaging are prepared by layer-by-layer assembly and mixing coating methods. The layer-by-layer assembly coated paper exhibits excellent water resistance (Cobb 60 value of 20.5 g/m2, water contact angle value of 132°). The mixed coated paper not only has good water resistance (Cobb 60 value of 27.1 g/m2, water contact angle value of 131°), but also has excellent oil resistance (kit rating value of 8/12). The oil-resistant and waterproof mechanism of the coated paper is confirmed through scanning electron microscopy. In addition, the mechanical performance and coating adhesion of the mixed coated paper are the best, with an increase in the tensile index of 73.1 %. This study provides a feasible strategy for preparing biodegradable, plastic-free, and fluorine-free food packaging oil- and water-resistant paper, which is beneficial for reducing plastic pollution. [ABSTRACT FROM AUTHOR]

With the implementation of the "plastic restriction order" and the demand for sustainable society development, biodegradable coatings derived from biomass materials have garnered significant interest. This study presents the synthesis of a double‐salt bio‐based waterborne polyurethane (PLA‐WPU) by utilizing poly(lactic acid) polyol (PLA) and isophorone diisocyanate (IPDI) as the main raw materials, along with 2,2‐dihydroxymethylpropionic acid (DMPA) and sodium ethylenediamine ethanesulfonate (A‐95) as a hydrophilic chain extender. Synergistic reinforcement of PLA‐WPU using hydrophobically modified cellulose nanocrystals (M‐CNC) and polycarbonate diimide (PDCDA). At an M‐CNC content of 3% relative to the effective mass of PLA‐WPU, the tensile strength reached 36.12 MPa. After 8 days a lipase PBS solution, the degradation rate reached 54%. Excellent waterproof performance was observed, exhibiting a contact angle of 143.5°. When applied as a surface coating on kraft paper, the Cobb 60 value decreased from 74.0 to 28.6 g/m2, while increasing the tensile strength by 451.3%. Importantly, the kraft paper maintained excellent waterproofing, mechanical strength, and high barrier properties even after repeated folding, high and low‐temperature conditions, and exposure to varying pH solutions. It proved to be both degradable and recyclable, making it a promising alternative to liner paper or plastic membrane, especially in food packaging. [ABSTRACT FROM AUTHOR]

The characteristics of fiber morphology and paper structure are critical to the barrier properties of food packaging paper. Herein, this study aimed to use pulp fibrillation, paper semi-dry pressing and carboxymethyl starch (CMS) coating to flatten the fibers, which were formed on the paper surface with good barrier properties due to the tight bond between fibers. The results showed that the permeability of paper was reduced by 87.56%, from 81.44 μm/Pa·s to 10.13 μm/Pa·s after the pulp fibrillation treatment (60 °SR). Moreover, semi-dry pressing treatment contributed to decreasing the water vapor transmission coefficient (WVP) by 50.98% to 2.74 × 10−10 g/m·s·Pa, and the oxygen permeation coefficient (OP) decreased by 98.04% to 1.93 × 10−14 cm3·cm/cm2·s·Pa. After coating the paper surface with titanium dioxide (TiO2) and CMS, the WVP of the paper was further reduced to 1.55 × 10−10 g/m·s·Pa, and OP was reduced to 0.19 × 10−14 cm3·cm/cm2·s·Pa. These values were 72.27% and 99.8% lower than those of the original paper, respectively. Therefore, through pulp fibrillation, semi-dry pressing of paper, TiO2 filling, and surface coating with CMS, there is no need to use synthetic polymer surface film-forming agents to achieve the high barrier properties that are required for low water and oxygen molecules permeation in food packaging paper.

The residue of fungicides in food packaging paper materials is one of the important factors leading to food safety problems, which poses a serious threat to public health. (2-benzothiazolylthio) methyl thiocyanate (TCMTB) is an important anti-mildew fungicide, which is widely used in wood and paper industry. In order to ensure the health of consumers, it is of great significance to establish an efficient and sensitive rapid detection method for TCMTB in food packaging materials. In this study, we prepared monoclonal antibody (mAb) against TCMTB with the IC 50 value of 7.60 ng/mL, and subsequently developed an immunochromatographic assay (ICA) strip based on the mAb for the rapid detection of TCMTB residues. The calculated detection limit of the ICA strip in food packaging paper was 3.20 ng/g, and the recovery rate was within an acceptable range, ranging from 97.7% to 102.7%. Therefore, the developed ICA is expected to realize the rapid screening of TCMTB residues in food packaging paper. [ABSTRACT FROM AUTHOR]

Renewable materials and material circularity are key priorities for the coming decades. While paper is the most utilized material in the packaging sector, its applications in food packaging are limited due to low barrier properties. Coating it with petroleum-based polymer barrier coatings renders it unrecyclable both mechanically and biologically. Bio-coated paper packaging, made from agricultural waste or by-products, presents environmentally favorable solutions that can benefit the biological cycle of the circular economy. The main objective of this study is to assess the applicability of grain and beer production by-products in wood pulp food packaging materials. It examines the effects of different grain by-products (industrial wheat grain processing residues and wheat bran) particles and concentrations (15 wt% and 40 wt%), as well as the impact of brewer's yeast (Saccharomyces cerevisiae) at a concentration of 10 wt%, on the physical–mechanical and barrier properties of Northern bleached softwood kraft (NBSK) and chemithermomechanical (CTMP) pulps. Material composites were fabricated using a standard sheet forming method. Physical–mechanical properties were analyzed through tensile strength, strain at break, tear resistance, and bending stiffness tests. Barrier-related properties were analyzed through roughness, air permeance, and water contact angle tests. Results revealed that the vast majority of physical–mechanical properties decreased with the increase of both types of grain production fillers. Industrial wheat grain processing residues had a lower impact on physical–mechanical properties than wheat bran filler. A higher percentage of property decrease was absorbed in NBSK pulp than in CTMP. Roughness of CTMP can be improved by adding both industrial wheat grain processing residues and wheat bran. Wheat bran particles can increase hydrophobicity. CTMP pulp strength properties can be increased with the addition of yeast; however, the yeast additive's effect on air permeance demonstrated a negative impact. In the case of NBSK pulp, which has higher primary strength properties, the addition of yeast does not make any significant changes. The conducted experiments demonstrated that, overall, the addition of these fillers resulted in a decline in physical–mechanical properties such as tensile strength, strain at break, tear resistance, and bending stiffness. This decline was more pronounced with higher concentrations of fillers. In the case of CTMP pulp, both types of fillers exhibited similar trends in affecting properties, whereas for NBSK pulp, wheat bran had a more significant impact compared to wheat grain processing residues. The addition of yeast generally led to a reduction in physical–mechanical properties, particularly in tensile strength and tear resistance. However, samples containing yeast displayed increased flexibility compared to controls. The influence on barrier properties varied: while yeast increased air permeability, it also enhanced surface hydrophobicity, thereby reducing the paper's receptivity to liquids. [ABSTRACT FROM AUTHOR]

The preparation of biodegradable mulch film with paper-based materials has become a significant focus in mulch film development due to the serious pollution caused by plastic mulch film. This study utilized the esterification cross-linking reaction of LA, PVA, and GA to coat the surface of paper as the substrate. FTIR, TGA, XRD, SEM, tensile testing, and oxygen, water vapor barrier performance tests were performed. The optimal conditions for film preparation were determined to be a 10 % PVA aqueous solution, 5 % GA content, and a PVA/LA/GA ratio of 1:2:1. The resulting film paper exhibited a dry strength of 6.52 kN/m, a wet strength of 0.23 kN/m, a tearing degree of 969.35 mN, a Cobb value of 12.04 g/m2, a water vapor transmission rate of 573.27 g m−2 24 h−1, and an oxygen transmission rate of 7.373 cm3 m−2 24 h−1. After a 6-week landfill degradation test, the film showed a degradation rate of 25.3 %, while still maintaining a tensile strength of 1.89 kN/m. Field application tests in greenhouses confirmed that the film paper facilitated the growth of strawberry, its mechanical and barrier properties suitable for a biodegradable paper mulch. [ABSTRACT FROM AUTHOR]

In this research work, a coated paper was prepared with poly (butylene adipate-co-terephthalate) (PBAT) film to explore its use in eco-friendly food packaging. The paper was coated with PBAT film for packaging using hot pressing, a production method currently employed in the packaging industry. The coated papers were evaluated for their structural, mechanical, thermal, and barrier properties. The structural morphology and chemical analysis of the coated paper confirmed the consistent formation of PBAT bi-layered on paper surfaces. Surface coating with PBAT film increased the water resistance of the paper samples, as demonstrated by tests of barrier characteristics, including the water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and water contact angle (WCA) of water drops. The transmission rate of the clean paper was 2010.40 cc m−2 per 24 h for OTR and 110.24 g m−2 per 24 h for WVTR. If the PBAT-film was coated, the value decreased to 91.79 g m−2 per 24 h and 992.86 cc m−2 per 24 h. The hydrophobic nature of PBAT, confirmed by WCA measurements, contributed to the enhanced water resistance of PBAT-coated paper. This result presents an improved PBAT-coated paper material, eliminating the need for adhesives and allowing for the fabrication of bi-layered packaging. [ABSTRACT FROM AUTHOR]

In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties were examined using a uniaxial tensile tester, revealing that starch coated with the highest G-AgNPs concentration (12.75 ppm) exhibited UTS of 87.6 MPa compared to 48.48 MPa of control paper, a significant (p < 0.02) 65% increase. The assessment of the WVP showcased a statistical reduction in permeability by up to 8% with the incorporation of the hydrophobic layer. Furthermore, antibacterial properties were assessed following ISO 22196:2011, demonstrating a strong and concentration-dependent activity of G-AgNPs against E. coli. All samples successfully disintegrated in both simulated environments (soil and seawater), including samples presenting G-AgNPs. In the food trial analysis, the presence of starch and G-AgNPs significantly reduced weight loss after 6 days, with cherry tomatoes decreasing by 8.59% and green grapes by 6.77% only. The results of this study contribute to the advancement of environmentally friendly packaging materials, aligning with the UN sustainable development goals of reducing food waste and promoting sustainability. [ABSTRACT FROM AUTHOR]

In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties were examined using a uniaxial tensile tester, revealing that starch coated with the highest G-AgNPs concentration (12.75 ppm) exhibited UTS of 87.6 MPa compared to 48.48 MPa of control paper, a significant (p < 0.02) 65% increase. The assessment of the WVP showcased a statistical reduction in permeability by up to 8% with the incorporation of the hydrophobic layer. Furthermore, antibacterial properties were assessed following ISO 22196:2011, demonstrating a strong and concentration-dependent activity of G-AgNPs against E. coli. All samples successfully disintegrated in both simulated environments (soil and seawater), including samples presenting G-AgNPs. In the food trial analysis, the presence of starch and G-AgNPs significantly reduced weight loss after 6 days, with cherry tomatoes decreasing by 8.59% and green grapes by 6.77% only. The results of this study contribute to the advancement of environmentally friendly packaging materials, aligning with the UN sustainable development goals of reducing food waste and promoting sustainability.

Kraft paper (KP) has the advantages of being biodegradable, recyclable, and environmentally friendly. It has a wide range of applications in paper packaging, food packaging, and other fields. However, the non-waterproof characteristic of KP limits its application in harsh environments or special paper packaging, etc. To solve the problem of poor water resistance of KP, a simple and efficient method is proposed to prepare superhydrophobic coatings on kraft paper (SKP) by spraying method using hydrophobic Nano-calcium carbonate (Nano-CaCO 3) particles and rosin (RA) as raw materials. Here, the micro-nano structures are mainly constructed by hydrophobic Nano-CaCO 3 particles, and RA is utilized as a binder to improve the adhesion between the nanoparticles and the paper. The results indicated that the water contact angle (WCA) of SKP reached 154.5° and the water sliding angle (WSA) was 3.2°. And after 34 h of immersion in water, the WCA of SKP surface can remain above 150°. It can also withstand 30 times of sandpaper abrasion and 30 times of tape peeling. Overall, SKP shows excellent stability, water resistance, stain resistance and self-cleaning. It is expected to protect important documents in harsh environments. [Display omitted] [ABSTRACT FROM AUTHOR]

A reversible optoelectronic nose is presented consisting of ten acid-base indicators incorporated into a starch-based film, covering a wide pH range. The starch substrate is odorless, biocompatible, flexible, and exhibits high tensile resistance. This optical artificial olfaction system was used to detect the early stages of food decomposition by exposing it to the volatile compounds produced during the spoialge process of three food products (beef, chicken, and pork). A smartphone was used to capture the color changes caused by intermolecular interactions between each dye and the emitted volatiles over time. Digital images were processed to generate a differential color map, which uses the observed color shifts to create a unique signature for each food product. To effectively discriminate among different samples and exposure times, we employed chemometric tools, including hierarchical cluster analysis (HCA) and principal component analysis (PCA). This approach detects food deterioration in a practical, cost-effective, and user-friendly manner, making it suitable for smart packaging. Additionally, the use of starch-based films in the food industry is preferable due to their biocompatibility and biodegradability characteristics., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Recently, food spoilage caused by pathogens has been increasing. Therefore, applying control strategies is essential. Bacteriophages can potentially reduce this problem due to their host specificity, ability to inhibit bacterial growth, and extend the shelf life of food. When bacteriophages are applied directly to food, their antibacterial activity is lost. In this regard, bacteriophage-loaded biopolymers offer an excellent option to improve food safety by extending their shelf life. Applying bacteriophages in food preservation requires comprehensive and structured information on their isolation, culturing, storage, and encapsulation in biopolymers for active food packaging applications. This review focuses on using bacteriophages in food packaging and preservation. It discusses the methods for phage application on food, their use for polymer formulation and functionalization, and their effect in enhancing food matrix properties to obtain maximum antibacterial activity in food model systems., (© 2024 Institute of Food Technologists®.)

Nanocelluloses have gained significant attention in recent years due to their singular properties (good biocompatibility, high optical transparency and mechanical strength, large specific surface area, and good film-forming ability) and wide-ranging applications (paper, food packaging, textiles, electronics, and biomedical). This article is a comprehensive review of the applications of nanocelluloses (cellulose nanocrystals, cellulose nanofibrils, and bacterial nanocellulose) in the conservation and restoration of historical paper documents, including their preparation methods and main properties. The novelty lies in the information collected about nanocelluloses as renewable, environmentally friendly, and sustainable materials in the field of cultural heritage preservation as an alternative to conventional methods. Several studies have demonstrated that nanocelluloses, with or without other particles, may impart to the paper documents excellent optical and mechanical properties, very good stability against temperature and humidity aging, higher antibacterial and antifungal activity, high protection from UV light, and may be applied without requiring additional adhesive. [ABSTRACT FROM AUTHOR]

In response to the need to employ recyclable materials for food packaging, the resurgence of paper as a primary flexible packaging material is driven by consumer trust in paper and its renewable wood fibre composition, strengthened by a well‐established recycling infrastructure. A diverse range of coated papers and coatings has become accessible in the market, specifically tailored for applications in horizontal and vertical form‐fill sealing. Within the framework of the CORNET‐TETRA project HBC.2021.0288 REPAC2, a careful selection of 16 food‐grade coated papers and/or coatings, slated for introduction to the market either presently or within the next 2 years, has been undertaken. This study focused on evaluating the processing window for superior hot tack and cooled seal performance of coated papers, in relation with the composition of paper coatings as identified using Fourier transform infrared (FTIR) measurements, and their thermal softening or melting characteristics as identified through differential scanning calorimetry (DSC). Thermal behaviour in DSC thermograms is used to categorize the commercial coated papers into distinct classes. Class I papers, mainly with acrylic‐based coatings, exhibit high hot tack strengths (0.2–0.7 N/mm) and a glass transition temperature (Tg) close to the seal initiation temperature but do not considerably gain strength with further cooling. Class II papers are thermally inert in DSC with minimal thermoplastics, leading to weak seals. In contrast, classes III and IV, including wax‐based and polyolefin‐based or polyvinylalcohol‐based (PVOH) coatings, respectively, show low initial hot tack strengths that considerably increase upon adequate cooling. Particularly, the Class IV papers with polyolefin‐based coatings have well‐performing seals. Despite having relatively low hot tack strengths after cool times of 0.1 s, below 0.3 N/mm, high strengths can be obtained after adequate cooling with outliers reaching 0.74 and 1.14 N/mm. Additionally, the influences of seal parameters on seal performance were evaluated. The study reveals that cool time, seal pressure and, to a lesser extent, seal time significantly impact hot tack strength, consistent with prior research. The critical role of jaw temperature in heat conductive sealing is affirmed, as it dictates the efficacy of other seal parameters. Seal initiation occurs at 75°C for four papers, and nine others necessitate temperatures equal to or exceeding 100°C, with one paper only displaying seal initiation at 195°C. This variation highlights the requisite for tailored temperature windows for effective sealing of these papers. As such, deeper insights into the intricate interplay between coating composition, thermal properties and seal performance are obtained in order to support advances in sustainable packaging technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • The high-barrier paper packaging was prepared by the solution casting method. • Epichloroghyrin (ECH) was deployed to improve the interfacial interactions. • ECH treatment realized the coating process of hydrophilic polymer on paper. • Coated paper packaging treated by ECH showed high barrier and sealing properties. • The high-barrier paper packaging extended the shelf life of biscuits. The fabrication of coated papers using hydrophilic and biodegradable polymers is important for developing sustainable packaging materials with high barrier and superior mechanical properties. However, water, which is used as the solvent in the paper coating process using hydrophilic polymers, deforms the shape of the paper and deteriorates performance. Therefore, we propose a new coating process that treats Kraft paper (KP) with epichlorohydrin (ECH) as a binder before the coating process. Crosslinked polyvinyl alcohol is coated on the ECH-treated KP using a solution casting method. ECH maintains the shape of the paper and improves coating uniformity; significantly enhances interfacial interactions, which increases barrier properties and sealing strength; and extends the shelf life of biscuits by reducing oxygen and moisture permeability. An ecotoxicity test using Lolium multiflorum demonstrates an insignificant phytotoxicity level for the as-prepared coated papers. Thus, ECH-treated KP is a potential candidate for high-barrier food packaging. [ABSTRACT FROM AUTHOR]

Naturally sourced pH-sensitive indicator films are of interest for real-time monitoring of food freshness through color changes because of their safety. Therefore, natural pigments for indicator films are required. However, pigment stability is affected by environmental factors, which can in turn affect the sensitivity and color stability of the pH-sensitive indicator film. First, natural pigments (anthocyanin, betalain, curcumin, alizarin, and shikonin) commonly used in pH-sensitive indicator films are presented. Subsequently, the mechanisms behind the change in pigment color under different pH environments and their applications in monitoring food freshness are also described. Third, influence factors, such as the sources, types, and pH sensitivity of pigments, as well as environmental parameters (light, temperature, humidity, and oxygen) of sensitivity and color stability, are analyzed. Finally, methods for improving the pH-sensitive indicator film are explored, encapsulation of natural pigments, incorporation of a hydrophobic film-forming matrix or function material, and protective layer have been shown to enhance the color stability of indicator films, the addition of copigments or mental ions, blending of different natural pigments, and the utilization of electrospinning have been proved to increase the color sensitivity of indicator films. This review could provide theoretical support for the development of naturally sourced pH-sensitive indicator films with high stability and sensitivity and facilitate the development in the field of monitoring food freshness., (© 2024 Institute of Food Technologists®.)

The usage of bio-based polymers to construct paper-based functional materials is currently an important topic in the food packaging industry. Nevertheless, the facile and effective construction of packaging paper materials with excellent water and oil repellency, self-cleaning property, biodegradability and recyclability currently faces distinct challenges. In this aspect, we have developed a one-step coating method for preparing hydrophobic and grease-resistant paper basing on templating dichloromethane-in-water (O/W) cellulose nanocrystals-stabilized Pickering emulsions, which contain chitosan (CS) and glutinous rice starch (GRS) in water phase and polylactic acid (PLA) in oil phase. Herein, the greaseproof polysaccharides CS and GRS are served as the coating film matrix, where the hydrophobic PLA is embedded in the form of microspheres. The optimized coated paper with rough surface structure display highly hydrophobic and water barrier properties with the water contact angle of larger than 130° and water vapor transmission rate of 3.57 × 10−10 gm−1s−1Pa−1, outstanding oil resistance with the kit rating of 9.5/12 and self-cleaning performance. Most interestingly, the soil burial test shows the favourable biodegradability of the coated paper. In addition, the pulp can be recycled from the coated paper and then reused to make paper, validating the recyclability of the coated paper. This study provides a new sustainable and universal research strategy for the large-scale preparation of fully bio-based, recyclable, hydrophobic and oil-resistant, self-cleaning, biodegradable paper materials, which exhibit the highly promising applications in food packaging industry. [Display omitted] • Pickering emulsion template is used to one-step prepare packaging paper coatings. • Water and oil resistance of paper clearly increased after coating treatment. • Coated paper displays excellent biodegradability and self-cleaning performance. • •Coated paper can be recycled by a simple recycling process. • Coated paper shows promising potential application in food packaging. [ABSTRACT FROM AUTHOR]

In recent years, researchers have put much attention on the improvements and upgrades of novel wet strength agent in the papermaking fields, especially in the usage of household paper. Herein, PEI M -KH560 by polyethyleneimine (PEI) and γ-glycidyl ether propyl trimethoxysilane (KH560) was synthesized with five molecular weights (Mw) of PEI at 600, 1800, 10,000, 70,000 and 750,000. Results showed that the molecular weight greatly influenced the physicochemical properties of PEI-KH560, such as the size and thermal stability. The intrinsic cationic charge of PEI-KH560 provided the bonding sites with the paper fibers, forming strengthened fiber-fiber joints. It was shown that the dry, wet strength and hydrophobicity of cellulosic paper sheets were obviously improved. When the m (PEI):m(KH560) is 1:2, the strength of papers after sizing by Mw of PEI at 600 and 1800 is the most obvious, with the dry strength increased by 227.9 % and 187.5 %, and the wet strength increased by 183.8 % and 207.8 %, respectively. The maximum hydrophobicity was found at the PEI 1800 -KH560 with the contact angle value of 130.6°. The resultant environmental-friendly agent (PEI-KH560) obtained in this work provides valuable significance for the preparation of household and food packaging paper. • Chlorine-free agents were prepared by different molecular weight of PEI and KH560. • The size and carbon residue content of PEI-KH560 were related with Mw of PEI. • PEI-KH560 significantly enhanced the wet strength of papers after surface sizing. • Mw of PEI influenced the strength and hydrophobicity of sized papers obviously. • The tensile strength was most effective at PEI M w of 600 with an increase of 227 %. [ABSTRACT FROM AUTHOR]

Innovations in food packaging systems could meet the evolving needs of the market; emerging concepts of non-migrating technologies reduce the negative migration of preservatives from packaging materials, extend shelf life, and improve food quality and safety. Non-migratory packaging activates the surface of inert materials through pretreatment to generate different active groups. The preservative is covalently grafted with the resin of the pretreated packaging substrate through the graft polymerization of the monomer and the coupling reaction of the polymer chain. The covalent link not only provides the required surface properties of the material for a long time but also retains the inherent properties of the polymer. This technique is applied to the processing for durable, stable, and easily controllable packaging widely. This article reviews the principles of various techniques for packaging materials, surface graft modification, and performance characterization of materials after grafting modification. Potential applications in the food industry and future research trends are also discussed., (© 2024 Institute of Food Technologists®.)

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. [ABSTRACT FROM AUTHOR]

Conventional food preservation methods such as heat treatment, irradiation, chemical treatment, refrigeration, and coating have various disadvantages, like loss of food quality, nutrition, and cost-effectiveness. Accordingly, cold plasma is one of the new technologies for food processing and has played an important role in preventing food spoilage. Specifically, in-package cold plasma has become a modern trend to decontaminate, process, and package food simultaneously. This strategy has proven successful in processing various fresh food ingredients, including spinach, fruits, vegetables, and meat. In particular, cold plasma treatment within the package reduces the risk of post-processing contamination. Cryoplasm decontamination within packaging has been reported to reduce significantly the microbial load of many foods' spoilage-causing pathogens. However, studies are needed to focus more on the effects of in-package treatments on endogenous enzyme activity, pest control, and removal of toxic pesticide residues. In this review, we comprehensively evaluated the efficacy of in-package low-temperature plasma treatment to extend the shelf life of various foods. The mechanisms by which cold plasma interacts with food were investigated, emphasizing its effects on pathogen reduction, spoilage mitigation, and surface modification. The review also critically assessed the effects of the treatments on food quality, regulatory considerations, and their potential as viable technologies to improve food safety and packaging life. In-package cold plasma treatment could revolutionize food storage when combined with other sophisticated technologies such as nanotechnology., (© 2024 Institute of Food Technologists®.)

Benzophenone and related derivatives are widely used as photoinitiators for food packaging to cure inks or lacquers with ultraviolet (UV) light on cardboard and paper. However, there are concerns about the potential health risks of their migration into food. Knowing the physical and chemical properties of benzophenone and its derivatives could play a significant role in their quantification and analysis using chemical ionization mass spectrometry (CI-MS) methods. These parameters are evaluated using B3LYP/6-311++** density functional theory (DFT) implemented on Gaussian code. Ion-molecule chemistry through the selection of reagent ions, reaction energetics and kinetics, thermodynamic stability, and reactivity of molecules deemed to foster VOC identification and quantification via CI-MS techniques. The VOCs under study are expected to undergo exothermic reactions from H 3 O + , NH 4 + , NO + , and O 2 + ions, except endothermic proton transfer from NH 4 + to 2-hydroxy-4-methoxybenzophenone and 2,3,4-trihydroxy benzophenone. These compounds possess less proton affinities than NH 3 and are least stable in their protonated forms. The DFT computed properties provide the basis for developing reliable and accurate methods to detect and measure the presence of benzophenone and its derivatives in packaging materials and food products., (© 2024 John Wiley & Sons Ltd.)

Mineral oil saturated hydrocarbons (MOSHs) are commonly found in food packaging printing inks. They can migrate into packaged food, posing risks to human health. In this study, a bio-based coating using sugarcane fibre (SF), anionic starch (AS), nanofibrated cellulose (NFC), and chitosan (CTS) is developed and applied to the internal surface of a food packaging white cardboard. The coating is investigated for its efficiency in reducing MOSH migration into dry food simulants (Porapak). The MOSH adsorption capacity of coated white cardboard is 4.6 and 14 times greater than those of uncoated and polythene (PE)-coated versions, respectively. Hence, the surface of SF-AS-NFC-CTS coating functions as a sponge and protective screen, adsorbing and hindering significant amounts of MOSH and subsequently slowing and reducing the migration of MOSH to food. Meanwhile, the basic properties, such as mechanical properties, air permeability (barrier property to MOSH), oil resistance, thermal stability, and antibacterial efficacy, of the coated cardboard for food packaging are all improved. Therefore, this study can offer a promising solution to food contamination concerns for food packaging. • SF-AS-NFC-CTS coating improves the gas barrier properties of white cardboard. • SF-AS-NFC-CTS coating enhances the antibacterial performance of the cardboard. • SF-AS-NFC-CTS exhibits excellent adsorption and slow discharge effect on MOSH. • SF-AS-NFC-CTS coating improved gas–oil barrier characteristics. [ABSTRACT FROM AUTHOR]

Effective packaging solutions are pivotal in addressing sustainability challenges associated with food consumption. Sustainable packaging must not only reduce ecological impact but also ensure food quality preservation, minimize the risk of foodborne diseases, and contribute to mitigating the accumulation of plastic waste. While paper-based food packaging is environmentally friendly, it is susceptible to mold growth when exposed to specific humidity and temperatures, potentially leading to spoilage and safety concerns. This study introduces an innovative modeling approach employing survival analysis to estimate time to visible mold growth on paper-based materials used in food-contact packaging under varying environmental conditions. The objective is to establish an alternative statistical framework for assessing the impact of relative humidity and temperature on mold proliferation. This approach is particularly relevant to novel sustainable packaging materials in the food industry, especially when dealing with censored data. Survival heatmaps are developed to simplify the visualization of spoilage likelihood, measured by time to visible growth at a given confidence level. Although the survival model is proposed for paper-based materials, there are no theoretical limitations to its extension for use with other materials within and beyond the food industry. • Proposed survival heatmaps to simplify spoilage likelihood visualization. • Investigated spoilage characteristics of novel paper-based packaging. • Addressed challenges of censored data in mold growth modeling. • Proposed a conservative predictive model to assess spoilage timelines. [ABSTRACT FROM AUTHOR]

Paper coatings based on petroleum-based compounds such as fluoro-compounds, polyethylene, and waxes are utilized to alter the properties of paper, such as wettability and oil and water transport. Although such polymers promote surface water resistance, their unfavorable qualities—poor recycling and lack of biodegradability—have led to their decline. However, using such non-renewable and non-biodegradable materials not only poses a threat to the environment and human health but also releases greenhouse gases. In addition, the use of plastic and fossil-fuel-based materials as barrier coatings in paper-based packaging boxes makes recycling difficult, enhancing overall recycling costs and causing environmental concerns about the waste created due to lack of biodegradation. Due to increasing worries about using petroleum-based polymeric packaging compounds and coatings and rising consumer demands for items with nutritive quality and prolonged shelf life, studies on alternative packaging materials are getting more popular. On the other hand, fresh techniques for environmentally friendly coatings may be constructed by employing biological polymers like polyesters, amino acids, and carbohydrates. These biopolymer coatings are powerful oil and water protectors that can substitute chemical-based paper and paperboard coatings. They could also stop inadvertent water transfer in food products. Nevertheless, many biopolymers may encounter challenges during manufacturing due to the material's innate water-holding capacity, crystallinity, and fragility, which precludes their usage in industrial applications. For that reason, it will be preferable to use polymer blends by combining them with other polymers, fillers, and plasticizers to enhance coating efficacy. This review paper will cover a detailed analysis of the water and oil resistance characteristics of several synthetic and naturally occurring polymers and their composites used as paper coatings for food packaging applications. The combination of polymers and their modifications with various agents and fillers can be utilized to build coatings that enhance the water and oil resistance of papers. There are also discussions about different coating techniques and the various solvents used to prepare coating solutions. [Display omitted] • The oil and water resistance of paper substrates were thoroughly discussed. • Various coating techniques have been discussed. • Applications of the coated papers were discussed. [ABSTRACT FROM AUTHOR]

Traditional paper-based packaging commonly needs to be coated to achieve sufficient mechanical and barrier performances. In this research, a bio-based coating for paper was developed from carbamate starch (Sc), calcium lignosulfonate (CL), and cellulose nanofibrils (CNF). Controlling the electrostatic and hydrogen-bonding interactions among the components of the coating was conducive to tailoring the structure and performance of the coated paper. When the degree of substitution (Ds) of Sc was 0.10, the amount of CL was 1.00 g, and the amount of CNF was 0.65 % of the weight of Sc, the paper coated with the resulting 0.10Sc-1.00CL-0.65CNF coating exhibited increased hydrophobicity and excellent mechanical, air-barrier, and UV-light-barrier properties. After the addition of 0.10 % of silver nano-particles (AgNPs) to the 0.10Sc-1.00CL-0.65CNF coating, the paper coated with the resulting 0.10Sc-1.00CL-0.65CNF-0.10AgNPs coating exhibited good antibacterial activity against Escherichia coli and Staphylococcus aureus. The coated paper was used as the packaging for cherry tomatoes stored under ambient conditions. Due to the synergistic preservation effects of the Sc-CL-CNF coating and AgNPs, the shelf life of the cherry tomatoes was at least 7 days. The coated paper described herein has the potential for applications in the food packaging sector. The freshness of the cherry tomatoes was effectively prolonged by a coated paper, whose multifunctional ability derived from the synergistic preservation effects of the components of the bio-based Sc-CL-CNF-AgNPs coating. [Display omitted] • A bio-based paper coating was developed by using three polysaccharide derivatives. • The mechanical, barrier and antibacterial properties of the coated paper were enhanced. • Paper coated with the bio-based coating prolonged the freshness of cherry tomatoes. • There is a synergistic preservation effect in the components of the bio-based coating. • The coated paper has the potential for applications in the food packaging sector. [ABSTRACT FROM AUTHOR]

In this study, a novel cellulose nanocrystal/metal-organic framework composite (MC) was developed as a stabilizer for alkenyl succinic anhydride (ASA) Pickering emulsions, demonstrating remarkable sizing performance and antimicrobial properties for advanced food packaging applications. The MCs exhibited superior emulsion stabilization capabilities compared to pure metal-organic frameworks, with the optimum MC concentration identified as 1.0 wt% CNC. The hydrophobicity of the sizing paper was found to be enhanced with increasing CNC content. The MC-ASA sized paper demonstrated commendable storage stability, robust gas adsorption, and resistance to water vapor or water droplets. The MCs-ASA sized paper showed excellent food preservation efficacy, maintaining the freshness of strawberries for up to seven days, compared to ASA-sized paper without MCs. The antimicrobial assays targeting Escherichia coli and Staphylococcus aureus highlighted the intrinsic antimicrobial properties of the MCs, contributing to the extended freshness of the encased strawberries. The water vapor barrier efficacy and water retention capabilities of MCs-ASA sized paper were found to be superior to those of the paper without MCs, emphasizing the potential of the developed composite as an innovative and effective food packaging solution. This study offers valuable insights into the synthesis and implementation of CNC/MOF composite particles for versatile applications in food packaging, water-resistant materials, and environmental protection. [Display omitted] • CNC/MOF composites boost ASA Pickering emulsions' sizing performance. • MCs elevate hydrophobicity, gas adsorption, and sizing paper stability. • MCs-ASA paper extends strawberry freshness to 7 days in food packaging. • Research paves way for sustainable, eco-friendly advanced packaging solutions. [ABSTRACT FROM AUTHOR]

In this research work, a coated paper was prepared with poly (butylene adipate-co-terephthalate) (PBAT) film to explore its use in eco-friendly food packaging. The paper was coated with PBAT film for packaging using hot pressing, a production method currently employed in the packaging industry. The coated papers were evaluated for their structural, mechanical, thermal, and barrier properties. The structural morphology and chemical analysis of the coated paper confirmed the consistent formation of PBAT bi-layered on paper surfaces. Surface coating with PBAT film increased the water resistance of the paper samples, as demonstrated by tests of barrier characteristics, including the water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and water contact angle (WCA) of water drops. The transmission rate of the clean paper was 2010.40 cc m−2 per 24 h for OTR and 110.24 g m−2 per 24 h for WVTR. If the PBAT-film was coated, the value decreased to 91.79 g m−2 per 24 h and 992.86 cc m−2 per 24 h. The hydrophobic nature of PBAT, confirmed by WCA measurements, contributed to the enhanced water resistance of PBAT-coated paper. This result presents an improved PBAT-coated paper material, eliminating the need for adhesives and allowing for the fabrication of bi-layered packaging.