Smart colorimetric indicator films prepared from chitosan and polyvinyl alcohol with high mechanical strength and hydrophobic properties for monitoring shrimp freshness

This work aimed to develop and characterize a colorimetric indicator films based on chitosan (CS), polyvinyl alcohol (PVA), and shikonin (SKN) from radix Lithospermi by casting method. The prepared films can serve as smart packaging for monitoring shrimp freshness which having excellent antimicrobial and antioxidant activity. The shikonin containing films have better hydrophobicity, barrier properties, and tensile strength. The release kinetics analysis shows that the loading amount causes a prolonged release of SKN from the prepared films. Increasing SKN in the CS/PVA film from 1 wt% to 2 wt% improved antibacterial effect for 24 h. Additionally, pH-sensitive color shifts from reddish (pH 2) to purple-bluish (pH 13) were visually seen in shikonin based solutions as well as films. The CS/PVA/SKN film detected shrimp deterioration at three temperatures (25, -20, and 4 °C) through color change. This study introduces a favorable approach for smart packaging in the food industry using multifunctional films.

Advances in sustainable food packaging applications of chitosan/polyvinyl alcohol blend films

Researchers are addressing environmental concerns related to petroleum-based plastic packaging by exploring biopolymers from natural sources, chemical synthesis, and microbial fermentation. Despite the potential of individual biopolymers, they often exhibit limitations like low water resistance and poor mechanical properties. Blending polymers emerges as a promising strategy to overcome these challenges, creating films with enhanced performance. This review focuses on recent advancements in chitosan/polyvinyl alcohol (PVA) blend food packaging films. It covers molecular structure, properties, strategies for performance improvement, and applications in food preservation. The blend's excellent compatibility and intermolecular interactions make it a promising candidate for biodegradable films. Future research should explore large-scale thermoplastic technologies and investigate the incorporation of additives like natural extracts and nanoparticles to enhance film properties. Chitosan/PVA blend films offer a sustainable alternative to petroleum-based plastic packaging, with potential applications in practical food preservation.

Potential applications of Rhodomyrtus tomentosa leaf extract as natural anti-staphylococcal additive in food systems: Efficacy and in vivo safety evaluation

This work aimed to explore the potential use of Rhodomyrtus tomentosa ethanol leaf extract (RTEL) as an alternative food preservative agent for controlling the growth of Staphylococcus aureus. Antibacterial activities against food-isolated S. aureus were performed using disc diffusion and broth microdilution assays, followed by evaluating in vivo subacute oral toxicity of the extract. Salad dressing was used as a food model to study bactericidal properties and consumer acceptability. RTEL remarkably inhibited S. aureus with minimum inhibitory concentrations (MICs) ranging from 7.81-62.5 µg/mL. Repeated oral doses (5, 50, and 300 mg/kg RTEL) for 28 days did not affect any of the measured toxicity parameters. The no-observed-adverse-effect-level (NOAEL) of RTEL was noted as more than 300 mg/kg body weight/day. The utilization of RTEL (12.5 mg/mL) in the vinaigrette salad dressing did not affect the consumer acceptability of the product, remarkably killed the pathogen within 3-9 h of exposure. The results indicated that RTEL is safe and effective as a natural anti-staphylococcal controlling agent that could be utilized in food systems. Further work is required on the effects of enterotoxin production, an important virulence factor of S. aureus responsible for food-borne disease.

Characterization of active films based on chitosan/polyvinyl alcohol integrated with ginger essential oil-loaded bacterial cellulose and application in sea bass (Lateolabrax japonicas) packaging

The poor mechanical properties, low water-resistance, and limited antimicrobial activity of chitosan (CS)/polyvinyl alcohol (PVA) based film limited its application in aquatic product preservation. Herein, bacterial cellulose (BC) was used to load ginger essential oil (GEO). The effects of the addition of BC and different concentrations of GEO on the physicochemical and antimicrobial activities of films were systematically evaluated. Finally, the application of sea bass fillets was investigated. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) analysis indicated dense networks were formed, which was verified by enhanced physical properties. The mechanical properties, barrier properties, and antimicrobial activities enhanced as GEO concentration increased. CPB0.8 (0.8 % GEO) film had better tensile strength (TS) and barrier performance, improved the quality, and extended the shelf-life of sea bass for another 6 days at least. Overall, active films are potential packaging materials for aquatic products.

Free-standing carboxymethyl cellulose film incorporating nanoformulated pomegranate extract for meat packaging

This study aimed to explore an innovative approach to enhancing the shelf-life and quality of meat products through the application of an active packaging system. The study involved the development of new free-standing carboxymethyl cellulose (CMC) nanocomposite films incorporated with nanoencapsulated flavonoids derived from pomegranate extract. The loaded flavonoids, known for their antioxidant and antimicrobial properties, were nanoencapsulated via a self-assembly approach in a mixture of chitosan and sodium alginate to improve their stability, solubility, and controlled release characteristics. Chemical structure, size, and morphology of the obtained nanoparticles (Pg-NPs) were studied with FTIR, zeta-sizer, and TEM. The Pg-NPs showed particle size of 232 nm, and zeta-potential of -20.7 mV. Various free-standing nanocomposite films were then developed via incorporation of Pg-NPs into CMC-casted films. FTIR, SEM, thermal and mechanical properties, and surface wettability were intensively studied for the nanocomposite films. Barrier properties against water vapor were investigated at 2022 g·m-2d-1. The nanocomposite films possessed superior properties for inhibiting bacterial growth and extending the shelf-life of beef and poultry meat for 12 days compared with the Pg-NPs-free CMC films. This study presented a promising approach for development of active packaging systems with improved antimicrobial and antioxidant properties, and economic and environmental impacts.

Development of packaging films based on UiO-66 MOF loaded melatonin with antioxidation functions for spinach preservation

Spinach tends to deteriorate after harvest due to physiological metabolic activities. As a natural, pollution-free, and environmentally friendly preservative, melatonin (MT) can effectively maintain the quality of fruits and vegetables after harvest and delay senescence. To enhance the preservation effect of MT, this study developed antioxidant films using MT-loaded UiO-66 metal-organic framework (MOF) nanoparticles. This approach effectively extends the shelf life of spinach while preserving its quality. The underlying mechanism involves leveraging the microporous structure and stability of UiO-66 MOF. Experimental results obtained from the packaging films demonstrated significant improvements in both mechanical strength and antioxidant properties when UiO-66 was loaded with MT at a concentration of 0.20 mg/mL and combined with sodium alginate. Freshness preservation experiments also indicated the effective preservation effect of these films on spinach. In conclusion, the results of this study suggest that MT-loaded UiO-66 MOF is a promising active packaging material for spinach preservation.

An in vivo appraisal of Punica granatum peel extract's ultrastructural effect on cystic echinococcosis in mice

In the past decade, interest has significantly increased regarding the medicinal and nutritional benefits of pomegranate (Punica granatum) peel. This study examined the effects of using pomegranate peel extract (PGE) alone and in combination with albendazole (ABZ) on ultrastructural and immunological changes in cystic echinococcosis in laboratory-infected mice. Results revealed that the smallest hydatid cyst size and weight (0.48 ± 0.47mm, 0.17 ± 0.18 gm) with the highest drug efficacy (56.2%) was detected in the PGE + ABZ group, which also exhibited marked histopathological improvement. Ultrastructural changes recorded by transmission electron microscopy including fragmentation of the nucleus, glycogen depletion, and multiple lysosomes in vacuolated cytoplasm were more often observed in PGE + ABZ group. IFN-γ levels were significantly increased in the group treated with ABZ, with a notable reduction following PGE treatment, whether administered alone or in combination with ABZ. Thus, PGE enhanced the therapeutic efficiency of ABZ, with improvement in histopathological and ultrastructural changes.

Toxicity of water-soluble polymers polyethylene glycol and polyvinyl alcohol for fish and frog embryos

Personal Care Products (PCPs) have been one of the most studied chemicals in the last twenty years since they were identified as pseudo-persistent pollutants by the European Union in the early 2000s. The accumulation of PCPs in the aquatic environment and their effects on non-target species make it necessary to find new, less harmful, substances. Polyethylene glycol (PEGs) and polyvinyl alcohol (PVAs) are two polymers that have increased their presence in the composition of PCPs in recent years, but little is known about the effect of their accumulation in the environment on non-target species. Through embryotoxicity tests on two common models of aquatic organisms (Danio rerio and Xenopus laevis), this work aims to increase the knowledge of PEGs and PVAs' effects on non-target species. Animals were exposed to the pollutant for 96 h. The main embryotoxicity endpoint (mortality, hatching, malformations, heartbeat rate) was recorded every 24 h. The most significant results were hatching delay in Danio rerio exposed to both chemicals, in malformations (oedema, body malformations, changes in pigmentation and deformations of spine and tail) in D. rerio and X. laevis and significant change in the heartbeat rate (decrease or increase in the rate) in both animals for all chemicals tested.

Quantum dots as advanced nanomaterials for food quality and safety applications: A comprehensive review and future perspectives

The importance of food quality and safety lies in ensuring the best product quality to meet consumer demands and public health. Advanced technologies play a crucial role in minimizing the risk of foodborne illnesses, contamination, drug residue, and other potential hazards in food. Significant materials and technological advancements have been made throughout the food supply chain. Among them, quantum dots (QDs), as a class of advanced nanomaterials with unique physicochemical properties, are progressively demonstrating their value in the field of food quality and safety. This review aims to explore cutting-edge research on the different applications of QDs in food quality and safety, including encapsulation of bioactive compounds, detection of food analytes, food preservation and packaging, and intelligent food freshness indicators. Moreover, the modification strategies and potential toxicities of diverse QDs are outlined, which can affect performance and hinder applications in the food industry. The findings suggested that QDs are mainly used in analyte detection and active/intelligent food packaging. Various food analytes can be detected using QD-based sensors, including heavy metal ions, pesticides, antibiotics, microorganisms, additives, and functional components. Moreover, QD incorporation aided in improving the antibacterial and antioxidant activities of film/coatings, resulting in extended shelf life for packaged food. Finally, the perspectives and critical challenges for the productivity, toxicity, and practical application of QDs are also summarized. By consolidating these essential aspects into this review, the way for developing high-performance QD-based nanomaterials is presented for researchers and food technologists to better capitalize upon this technology in food applications.

UV blocking edible films based on corn starch/moringa gum incorporated with pine cone extract for sustainable food packaging

Corn starch (CS) is a good alternative to synthetic polymers due to its sustainability; nevertheless, because of its weak tensile strength, the matrix requires another polymer. Therefore, 0.5 % (w/v) moringa gum (MG) was added. The purpose of this study was to assess how pine cone extract (PCE) affected the physiochemical and mechanical properties of corn starch and moringa gum (CS/MG) films and their use as UV-blocking composites. The findings suggest that the PCE improved the elongation at break from 3.27 % to 35.2 % while greatly reducing the tensile strength. The hydrogen bonding between CS/MG and PCE was visible in the FTIR spectra. The XRD graph indicated that the films were amorphous. In comparison to CS/MG films, PCE-incorporated edible films demonstrated significant UV-blocking ability indicating their potential as sustainable packaging material for light-sensitive food products.

Citric acid crosslinked carboxymethyl cellulose edible films: A case study on preserving freshness in bananas

The study involves the preparation and characterization of crosslinked-carboxymethyl cellulose (CMC) films using varying amounts of citric acid (CA) within the range 5 %-20 %, w/w, relative to the dry weight of CMC. Through techniques such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, carbonyl content analysis, and gel fraction measurements, the successful crosslinking between CMC and CA is confirmed. The investigation includes an analysis of chemical structure, physical and optical characteristics, swelling behavior, water vapor transmission rate, moisture content, and surface morphologies. The water resistance of the cross-linked CMC films exhibited a significant improvement when compared to the non-crosslinked CMC film. The findings indicated that films crosslinked with 10 % CA demonstrated favorable properties for application as edible coatings. These transparent films, ideal for packaging, prove effective in preserving the quality and sensory attributes of fresh bananas, including color retention, minimized weight loss, slowed ripening through inhibiting amyloplast degradation, and enhanced firmness during storage.

Electrospun fiber mats based on chitosan-carrageenan containing Malva sylvestris anthocyanins: Physic-mechanical, thermal, and barrier properties along with application as intelligent food packaging materials

This study aimed to encapsulate Malva sylvestris extract (MSE) into chitosan-carrageenan (CH-KC) fibers using the electrospinning technique and monitor the freshness of silver carp fillets during the refrigerated storage conditions for 8 days. The CH-KC + MSE 4 % fiber mats were red at pH values lower than 3, purple at pH 4-6, dark blue at pH 7, green at pH 8-10, and brown at pH 11-12. The tensile strength, elongation at break, water vapor permeability, oxygen transmission rate, moisture content, and water solubility of fabricated fiber mats were 7.71-11.02 MPa, 13.12 %-30.00 %, 7.35-20.01 × 10-4 g mm/m2 h Pa, 3.81-8.23 cm3/m2 h, 15.74 %-27.34 %, and 3.90 %-7.56 %, respectively. Regarding the potential application of a fabricated indicator for freshness monitoring of silver carp fillets, total viable count, psychrotrophic bacterial count, pH, and total volatile basic nitrogen reached 8.91 log CFU/g, 8.03 log CFU/g, 8.10, and 40.18 mg N/100 g at the end of the study, respectively. Meanwhile, the CH-KC + MSE 4 % fiber mat color changed from white to green. These findings suggest that CH-KC + MSE 4 % fiber mats can be further utilized in the food industry to control the freshness of refrigerated silver carp fillets.

Combined Effect of an Active AgIon® Absorbent Pad and a Chitosan Coating on the Preservation of Fresh Beef

In the present study, the combined effect of an AgIon® antimicrobial absorbent (Ζ) pad and a chitosan coating (C) on the preservation of fresh beef stored aerobically at 5 °C was investigated. Microbiological, physicochemical, and sensory attributes were monitored for up to 10 days of storage. The microbiological data indicated that the C and chitosan coating plus absorbent pad (CZ) treatments were the most efficient in reducing total viable counts (TVC) by 4.09 and 3.53 log cfu/g compared to the control W and Z treatments on day 4 of storage (p < 0.05). An analogous reduction in the counts of the other microbial groups monitored was recorded. pH values were ca. 5.7 for treatments W and Z and 5.45 for treatments C and CZ on day 4 of storage (p < 0.05). The total volatile basic nitrogen (TVB-N) values remained <20 mg/100 g for all treatments on day 4 and for treatments C and CZ on day 10 of storage. The total color difference values decreased (p < 0.05) during storage for treatments W and Z, but remained constant for treatments C and CZ. Based on sensory, microbiological and physico-chemical data, beef shelf life was ca ^# + 3 days for samples W and Z and at least 10 + 3 days for samples C and CZ. Between the two antimicrobial treatments, chitosan was considerably more effective than the AgIon® antimicrobial absorbent pad, which showed practically no antimicrobial activity in direct contact with beef meat.

Characterization of multilayer bacterial cellulose-chitosan films loaded with grape bagasse antioxidant extract: Insights into spectral and water properties, microstructure, and antioxidant activity

This work explores the development and characterization of composite multilayer films comprising bacterial cellulose (BC) and chitosan enriched with antioxidant compounds from grape bagasse extract (GE) and glycerol. SEM images revealed a compact structure with successful interactions between BC and chitosan, confirmed by FT-IR analysis. Equilibrium moisture content, water vapor permeability (WVP), swollen capacity, and solubility were systematically investigated, unveiling the influence of glycerol and GE concentrations. Moisture content increased with elevated glycerol and GE levels, attributed to their hydrophilic nature. WVP rose with higher concentrations of hydrophilic compounds, affecting the films' permeability. Swollen capacity decreased, and solubility increased with the addition of GE and glycerol, indicating a more compact film structure. The incorporation of GE conferred antioxidant properties to the films, as evidenced by DPPH and ABTS+ assays, and Total Phenolic Content (TPC) determination. TPC values varied from 0 to 1.75 mg GAE/g dried film, depending on GE. Fourier Transform Infrared Spectroscopy (FT-IR) highlighted polymeric associations, and UV-Vis spectra demonstrated enhanced UV-blocking properties. Overall, these multilayer films offer promising applications in food packaging, leveraging natural antioxidant sources for an enhanced functionality.

Antimicrobial efficacy of Punica granatum Lythraceae peel extract against pathogens belonging to the ESKAPE group

The improper use and abuse of antibiotics have led to an increase in multidrug-resistant (MDR) bacteria resulting in a failure of standard antibiotic therapies. To date, this phenomenon represents a leading public health threat of the 21st century which requires alternative strategies to fight infections such as the identification of new molecules active against MDR strains. In the last 20 years, natural extracts with biological activities attracted scientific interest. Following the One Health Approach, natural by-products represent a sustainable and promising alternative solution. Consistently, the aim of the present study was to evaluate the antimicrobial activity of hydro-alcoholic pomegranate peel extract (PPE) against MDR microorganisms belonging to Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. "ESKAPE" group pathogens. Through semiquantitative and quantitative methods, the PPE showed effective antimicrobial activity against Gram-positive and Gram-negative MDR bacteria. The kinetics of bactericidal action of PPE highlighted that microbial death was achieved in a time- and dose-dependent manner. High concentrations of PPE exhibited antioxidant activity, providing a protective effect on cellular systems and red blood cell membranes. Finally, we report, for the first time, a significant intracellular antibacterial property of PPE as highlighted by its bactericidal action against the staphylococcal reference strain and its bacteriostatic effect against clinical resistant strain in the HeLa cell line. In conclusion, due to its characterized content of polyphenolic compounds and antioxidant activity strength, the PPE could be considered as a therapeutic agent alone or in conjunction with standard antibiotics against challenging infections caused by ESKAPE pathogens.

Unveiling the Nanoconfinement Effect on Crystallization of Semicrystalline Polymers Using Coarse-Grained Molecular Dynamics Simulations

Semicrystalline polymers under nanoconfinement show distinct structural and thermomechanical properties compared to their bulk counterparts. Despite extensive research on semicrystalline polymers under nanoconfinement, the nanoconfinement effect on the local crystallization process and the unique structural evolution of such polymers have not been fully understood. In this study, we unveil such effects by using coarse-grained molecular dynamics simulations to study the crystallization process of a model semicrystalline polymer-polyvinyl alcohol (PVA)-under different levels of nanoconfinement induced by nanoparticles that are represented implicitly. We quantify in detail the evolution of the degree of crystallinity (XC) of PVA and examine distinct crystalline regions from simulation results. The results show that nanoconfinement can promote the crystallization process, especially at the early stage, and the interfaces between nanoparticles and polymer can function as crystallite nucleation sites. In general, the final XC of PVA increases with the levels of nanoconfinement. Further, nanoconfined cases show region-dependent XC with higher and earlier increase of XC in regions closer to the interfaces. By tracking region-dependent XC evolution, our results indicate that nanoconfinement can lead to a heterogenous crystallization process with a second-stage crystallite nucleation in regions further away from the interfaces. In addition, our results show that even under very high cooling rates, the nanoconfinement still promotes the crystallization of PVA. This study provides important insights into the underlying mechanisms for the intricate interplay between nanoconfinement and the crystallization behaviors of semicrystalline polymer, with the potential to guide the design and characterization of semicrystalline polymer-based nanocomposites.

Development of eco-friendly biofilms by utilizing microcrystalline cellulose extract from banana pseudo-stem

Banana pseudo-stem, often considered as an underutilized plant part was explored as a potential reinforced material to develop an eco-friendly biofilm for food packaging applications. In this study, Microcrystalline cellulose (MCC) was extracted from banana pseudo-stem by alkali and acid hydrolysis treatment. The extracted MCC was used as a reinforced material in different concentrated polyvinyl alcohol (PVA) matrix alone as well as both PVA and Carboxymethyl Cellulose (CMC) matrix to develop biofilm by solvent casting method. The synthesized MCC powder was characterized by scanning electron microscope to ensure its microcrystalline structure and to observe surface morphology. The biofilms composed of MCC, PVA, and CMC were assessed through Fourier-transform infrared spectroscopy (FTIR), mechanical properties, water content, solubility, swelling degree, moisture barrier property (Water Vapor Permeability - WVP), and light barrier property (Light Transmission and Transparency). The FTIR analysis showed the rich bonding between the materials of the biofilms. The film incorporating a combination of PVA, CMC, and MCC (S6) exhibited the highest tensile strength at 26.67 ± 0.152 MPa, making it particularly noteworthy for applications in food packaging. MCC incorporation increased the tensile strength. The WVP content of the films was observed low among the MCC-induced films which is parallel to other findings. The lowest WVP content was showed by 1% concentrated PVA with MCC (S4) (0.223 ± 0.020 10-9 g/Pahm). The WVP content of S6 film was also considerably low. MCC-incorporated films also acted as a good UV barrier. Transmittance of the MCC induced films at UV range were observed on average 38% (S2), 36% (S4) and 6% (S6) which were almost 6% lower than the control films. The S6 film demonstrated the lowest swelling capacity (1.42%) and water content, indicating a significantly low solubility of the film. The film formulated with mixing of PVA, CMC and MCC (S6) was ahead in terms of food packaging characteristics than other films. Also, the outcomes of this study point out that MCC can be a great natural resource for packaging applications and in that regard, banana pseudo-stem proves to be an excellent source for waste utilization.

Recent Progress of Carrageenan-Based Composite Films in Active and Intelligent Food Packaging Applications

Recently, as concerns about petrochemical-derived polymers increase, interest in biopolymer-based materials is increasing. Undoubtedly, biopolymers are a better alternative to solve the problem of synthetic polymer-based plastics for packaging purposes. There are various types of biopolymers in nature, and mostly polysaccharides are used in this regard. Carrageenan is a hydrophilic polysaccharide extracted from red algae and has recently attracted great interest in the development of food packaging films. Carrageenan is known for its excellent film-forming properties, high compatibility and good carrier properties. Carrageenan is readily available and low cost, making it a good candidate as a polymer matrix base material for active and intelligent food packaging films. The carrageenan-based packaging film lacks mechanical, barrier, and functional properties. Thus, the physical and functional properties of carrageenan-based films can be enhanced by blending this biopolymer with functional compounds and nanofillers. Various types of bioactive ingredients, such as nanoparticles, natural extracts, colorants, and essential oils, have been incorporated into the carrageenan-based film. Carrageenan-based functional packaging film was found to be useful for extending the shelf life of packaged foods and tracking spoilage. Recently, there has been plenty of research work published on the potential of carrageenan-based packaging film. Therefore, this review discusses recent advances in carrageenan-based films for applications in food packaging. The preparation and properties of carrageenan-based packaging films were discussed, as well as their application in real-time food packaging. The latest discussion on the potential of carrageenan as an alternative to traditionally used synthetic plastics may be helpful for further research in this field.

Plant-Derived Caffeic Acid and Its Derivatives: An Overview of Their NMR Data and Biosynthetic Pathways

In recent years, caffeic acid and its derivatives have received increasing attention due to their obvious physiological activities and wide distribution in nature. In this paper, to clarify the status of research on plant-derived caffeic acid and its derivatives, nuclear magnetic resonance spectroscopy data and possible biosynthetic pathways of these compounds were collected from scientific databases (SciFinder, PubMed and China Knowledge). According to different types of substituents, 17 caffeic acid and its derivatives can be divided into the following classes: caffeoyl ester derivatives, caffeyltartaric acid, caffeic acid amide derivatives, caffeoyl shikimic acid, caffeoyl quinic acid, caffeoyl danshens and caffeoyl glycoside. Generalization of their 13C-NMR and 1H-NMR data revealed that acylation with caffeic acid to form esters involves acylation shifts, which increase the chemical shift values of the corresponding carbons and decrease the chemical shift values of the corresponding carbons of caffeoyl. Once the hydroxyl group is ester, the hydrogen signal connected to the same carbon shifts to the low field (1.1~1.6). The biosynthetic pathways were summarized, and it was found that caffeic acid and its derivatives are first synthesized in plants through the shikimic acid pathway, in which phenylalanine is deaminated to cinnamic acid and then transformed into caffeic acid and its derivatives. The purpose of this review is to provide a reference for further research on the rapid structural identification and biofabrication of caffeic acid and its derivatives.

Sustainable food packaging: Harnessing biowaste of Terminalia catappa L. for chitosan-based biodegradable active films for shrimp storage

Shrimp, a globally consumed perishable food, faces rapid deterioration during storage and marketing, causing nutritional and economic losses. With a rising environmental consciousness regarding conventional plastic packaging, consumers seek sustainable options. Utilizing natural waste resources for packaging films strengthens the food industry. In this context, we aim to create chitosan-based active films by incorporating Terminalia catappa L. leaves extract (TCE) to enhance barrier properties and extend shrimp shelf life under refrigeration. Incorporation of TCE improves mechanical, microstructural, UV, and moisture barrier properties of the chitosan film due to cross-linking interactions, resulting in robust, foldable packaging film. Active TCE film exhibits high antioxidant property due to polyphenols. These films also exhibited low wettability and showed hydrophobicity than neat CH films which is essential for meat packaging. These biodegradable films offer an eco-friendly end-of-life option when buried in soil. TCE-loaded films effectively control spoilage organisms, prevent biochemical spoilage, and maintain shrimp freshness compared to neat CH films during refrigerated condition. The active TCE film retains sensory attributes better than neat chitosan, aligning with consumer preference. The developed edible and active film from waste sources might offer sustainable, alternative packaging material with a lower carbon footprint than petroleum-based sources.

Three stilbenes from pigeon pea with promising anti-methicillin-resistant Staphylococcus aureus biofilm formation activity

Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 μg/mL followed by LLC with MIC and MBC values of 3.12 μg/mL and 6.25 μg/mL as well as CSA with MIC and MBC values of 6.25 μg/mL and 6.25-12.5 μg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.

Alizarin-embedded γ-cyclodextrin-based metal-organic framework in a methylcellulose/polyvinyl alcohol film for maintaining and monitoring grass carp freshness

Multifunctional packaging films that monitor and maintain fish freshness hold significant potential for use in the food industry. This study introduces a multifunctional intelligent packaging film comprising alizarin (ALI)-embedded cubic γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) (denoted as γ-CD-MOFs@ALI) in a methylcellulose/polyvinyl alcohol (MP)-based matrix to achieve colorimetric monitoring and enhanced preservation of fish freshness. The MP/γ-CD-MOFs@ALI reveals a rapid color transition in 3 min from yellow color progressively darkens to purple as the pH increases from 2.0 to 10.0. And it is proved that the as-prepared film owns high antibacterial activity against Gram-positive bacteria (S. aureus), impressive ABTS+ radical scavenging rates of 85.54 ± 1.25 %, and effective ALI sustained-release properties. The intelligent packaging film exhibits an excellent colorimetric response to total volatile basic nitrogen and provides exceptional freshness preservation performance, effectively prolonging the shelf life of Ctenopharyngodon idella (grass carp) under 25 °C to 42 h.

Synergistic impact of natural gums and crosslinkers on the properties of oilseed meals based biopolymeric films

The waste material utilization from available agricultural resources can be beneficial in the field of economic, social, and environmental well-being. One of the main industrial crops used to manufacture oil from oilseeds worldwide is agricultural waste, such as the cake made from oilseeds. In this study, de-oiled cakes are used to create biopolymeric films. Three widely accessible oilseed meals viz. flaxseed, soybean, and mustard were gathered, ground, and sieved. A film forming suspension of defatted meals along with natural gums (acacia and xanthan gum) and crosslinkers (citric acid and glutaraldehyde) were formed. The suspension was cast into petri dishes and dried to produce smooth and even films. The physical, functional, color, thermal and morphological properties of the oilseed meals-gums crosslinked biopolymeric film were evaluated and statistical analysis was performed. The solubility was found to be decreased and tensile strength was increased with the addition of citric acid and increase in tensile strength. There was significant difference observed in the values of elongation at break after addition of citric acid as crosslinker. The research shows how oilseed meals enriched with natural gum and crosslinkers may be converted into biopolymeric films, which can then be used in food packaging to lessen reliance on petroleum-based, non-biodegradable plastics.

Active packaging: Development and characterization of polyvinyl alcohol (PVA) and nitrite film for pork preservation

In this study, an active films of polyvinyl alcohol (PVA) films, incorporated with sodium nitrite were developed, characterized and applied to pork stored for six days at 25 °C. As for the film characterization by FTIR, no chemical interactions were observed between nitrite and PVA under the studied conditions. The physical properties of the PVA films were not altered by the presence of nitrite. PVA films incorporated with 100 ppm nitrite reduced TBARS values of refrigerated pork from 0.63 µmol MDA/g (control) to 0.49 µmol MDA/g (PVA 01). Color changes were observed in all meat samples packaged with the film. It is concluded that the presence of nitrite does not interfere in the physical properties of the PVA films and that the developed films have an active potential for application in pork in natura.

Evaluation of whey protein coating containing nanoliposome dill (Anethum graveolens L.) essential oil on microbial, physicochemical and sensory changes of rainbow trout fish

The aim of this study was to investigate the effect of whey coating containing dill (Anethum graveolens L.) essential oil nanoliposome on the physicochemical, microbiological and sensory characteristics of rainbow trout (Oncorhynchus mykiss). Treatments comprise: sample without coating (control), coating containing whey, coating containing whey with essential oil (whey-EO) and coating containing whey with nano EO (whey-NEO). The particle size, zeta potential, polydispersity index and the encapsulation efficiency were ranged from 142 to 159 nm, -16.3 to -11.7 mV, 0.79 to 0.88 Mw/Mn and 45.85-70.01 %, respectively. Microbial analysis, after 21 days, the maximum and minimum of TVC (total viable counts), TPC (total psychrophilic counts) and LAB (lactic acid bacteria) counts were related to control (8.16 for TVC, 8.46 for TPC and 7.7 log CFU/g for LAB) and whey + NEO (7 for TVC, 7.3 for TPC and 6.16 log CFU/g for LAB), respectively. Also, results of pH, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and total volatile base-nitrogen (TVB-N) after 21 days were ranged from 6.3 (whey-NEO) to 7.5 (control), from 11.5(whey-NEO) to 20.9 mEq/Kg (control), from 5.23(whey-NEO) to 8.34 mg MDA/kg (control) and from 22.5 (whey-NEO) to 37 mg N/100 g (control), respectively. Finally, in all sensory evaluation items (texture, off-odor, discoloration and red color), the best result after 21 days was related to whey-NEO (score = 1). Consequently, the edible coating comprising whey and nanoliposome of EO could be effective to the maintenance of fish's microbiological, physicochemical, and sensory properties.

Fabrication of flexible chitosan film reinforced with pulping by-product lignosulfonates for cherry-tomato preservation

The massive production of food waste and plastic pollution necessitates innovative solutions. This study reports the first fabrication of a flexible chitosan (CH) film reinforced with lignosulfonate (LS) derived from pulping byproduct as a sustainable alternative to synthetic food packaging. The CH/LS composite film was prepared by a simple casting method with varying LS contents of 1 % and 2 %. Compared to CH film, the addition of 2 % LS increased the tensile strength by over 4 times and decreased water vapor permeability by 11 %. Moreover, the CH/LS film exhibited excellent UV-shielding properties. This novel use of LS to reinforce CH film presents an eco-friendly active packaging material. When used to package cherry tomatoes for 2 weeks, the CH/LS film effectively maintained fruit freshness and hardness while minimizing weight loss. This work provides new scientific evidence on the optimized preparation and application of CH/LS composite films from renewable resources for food preservation.

Conjugation of Soybean Proteins 7S/11S Isolate with Glucose/Fructose in Gels through Wet-Heating Maillard Reaction

Conjugation with glucose (G) and fructose (F) via the Maillard reaction under the wet-heating condition is a natural and non-toxic method of improving the technological functions of 7S/11S proteins in different kinds of gels. It may be used as an affordable supply of emulsifiers and an excellent encapsulating matrix for gels. This study aimed to create a glucose/fructose-conjugated 7S/11S soy protein via the Maillard reaction. The conjugation was confirmed by determining the SDS-PAGE profile and circular dichroism spectra. In addition, these conjugates were comprehensively characterized in terms of grafting degree, browning degree, sulfhydryl content, surface hydrophobicity (H0), and differential scanning calorimetry (DSC) through various reaction times (0, 24, 48, and 72 h) to evaluate their ability to be used in food gels. The functional characteristics of the 7S/11S isolate-G/F conjugate formed at 70 °C, with a high degree of glycosylation and browning, were superior to those obtained at other reaction times. The SDS-PAGE profile indicated that the conjugation between the 7S and 11S proteins and carbohydrate sources of G and F through the Maillard reaction occurred. Secondary structural results revealed that covalent interactions with G and F affected the secondary structural components of 7S/11S proteins, leading to increased random coils. When exposed to moist heating conditions, G and F have significant potential for protein alteration through the Maillard reaction. The results of this study may provide new insights into protein modification and establish the theoretical basis for the therapeutic application of both G and F conjugation with soy proteins in different food matrixes and gels.

A co-type ductile film with high tensile strength and fast self-healing properties for shaped fruit preservation

Traditional petroleum-based plastics have high energy consumption, require professional equipment, are non-degradable after use, and lack antibacterial properties, making it impossible to achieve long-lasting freshness in fruits and vegetables. Herein, we report a novel co-type film-forming method with low energy consumption and without production equipment, which uses PVA-borax gel as a substrate and adds a certain proportion of CMC and TA to prepare multifunctional CMC/TA@PVA-borax composite hydrogels (CTPB). The dynamic borax ester bonding and hydrogen bonding in the CTPB hydrogel results in an ultra-high tensile strength of more than 5500% and rapid self-healing within 8 s. Interestingly, hydrogels can be arbitrarily shaped and stretched like play dough and thus can be stretched into ductile films by co-type film formation. The antimicrobial properties of the hydrogel film can be attributed to the synergistic effects of TA and borax. The mussel structure of TA allows the hydrogel film to adhere directly to different surfaces for more effective bacterial killing. In addition, the hydrogel film has a high level of biosafety and biodegradability and shows good performance in fruit storage. This study provides a convenient and low-energy method for the preparation of films, which in part reduces the increasing environmental pollution caused by petroleum-based plastics.

Tannic acid crosslinked chitosan-guar gum composite films for packaging application

Chitosan (CH)-guar gum (GG) composite films crosslinked with tannic acid (TnA) were prepared by solution casting method. The films were then immersed in 5 % aqueous NH3 and dried again. They were characterized by IR spectroscopy, wide angle x-ray diffraction and thermogravimetric analysis. All the films were studied for physicochemical properties such as moisture content, swelling, solubility in water, water contact angle, water vapor permeability, opacity, tensile strength and antioxidant activity. The physicochemical and mechanical properties of films changed significantly when compared to CH as reflected by an increase in the amorphous domains of the films, a decrease in moisture content, swelling and solubility in water. The films turned hydrophobic with concomitant decrease in moisture content, swelling, water-solubility and exhibited improved UV absorption as well as mechanical strength, which in turn was dependent on the tannic acid concentration. These results along with enhanced antioxidant properties, UV absorption with no significant change in water vapor permeation compared to CH suggested that the films could find application in packaging applications.

Facile exfoliation and physicochemical characterization of Thespesia populnea plant leaves based bioplasticizer macromolecules reinforced with polylactic acid biofilms for packaging applications

Plasticizers are active ingredients added to the polymer to increase its workability. Since synthetic plasticizer is not ecofriendly and toxic in nature, it is a real cause for concern. On this basis, our study focuses on plasticizer extraction from plant-based resources. In this research work, Thespesia populnea leaves are utilized for the isolation of biological macromolecules with a plasticizing effect for biofilm applications. This extraction process is done through solvent extraction, amination, slow pyrolysis, and surface catalysis process. The physico-chemical and microstructural characterization of novel plasticizer particles were studied for the first time. The lower crystallinity index and crystalline size obtained from X-ray diffraction is 50.08 % and 20.45 nm respectively. Energy dispersive spectroscopy, particle sizer analysis, atomic force microscopy, and scanning electron microscopy are used to assess surface morphology of this plasticizer. The thermogram and differential thermal analysis curves give the information about degradation behavior of plasticizers and their thermal stability. The glass transition temperature of the extracted plasticizer is 60.56 °C. The plasticizing effect of the plasticizer is studied through film fabrication of polylactic acid which was blended with the extracted plasticizer. The mechanical property of biofilm was improved with the addition of plasticizer. The elongation break percentage (for 5 % plasticizer 46.12 %) was increased compared to others with moderate tensile strength. However, the tensile and elongation modulus decreases with the increase of plasticizer content. The crystallinity of the PLA film was improved after the plasticization. The thermal stability also increased with 3 % addition of the plasticizer. The isolated plasticizer was soluble in water and its molecular weight ≈380.

Sustainable papaya plant waste and green tea residue composite films integrated with starch and gelatin for active food packaging applications

This study explores the sustainable utilization of wastes from a papaya plant (papaya peels (PP), papaya seeds (PS), leaf-stem (PL)) and dried green tea residues (GTR) for the synthesis of bioplastics. The dried GTR were individually blended with each papaya waste extract and then boiled in water to get three composite papaya plant waste-green tea supernatants. Potato starch and gelatin-based functional films were prepared by integrating each with the composite papaya waste-green tea supernatant liquid. This work introduces a dissolved organic matter (DOM) study to the field of bioplastics, with the goal of identifying the organic components and macromolecules inherent in the PW supernatants. When compared with the films prepared solely from papaya waste (PW) supernatants, PW-GTR composite supernatant films prevent UV light transmission with superior antioxidant and mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM) were utilized to characterize the starch and gelatin PW-GTR films. Owing to the exceptional antioxidant, UV barrier, and remarkable biodegradable properties of the starch/PW/GTR and gelatin/PW/GTR composite films, make them ideal for use in food packaging applications.

Insight into the Relationship between the Causes of Off-Odour and Microorganism Communities in Xuanwei Ham

To expound on the correlation between the microorganism communities and the formation of off-odour in Xuanwei ham, the microorganism communities and volatile compounds were investigated in the biceps femoris (BF) and semimembranosus (SM) of Xuanwei ham with different quality grades (normal ham and spoiled ham). The single molecule real-time sequencing showed that differential bacteria and fungi were more varied in normal hams than in spoiled hams. Headspace solid-phase microextraction-gas chromatography (HS-SPME-GC-MS) results indicated that aldehydes and alcohols were significantly higher in spoiled hams than those in normal hams (p < 0.05). The off-odour of spoiled hams was dominated by ichthyic, malodourous, sweaty, putrid, sour, and unpleasant odours produced by compounds such as trimethylamine (SM: 13.05 μg/kg), hexanal (BF: 206.46 μg/kg), octanal (BF: 59.52 μg/kg), methanethiol (SM: 12.85 μg/kg), and valeric acid (BF: 15.08 μg/kg), which are positively correlated with Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Pseudomonas sp., Aspergillus ruber, and Moraxella osloensis. Furthermore, the physicochemical property and quality characteristics results showed that high moisture (BF: 56.32 g/100 g), pH (BF: 6.63), thiobarbituric acid reactive substances (TBARS) (SM: 1.98 MDA/kg), and low NaCl content (SM: 6.31%) were also responsible for the spoilage of hams with off-odour. This study provided a deep insight into the off-odour of Xuanwei ham from the perspective of microorganism communities and a theoretical basis for improving the flavour and overall quality of Xuanwei hams.

Effect of Addition of Mango Seed Extract on Storage Stability of Chevon Meatballs at Refrigeration Temperature

In this study, the addition of mango seed extract (MSE) in goat meatballs was assessed. The efficacy of three different levels of MSE extract, namely T1 = (2.5 mL/100 g of meat emulsion v/w), T2 = (5.0 mL/100 g of meat emulsion v/w), T3 = (7.5 mL/100 g of meat emulsion v/w), and T0 (control without mango seed extract), was conducted for evaluation of changes in water activity (aW), pH, total phenolic compounds, DPPH, peroxide value, TBARS, microbial quality, and sensory attributes of the goat meatballs stored at refrigerated temperature (4 ± 1 °C). Incorporation of the mango seed extract T3 (7.5 mL/100 g) showed that it can potentially better maintain change in pH and water activity. Total phenolic and DPPH activity decreased significantly (P0.05) among all samples throughout storage; however, the highest value was noted for T3 among all samples. The MSE-added goat meatballs (T3) group had lower significant (p < 0.05) peroxide values than the other samples. The T3 sample added with MSE exhibited significant (p < 0.05) lower TBRAS values as compared to other treatments. Comparatively lower microbial proliferation and better sensory attributes were maintained among the treated groups during the entire storage time. The results show that the inclusion of MSE extract T3 (7.5 mL/100 g) is a promising natural antioxidant that can maintain a better quality of goat meatballs at refrigerated temperature (4 ± 1 °C) under aerobic packaging conditions.

Effects of Maillard reaction products on myoglobin-mediated lipid oxidation during refrigerated storage of carp

Lipid oxidation is the major cause of quality deterioration in freshwater fish, especially mediated by myoglobin (Mb). This study aimed to investigate the antioxidant mechanism of Maillard reaction products (MRPs) in Mb-mediated lipid oxidation in common carp (Cyprinus carpio). MRPs exhibited promising antioxidant and antimicrobial capacities based on the reduced content of peroxide and thiobarbituric acid-reactive substances and inhibited microbial growth. MRPs inhibited the oxidation of Mb by lowering the transfer from oxymyoglobin to metmyoglobin and improving the stability of heme iron. The correlation analysis showed that MRPs regulated the formation of free radicals by maintaining the reduced structure of Mb and the integrity of heme iron, and also directly inhibited the formation of oxidation products in a chain radical reaction. The texture and electronic nose analysis indicated that MRPs could delay the structural disruption and flavor deterioration of surimi. Therefore, MRPs could effectively inhibit Mb-induced lipid oxidation and further control the resulting changes in the flavor and texture of surimi.

Improved Cardiovascular Effects of a Novel Pomegranate Byproduct Extract Obtained through Hydrodynamic Cavitation

The healthy properties of pomegranate fruit, a highly consumed food, have been known for a long time. However, the pomegranate supply chain is still rather inefficient, with the non-edible fraction, whose weight is roughly half the total and is endowed with plenty of valuable bioactive compounds, either disposed of or underutilized. A novel extract obtained from non-edible byproducts (called PPE), using hydrodynamic cavitation, a green, efficient, and scalable technique, was investigated for its cardiovascular effects in vivo. PPE showed efficacy in an acute phenylephrine (PE)-induced hypertensive rat model, similar to the extract of whole fruit (PFE) obtained using the same extractive technique, along with good intestinal bioaccessibility after oral administration. Finally, when chronically administered for 6 weeks to spontaneously hypertensive rats, PPE was shown to significantly contain the increase in systolic blood pressure, comparable to the reference drug Captopril, and at a dose remarkably lower than the reported effective dose of ellagic acid. The extract from the non-edible fraction of the pomegranate fruit also showed good anti-inflammation and anti-fibrotic effects. The findings of this study, along with the extraction technique, could contribute to enhancing the value of the pomegranate supply chain, relieve the related environmental burden, and potentially improve public health.

Banana fibre-chitosan-guar gum composite as an alternative wound healing material

Bio-composites, which can be obtained from the renewable natural resources, are fascinating material for use as sustainable biomaterials with essential properties like biodegradable, bio-compatibility as well cyto-compatibility etc. These properties are useful for bio-medical including wound healing applications. In this study, fibre obtained banana pseudo stem of banana plant, which is otherwise wasted, was used as a material along with chitosan and guar gum to fabricate a banana fibre-biopolymer composite patch. The physiochemical properties of the patches were examined using Fourier Transformed Infra-red spectrophotometer (FT-IR), tensile tester, Scanning Electron Microscope (SEM), contact angle tester, swelling and degradation studies. We further demonstrated that a herbal drug, Nirgundi could be loaded to the patch showed controlled its release at different pHs. The patch had good antibacterial property and supported proliferation of mouse fibroblast cells. The study thus indicates that banana fibre-chitosan-guar gum composite can be developed into an alternative wound healing material.

Carrageenan-based active and intelligent packaging films integrated with anthocyanin and TiO2-doped carbon dots derived from sweet potato peels

Carrageenan-based sustainable active and pH-dependent color-changing composite films were fabricated by blending anthocyanin extracted from sweet potato peel (SPA) with TiO2-doped carbon dots (Ti-CDs) prepared using the biowaste of SPA extraction. The SPA and Ti-CDs were compatible with the carrageenan matrix and were uniformly dispersed in the used polymer to form a homogeneous film with increased mechanical properties. The composite film added with SPA and 3 wt% Ti-CD showed 100 % UV protection, superb antioxidant (100 % DPPH and ABTS scavenging assay), and potent antibacterial activity (complete eradication of foodborne L.monocytogenes and E. coli strains after 3 h incubation). Additionally, the composite films showed distinguishable colorimetric responses to pH 7-12 buffers and volatile ammonia. The intelligent sensing ability of the composite film was assessed through shrimp freshness monitoring, and the film's hue shifted from pink (fresh shrimp) to yellow/brown (inedible shrimp) during storage. Shrimp packaging studies have shown that composite films retard the rate of food quality change during storage and are a good indicator of shrimp spoilage. Therefore, the designed film is expected to have high applicability as a chip, and quick on-site sensor that detects seafood quality in real-time, and a highly effective multifunctional film for better product quality preservation.

Recent advances in carboxymethyl cellulose-based active and intelligent packaging materials: A comprehensive review

Researchers have concentrated on innovative approaches to increase the shelf life of perishable food products and monitor their quality during storage and transportation as consumer demand for safe, environmentally friendly, and effective packaging develops. This comprehensive review aims to provide an overview of recent developments in carboxymethyl cellulose (CMC) chemical synthesis and its applications in active and intelligent packaging materials. It explores various methods for modifying cellulose to produce CMC and highlights the unique properties that make it suitable for addressing packaging industry challenges. The integration of CMC into active packaging systems, which helps reduce food waste and enhance food preservation, is discussed in depth. Furthermore, the integration of CMC in smart sensors and indicators for real-time monitoring and quality assurance in intelligent packaging is examined. The chemical synthesis of CMC and strategies to optimise its properties were studied, and the review concluded by examining the challenges and prospects of CMC-based packaging in the industry. This review is intended to serve as a valuable resource for researchers, industry professionals, and policymakers interested in the evolving landscape of CMC and its role in shaping the future of packaging materials.

Design and Development of an Edible Coating for a Ready-to-Eat Fish Product

The application of chitosan and alginate coatings for a ready-to-eat (RTE) baked fish product was studied. An experimental design was used to investigate the effect of coating a polysaccharide concentration and glycerol addition on the safety (microbial growth) and quality (water loss and lipid oxidation) of an RTE fish product under optimal and abused storage conditions. The results showed that a chitosan coating with 1% (w/v) chitosan in 1% (v/v) acetic acid and 15% (w/w chitosan) glycerol, or a 1% (w/v) alginate coating with no glycerol and no crosslinking, showed the best performance in controlling the tested safety and quality parameters. The desirability method was used to identify the shelf lives of chitosan, alginate, and double-coated RTE products. The chitosan-coated samples showed the best performance with a three-fold shelf-life extension compared to the uncoated products stored at 4 °C. Moreover, the tested coatings demonstrated their ability to provide protective functions under abused storage conditions. These results strongly suggest that edible coatings have significant potential in enhancing the shelf life and safety of ready-to-eat (RTE) fish products.

Development, characterization and application of starch-based film containing polyphenols of piper betle L. waste in chicken meat storage

The current study aimed to develop a sustainable solution to extend the shelf life of chicken meat by developing starch-based functional film embedded with polyphenolic extract of waste petioles of betel leaf (BLP). The results showed that loading of the extract significantly (p < 0.05) improved flexibility, thickness, water solubility, DPPH radical scavenging activity, and UV light protection ability by enhancing intermolecular interactions among potato starch, guar gum, and the extract. The developed film showed optimum mechanical and water barrier properties at a 4% BLP extract concentration computed through TOPSIS method (A multi-criteria decision-making approach). During the shelf life study, the extract embedded film maintained the quality of chicken meat for up to 12 days at refrigerated temperature. Biodegradation time of the extract-blended films was considerably decreased to 14 days from 28 days for the native film, indicating suitable alternative to non-biodegradable film for storing the raw meat.

Purification, bioactivity and application of maltobionic acid in active films

The objective of this study was to purify sodium maltobionate using Zymomonas mobilis cells immobilized in situ on flexible polyurethane (PU) and convert it into maltobionic acid for further evaluation of bioactivity (iron chelating ability, antibacterial potential and cytoprotection) and incorporation into films based on cassava starch, chitosan, and cellulose acetate. Sodium maltobionate exhibited a purity of 98.1% and demonstrated an iron chelating ability of approximately 50% at concentrations ranging from 15 to 20 mg mL-1. Maltobionic acid displayed minimal inhibitory concentrations (MIC) of 8.5, 10.5, 8.0, and 8.0 mg mL-1 for Salmonella enterica serovar Choleraesuis, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes, respectively. Maltobionic acid did not exhibit cytotoxicity in HEK-293 cells at concentrations up to 500 µg mL-1. Films incorporating 7.5% maltobionic acid into cassava starch and chitosan demonstrated inhibition of microbial growth, with halo sizes ranging from 15.67 to 22.33 mm. These films had a thickness of 0.17 and 0.13 mm, water solubility of 62.68% and 78.85%, and oil solubility of 6.23% and 11.91%, respectively. The cellulose acetate film exhibited a non-uniform visual appearance due to the low solubility of maltobionic acid in acetone. Mechanical and optical properties were enhanced with the addition of maltobionic acid to chitosan and cassava films. The chitosan film with 7.5% maltobionic acid demonstrated higher tensile strength (30.3 MPa) and elongation at break (9.0%). In contrast, the cassava starch film exhibited a high elastic modulus (1.7). Overall, maltobionic acid, with its antibacterial activity, holds promise for applications in active films suitable for food packaging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03879-3.

Carboxymethyl cellulose/poly (vinyl alcohol) based active film incorporated with tamarind seed coat waste extract for food packaging application

Incorporating a bioactive food waste extract into biodegradable polymers is a promising green approach to producing active films with antioxidant and antibacterial activity for food packaging. Active packaging films from carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) incorporated with tamarind seed coat waste extract (TS) were prepared by solvent casting method using citric acid as a crosslinking agent. The effect of TS content on the film properties was determined by measuring the optical, morphology, mechanical, water vapor transmission rate (WVTR), antioxidant, and antimicrobial attributes. The CMC/PVA-TS films were also tested on fresh pork. The addition of TS did not significantly affect the film structure and WVTR but it improved the mechanical and UV barrier properties. The films possessed antioxidant and antimicrobial ability against bacteria (S. aureus and E. coli). Thus, CMC/PVA packaging was successfully prepared, and the incorporation of TS enhanced the antioxidant and antimicrobial properties of the film, which extended the shelf-life of fresh pork.

Quality of pork after electron-beam irradiation: A meta-analysis study

Background and Aim

Irradiation has become a preferred method for pork preservation in recent years. Electron-beam irradiation is notably recognized for its feasibility and safety among various irradiation methods. This meta-analysis study aims to elucidate the impact of electron-beam irradiation on oxidation parameters, color, sensory attributes, and microbiological conditions in pork.

Materials and Methods

A total of 79 data from 22 articles were aggregated into an extensive database. The irradiation dose ranged from 0 to 20 kGy in this current meta-analysis. The observed parameters encompassed oxidation, color, sensory attributes, and microbiological conditions. A mixed-model approach was used to perform the meta-data analysis, in which irradiation dose was treated as fixed effects and distinct studies (articles) as random effects.

Results

Electron-beam irradiation resulted in an increase in thiobarbituric acid-reactive substances levels and peroxide-oxygen value of pork (p < 0.01). Conversely, total volatile-base-nitrogen values (p < 0.05) were observed. Following irradiation, the pH value, lightness (L*), redness (a*), and yellowness (b*) remained unaffected. Pork color tended to decrease after irradiation treatment (p = 0.095 and p = 0.079, respectively) at 7 and 14 days of storage. The irradiation process resulted in an increase in the values of texture and juiciness parameters (p < 0.05). However, electron-beam irradiation resulted in decreased overall acceptability (p = 0.089). In terms of microbiological status, electron-beam irradiation led to a reduction in the populations of Salmonella (p < 0.01), Escherichia coli (p < 0.01), Listeria monocytogenes (p < 0.05), and coliforms (p < 0.05) at 7 and 14 days of storage.

Conclusion

Electron-beam irradiation enhances lipid peroxidation in porcine meat. The color of the meat remained unchanged after treatment. However, with regard to sensory properties, electron-beam irradiation showed a tendency to decreased overall acceptability. Most microbiological parameters decreased following electron-beam irradiation.

Experimental investigations on PVA/chitosan and PVA/chitin films for active food packaging using Oxytenanthera abyssinica lignin nanoparticles and its UV-shielding, antimicrobial, and antiradical effects

This study investigated the effect of adding lignin nanoparticles (LNPs) derived from Oxytenanthera abyssinica via alkali-acid nanoprecipitation method to polyvinyl alcohol/chitosan (PVA/CI) and polyvinyl alcohol/chitin (PVA/CH) films for the active food packaging applications. Adding LNPs at concentrations of 1 % and 3 % improved the films' thermal stability and mechanical properties. The lowest water solubility and moisture content were observed in PVA/CI/LNPs films. LNPs exhibited effective 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, with the highest values observed in PVA/CH/LNPS and PVA/CI/LNPS films with values of 87.47 and 88.74 % respectively. The addition of LNPs also improved the UV-blocking abilities of the films. PVA/CH/LNP3 and PVA/CI/LNP3 have the smallest percentage transmission values of 3.34 % and 0.86 % in the UV range. The overall migration of dietary stimulants was lower in PVA/CI/LNPS and PVA/CH/LNPS films compared to PVA film. Antibacterial tests demonstrated the inhibitory capacity of the synthesized biofilms against both gram-positive and negative bacterial species, with the highest inhibitory value of 26 mm. The study suggests that PVA/CH/LNPS and PVA/CI/LNPS films have potential applications as active food packaging materials and can be explored in other potential applications such as drug delivery, tissue engineering, wound healing, and slow-release urea fertilizer development.

Smart packaging films based on corn starch/polyvinyl alcohol containing nano SIM-1 for monitoring food freshness

There is at present an acute need for the construction of biopolymer-based smart packaging material that can be applied for the real-time visual monitoring of food freshness. Herein, a nano-sized substituted imidazolate material (SIM-1) with ammonia-sensitive and antibacterial ability was effectively manufactured and then anchored within corn starch/polyvinyl alcohol (CS/PVA) blend to construct biopolymeric smart active packaging material. The structure, physical and functional performances of CS/PVA-based films with different content of SIM-1 (0.5, 1.0 and 2.0 wt% on CS/PVA basis) were then explored in detail. Results revealed that the incorporated SIM-1 nanocrystals were equally anchored within the CS/PVA matrix owing to the establishment of potent hydrogen-bonding interactions, which produced an obvious improvement in the compatibility of CS/PVA blend film, as well as its mechanical strength, water/oxygen barrier and UV-screening performances. The constructed CS/PVA/SIM-1 blend films further demonstrated superior long-term color stability property, ammonia-sensitive and antibacterial functions. Furthermore, the CS/PVA/SIM-1 blend films were utilized for effectively monitoring the deterioration of shrimp via observable color alteration. The above findings suggested the potential applications of CS/PVA/SIM-1 blend films in smart active packaging.

Collagen and gelatin: Structure, properties, and applications in food industry

Food-producing animals have the highest concentration of collagen in their extracellular matrix. Collagen and gelatin are widely used in food industry due to their specific structural, physicochemical, and biochemical properties, which enable them to improve health and nutritional value as well as to increase the stability, consistency, and elasticity of food products. This paper reviews the structural and functional properties including inherent self-assembly, gel forming, water-retaining, emulsifying, foaming, and thickening properties of collagen and gelatin. Then the colloid structures formed by collagen such as emulsions, films or coatings, and fibers are summarized. Finally, the potential applications of collagen and gelatin in muscle foods, dairy products, confectionary and dessert, and beverage products are also reviewed. The objective of this review is to provide the current market value, progress as well as applications of collagen and its derivatives in food industry.

Development of ternary polymeric films based on cassava starch, pea flour and green banana flour for food packaging

The development of alternative materials to replace plastics used in food packaging is an important approach to reducing environmental pollution and minimizing harmful impacts on ecosystems. In this study, biopolymeric films were formulated using cassava starch (Manihot esculenta Crantz), pea flour (Pisum sativum) and green banana flour (Musa sp.) to obtain a material for application in food packaging. The influence of a plasticizer on the optical and physicochemical properties of the films was analyzed and the synergy between higher concentrations of starch and plasticizer resulted in films with low opacity. In addition, the morphology, thermal, mechanical and barrier properties were examined. The film with the best formulation (p < 0.05) contained 12 g cassava starch, 3.6 g pea flour and 30 % glycerol (the maximum levels of the experiment). This film presented average values of thickness, moisture, solubility, opacity, maximum strength (F), maximum tensile stress (σ), elongation at break (ε) and elasticity (E) of 0.47 mm, 19.95 %, 87.45 %, 20.93 %, 9.30 N, 1.75 MPa, 30.10 % and 5.93 %, respectively. This research demonstrates the potential application of films obtained by combining starches from different sources. The sustainable production of environmentally-friendly packaging provides an alternative to fossil-based plastics, which have well-documented adverse effects on the environment.

Preparation, physicochemical and biological evaluation of chitosan Pleurotus ostreatus polysaccharides active films for food packaging

The aim of this study was to create CS-POP composite films by blending Pleurotus ostreatus stalk polysaccharides (POP) and chitosan (CS). The effects of adding different concentrations (0 %, 0.25 %, 0.5 %, 0.75 %, and 1 %) of POP on the mechanical, barrier, and optical properties of the CS films were investigated. When the POP content is at 0.5 %, the tensile strength of the composite film reaches its maximum value at 13.691 MPa, showing a significant improvement compared to the tensile strength of the pure CS film. The structure of the CS and CS-POP composite films was characterized by FT-IR spectroscopy, XRD, TGA and SEM. The results indicate that due to the interaction between the two types of CS and POP, the formation of Schiff base, and the intermolecular hydrogen bonds between CS and POP, the addition of POP to CS films can result in a smoother and more stable crystalline structure in the composite film. The CS-POP composite films exhibited enhanced antioxidant and antibacterial activity compared to the CS films alone, with the highest DPPH scavenging activity of 72.43 %. The composite films also showed significant inhibitory effects on the growth of E. coli.

Novel applications of black pepper essential oil as an antioxidant agent in sodium caseinate and chitosan based active edible films

In the current study, sodium caseinate and chitosan-based composite edible films were developed with the incorporation of black pepper (Piper nigrum) essential oil (BPO) in various concentrations (0.05, 0.1 and 0.15 %) for potential food packaging applications. The chemical composition of BPO was determined using GCMS and the major compound detected were β-caryophyllene, limonene, β-phellandren, pinene, copaene and α-humulene. The addition of BPO resulted in an increase in the thickness, EAB, WVP, moisture content and swelling index values of the films; however, the TS and water solubility decreased. The inclusion of BPO led to a substantial enhancement in the DPPH and ABTS radical scavenging capabilities of the edible films. SEM micrographs demonstrated intermolecular interaction between BPO, sodium caseinate, and chitosan. FTIR spectra confirmed the interaction of the functional groups of the polymers and BPO. The incorporation of the BPO increased the crystallinity of the films. Moreover, the thermal analysis including TGA, DSC and DTG demonstrated an increase in the thermal stability of the edible films with the addition of the BPO. These findings demonstrated that sodium caseinate and chitosan composite based edible films loaded with BPO can be used as sustainable active food packaging material.

Multifunctional composite films based on polyvinyl alcohol, quaternary ammonium salt modified cellulose nanofibers and tannic acid-iron ion coordination complexes for food packaging

The development of sustainable and well-performing food packaging materials takes on critical significance, whereas it is still challenging. To overcome the shortcomings of polyvinyl alcohol (PVA) as a degradable packaging material, in this work, hydrophobic quaternary ammonium salt (QAS) modified cellulose nanofibers (CNF) and tannic acid‑iron ion coordination complexes (TA-Fe) were adopted for the preparation of functional PVA films. The modified CNF (CNF-QAS) not only improved the mechanical properties and water resistance of PVA, but also endowed it with antibacterial ability. In addition, the synergistic antibacterial capability with CNF-QAS was achieved using TA-Fe with photothermal therapy. As a result, the modulus, elongation at break, tensile strength, and water contact angle of the prepared PVA films were examined as 88 MPa, 200 %, 11.7 MPa, and 94.8°, respectively. Furthermore, with the assistance of CNF-QAS and TA-Fe, the films inhibited the growth of E. coli and S. aureus by 99.8 % and 99.7 %, respectively, and they exhibited high cell viability of 90.5 % for L929 fibroblasts. Based on the above encouraging properties, the functional PVA films could significantly extend the shelf life of oranges for over two weeks, proving the excellent application prospects in the food packaging field.