Electrospun antimicrobial materials: Advanced packaging materials for food applications

Amine response smartphone-based portable and intelligent polyvinyl alcohol films for real-time detection of shrimp freshness

Food freshness monitoring is an important component in ensuring food safety for consumers and the food industry. Therefore, there is an urgent need for a portable, low-cost, and efficient detection method to determine the freshness. In this study, polyvinyl alcohol (PVA) was used as polymer carrier to prepare electrospinning film containing curcumin (Cur) and gardenia blue (GB) as intelligent indicator label on food packaging for real-time nondestructive detection of freshness of shrimp. The detection limit of ammonia response is less than or equal to 20 ppm, and the detection time is about 1 min, indicating that it has a sensitive response effect. At the same time, a smartphone application that can identify amines in response to color changes has been developed, and consumers can understand freshness by scanning the label. This study demonstrates the huge potential of smart indicator labels for food freshness monitoring.

Lactobacillus bulgaricus-loaded and chia mucilage-rich gum arabic/pullulan nanofiber film: An effective antibacterial film for the preservation of fresh beef

In recent years, the development of probiotic film by incorporating probiotics into edible polymers has attracted significant research attention in the field of active packaging. However, the influence of the external environment substantially reduces the vitality of probiotics, limiting their application. Therefore, to improve the probiotic activity, this study devised a novel nanofiber film incorporating chia mucilage protection solution (CPS), gum arabic (GA), pullulan (PUL), and Lactobacillus bulgaricus (LB). SEM images indicated the successful preparation of the nanofiber film incorporating LB. CPS incorporation significantly improved the survival ability of LB, with a live cell count reaching 7.62 log CFU/g after 28 days of storage at 4 °C - an increase of 1 log CFU/g compared to the fiber film without CPS. The results showed that the fiber film containing LB inhibited Escherichia coli and Staphylococcus aureus. Finally, the novel probiotic nanofiber film was applied to beef. The results showed that the shelf life of the beef during the experiments was extended for 2 days at 4 °C. Therefore, the novel probiotic film containing LB was suitable for meat preservation.

Design and characterization of edible chitooligosaccharide/fish skin gelatin nanofiber-based hydrogel with antibacterial and antioxidant characteristics

Antibacterial and active packaging materials have gained significant research attention in response to the growing interest in food packaging. In this investigation, we developed hydrogel packaging materials with antibacterial and antioxidant properties by incorporating chitooligosaccharide (COS) and fish skin gelatin (FSG) nanofiber membranes, which readily absorbed water and exhibited swelling characteristics. The nanofiber membranes were fabricated by electrospinning technology, embedding COS within FSG, and subsequently crosslinked through the Maillard reaction facilitated by the addition of glucose. The behavior of conductivity, viscosity, and surface tension in the spinning solutions was analyzed to understand their variation patterns. Scanning electron microscopy (SEM) results revealed that the crosslinked COS/FSG nanofiber membranes possessed a uniform yet disordered fiber structure, with the diameter of the nanofibers increasing as the COS content increased. Remarkably, when the COS content reached 25 %, the COS/FSG nanofiber membranes (CF-C-25) exhibited a suitable fiber diameter of 437.16 ± 63.20 nm. Furthermore, the thermal crosslinking process involving glucose supplementation enhanced the hydrophobicity of CF-C-25. Upon hydration, the CF-H-25 hydrogel displayed a distinctive porous structure, exhibiting a remarkable swelling rate of 954 %. Notably, the inclusion of COS significantly augmented the antibacterial and antioxidant properties of the hydrogel-based nanofiber membranes. CF-H-25 demonstrated an impressive growth inhibition of 90.56 ± 5.91 % against E. coli, coupled with excellent antioxidant capabilities. In continuation, we performed a comprehensive analysis of the total colony count, pH, TVB-N, and TBA of crucian carp. The CF-H-25 hydrogel proved highly effective in extending the shelf life of crucian carp by 2-4 days, suggesting its potential application as an edible membrane for aquatic product packaging.

Recent advances in the production of bionanomaterials for development of sustainable food packaging: A comprehensive review

Polymers originating from natural macromolecule based polymeric materials have gained popularity due to the demand for green resources to develop unique, eco-friendly, and high-quality biopolymers. The objective of this review is to address the utilization of bionanomaterials to improve food quality, safety, security, and shelf life. Bionanomaterials are synthesized by integrating biological molecules with synthetic materials at the nanoscale. Nanostructured materials derived from biopolymers such as cellulose, chitin, or collagen can be employed for the development of sustainable food packaging. Green materials are cost-effective, biocompatible, biodegradable, and renewable. The interaction of nanoparticles with biological macromolecules must be analyzed to determine the properties of the packaging film. The nanoparticles control the growth of bacteria that cause food spoiling by releasing distinctive chemicals. Bio-nanocomposites and nanoencapsulation systems have been used in antimicrobial bio-based packaging solutions to improve the efficiency of synergism. Nanomaterials can regulate gas and moisture permeability, screen UV radiation, and limit microbial contamination, keeping the freshness and flavor of the food. Food packaging based on nanoparticles embedded biopolymers can alleviate environmental concerns by lowering the amount of packaging materials required and enhancing packaging recyclability. This results in less waste and a more eco-sustainable approach to food packaging. The study on current advances in the production of bionanomaterials for development of sustainable food packaging involves a detailed investigation of the available data from existing literature, as well as the compilation and analysis of relevant research results using statistical approaches.

Fabrication of ɛ-Polylysine-Loaded Electrospun Nanofiber Mats from Persian Gum-Poly (Ethylene Oxide) and Evaluation of Their Physicochemical and Antimicrobial Properties

In the present study, electrospun nanofiber mats were fabricated by mixing different ratios (96:4, 95:5, 94:6, 93:7, and 92:8) of Persian gum (PG) and poly (ethylene oxide) (PEO). The SEM micrographs revealed that the nanofibers obtained from 93% PG and 7% PEO were bead-free and uniform. Therefore, it was selected as the optimized ratio of PG:PEO for the development of antimicrobial nanofibers loaded with ɛ-Polylysine (ɛ-PL). All of the spinning solutions showed pseudoplastic behavior and the viscosity decreased by increasing the shear rate. Additionally, the apparent viscosity, G', and G″ of the spinning solutions increased as a function of PEO concentration, and the incorporation of ɛ-PL did not affect these parameters. The electrical conductivity of the solutions decreased when increasing the PEO ratio and with the incorporation of ɛ-PL. The X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectra showed the compatibility of polymers. The antimicrobial activity of nanofibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated, and the samples loaded with ɛ-PL demonstrated stronger antimicrobial activity against S. aureus.

Chitosan-based electrospun nanofibers for encapsulating food bioactive ingredients: A review

Today, society has been more aware of healthy food products and related items containing bioactive compounds, which potentially contribute to human health. Unfortunately, the long-term stability and bioactivity of biologically active compounds against environmental factors compromise their target and effective action. In this way, lab-designed vehicles, such as nanoparticles and nanofibers, provide enough properties for their preservation and suitable delivery. Here, the electrospinning technique acts as an effective pathway for fabricating and designing nanofibers for the entrapments of biomolecules, in which several biopolymers such as proteins, polysaccharides (e.g., maltodextrin, agarose, chitosan), silk, among others, can be used as a wall material. It is likely that chitosan is one of the most employed biomaterials in this field. Therefore, in this review, we reveal the latest advances (over the last 2-3 years) in designing chitosan-based electrospun nanofibers and nanocarriers for encapsulation of bioactive compounds, along with the key applications in smart food packaging as well. Key findings and relevant breakthroughs are a priority in this review to provide a cutting-edge analysis of the literature. Finally, particular attention has been paid to the most promising developments.

Gelatin as a bioactive nanodelivery system for functional food applications

Gelatin has long been used as an encapsulant agent in the pharmaceutical and biomedical industries because of its low cost, wide availability, biocompatibility, and degradability. However, the exploitation of gelatin for nanodelivery application is not fully achieved in the functional food filed. In this review article, we highlight the latest work being performed for gelatin-based nanocarriers, including polyelectrolyte complexes, nanoemulsions, nanoliposomes, nanogels, and nanofibers. Specifically, we discuss the applications and challenges of these nanocarriers for stabilization and controlled release of bioactive compounds. To achieve better efficacy, gelatin is frequently used in combination with other biomaterials such as polysaccharides. The fabrication and synergistic effects of the newly developed gelatin composite nanocarriers are also present.

Recent advances in encapsulation of fat-soluble vitamins using polysaccharides, proteins, and lipids: A review on delivery systems, formulation, and industrial applications

Fat-soluble vitamins (FSVs) offer a range of beneficial properties as important nutrients in human nutrition. However, the high susceptibility to environmental conditions such as high temperature, light, and oxygen leads to the degradation of these compounds. This review highlights the different formulations underlying the encapsulation of FSVs in biopolymer (polysaccharide and protein) and lipid-based micro or nanocarriers for potential applications in food and pharmaceutical industries. In particular, the function of these carrier systems in terms of encapsulation efficiency, stability, bioavailability, and bio-accessibility is critically discussed. Recently, tremendous attention has been paid to encapsulating FSVs in commercial applications. According to the chemical nature of the active compound, the vigilant selection of delivery formulation, method of encapsulation, and final application (type of food) are the key important factors to be considered in the encapsulation of FSVs to ensure a high loading capacity, stability, bioavailability, and bio-accessibility. Future studies are recommended on the effect of different vitamin types and micro and nano encapsulate sizes on bioaccessibility and biocompatibility through in vitro/in vivo studies. Moreover, the toxicity and safety evaluation of encapsulated FSVs in human health should be evaluated before commercial application in food and pharmaceuticals.

Recent advance in biomass membranes: Fabrication, functional regulation, and antimicrobial applications

Both inorganic and polymeric membranes have been widely applied for antimicrobial applications. However, these membranes exhibit low biocompatibility, weak biodegradability, and potential toxicity to human being and environment. Biomass materials serve as excellent candidates for fabricating functional membranes to address these problems due to their unique physical, chemical, and biological properties. Here we present recent progress in the fabrication, functional regulation, and antimicrobial applications of various biomass-based membranes. We first introduce the types of biomass membranes and their fabrication methods, including the phase inversion, vacuum filtration, electrospinning, layer-by-layer self-assembly, and coating. Then, the strategies on functional regulation of biomass membranes by adding 0D, 1D, and 2D nanomaterials are presented and analyzed. In addition, antibacterial, antifungal, and antiviral applications of biomass-based functional membranes are summarized. Finally, potential development aspects of biomass membranes are discussed and prospected. This comprehensive review is valuable for guiding the design, synthesis, structural/functional tailoring, and sustainable utilization of biomass membranes.

Antimicrobial Active Packaging Containing Nisin for Preservation of Products of Animal Origin: An Overview

The preservation of food represents one of the greatest challenges in the food industry. Active packaging materials are obtained through the incorporation of antimicrobial and/or antioxidant compounds in order to improve their functionality. Further, these materials are used for food packaging applications for shelf-life extension and fulfilling consumer demands for minimal processed foods with great quality and safety. The incorporation of antimicrobial peptides, such as nisin, has been studied lately, with a great interest applied to the food industry. Antimicrobials can be incorporated in various matrices such as nanofibers, nanoemulsions, nanoliposomes, or nanoparticles, which are further used for packaging. Despite the widespread application of nisin as an antimicrobial by directly incorporating it into various foods, the use of nisin by incorporating it into food packaging materials is researched at a much smaller scale. The researchers in this field are still in full development, being specific to the type of product studied. The purpose of this study was to present recent results obtained as a result of using nisin as an antimicrobial agent in food packaging materials, with a focus on applications on products of animal origin. The findings showed that nisin incorporated in packaging materials led to a significant reduction in the bacterial load (the total viable count or inoculated strains), maintained product attributes (physical, chemical, and sensorial), and prolonged their shelf-life.

New perspectives on electrospun nanofiber applications in smart and active food packaging materials

Packaging plays a critical role in determining the quality, safety, and shelf-life of many food products. There have been several innovations in the development of more effective food packaging materials recently. Polymer nanofibers are finding increasing attention as additives in packaging materials because of their ability to control their pore size, surface energy, barrier properties, antimicrobial activity, and mechanical strength. Electrospinning is a widely used processing method for fabricating nanofibers from food grade polymers. This review describes recent advances in the development of electrospun nanofibers for application in active and smart packaging materials. Moreover, it highlights the impact of these nanofibers on the physicochemical properties of packaging materials, as well as the application of nanofiber-loaded packaging materials to foods, such as dairy, meat, fruit, and vegetable products.

Electrospun Polymer Materials with Fungicidal Activity: A Review

In recent years, there has been special interest in innovative technologies such as polymer melt or solution electrospinning, electrospraying, centrifugal electrospinning, coaxial electrospinning, and others. Applying these electrokinetic methods, micro- or nanofibrous materials with high specific surface area, high porosity, and various designs for diverse applications could be created. By using these techniques it is possible to obtain fibrous materials from both synthetic and natural biocompatible and biodegradable polymers, harmless to the environment. Incorporation of low-molecular substances with biological activity (e.g., antimicrobial, antifungal) is easily feasible. Moreover, biocontrol agents, able to suppress the development and growth of plant pathogens, have been embedded in the fibrous materials as well. The application of such nanotechnologies for the creation of plant protection products is an extremely promising new direction. This review emphasizes the recent progress in the development of electrospun fungicidal dressings and their potential to be applied in modern agriculture.

High- sensitivity bilayer nanofiber film based on polyvinyl alcohol/sodium alginate/polyvinylidene fluoride for pork spoilage visual monitoring and preservation

A colorimetric bilayer film for pork freshness detection and preservation was developed using electrospinning technique. The bilayer film consisted of a layer with polyvinyl alcohol - sodium alginate - alizarin as sensor layer and a layer with polyvinylidene fluoride - vanillin as antibacterial layer. The water contact angle of bilayer film was larger than the single colorimetric layer. The color sensitivity to the ammonia of the bilayer film was higher, with an ΔE value of 47.99. The film could display color shifts from yellow to purple with the naked eye is critical for checking pork freshness. In addition, the bilayer film exhibited sensitive antibacterial activity, with an inhibition zone against S. aureus (8.3 mm) and E. coli (14.7 mm), respectively. Finally, the bilayer film was applied to freshness monitoring of pork. The film displayed significant color changes and prolonged the pork shelf life by 24 h at 25 °C.

Electrospinning as a Promising Process to Preserve the Quality and Safety of Meat and Meat Products

Fresh and processed meat products are staple foods worldwide. However, these products are considered perishable foods and their deterioration depends partly on the inner and external properties of meat. Beyond conventional meat preservation approaches, electrospinning has emerged as a novel effective alternative to develop active and intelligent packaging. Thus, this review aims to discuss the advantages and shortcomings of electrospinning application for quality and safety preservation of meat and processed meat products. Electrospun fibres are very versatile, and their features can be modulated to deliver functional properties such as antioxidant and antimicrobial effects resulting in shelf-life extension and in some cases product quality improvement. Compared to conventional processes, electrospun fibres provide advantages such as casting and coating in the fabrication of active systems, indicators, and sensors. The approaches for improving, stabilizing, and controlling the release of active compounds and highly sensitive, rapid, and reliable responsiveness, under changes in real-time are still challenging for innovative packaging development. Despite their advantages, the active and intelligent electrospun fibres for meat packaging are still restricted to research and not yet widely used for commercial products. Industrial validation of lab-scale achievements of electrospinning might boost their commercialisation. Safety must be addressed by evaluating the impact of electrospun fibres migration from package to foods on human health. This information will contribute into filling knowledge gaps and sustain clear regulations.

Expanding the application of ion exchange resins for the preparation of antimicrobial membranes to control foodborne pathogens

Although ion exchange resins (IERs) have been extensively adopted in water treatment, there are no reports on the application thereof for synthesizing antibacterial materials against pathogenic bacteria. The present study is the first in which the ion exchange characteristic of IERs was utilized to introduce silver ions that possess efficient antibacterial properties. The resulting antibacterial materials were incorporated into polylactic acid (PLA) and/or polybutylene adipate terephthalate (PBAT) to prepare antibacterial membranes. XPS spectra revealed the occurrence of in-situ reduction of silver ions to metallic silver, which was preferable since the stability of silver in the materials was improved. EDS mapping analysis indicated that the distribution of silver was consistent with the distribution of sulfur in the membranes, verifying the ion exchange methodology proposed in the present study. To investigate the antibacterial performance of the prepared membranes, zone of inhibition tests and bacteria-killing tests were performed. The results revealed that neither bare polymeric membranes of PLA and PBAT nor IER-incorporated polymeric membranes exhibited noticeable antibacterial activities. In comparison, the antibacterial membranes demonstrated effective and sustainable antibacterial activities against pathogenic bacteria Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The prepared antibacterial membranes exhibited potential in food-related applications such as food packaging to delay food spoilage due to microbial growth.

Recent development in antibacterial activity and application of nanozymes in food preservation

Nanozymes with excellent broad-spectrum antibacterial properties offers an alternative strategy for food preservation. This review comprehensively summarized the antibacterial mechanisms of nanozymes, including the generation of reactive oxygen species (ROS) and the destruction of biofilms. Besides, the primary factors (size, morphology, hybridization, light, etc.) regulating the antibacterial activity of different types of nanozymes were highlighted in detail, which provided effective guidance on how to design highly efficient antibacterial nanozymes. Moreover, this review presented elaborated viewpoints on the unique applications of nanozymes in food preservation, including the selection of nanozymes loading matrix, fabrication techniques of nanozymes-based antibacterial films/coatings, and the recent advances in the application of nanozymes-based antibacterial films/coatings in food preservation. In the end, the safety issues of nanozymes have also been mentioned. Overall, this review provided new avenues in the field of food preservation and displayed great prospects.

Industrial application of antimicrobial peptides based on their biological activity and structure-activity relationship

Last several years, a rapid increase in drug resistance to traditional antibiotics has driven the emergence and development of antimicrobial peptides (AMPs). AMPs have also gained considerable attention from scientists due to their high potency in combatting infectious pathogens. A subset of analogues and their derivatives with specific targets have been successfully designed based on natural peptide patterns. In this review, scientific knowledge on the mechanisms of action related to biological activity and structure-activity relationship (SAR) of AMPs are summarized, and the biological applications in several important fields are critically discussed. SAR shows that the positive charge, secondary structure, special amino acid residues, hydrophobicity, and helicity of AMPs are closely related to their biological activities. The combination of nanotechnology, bioinformatics, and genetic engineering can accelerate to achieve the application of AMPs as effective, safe, economical, and nonresistant antimicrobial agents in medicine, the food and feed industries, and agriculture in coming years. Given the intense interest in AMPs, further investigations are needed in the future to evaluate the specific structure and function that make their use favorable in several industries. This review may provide a comprehensive reference for future studies on chemical modifications, mechanistic exploration, and applications of AMPs.

Bioactive Electrospun Fibers of Poly(ε-Caprolactone) Incorporating α-Tocopherol for Food Packaging Applications

Antioxidant activity is an important feature for food contact materials such as packaging, aiming to preserve freshness and retard food spoilage. Common bioactive agents are highly susceptible to various forms of degradation; therefore, protection is required to maintain functionality and bioavailability. Poly(ε-caprolactone) (PCL), a biodegradable GRAS labeled polymer, was used in this study for encapsulation of α-tocopherol antioxidant, a major component of vitamin E, in the form of electrospun fibers. Rheological properties of the fiber forming solutions, which determine the electrospinning behavior, were correlated with the properties of electrospun fibers, e.g., morphology and surface properties. Interactions through hydrogen bonds were evidenced between the two components. These have strong effect on structuration of macromolecular chains, especially at low α-tocopherol amounts, decreasing viscosity and elastic modulus. Intra-molecular interactions in PCL strengthen at high α-tocopherol amounts due to decreased solvation, allowing good structural recovery after cease of mechanical stress. Morphologically homogeneous electrospun fibers were obtained, with ~6 μm average diameter. The obtained fibers were highly hydrophobic, with fast release in 95% ethanol as alternative simulant for fatty foods. This induced good in vitro antioxidant activity and significant in vivo reduction of microbial growth on cheese, as determined by respirometry. Therefore, the electrospun fibers from PCL entrapping α-tocopherol as bioactive agent showed potential use in food packaging materials.

Development and characterization of electrospun nanofibers based on pullulan/chitin nanofibers containing curcumin and anthocyanins for active-intelligent food packaging

An electrospun nanofiber based on pullulan/chitin nanofibers (PCN) containing curcumin (CR) and anthocyanins (ATH) was developed using an electrospinning technique for active-intelligent food packaging. The results of scanning electron microscopy and attenuated total reflection Fourier transform infrared spectroscopy indicated that CR and ATH were successfully immobilized on the film-forming substrate based on PCN. The physical and chemical properties of nanofibers with no colorant, a single colorant, and double colorants were compared. The nanofiber containing ATH and CR (PCN/CR/ATH) had stronger antioxidant and antimicrobial activities than those of nanofibers containing CR (PCN/CR) or ATH (PCN/ATH). With respect to pH sensitivity, the color of the PCN/CR nanofibers did not change obviously, but the color of the PCN/ATH and PCN/CR/ATH nanofibers changed significantly with the change in pH. Furthermore, the PCN/CR/ATH nanofibers clearly changed color with the progressive spoilage of Plectorhynchus cinctus at room temperature. Therefore, the electrospun PCN/CR/ATH nanofiber have great application potential in active-intelligent food packaging.