Edible coating with resveratrol loaded electrospun zein nanofibers with enhanced bioaccessibility

Nano-enabled smart and functional materials toward human well-being and sustainable developments

Fabrication and operation on increasingly smaller dimensions have been highly integrated with the development of smart and functional materials, which are key to many technological innovations to meet economic and societal needs. Along with researchers worldwide, the Waterloo Institute for Nanotechnology (WIN) has long realized the synergetic interplays between nanotechnology and functional materials and designated 'Smart & Functional Materials' as one of its four major research themes. Thus far, WIN researchers have utilized the properties of smart polymers, nanoparticles, and nanocomposites to develop active materials, membranes, films, adhesives, coatings, and devices with novel and improved properties and capabilities. In this review article, we aim to highlight some of the recent developments on the subject, including our own research and key research literature, in the context of the UN Sustainability development goals.

Improvement in the Sustained-Release Performance of Electrospun Zein Nanofibers via Crosslinking Using Glutaraldehyde Vapors

Volatile active ingredients in biopolymer nanofibers are prone to burst and uncontrolled release. In this study, we used electrospinning and crosslinking to design a new sustained-release active packaging containing zein and eugenol (EU). Vapor-phase glutaraldehyde (GTA) was used as the crosslinker. Characterization of the crosslinked zein nanofibers was conducted via scanning electron microscopy (SEM), mechanical properties, water resistance, and Fourier transform infrared (FT-IR) spectroscopy. It was observed that crosslinked zein nanofibers did not lose their fiber shape, but the diameter of the fibers increased. By increasing the crosslink time, the mechanical properties and water resistance of the crosslinked zein nanofibers were greatly improved. The FT-IR results demonstrated the formation of chemical bonds between free amino groups in zein molecules and aldehyde groups in GTA molecules. EU was added to the zein nanofibers, and the corresponding release behavior in PBS was investigated using the dialysis membrane method. With an increase in crosslink time, the release rate of EU from crosslinked zein nanofibers decreased. This study demonstrates the potential of crosslinking by GTA vapors on the controlled release of the zein encapsulation structure containing EU. Such sustainable-release nanofibers have promising potential for the design of fortified foods or as active and smart food packaging.

Polysaccharide-Based Edible Biopolymer-Based Coatings for Fruit Preservation: A Review

Over the last decades, a significant rise in fruit consumption has been noticed as they contain numerous nutritional components, which has led to the rise in fruit production globally. However, fruits are highly liable to spoilage in nature and remain vulnerable to losses during the storage and preservation stages. Therefore, it is crucial to enhance the storage life and safeness of fruits for the consumers. To keep up the grade and prolong storage duration, various techniques are employed in the food sector. Among these, biopolymer coatings have gained widespread acceptance due to their improved characteristics and ideal substitution for synthetic polymer coatings. As there is concern regarding the safety of the consumers and sustainability, edible coatings have become a selective substitution for nurturing fruit quality and preventing decay. The application of polysaccharide-based edible coatings offers a versatile solution to prevent the passage of moisture, gases, and pathogens, which are considered major threats to fruit deterioration. Different polysaccharide substances such as chitin, pectin, carrageenan, cellulose, starch, etc., are extensively used for preparing edible coatings for a wide array of fruits. The implementation of coatings provides better preservation of the fruits such as mango, strawberry, pineapple, apple, etc. Furthermore, the inclusion of functional ingredients, including polyphenols, natural antioxidants, antimicrobials, and bio-nanomaterials, into the edible coating solution matrix adds to the nutritional, functional, and sensory attributes of the fruits. The blending of essential oil and active agents in polysaccharide-based coatings prevents the growth of food-borne pathogens and enhances the storage life of the pineapple, also improving the preservation of strawberries and mangoes. This paper aims to provide collective data regarding the utilization of polysaccharide-based edible coatings concerning their characteristics and advancements for fruit preservation.

Fabrication and characterization of electrospun catechins-loaded nanofibres for fortification of milk

Catechins in their free form are bitter in taste, and undergo deterioration and oxidation during processing and storage that limit their use as nutraceuticals in foods. Therefore, catechins were electrospun using zein as encapsulating polymer into nanofibres at 15, 18 and 21% w/w concentrations, 16, 20 and 24 kV applied voltage and 0.5 and 1.0 mL/h feed rate. The electrospinning conditions were optimized using Taguchi L18 (21 × 32) design. Encapsulation efficiency as high as 92.8% and mean fibre diameter as low as 95.2 nm were obtained at 18% concentration of zein, 0.5 mL/h feed rate and 20 kV applied voltage. Scanning electron and atomic force micrographs revealed that the nanofibres produced at zein concentration of 18% and above were clean and beadfree, with cylindrical morphology and non-porous topography. The hydrodynamic diameter, zeta potential and polydispersity index of catechins-loaded nanofibres at optimized conditions were 172.3 nm, -26.3 mV and 0.15. FTIR spectroscopy and X-ray diffractometry confirmed that catechins were encapsulated within the nanofibres. The catechins got released from loaded nanofibres in a controlled and sustained manner, while their antioxidant property was retained. The physico-chemical and sensory qualities of milk were not affected after fortification with catechins-loaded nanofibres.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05891-0.

Fabrication of resveratrol-loaded soy protein isolate-glycyrrhizin nanocomplex for improving bioavailability via pH-responsive hydrogel properties

Resveratrol (RES) is a functional polyphenol that suffers from low water solubility and poor bioavailability. A novel RES-loaded soy protein isolate-dipotassium glycyrrhizinate (SPI-DG) nanocomplex (RES@SPI-DG) was designed and evaluated in this study. RES@SPI-DG was prepared using a simple but novel self-assembly ultrasonic-assisted pH-driven method. The interactions between RES and SPI-DG were non-covalent bonds, including hydrophobic interactions, hydrogen bonds, and van der Waals interactions. RES@SPI-DG exhibited high encapsulation efficiency (97.60 ± 0.38 %) and loading capacity (8.74 ± 0.03 %) of RES with a uniform small size (68.39 ± 1.10 nm). RES in RES@SPI-DG was in an amorphous state and demonstrated a 24-h apparent solubility 482.53-fold higher than bare RES. RES@SPI-DG also showed strong in vitro antioxidant properties. The pH-responsive hydrogel character of SPI-DG makes it an effective intestine-targeted delivery system that could retard the release of RES in a simulated stomach and accelerate it in a simulated intestine. In animal experiments, the bioavailability of RES@SPI-DG was 5.17 times higher than that of bare RES, and the biodistribution was also significantly improved. RES@SPI-DG demonstrated a strong hepatoprotective effect against overdose acetaminophen-induced liver injury. The SPI-DG complex might be a promising nano-platform for enhancing the bioavailability and efficacy of hydrophobic polyphenols such as RES.

Characteristics, antimicrobial capacity, and antioxidant potential of electrospun zein/polyvinyl alcohol nanofibers containing thymoquinone and electrosprayed resveratrol nanoparticles

The aim of the present study was to fabricate, characterize, and evaluate the in vitro antimicrobial and antioxidant properties of zein/polyvinyl alcohol (ZN/PVA) nanofibers containing 2% and 4% of thymoquinone (TQ), either alone or in combination with electrosprayed ZN nanoparticles containing 1% and 2% of resveratrol (RS). According to scanning electron microscopy analysis, the diameter of nanofibers and nanoparticles increased with increasing TQ and RS concentrations, respectively. The molecular interaction between ZN or PVA polymers and TQ or RS was confirmed by Fourier transform infrared spectroscopy. Thermogravimetric analysis showed that the thermal stability of nanofibers did not change with the addition of TQ and RS. Moreover, incorporation of TQ in nanofibers along with RS nanoparticles increased their antibacterial and free radical scavenging activities based on broth dilution and DPPH methods, respectively (p ≤ .05). Escherichia coli O157:H7 (as a Gram-negative pathogenic bacteria) was more resistant to all treatments than Staphylococcus aureus (as a Gram-positive pathogenic bacteria). In addition, the combined use of TQ in nanofibers and RS nanoparticles had antagonistic antibacterial and synergistic antioxidant effects. The best results were obtained with ZN/PVA nanofiber containing 4% TQ and electrosprayed with 2% RS nanoparticles (p ≤ .05). According to the results of the present study, biodegradable ZN/PVA nanofiber containing TQ and electrosprayed with RS nanoparticles can be used as a novel active packaging material in the food industry.

Recent advances in oral delivery systems of resveratrol: foreseeing their use in functional foods

Herein, we review the current state-of-the-art on the use of micro- and nano-delivery systems, a possible solution to some of the drawbacks associated with the incorporation of resveratrol in foods. Specifically, we present an overview of a wide range of micro-nanostructures, namely, lipidic and polymeric, used for the delivery of resveratrol. Also, the gastrointestinal fate of resveratrol-loaded micro-nanostructures, as a critical parameter for their use as functional food, is explored in terms of stability, bioaccessibility, and bioavailability. Different micro-nanostructures are of interest for the development of functional foods given that they can provide different advantages and properties to these foods and even be tailor-made to address specific issues (e.g., controlled or targeted release). Therefore, we discuss a wide range of micro-nanostructures, namely, lipidic and polymeric, used to deliver resveratrol and aimed at the development of functional foods. It has been reported that the use of some production methodologies can be of greater interest than others, for example, emulsification, solvent displacement and electrohydrodynamic processing (EHDP) enable a greater increase in bioaccessibility. Additionally, the use of coatings facilitates further improvements in bioaccessibility, which is likely due to the increased gastric stability of the coated micro-nanostructures. Other properties, such as mucoadhesion, can also help improve bioaccessibility due to the increase in gut retention time. Additionally, cytotoxicity (e.g., biocompatibility, antioxidant, and anti-inflammatory) and possible sensorial impact of resveratrol-loaded micro- and nano-systems in foods are highlighted.

The Antioxidant Potential of Resveratrol from Red Vine Leaves Delivered in an Electrospun Nanofiber System

Despite the wide pharmacological action of polyphenols, their usefulness is limited due to their low oral bioavailability, which is due to their low solubility and rapid first-pass metabolism. Red vine leaf extract is an herbal medicine containing several polyphenols, with resveratrol and polydatin as the main compounds exhibiting antioxidant and anti-inflammatory properties. In the first stage of the work, using the Design of Experiment (DoE) approach, the red vine leaf extract (50% methanol, temperature 70 °C, and three cycles per 60 min) was obtained, which showed optimal antioxidant and anti-inflammatory properties. In order to circumvent the above-described limitations and use innovative technology, electrospun nanofibers containing the red vine leaf extract, polyvinylpyrrolidone (PVP), and hydroxypropyl-β-cyclodextrin (HPβCD) were first developed. The optimization of the process involved the time of system mixing prior to electrospinning, the mixture flow rate, and the rotation speed of the collector. Dissolution studies of nanofibers showed improved resveratrol release from the nanofibers (over five-fold). Additionally, a PAMPA-GIT assay confirmed significantly better buccal penetration of resveratrol from this nanofiber combination (over ten-fold). The proposed strategy for electrospun nanofibers with the red vine leaf extract is an innovative approach to better use the synergy of the biological action of active compounds present in extracts that are beneficial for the development of nutraceuticals.

The potential of curcumin-based co-delivery systems for applications in the food industry: Food preservation, freshness monitoring, and functional food

Currently, curcumin-based co-delivery systems are receiving widespread attention. However, a systematic summary of the possibility of curcumin-based co-delivery systems used for the food industry from multiple directions based on the functional characteristics of curcumin is lacking. This review details the different forms of curcumin-based co-delivery systems including the single system of nanoparticle, liposome, double emulsion, and multiple systems composed of different hydrocolloids. The structural composition, stability, encapsulation efficiency, and protective effects of these forms are discussed comprehensively. The functional characteristics of curcumin-based co-delivery systems are summarized, involving biological activity (antimicrobial and antioxidant), pH-responsive discoloration, and bioaccessibility/bioavailability. Correspondingly, potential applications for food preservation, freshness detection, and functional foods are introduced. In the future, more novel co-delivery systems for active ingredients and food matrices should be developed. Besides, the synergistic mechanisms between active ingredients, delivery carrier/active ingredient, and external physical condition/active ingredient should be explored. In conclusion, curcumin-based co-delivery systems have the potential to be widely used in the food industry.

Factors affecting the fate of nanoencapsulates post administration

Nanoencapsulation has found numerous applications in the food and nutraceutical industries. Micro and nanoencapsulated forms of bioactives have proven benefits in terms of stability, release, and performance in the body. However, the encapsulated ingredient is often subjected to a wide range of processing conditions and this is followed by storage, consumption, and transit along the gastrointestinal tract. A strong understanding of the fate of nanoencapsulates in the biological system is mandatory as it provides valuable insights for ingredient selection, formulation, and application. In addition to their efficacy, there is also the need to assess the safety of ingested nanoencapsulates. Given the rising research and commercial focus of this subject, this review provides a strong focus on their interaction factors and mechanisms, highlighting their prospective biological fate. This review also covers various approaches to studying the fate of nanoencapsulates in the body. Also, with emphasis on the overall scope, the need for a new advanced integrated common methodology to evaluate the fate of nanoencapsulates post-administration is discussed.

Mechanochemical Properties of Mucoadhesive Tablets Based on PVP/HPβCD Electrospun Nanofibers as Local Delivery of Polygoni cuspidati Extract for Treating Oral Infections

This study investigated the ability of PVP/HPβCD-based electrospun nanofibers to enhance the dissolution rate of poorly soluble polydatin and resveratrol, the main active components of Polygoni cuspidati extract. To make a solid unit dosage form that would be easier to administer, extract-loaded nanofibers were ground. SEM examination was used to analyze the nanostructure of the fibers, and the results of the cross-section of the tablets showed that they had maintained their fibrous structure. The release of the active compounds (polydatin and resveratrol) in the mucoadhesive tablets was complete and prolonged in time. Additionally, the possibility of staying on the mucosa for a prolonged time has also been proven for both tablets from PVP/HPβCD-based nanofibers and powder. The appropriate physicochemical properties of the tablets, along with the proven antioxidant, anti-inflammatory, and antibacterial properties of P. cuspidati extract, highlight the particular benefits of the mucoadhesive formulation for use as a drug delivery system for periodontal diseases.

Nanocoating-konjac application as postharvest handling to extend the shelf life of Siamese oranges

Siamese orange fruit is very popular today, driven by the increasing public demand or healthy food. Siamese oranges contain bioactive phenolic compounds, carotenoids, vitamins, minerals, and fiber which are good for health. The weakness of Siamese oranges is their quality declines quickly and their short shelf life. Postharvest handling with the application of coatings from natural ingredients to extend the shelf life of orange fruits is currently needed to reduce the use of synthetic materials. Natural ingredients that have the potential to be used as base materials for coatings are konjac tubers because they contain glucomannan polysaccharides and bioactive compounds that can form coatings. The purpose of this study was to determine the effect of nanocoating-konjacon the shelf life of Siamese oranges. The research began with the preparation of the nanocoating-konjac formula as the main ingredient of the nanocoating and the application of the nano coating-konjac on the surface of Siamese oranges. This study used a completely randomized two-factor design, namely nanocoating-konjac application (without coating, coating, and nanocoating) and storage time (0, 5, 10, and 15 days), three replications. Variables observed: Weight loss, number of damaged fruits, color, texture, acidity, total soluble solids, water content, vitamin C, and total plate count. The data obtained was tested for diversity with SPSS, if it shows differences the test is continued with Duncan's Multiple Range Test. The conclusion of this research is the application of nanocoating-konjac, coating-konjac and without coating on Siamese oranges to determine the effect of weight loss, number of damaged fruits, color, texture, acidity, total dissolved solids, water content, vitamin C, and total plate count during storage. This research recommends that the application of nanocoating-konjac as postharvest handling can extend the shelf life of Siamese oranges until the 10th days.

Emerging plant proteins as nanocarriers of bioactive compounds

The high prevalence of chronic illnesses, including cancer, diabetes, obesity, and cardiovascular diseases has become a growing concern for modern society. Recently, various bioactive compounds (bioactives) are shown to have a diversity of health-beneficial impacts on a wide range of disorders. But the application of these bioactives in food and pharmaceutical formulations is limited due to their poor water solubility and low bioaccessibility/bioavailability. Plant proteins are green alternatives for designing biopolymeric nanoparticles as appropriate nanocarriers thanks to their amphiphilic nature compatible with many bioactives and unique functional properties. Recently, emerging plant proteins (EPPs) are employed as nanocarriers for protection and targeted delivery of bioactives and also improving their stability and shelf-life. EPPs could enhance the solubility, stability, and bioavailability of bioactives by different types of delivery systems. In addition, the use of EPPs in combination with other biopolymers like polysaccharides was found to make a favorable wall material for food bioactives. This review article covers the various sources and importance of EPPs along with different encapsulation techniques of bioactives. Characterization of EPPs for encapsulation is also investigated. Furthermore, the focus is on the application of EPPs as nanocarriers for food bioactives.

Emerging Food Packaging Applications of Cellulose Nanocomposites: A Review

Cellulose is the most abundant biopolymer on Earth, which is synthesized by plants, bacteria, and animals, with source-dependent properties. Cellulose containing β-1,4-linked D-glucoses further assembles into hierarchical structures in microfibrils, which can be processed to nanocellulose with length or width in the nanoscale after a variety of pretreatments including enzymatic hydrolysis, TEMPO-oxidation, and carboxymethylation. Nanocellulose can be mainly categorized into cellulose nanocrystal (CNC) produced by acid hydrolysis, cellulose nanofibrils (CNF) prepared by refining, homogenization, microfluidization, sonification, ball milling, and the aqueous counter collision (ACC) method, and bacterial cellulose (BC) biosynthesized by the Acetobacter species. Due to nontoxicity, good biodegradability and biocompatibility, high aspect ratio, low thermal expansion coefficient, excellent mechanical strength, and unique optical properties, nanocellulose is utilized to develop various cellulose nanocomposites through solution casting, Layer-by-Layer (LBL) assembly, extrusion, coating, gel-forming, spray drying, electrostatic spinning, adsorption, nanoemulsion, and other techniques, and has been widely used as food packaging material with excellent barrier and mechanical properties, antibacterial activity, and stimuli-responsive performance to improve the food quality and shelf life. Under the driving force of the increasing green food packaging market, nanocellulose production has gradually developed from lab-scale to pilot- or even industrial-scale, mainly in Europe, Africa, and Asia, though developing cost-effective preparation techniques and precisely tuning the physicochemical properties are key to the commercialization. We expect this review to summarise the recent literature in the nanocellulose-based food packaging field and provide the readers with the state-of-the-art of this research area.

Is It Possible to Improve the Bioavailability of Resveratrol and Polydatin Derived from Polygoni cuspidati Radix as a Result of Preparing Electrospun Nanofibers Based on Polyvinylpyrrolidone/Cyclodextrin?

The low bioavailability of resveratrol and polydatin obtained from Polygoni cuspidati extract limits the application of their pro-health properties. While nanofibers have attracted increasing attention in nutrition delivery due to their special properties, including an increase in the dissolution and permeability, which affects the bioavailability. Therefore, it is justified to obtain nanofibers from Polygoni cuspidati extract, which showed antioxidant and anti-inflammatory properties as a result of a presence of stilbene analogs in the Polygoni cuspidati extract (especially resveratrol and polydatin). In the first stage of the work, using the Design of Experiment (DoE) approach, the Polygoni cuspidati extract (70% of methanol, temperature 70 °C and 4 cycles) was obtained, which showed the best antioxidant and anti-inflammatory properties. Using the Polygoni cuspidati extract as a substrate, nanofibers were obtained by electrospinning. The identification of nanofibers was confirmed on the basis of the analysis of changes in XRPD diffractograms, SEM picture and FTIR-ATR spectra. Obtaining nanofibers from the Polygoni cuspidati extract significantly improved the solubility of resveratrol and polydatin (approx. 6-fold comparing to pure substance). As a consequence, the penetration coefficients of both tested resveratrol and polydatin also increased. The proposed strategy for the preparation of nanofibers from the Polygoni cuspidati extract is an innovative approach to better use the synergy of biological action of active compounds present in extracts. It is especially during the development of nutraceuticals based on the use of selected stilbenes.

Lecithin-Polysaccharide Self-Assembled Microspheres for Resveratrol Delivery

Poor water solubility and low chemical stability, seriously limit the efficient bioavailability of resveratrol. Here, we propose encapsulating resveratrol in lecithin-polysaccharide self-assembled microspheres (LPSM). An LPSM was designed with a lecithin core, and alginate-carboxymethyl chitosan biolayer shell. The LPSM had a spherical shape with 12.171 ± 0.960 μm of particle size and −30.86 ± 1.37 mV of zeta potential. The introduce of lecithin remarkably increased the encapsulation efficiency of resveratrol to 92.78 ± 0.82%. The LPSM elevated the antioxidant capacity and ultraviolet resistance of resveratrol. Moreover, LPSM inhibited release in a simulated gastric environment, promoted sustained release in simulated intestinal environment, and elevated the bioavailability of resveratrol during in vitro simulated digestion. Results indicate that LPSM is promising as a carrier for resveratrol delivery to enhance stability and bioaccessibility.

Electrospun Zein/Polyoxyethylene Core-Sheath Ultrathin Fibers and Their Antibacterial Food Packaging Applications

The purpose of this work is to develop a novel ultrathin fibrous membrane with a core-sheath structure as antibacterial food packaging film. Coaxial electrospinning was exploited to create the core-sheath structure, by which the delivery regulation of the active substance was achieved. Resveratrol (RE) and silver nanoparticles (AgNPs) were loaded into electrospun zein/polyethylene oxide ultrathin fibers to ensure a synergistic antibacterial performance. Under the assessments of a scanning electron microscope and transmission electron microscope, the ultrathin fiber was demonstrated to have a fine linear morphology, smooth surface and obvious core-sheath structure. X-ray diffraction and Fourier transform infrared analyses showed that RE and AgNPs coexisted in the ultrathin fibers and had good compatibility with the polymeric matrices. The water contact angle experiments were conducted to evaluate the hydrophilicity and hygroscopicity of the fibers. In vitro dissolution tests revealed that RE was released in a sustained manner. In the antibacterial experiments against Staphylococcus aureus and Escherichia coli, the diameters of the inhibition zone of the fiber were 8.89 ± 0.09 mm and 7.26 ± 0.10 mm, respectively. Finally, cherry tomatoes were selected as the packaging object and packed with fiber films. In a practical application, the fiber films effectively reduced the bacteria and decreased the quality loss of cherry tomatoes, thereby prolonging the fresh-keeping period of cherry tomatoes to 12 days. Following the protocols reported here, many new food packaging films can be similarly developed in the future.

Strategically designed SPEEK nanofibrous scaffold with tailored delivery ofresveratrolfor skin wound regeneration

Electro-spinnable polymeric materials can easily form two-dimensional (2D) nanofibrous scaffolds improving biochemical functionalities specially in the area of skin wound healing and nanomedicine, but it has been hard to achieve this on a highly mechanically stable biopolymer, Poly ether ether ketone (PEEK), due to its intrinsic hydrophobicity and chemical inertness. Herein, we demonstrated a novel nanomedicine healing system consisting of sulphonated poly ether ether ketone combined withresveratrol(SPEEK+RSV), which could act as an effective 2D nano bio-materialin vitroandin vivo, without observable cytotoxicity. The fabricated nanocomposites exhibited enriched skin cell proliferation and adhesion as confirmed from the results of MTT, cell adhesion and live-dead assay. Results of SEM analysis showed a uniform nano-sized distribution with adequate pore size and porosity % facilitating a desired breathable environment at the wound site. The results of FT-IR, tensile studies and TGA analyses confirmed the presence of appropriate bonds and improved mechanical stability of theRSVincorporated nanofibrous scaffold. Results of anti-microbial analysis portrayed good potentiality of the fabricated nanofibers in treating wounds colonized with bacterial infections. Controlled drug release of resveratrol established the bio-compatibility of the nanofibers in skin wound regeneration.In vivoanalysis assessed in female Wistar rats enabled complete wound closure with 100 % wound contraction within 16 days. Results of histopathology analysis through H-E and MT staining presented the re-surfing of the wound environment with regeneration of epithelium, granulation tissue and collagen. Thus, the fabricated 2D nanofibrous scaffold incorporated with pharmaceutical RSV bio-medicine perceptively mimicked skin ECM convincingly aiding the progression of skin wound regeneration mechanism.

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.

Antioxidants and Bioactive Compounds in Food: Critical Review of Issues and Prospects

This review paper gives an insight into the effective delivery mechanisms for health-promoting substances and highlights the challenges of using antioxidants and bioactives in foods. The selection criteria for choosing bioactives and their extraction in bioavailable form with their adequate incorporation techniques and delivery mechanisms are covered. Moreover, an overview of existing methods for determination of bioactivity is given. The importance of scientifically evaluating the effects of foods or food components on consumer health before making claims about the healthiness is aligned. Finally, a scientific perspective on how to respond to the booming demand for health-promoting products is given, and we acknowledge that despite the work done, there are still many challenges that need to be overcome.

Emerging trends in nano-bioactive-mediated mitochondria-targeted therapeutic stratagems using polysaccharides, proteins and lipidic carriers

The emergence of new lifestyle disorders and pharmaco-resistant variants of diseases has necessitated the search for effective therapeutic moieties and approaches that could overcome the limitations in the existing treatment modalities. In this context, bioactives such as flavonoids, polyphenols, tannins, terpenoids and alkaloids have demonstrated promise in therapy owing to their ability to scavenge free radicals and modulate the mitochondrial function as well as regulate metabolic pathways. However, their clinical applicability is low owing to their poor bioavailability and aqueous solubility. The encapsulation of bioactives in nanodimensional particles has overcome these limitations to a large extent while simultaneously conferring additional advantages of improved circulation time, enhanced cell uptake and target specific release. A wide range of nanocarriers derived from biopolymers such as polysaccharides, lipids and proteins, have been explored for encapsulation of different bioactives and have reported significant improvement of the bioavailability and therapeutic efficacy of the encapsulated cargo. However, incorporation of cell-specific and mitochondria-specific elements on the nanocarriers has been relatively less explored. This review summarizes some of the recent attempts to treat different disorders using bioactives encapsulated in biopolymer nanostructures and few instances of mitochondria-specific delivery.

Electrospun Nanofibers: Current Progress and Applications in Food Systems

Electrospinning has the advantages of simple manufacturing equipment, a low spinning cost, wide range of spinnable materials, and a controllable mild process, which can continuously fabricate submicron or nanoscale ultrafine polymer fibers without high temperature or high pressure. The obtained nanofibrous films may have a large specific surface area, unique pore structure, and easy-to-modify surface characteristics. This review briefly introduces the types and fiber structures of electrospinning and summarizes the applications of electrospinning for food production (e.g., delivery systems for functional food, filtration of beverages), food packaging (e.g., intelligent packaging, antibacterial packaging, antioxidant packaging), and food analysis (e.g., pathogen detection, antibiotic detection, pesticide residue detection, food compositions analysis), focusing on the advantages of electrospinning applications in food systems. Furthermore, the limitations and future research directions of the technique are discussed.

Nanofiber Systems as Herbal Bioactive Compounds Carriers: Current Applications in Healthcare

Nanofibers have emerged as a potential novel platform due to their physicochemical properties for healthcare applications. Nanofibers’ advantages rely on their high specific surface-area-to-volume and highly porous mesh. Their peculiar assembly allows cell accommodation, nutrient infiltration, gas exchange, waste excretion, high drug release rate, and stable structure. This review provided comprehensive information on the design and development of natural-based polymer nanofibers with the incorporation of herbal medicines for the treatment of common diseases and their in vivo studies. Natural and synthetic polymers have been widely used for the fabrication of nanofibers capable of mimicking extracellular matrix structure. Among them, natural polymers are preferred because of their biocompatibility, biodegradability, and similarity with extracellular matrix proteins. Herbal bioactive compounds from natural extracts have raised special interest due to their prominent beneficial properties in healthcare. Nanofiber properties allow these systems to serve as bioactive compound carriers to generate functional matrices with antimicrobial, anti-inflammatory, antioxidant, antiseptic, anti-viral, and other properties which have been studied in vitro and in vivo, mostly to prove their wound healing capacity and anti-inflammation properties.

Fabrication and characterization of dextran/zein hybrid electrospun fibers with tailored properties for controlled release of curcumin

BACKGROUND

In recent years, there has been considerable interest in the use of biopolymer electrospun nanofibers for various food applications due to the biocompatibility, biodegradability, and high loading capacity. Herein, we fabricated and characterized novel hybrid electrospun fibers from dextran (50%, w/v) and zein (0-30%, w/v) solutions, and the effects of various zein concentrations on the properties of the hybrid electrospun fibers were investigated.

RESULTS

When zein was added at low concentrations (5% and 10%), dextran and zein showed poor miscibility, as reflected by significantly decreased viscosity of the solutions, and the poor mechanical properties of the derived fiber membranes. When zein was added at medium concentrations (15-25%), hydrogen bonds were formed between dextran and zein molecules, as indicated by the red shift of Fourier-transform infrared bands and β-sheet to α-helix structural transformations. The fiber membranes electrospun from a solution with 25% zein showed the most hydrophobic surface, with a water contact angle of 116.9°. The homogenous dispersion of dextran and zein resulted in improved mechanical properties for fibers electrospun from a solution with 30% zein. Curcumin encapsulating dextran/zein electrospun fibers exhibited effective radical scavenging activity and ferric reducing power, along with the desired controlled release behavior for curcumin delivery.

CONCLUSION

Food grade dextran/zein hybrid electrospun fibers demonstrated tunable properties, and appear to be promising as delivery systems for bioactive and edible antimicrobial food packaging. © 2021 Society of Chemical Industry.

Latest Developments in Edible Coatings on Minimally Processed Fruits and Vegetables: A Review

The food industry nowadays is facing new challenges in terms of sustainability and health implications of packaging and processing techniques. Due to their desire for new and natural products coupled with changes in lifestyle, consumers are looking for food products that have been less processed but possess longer shelf life and maintain nutritional and sensorial proprieties during storage. These requirements represent real challenges when dealing with highly perishable food products, such as fruits and vegetables. Thus, in recent years, edible coatings have been intensively developed and studied because of their capacity to improve the quality, shelf life, safety, and functionality of the treated products. Edible coatings can be applied through different techniques, like dipping, spraying, or coating, in order to control moisture transfer, gas exchange, or oxidative processes. Furthermore, some functional ingredients can be incorporated into an edible matrix and applied on the surface of foods, thus enhancing safety or even nutritional and sensory attributes. In the case of coated fruits and vegetables, their quality parameters, such as color, firmness, microbial load, decay ratio, weight loss, sensorial attributes, and nutritional parameters, which are very specific to the type of products and their storage conditions, should be carefully monitored. This review attempts to summarize recent studies of different edible coatings (polysaccharides, proteins, lipids, and composites) as carriers of functional ingredients (antimicrobials, texture enhancers, and nutraceuticals) applied on different minimally processed fruits and vegetables, highlighting the coating ingredients, the application methods and the effects on food shelf life and quality.

Combining edible coatings technology and nanoencapsulation for food application: A brief review with an emphasis on nanoliposomes

The use of bioactive compounds within the biopolymer-based Edible Coatings (EC) matrices has certain limitations for their application at the food industry level. Encapsulation has been considered as a strategy that enables protecting and improving the physical and chemical characteristics of the compounds; as a result, it extends the shelf life of coated foods. This review discusses recent progress in combining edible coatings with nanoencapsulation technology. We also described and discussed various works, in which nanoliposomes are used as encapsulation systems to prepare, and subsequently apply the edible coatings in plant products and meat products. The use of nanoliposomes for the encapsulation of phenolic compounds and essential oils provides an improvement in the antioxidant and antimicrobial properties of coatings by extending the shelf life of food matrices. However, when liposomes are stored for a long period of time, they may present some degree of instability manifested by an increase in size, polydispersity index, and zeta potential. This is reflected in an aggregation, fusion, and rupture of the vesicles. This investigation can help researchers and industries to select an appropriate and efficient biopolymer to form EC containing nanoencapsulated active compounds. This work also addresses the use of nanoliposomes to create EC extending markedly the shelf life of fruit, reducing the weight loss, and deterioration due to the action of microorganisms.

Electrospun nanofibrous membrane for filtration of coconut neera

Coconut neera is a nutritious natural drink that is rich in amino acids, polyphenols, vitamins, and minerals. Nevertheless, the inherent presence of yeast activates natural fermentation. To prevent the fermentation process, it is necessary to reduce the yeast load in fresh neera, at the earliest possible. In this research, an electrospun polycaprolactone nanofibrous membrane was used for the removal of yeast from coconut neera. Randomly oriented non-woven nanofibers were fabricated using the electrospinning process. The process conditions were optimized at 15 kV applied voltage, 8 cm distance between the spinneret needle and the collector plate, and 1.6 ml/h feed flow rate for the best nanofiber characteristics and high filtration efficiency. The optimized nanofibrous membrane for neera filtration had an average fiber diameter of 942 nm, average porosity of 73.26%, and a mean thickness of 150 µm. Results confirmed that the porosity of the membrane had a significant effect on the flow rate of permeate. The biochemical characteristics of neera filtrate were investigated. In comparison with fresh neera, the filtered counterpart had significant changes in titratable acidity, pH, and color. While no significant changes were observed in total soluble solids content, slight reductions were noted in the total polyphenolic content and minerals. Importantly, the neera filtrate obtained through the optimized nanofibrous membrane showed a 2 log-reduction in yeast load. The effective reusability of the membrane and stability of the nanofiber morphology at repeated usage was confirmed. This approach shows prospects for neera filtration while retaining nutrient content and can be extended to other natural extract applications.

Electrospun nanofibers food packaging: trends and applications in food systems

Food safety is a bottleneck problem. In order to provide information about advanced and unique food packaging technique, this study summarized the advancements of electrospinning technique. Food packaging is a multidisciplinary area involving food science, food engineering, food chemistry, and food microbiology, and the interest in maintaining the freshness and quality of foods has grown considerably. For this purpose, electrospinning technology has gained much attention due to its unique functions and superior processing. Sudden advancements of electrospinning have been rapidly incorporated into research. This review summarized some latest information about food packaging and different materials used for the packaging of various foods such as fruits, vegetables, meat, and processed items. Also, the use of electrospinning and materials used for the formation of nanofibers are discussed in detail. However, in food industry, the application of electrospun nanofibers is still in its infancy. In this study, different parameters, structures of nanofibers, features and fundamental properties are described briefly, while polymers fabricated through electrospinning with advances in food packaging films are described in detail. Moreover, this comprehensive review focuses on the polymers used for the electrospinning of nanofibers as packaging films and their applications for variety of foods. This will be a valuable source of information for researchers studying various polymers for electrospinning for application in the food packaging industry.

Edible Coatings Containing Oregano Essential Oil Nanoemulsion for Improving Postharvest Quality and Shelf Life of Tomatoes

Edible coatings have attracted significant interest in maintaining quality and improving the shelf life of fresh fruit and vegetables. This study aimed to improve tomato storability by using edible coatings, based on alginate cross-linked with calcium chloride, and containing an oregano essential oil (OEO) nanoemulsion as a natural antimicrobial. The coating formulations were preliminary optimized in terms of alginate and calcium chloride concentrations, using response surface methodology, to obtain a thin (~5 µm) and uniform layer on the tomatoes surface. The optimized coating (prepared using sequential dipping in a 0.5% w/w sodium alginate solution and in a 2.0% w/w calcium chloride solution) was enriched by incorporating an OEO nanoemulsion, formulated with lecithin as a natural emulsifier, at an OEO concentration of 0.17% w/w in the alginate solution. The nanoemulsion did not significantly affect the coating thickness and uniformity but improved the wettability of the tomato skin. More specifically, the alginate-based edible coatings exhibited a strong interaction with the hydrophobic tomato skin surface (higher than water), promoting surface adhesion. The addition of OEO nanoemulsion in the coating, by providing more hydrophobic sites, further improved the wetting capability and adhesion of the coating solution on the tomato surface. The developed edible coatings successfully contributed to prolonging the tomato shelf life, by reducing the growth of the endogenous microbial flora (total microbial load, yeasts, and molds) over 14 days at room temperature in comparison with the control, with significantly better performances for the edible coating containing the OEO nanoemulsion.

A Review of Zein as a Potential Biopolymer for Tissue Engineering and Nanotechnological Applications

Tissue engineering (TE) is one of the most challenging fields of research since it provides current alternative protocols and materials for the regeneration of damaged tissue. The success of TE has been mainly related to the right selection of nano-sized biocompatible materials for the development of matrixes, which can display excellent anatomical structure, functionality, mechanical properties, and histocompatibility. Today, the research community has paid particular attention to zein as a potential biomaterial for TE applications and nanotechnological approaches. Considering the properties of zein and the advances in the field, there is a need to reviewing the current state of the art of using this natural origin material for TE and nanotechnological applications. Therefore, the goal of this review paper is to elucidate the latest (over the last five years) applications and development works in the field, including TE, encapsulations of drugs, food, pesticides and bandaging for external wounds. In particular, attention has been focused on studies proving new breakthroughs and findings. Also, a complete background of zein’s properties and features are addressed.