Crosslinked electrospun zein-based food packaging coatings containing bioactive chilto fruit extracts

Glutaraldehyde cross-linking for improving the techno-functional properties of biopolymeric food packaging films; a comprehensive review

Biodegradable and/or edible films made from polysaccharides and proteins have gained attention for their potential to replace some traditional packaging materials in the food industry due to their abundance, biodegradability, and nutritional value. Glutaraldehyde (GLA), rapidly reacts with free deprotonated ε-amino groups in proteins, leading to crosslinking (CL) reactions. This review delves into the chemistry of GLA and explores the various biopolymeric food packaging materials crosslinked by GLA. Furthermore, it summarizes recent applications of active and intelligent food packaging based on GLA-CL of biopolymers for food preservation. The comprehensive enhancement of biopolymeric films through GLACL is evident, with the impact on their properties depending on the concentration of GLA and reaction state. GLACL with biopolymer molecules enhances the cohesion of the polymer network, with physical and chemical covalent CL being the primary phenomena. Notably, biopolymeric food packaging films/coatings fabricated by GLACL have proven highly effectiveness in preserving fresh foods.

Zein Nanoparticles Loaded with Vitis vinifera L. Grape Pomace Extract: Synthesis and Characterization

This study investigates the synthesis and characterization of zein nanoparticles (ZNp) loaded with grape pomace extract (GPE) from Vitis vinifera L. for applications in controlled release and antioxidant delivery. Grape pomace, a byproduct of the winemaking industry, is rich in bioactive compounds, including phenols and flavonoids, which possess antioxidant properties. To overcome the limitations of these compounds, such as photosensitivity and thermal degradation, they were incorporated into zein nanoparticles using the antisolvent technique. The physicochemical properties of the ZNp-GPE system were thoroughly characterized, including size, morphology, ζ-potential, and total phenol content. Results showed high encapsulation efficiency (89-97%) and favorable loading capacities. Characterization techniques, such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS), confirmed that GPE was successfully incorporated into the nanoparticles, thereby enhancing their antioxidant properties. The encapsulation process did not significantly alter the spherical morphology of the nanoparticles, and loading GPE resulted in a decrease in particle size. Total phenol content analysis showed that the ZNp-GPE nanoparticles effectively retained these compounds, confirming their potential as efficient delivery systems for antioxidants. This approach not only provides a method for protecting and enhancing the bioavailability of natural antioxidants but also contributes to the valorization of agricultural waste, promoting sustainability in bio-based industries.

(E)-2-Hexenal-loaded ethyl cellulose/agarose aerogel: Preparation, characterization and application in fresh rice noodles preservation

This study aimed to develop food-grade ethyl cellulose/agarose aerogels for the controlled release of plant essential oils to extend the shelf life of fresh rice noodles. The antibacterial efficacy of ten unsaturated aldehyde essential oils was evaluated against primary spoilage bacteria, including Leuconostoc lactis, Lactococcus lactis, Acinetobacter johnsonii, Exiguobacterium indicum, and Enterobacter sichuanensis. Based on its superior antimicrobial performance, (E)-2-hexenal was selected for encapsulation within ethyl cellulose/agarose aerogels to achieve controlled release and extend the shelf life of fresh rice noodles. Increasing the ethyl cellulose concentration resulted in a more uniform pore size distribution, enhanced mechanical properties and hydrophobicity, and improved controlled release of (E)-2-hexenal in the aerogels. The optimized aerogel, loaded with 0.20 μL/mL of (E)-2-hexenal, exhibited significant antimicrobial activity, effectively inhibiting bacterial growth for 72 h. Moreover, the aerogel formulation effectively preserved the quality of fresh rice noodles by mitigating changes in total plate count, pH, water content, water activity, cooking properties, color, and texture, ultimately extending the product's shelf life by 4 days at 25 °C. These findings highlight the potential of ethyl cellulose/agarose aerogels loaded with (E)-2-hexenal as an innovative preservation strategy for fresh rice noodles, providing a promising method for enhancing food quality and longevity.

Boosting Food Packaging Sustainability Through the Valorization of Agri-Food Waste and By-Products

The environmental concerns associated with synthetic polymers have intensified the search for sustainable and biodegradable alternatives, particularly for food packaging applications. Natural biopolymers offer promising solutions due to their biodegradability, reduced environmental impact, and reliance on renewable resources. Among these, agri-food waste and by-products have gained significant attention as valuable feedstocks for polymer production, supporting a circular economy approach. This review critically examines the current status of biopolymers derived from plant, animal, and microbial sources, focusing on their physical and chemical properties and their application in food packaging. The findings underscore that the properties of plant- and animal-based biopolymers are heavily influenced by the source material and extraction techniques, with successful examples in biodegradable films, coatings, and composite materials. However, a critical gap remains in the characterization of microbial biopolymers, as research in this area predominantly focuses on optimizing production processes rather than evaluating their material properties. Despite this limitation, microbial biopolymers have demonstrated considerable potential in composite films and fillers. By addressing these gaps and evaluating the key factors that influence the success of biopolymer-based packaging, we contribute to the ongoing efforts to develop sustainable food packaging solutions and reduce the environmental impact of plastic waste.

Encapsulation of melatonin in zein/pectin composite nanoparticles: Fabrication, characterization, and in vitro release property

In this study, the encapsulation of melatonin (MT) in zein nanoparticles was investigated via anti-solvent co-precipitation method with pectin stabilization. Compared with MT-loaded zein nanoparticles (MT-Z NPs), 1.0 mg/mL pectin led to a 92.1 % of MT encapsulation efficiency, a 5.4 % of MT loading, a particle size growth from 111.3 to 294.8 nm, a ζ-potential reduction from +4.8 to -41.4 mV, and an irregular surface shape. Moreover, the hypsochromic and redshifts of the OH and amide I bands, and undetected MT crystalline characteristic peaks in MT-loaded zein/pectin nanoparticles (MT-Z/P NPs) revealed successful MT embedment governed by hydrogen and hydrophobic forces. The binding energies of zein with MT and pectin (-6.89 and - 7.01 kcal/mol) confirmed the stability of complex. MT-Z/P NPs prolonged MT release from 92.3 % to 63.6 % at 6 h in gastrointestinal tract (GIT) compared with MT-Z NPs, which could be a desirable MT delivery material in food industry.

Preparation and application of polycaprolactone/β-cyclodextrin/gamma-Decalactone nanofiber composites in citrus postharvest diseases

Citrus fruits are highly susceptible to pathogenic fungal infections after harvesting, which causes serious economic losses. Therefore, it's necessary to develop new antifungal packaging. In this study, gamma-Decanolactone (DL) was successfully encapsulated in a polycaprolactone (PCL)/β-cyclodextrin (β-CD) composite system using electrostatic spinning technology. PCL/β-CD was compounded in different ratios, the ratio was screened through other indicators such as fiber morphologies and mechanical properties. Then, antifungal mats were prepared by adding different concentrations of DL to the PCL/β-CD solution. The results showed that when the mixture ratio of PCL/β-CD was 6:1 and loaded with 6 % DL, the antifungal felt had strong mechanical, significantly inhibiting the growth of three citrus pathogens (P. digitatum, P. italicum and G. candidum), released DL for up to 204 h and effectively reduced the morbidity rate of citrus fruits. Therefore, the antifungal pad prepared in this study has great potential in the field of citrus disease control.

Effect of Polycaprolactone, Zinc Oxide, and Poly(ethylene glycol) on the Properties of Polylactic Acid Composite Fibers Obtained by Melt Electrospinning

Polylactic acid (PLA) composite fibers were obtained using melt electrospinning, in which a high voltage was applied to the nozzle of the 3D printer. Filaments for melt electrospinning were prepared by using an extruder operated at 155 °C. PLA was mixed with polycaprolactone (PCL; 95:5, 90:10, and 85:15 by wt %), zinc oxide (ZnO; 0.1 phr), and poly(ethylene glycol) (PEG; 1 phr). The prepared filaments and fibers were characterized by Fourier-transform infrared spectroscopy (FTIR), contact angle measurements, thermal gravimetry (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The measured contact angles of the filaments were in the range of 60.33° (±4.04) to 78° (±2.65), while the melt-electrospun fibers were in the range of 110.17° (±0.29) to 128.5° (±1.32). Melt electrospinning significantly increased the contact angle. According to the DSC analysis, the addition of 0.1% ZnO and 1% PEG increased the degree of crystallinity of PLA from 19.63 to 27.48% in the filaments and 11.54 to 20.79% in the fibers. The Avrami constant (n) values of the filaments and fibers were found in the range between 2.62-3.97 and 2.75-3.95, respectively. It was shown that the crystallization was controlled by nucleation. DMA analysis indicated that melt electrospinning and the addition of PCL decreased the storage modulus of the filaments, thereby increasing their plasticity.

Zein-based nisin-loaded electrospun nanofibers as active packaging mats for control of Listeria monocytogenes on peach

Zein-based nanofibers (NFs) functionalized with nisin (NS), reinforced with montmorillonite nanoclay (nMMT) were fabricated by uniaxial electrospinning (ES) for the first time to preserve yellow peach. Spinnability/viscosity/conductivity optimizations generated porous (95.09%), bead-free, ultrathin (119 nm) NFs of low hydrophobicity (26.05°). Glutaraldehyde (GTA) crosslinking fostered positive outcomes of tensile strength (1.23 MPa), elongation (5.0%), hydrophobicity (99.46°), surface area (201.38 m2.g-1), pore size (2.88 nm), thermal stability (Tmax = 342 °C), antioxidant/cytotoxic activities in optimized NFs that released NS sustainably according to Korsmeyer-Peppas model indicating a Fickian diffusion mechanism with R2 = 0.9587. The novel NFs inhibited growth of Listeria monocytogenes/aerobic mesophilic populations in peach after 4 days of abusive storage, evincing their robustness in food contact applications. Simultaneously, quality parameters (moisture/texture/browning/total soluble solids/pH) and peach physical appearance were maintained for up to 8 days, endorsing the practical value of zein-based NFs as a non-thermal postharvest intervention for prolonging fruits storage life.

Antimicrobial gelatin-based films with cinnamaldehyde and ZnO nanoparticles for sustainable food packaging

Cinnamaldehyde (CIN), a harmless bioactive chemical, is used in bio-based packaging films for its antibacterial and antioxidant properties. However, high amounts can change food flavor and odor. Thus, ZnO nanoparticles (NPs) as a supplementary antimicrobial agent are added to gelatin film with CIN. The CIN/ZnO interactions are the main topic of this investigation. FTIR-Attenuated Total Reflection (ATR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to investigate CIN/ZnO@gelatin films. Transmission electron microscope (TEM) images revealed nanospheres morphology of ZnO NPs, with particle sizes ranging from 12 to 22 nm. ZnO NPs integration increased the overall activation energy of CIN/ZnO@gelatin by 11.94%. The incorporation of ZnO NPs into the CIN@gelatin film significantly reduced water vapour permeability (WVP) of the CIN/ZnO@gelatin film by 12.07% and the oxygen permeability (OP) by 86.86%. The water sorption isotherms of CIN/ZnO@gelatin were described using Guggenheim-Anderson-de Boer (GAB) model. The incorporation of ZnO NPs into the CIN@gelatin film reduced monolayer moisture content (M0) by 35.79% and significantly decreased the solubility of CIN/ZnO@gelatin by 15.15%. The inclusion of ZnO into CIN@gelatin film significantly decreased tensile strength of CIN/ZnO@gelatin by 13.32% and Young`s modulus by 18.33% and enhanced elongation at break by 11.27%. The incorporation of ZnO NPs into the CIN@gelatin film caused a significant decrease of antioxidant activity of CIN/ZnO@gelatin film by 9.09%. The most susceptible organisms to the CIN/ZnO@gelatin film included Candida albicans, Helicobacter pylori, and Micrococcus leutus. The inhibition zone produced by the CIN/ZnO@gelatin film versus Micrococcus leutus was 25.0 mm, which was comparable to the inhibition zone created by antibacterial gentamicin (23.33 mm) and cell viability assessment revealed that ZnO/CIN@gelatin (96.8 ± 0.1%) showed great performance as potent biocompatible active packaging material.

Spinning a Sustainable Future: Electrospun Polysaccharide-Protein Fibers for Plant-Based Meat Innovation

This study aims to evaluate the feasibility of producing electrospun fibers by combining polysaccharides, zein, and poly(ethylene oxide) (PEO) to simulate the fibers applied in plant-based meat analogs. The rheological properties of biopolymer solutions were evaluated, and the electrospun fibers were characterized according to their morphology, structural interactions, and thermal analysis. The results indicated that the fibers prepared in a ratio of 90:10 of zein/carrageenan from the mixture of a solution containing 23 wt.% of zein with a solution containing 1 wt.% of carrageenan and with the addition of 1 wt.% of PEO presented a promising structure for application as fibers in meat analogs because they have a more hydrophilic surface. Thus, they have good moisture retention. In addition, they have good thermal stability at high temperatures, which is crucial to achieve a consistent and pleasant texture. Furthermore, it was observed that adding zein and PEO helps with the spinnability of the polysaccharides, producing fibers with good homogeneity.

Enhancement of Mechanical Properties of Zein-Based Nanofibers by Incorporation of Millet Gliadin

In this work, a novel reinforcing filler, millet gliadin (MG), was used for the improvement of the mechanical properties of zein nanofibers. The structural and physicochemical properties of MG were compared with those of zein, and the influence of MG on the morphology, physical properties, and molecular structure of zein nanofibers was investigated. The results indicated that MG has an obviously smaller weight-average molecular weight (7623) in comparison to zein (13,330). Transmission electron microscopy showed that zein molecules more easily form aggregates with larger diameters than MG molecules in acetic acid. At a concentration of 30% (w/v), MG exhibited a significantly higher viscosity (0.66 ± 0.03 Pa·s) than zein (0.32 ± 0.01 Pa·s), indicating the stronger interactions of MG molecules. With the incorporation of MG, the tensile strength was significantly increased to 49.32 MPa (ZM-1/2), which is 2.08 times and 4.45 times higher than that of pure zein nanofibers (ZM-1/0) and MG nanofibers (ZM-0/1-1), respectively. Moreover, zein/MG composite nanofibers exhibited improved water stability. Fourier transform infrared spectra showed evidence of the hydrogen bonding interaction between zein and MG. Therefore, MG is a good candidate for use as a natural reinforcing filler in electrospun nanofibers made of biopolymers.

Edible-algae base composite film containing gelatin for food packaging from macroalgae, Gracilaroid (Gracilaria fisheri)

BACKGROUND

Conventional petroleum-based packaging films cause severe environmental problems. In the present study, bio-edible film was introduced as being safe to replace petroleum-based polymers. A food application for edible sachets and a composite edible film (EF) from marine algae, Gracilaria fisheri (GF) extract, were proposed.

RESULTS

Carbohydrates were the most prevalent component in fresh GF fronds. Under neutral conditions comprising 90 °C for 40 min, the structure of the extract was determined by Fourier transform infrared to be a carrageenan-like polysaccharide. Glycerol was the best plasticizer for EF formation because it had the highest tensile strength (TS). The integration of gelatin into the algal composite film with gelatin (CFG) was validated to be significant. The best casting temperatures for 2 h were 70 and 100 °C among the four tested temperatures (25, 60, 70 and 100 °C). Temperatures did not result in any significant (P ≤ 0.05) differences in any character (color values, TS, water vapor permeability, oxygen transmission, thickness and water activity), except elongation at break. Visually, the CFG had a slightly yellow appearance. The best-to-worst order of film stability in the three tested solvents was oil, distilled water (DW) and ethanol. Its stability in ethanol (0-100%), temperature of DW (30-100 °C) and pH (3-7 in DW) demonstrated inverse relationships with the concentration or different conditions, except for pH 8-10 in DW. All treatments were significantly (P ≤ 0.05) different.

CONCLUSION

The novel material made from polysaccharides from algae, G. fisheri, was used to improve EF. The edible sachet application is plausible from the EF. © 2024 Society of Chemical Industry.

Development and characterization of active packaging system based on zein nanofibers mat incorporated with geraniol-loaded nanoliposomes

In recent years, development of biopolymeric nanofibers as an active biodegradable packaging system has attracted specific attention. The objective of this research was to develop zein-based electrospun nanofibers (NFs) incorporated with geraniol-loaded nanoliposomes (G-loaded NLPs). Geraniol was encapsulated into NLPs with an efficiency of 79.23%. The particle size and zeta potential of G-loaded NLPs were 121.50 nm and -38.30 mV, respectively. The successful loading of geraniol in the NLPs was approved by Fourier transform infrared (FT-IR) spectroscopy. The liposomal vesicles showed spherical shapes. G-loaded NLPs were added in the zein-based electrospun NFs at three different concentrations (0.25, 0.5, and 1%w/v). All NFs samples exhibited fibrillar structure. The increase of NLPs concentration enhanced the thermal stability of the NFs. However, the crystalline structure of zein NFs did not change by the addition of G-loaded NLPs. The highest surface hydrophobicity was related to the NFs containing 1% G-loaded NLPs. The mechanical parameters of NFs depend on the concentration of NLPs. The NFs incorporated with G-loaded NLPs showed inhibition activity against four foodborne pathogenic bacteria (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium) with an inhibition zone of 4.5-22 mm. Moreover, the α-diphenyl-β-picrylhydrazyl (DPPH) scavenging activity of NFs samples was located at the range of 20%-48%. These findings represent the Efficiency of the G-loaded NLPs for use as bioactive compound in the zein-based NFs as an active packaging material.

Application of electrospinning to fabricate phycocyanin- and Spirulina extract-loaded gliadin fibers for active food packaging

This study explored the active food packaging application of phycocyanin- and Spirulina extract-loaded gliadin electrospun fibers (GPhy and GSPE5%). SEM findings confirmed that the morphology of fibers was tubular, showing the GPhy and GSPE5% as the optimum fibers. The loading efficiencies of GPhy and GSPE5% were also around 90%, which proved the well-incorporated compounds within the fibers. Simulation results of α-gliadin dissolved in acetic acid illustrated the denaturation of the protein. FTIR and TGA confirmed that after electrospinning the chemical/structural changes and enhanced thermostabilities occurred, respectively. Antibacterial and antioxidant tests detected higher bactericidal and antioxidative effects of GSPE5% than GPhy. In the application part, it was found that GPhy and GSPE5% were able to decrease PV and TBA values as the indications of walnut kernels' protection from lipid oxidation. This work shows a facile and an efficient way to fabricate active food packaging materials using electrospinning and natural compounds.

Advances and applications of crosslinked electrospun biomacromolecular nanofibers

Electrospinning is a technology for fabricating ultrafine fibers from natural or synthetic polymers that have novel or enhanced functional properties. These fibers have found applications in a diverse range of fields, including the food, medicine, cosmetics, agriculture, and chemical industries. However, the tendency for electrospun nanofibers to dissociate when exposed to certain environmental conditions limits many of their practical applications. The structural integrity and functional attributes of these nanofibers can be improved using physical and/or chemical crosslinking methods. This review article discusses the formation of polymeric nanofibers using electrospinning and then describes how different crosslinking methods can be used to enhance their mechanical, thermal, and biological attributes. Methods for optimizing the crosslinking reactions are discussed, including proper selection of crosslinker type and reaction conditions. Then, food, medical, and separation applications of crosslinked electrospun fibers are assessed, including in bone and skin tissue engineering, wound healing, drug delivery, air filtration, water filtration, oil removal, food packaging, food preservation, and bioactive delivery. Finally, areas where future research are needed are highlighted, as well as possible future applications of crosslinked nanofibers.

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.

Natural Polymers as Carriers for Encapsulation of Volatile Oils: Applications and Perspectives in Food Products

The technique of encapsulating different materials into matrices that can both protect and release their contents under specific circumstances is known as encapsulation. It serves the primary function of shielding delicate components from outside influences, including heat, light, and humidity. This can be accomplished by a variety of procedures that, depending on the method and materials selected, result in the creation of particles with various structures. The materials used for encapsulation in food applications must be of high quality, acceptable for human consumption, and stable during processing and storage. The most suitable natural polymers for food applications are carbohydrates, proteins, or mixtures thereof. Volatile oils are end products of plant metabolism, accumulated and stored in various plant organs, cells, or secretory tissues. These are natural and are characterized by the scent of the aromatic plants they come from. Because of their antibacterial and antioxidant qualities, they are being utilized more and more in the food and pharmaceutical industries. Since volatile oils are highly sensitive to environmental changes, they must be stored under specific conditions after being extracted from a variety of plant sources. A promising method for increasing the applicability of volatile oils is their encapsulation into colloidal particles by natural polymers such as carbohydrates and proteins. Encapsulation hides the unfavorable taste of nutrients while shielding delicate dietary ingredients from the effects of heat, moisture, oxygen, and pH. This technique results in improved stability for volatile oils that are often sensitive to environmental factors and offers the possibility of using them in an aqueous system even if they are insoluble in water. This paper aims to provide an overview of the current advances in volatile oil encapsulation technologies and presents a variety of natural polymers used in the food industry for encapsulation. Also, a distinct section is created to highlight the current advances in dairy products enriched with encapsulated volatile oils.

The alginate dialdehyde crosslinking on curcumin-loaded zein nanofibers for controllable release

In this study, electrospun zein/alginate dialdehyde (AD) nanofibers were prepared by green crosslinking. The degree of crosslinking could reach 50.72 %, and the diameter of electrospun fibers ranged from 446.2 to 541.8 nm. The generation of AD and the bonding of crosslinking were further confirmed by the changes on characteristic peaks and conformational ratios in the infrared spectroscopy and secondary structure analysis. High concentrations of AD led to improved thermal stabilities, mechanical properties, and hydrophobicity. And the highly crosslinked nanofibers (Z-8) owned the highest elastic modulus (24.92 MPa), tensile strength (0.28 MPa), and elongation at break (8.14 %) among five samples. Moreover, Z-8 possessed a high swelling ratio of 5.45 g/g, and a low weight loss of 6.09 %. The samples could encapsulate curcumin efficiently and show controllable release behaviors based on different AD addition. And the oxidation resistance of nanofibers gradually improved, consistent with the release performances. This study indicated AD crosslinking favored the preparation and application of zein nanofibers, and the oxidized polysaccharide acted as the green crosslinking agent, which provided reference value for the application of polysaccharides in food-related electrospun materials.

Electrospun plant protein-based nanofibers in food packaging

Electrospinning is a relatively simple technology capable to produce nano- and micron-scale fibers with different properties depending on the electrospinning conditions. This review critically investigates the fabrication of electrospun plant protein nanofibers (EPPNFs) that can be used in food and food packaging applications. Recent progress in the development and optimization of electrospinning techniques for production of EPPNFs is discussed. Finally, current challenges to the implementation of EPPNFs in food and food packaging applications are highlighted, including potential safety and scalability issues. The production of plant protein nanofibers and microfibers is likely to increase in the future as many industries wish to replace synthetic materials with more sustainable, renewable, and environmentally friendly biopolymers. It is therefore likely that EPPNFs will find increasing applications in various fields including active food packaging and drug delivery.

In situ extraction/encapsulation of olive leaves antioxidants in zein for improved oxidative stability of edible oils

This study presents a sustainable and cost-effective method for preserving the bioactivity of phenolic compounds in olive leaves (OLE) during their application. The extraction and nanoencapsulation of OLE were performed in a single-step process using a rotor-stator system with zein as the encapsulating agent. The nanoprecipitation step was carried out using an aqueous sodium caseinate solution, resulting in spherical particles with an average diameter of about 640 nm, as confirmed by Transmission Electron Microscopy. Thermal characterization showed that the produced nanoparticles were more thermally stable than free OLE until 250 °C, and FTIR spectra indicated effective interaction between the phenolic compounds and zein. Antioxidant activity was evaluated using TBARS, DPPH, ABTS, and FRAP assays, with results showing that encapsulated OLE had lower antioxidant activity than free OLE. The best antioxidant capacity results were determined by TBARS assay, with IC50 results equal to 43 and 103 µgOLE/mL for free and encapsulated OLE, respectively. No anti-inflammatory potential was detected for both samples using the RAW 264.7 model, and only free OLE showed cytotoxic activity against lung cancer and gastric carcinoma. Encapsulated and free OLE were used as antioxidants in soy, palm, and palm kernel oils and compared to BHT using Rancimat. The Schaal Oven Test was also performed, and the PARAFAC chemometric method analyzed the UV-Vis spectra, which revealed high stability of the oil when 300 mg or the nanoparticles were added per kg oil. Results suggested that zein-encapsulated olive leaf antioxidants can improve the oxidative stability of edible oils.

Encapsulation of quercetin into zein-ethyl cellulose coaxial nanofibers: Preparation, characterization and its anticancer activity

In order to efficiently improve the colon-targeted delivery of quercetin, the hydrophobic core-shell nanofibers were fabricated to encapsulate quercetin using ethyl cellulose as the shell and zein as the core by coaxial electrospinning. The encapsulation efficiency of coaxial nanofibers reached >97 %. FTIR and XRD results revealed the interactions between quercetin and wall materials and quercetin was encapsulated in an amorphous state. The thermal stability and surface hydrophobicity of coaxial nanofibers were improved compared to the uniaxial zein fibers. After in vitro gastrointestinal digestion, the quercetin release from core-shell nanofibers was <12.38 %, while the corresponding value for zein fibers was 36.24 %. DPPH and FRAP assays showed that there was no significant difference in the antioxidant activity of quercetin before and after encapsulation. Furthermore, the encapsulated quercetin exhibited similar anti-proliferative activity against HCT-116 cells compared to the free form. The results suggest these coaxial nanofibers have potential applications in functional foods.

Electrospun Nanofibers for Functional Food Packaging Application

With the strengthening of the public awareness of food safety and environmental protection, functional food packaging materials have received widespread attention. Nanofibers are considered as promising packaging materials due to their unique one-dimensional structure (high aspect ratio, large specific surface area) and functional advantages. Electrospinning, as a commonly used simple and efficient method for preparing nanofibers, can obtain nanofibers with different structures such as aligned, core-shell, and porous structures by modifying the devices and adjusting the process parameters. The selection of raw materials and structural design of nanofibers can endow food packaging with different functions, including antimicrobial activity, antioxidation, ultraviolet protection, and response to pH. This paper aims to provide a comprehensive review of the application of electrospun nanofibers in functional food packaging. Advances in electrospinning technology and electrospun materials used for food packaging are introduced. Moreover, the progress and development prospects of electrospun nanofibers in functional food packaging are highlighted. Meanwhile, the application of functional packaging based on nanofibers in different foods is discussed in detail.

A Review on Edible Coatings and Films: Advances, Composition, Production Methods, and Safety Concerns

Food is a crucial source for the endurance of individuals, and quality concerns of consumers are being raised with the progression of time. Edible coatings and films (ECFs) are increasingly important in biobased packaging because they have a prime role in enhancing the organoleptic characteristics of the food products and minimizing the spread of microorganisms. These sustainable ingredients are crucial for a safer and healthier environment. These are created from proteins, polysaccharides, lipids, plasticizers, emulsifiers, and active substances. These are eco-friendly since made from innocuous material. Nanocomposite films are also beginning to be developed and support networks of biological polymers. Antioxidant, flavoring, and coloring compounds can be employed to improve the quality, wellbeing, and stability of packaged foods. Gelatin-enhanced fruit and vegetable-based ECFs compositions have the potential to produce biodegradable films. Root plants like cassava, potato, and sweet potato have been employed to create edible films and coatings. Achira flour, amylum, yam, ulluco, and water chestnut have all been considered as novel film-forming ingredients. The physical properties of biopolymers are influenced by the characteristics, biochemical confirmation, compatibility, relative humidity, temperature, water resistance, and application procedures of the components. ECFs must adhere to all regulations governing food safety and be generally recognized as safe (GRAS). This review covers the new advancements in ECFs regarding the commitment of novel components to the improvement of their properties. It is expected that ECFs can be further investigated to provide innovative components and strategies that are helpful for global financial issues and the environment.

Functional Characterization and Toxicity of Pectin from Red Chilto Fruit Waste (Peels)

BACKGROUND

Food and agricultural wastes constitute a rich source of functional ingredients for the food, pharmaceutical, and cosmetic industries. In this context, by-products from the red variety of Solanum betaceum fruits (chilto) from Northwestern Argentina are suitable sources for pectin extraction.

METHODS

In this study, pectin from the peels of red chilto fruits was extracted and characterized.

RESULTS

The recovery yield of red chilto peel pectin was about 24%, and it was co-extracted with 40.0 mg phenolic compounds, 6.5 mg anthocyanins, and 4.7 g proteins per 100 g of pectin. The pectin obtained from red chilto showed proper technological functionality displaying water and oil holding capacities of 4.2 and 2.0%, respectively, an emulsifying capacity of 83%, emulsion stability of 87.5%, foaming capacity of 21.1%, and foaming stability of 79.1%. The pectin displayed antioxidant activity with the ability to scavenge ABTS radical, superoxide anion, and H₂O₂. The polysaccharide exhibited in vitro hypoglycemic potential and inhibited the α-amylase enzyme, retarded glucose diffusion, and improved the cellular uptake of glucose in a Saccharomyces cerevisiae model. The extract was non-toxic on acute toxicity tests.

CONCLUSIONS

Red chilto pectin showed potential as a new and safe functional ingredient for the design of foods, health products, and cosmetics.

Development of an edible food packaging gelatin/zein based nanofiber film for the shelf-life extension of strawberries

An edible food packaging gelatin/zein nanofiber film co-loaded with cinnamaldehyde (CA)/thymol (THY) was developed, which possessed outstanding features conducive to strawberries preservation. Firstly, the synergistic antibacterial behavior of CA and THY was investigated. Then CA and THY were co-loaded into gelatin/zein nanofiber films by electrospinning technology. The addition of CA and THY increased water contact angle to 85.1° after 10 s and decreased the water vapor transmission rate of 3.1×10^-8 g·mm^-1·h^-1·Pa^-1. The tensile strength was 1.30 MPa and the elongation at break was 185%. The nanofiber films exhibited good shielding effect of ultraviolet-visible light and excellent antioxidant capacity with DPPH free radical scavenging percentage of 99.9% in 4 h. The nanofiber films (12.5 mg/mL) could achieve significant inhibition effects on Escherichia coli ATCC 25922 with the bacteriostatic ratio of 67.5%, Staphylococcus aureus ATCC 6538 and Listeria monocytogenes ATCC 19115 with the antibacterial ratios of 100%. A real-time study on the nanofiber films as fruit packaging materials was carried out on strawberries and the packaged strawberries kept their freshness as long as 7 days at room temperature. Therefore, the GZ/CT nanofiber film prepared in this work has good application potential in the field of fruit packaging.

Natural and biocompatible dressing unit based on tea carbon dots modified core-shell electrospun fiber for diabetic wound disinfection and healing

Wound infection and healing in patients with diabetes is one of the complex problems in trauma treatment. Therefore, designing and preparing an advanced dressing membrane for treating the wounds of such patients is essential. In this study, a zein film with biological tea carbon dots (TCDs) and calcium peroxide (CaO2) as the main components for promoting diabetic wound healing was prepared by an electrospinning technique, which combines the advantages of natural degradability and biosafety. CaO2 is a biocompatible material with a microsphere structure that reacts with water to release hydrogen peroxide and calcium ions. TCDs with a small diameter were doped in the membrane to mitigate its properties while improving the antibacterial and healing effects of the membrane. TCDs/CaO2 was mixed with ethyl cellulose-modified zein (ZE) to prepare the dressing membrane. The antibacterial properties, biocompatibility and wound-healing properties of the composite membrane were investigated by antibacterial experiment, cell experiment and a full-thickness skin defect. TCDs/CaO2 @ZE exhibited significant anti-inflammatory and wound healing-promoting properties in diabetic rats, without any cytotoxicity. This study is meaningful in developing a natural and biocompatible dressing membrane for diabetic wound healing, which shows a promising application in wound disinfection and recovery in patients with chronic diseases.

A Brief Review on the Electrohydrodynamic Techniques Used to Build Antioxidant Delivery Systems from Natural Sources

Extracts from plants have been one of the main sources of antioxidants, namely polyphenols. The associated drawbacks, such as instability against environmental factors, low bioavailability, and loss of activity, must be considered during microencapsulation for a better application. Electrohydrodynamic processes have been investigated as promising tools to fabricate crucial vectors to minimize these limitations. The developed microstructures present high potential to encapsulate active compounds and for controlling their release. The fabricated electrospun/electrosprayed structures present different benefits when compared with structures developed by other techniques; they present a high surface-area-to-volume ratio as well as porosity, great materials handling, and scalable production-among other advantages-which make them able to be widely applied in different fields, namely in the food industry. This review presents a summary of the electrohydrodynamic processes, main studies, and their application.

Powdered Beverage from Native Plants from Argentina (Zuccagnia punctata and Solanum betaceum) Obtained by Spray-Drying: A Promising Source of Antioxidant Compounds

In previous studies, the Argentinean native plants called Zuccagnia punctata (jarilla, pus pus, lata) and Solanum betaceum (chilto, tree tomato) were reported as new natural sources of antioxidant compounds, mainly chalcones, anthocyanins and rosmarinic acid derivates. The present study deals with the production of antioxidant beverages of Z. punctata (Zp) extract and chilto juice with honey as sweetener. A Zp extract and red chilto juice were obtained according to Food Code and characterized. The beverages were formulated by using maltodextrin (MD) with two dextrose equivalents (DE), 10 and 15, and then spray-dried at an inlet air temperature of 130 °C. The physicochemical, microscopical, phytochemical and functional characteristics of the powders were surveyed. The experiments carried out showed good physical properties for both formulations showing high water solubility with adequate features for handling, transport and storage. The chromatic parameters of both powdered beverages indicate orange-pink tones regardless of the wall material used. The total polyphenol and flavonoid content in the beverages were kept after spray-drying (92 and 100%, respectively). The anthocyanins were less stable under drying conditions (yield 58%). Both powdered beverages showed high scavenger capacity on ABTS^•+, HO^• and H₂O₂ (SC₅₀ between 3.29 to 41.05 µg GAE/mL) and were able to inhibit xanthine oxidase (XOD) activity (CI₅₀ between 91.35 and 114.43 µg GAE/mL). The beverages were neither toxic nor mutagenic in the concentration range with biological activity. The results obtained in the present work scientifically support the use of the powdered beverages of Argentinean native plants as antioxidant.

Insights on Chemical Crosslinking Strategies for Proteins

Crosslinking of proteins has gained immense significance in the fabrication of biomaterials for various health care applications. Various novel chemical-based strategies are being continuously developed for intra-/inter-molecular crosslinking of proteins to create a network/matrix with desired mechanical/functional properties without imparting toxicity to the host system. Many materials that are used in biomedical and food packaging industries are prepared by chemical means of crosslinking the proteins, besides the physical or enzymatic means of crosslinking. Such chemical methods utilize the chemical compounds or crosslinkers available from natural sources or synthetically generated with the ability to form covalent/non-covalent bonds with proteins. Such linkages are possible with chemicals like carbodiimides/epoxides, while photo-induced novel chemical crosslinkers are also available. In this review, we have discussed different protein crosslinking strategies under chemical methods, along with the corresponding crosslinking reactions/conditions, material properties and significant applications.

Solanum betaceum Fruits Waste: A Valuable Source of Bioactive Compounds to Be Used in Foods and Non-Foods Applications

The fruit supply chain generates large amounts of waste that are often used as animal feed and in the production of both composts and fertilizers and biogas (anaerobic digestion). Since these types of procedures imply high economic costs related to drying, storage, and transport processes, more efficient and environmentally friendly utilization and recycling of this kind of waste are becoming significant for governments and industries. However, improper waste disposal increases the burden on the environment. Many of these fruit wastes, such as Solanum betaceum fruit waste, viz., peels, seeds, and pomace, could be considered potent bio-resource materials for several applications in the food and non-food industries due to their richness in valuable compounds. The basic composition of Solanum betaceum fruits seed has a high content of protein (20%), fiber (around 25%), sugar (11-20%) and low lipid content (0.4%), while S. betaceum peel has a low content of sugar (2-9%), protein (8-10%) and lipid (0.2-0.8%) and high fiber content (23%). Regarding the phytochemicals, the wastes have a high level of phenolics (0.2-0.6%) and pigments such as anthocyanins (0.06%). The inherent bioactive compounds of waste can be used as natural ingredients for foods, cosmetics, medicines, and the production of packaging materials production. Along this line, the present review covers all possible approaches for the valorization of S.betaceum waste in the food and non-food sectors.

Recent advances in carrageenan-based films for food packaging applications

In order to solve the increasingly serious environmental problems caused by plastic-based packaging, carrageenan-based films are drawing much attentions in food packaging applications, due to low cost, biodegradability, compatibility, and film-forming property. The purpose of this article is to present a comprehensive review of recent developments in carrageenan-based films, including fabrication strategies, physical and chemical properties and novel food packaging applications. Carrageenan can be extracted from red algae mainly by hydrolysis, ultrasonic-assisted and microwave-assisted extraction, and the combination of multiple extraction methods will be future trends in carrageenan extraction methods. Carrageenan can form homogeneous film-forming solutions and fabricate films mainly by direct coating, solvent casting and electrospinning, and mechanism of film formation was discussed in detail. Due to the inherent limitations of the pure carrageenan film, physical and chemical properties of carrageenan films were enhanced by incorporation with other compounds. Therefore, carrageenan-based films can be widely used for extending the shelf life of food and monitoring the food freshness by inhibiting microbial growth, reducing moisture loss and the respiration, etc. This article will provide useful guidelines for further research on carrageenan-based films.

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.

A Review on Biodegradable Packaging Films from Vegetative and Food Waste

Plastics around the globe have been a matter of grave concern due to the unavoidable habits of human mankind. Taking waste statistics in India for the year 2019-20 into account, the data of 60 major cities show that the generation of plastic waste stands tall at around 26,000 tonnes/day, of which only about 60 % is recycled. A majority of the non-recycled plastic waste is petrochemical-based packaging materials that are non-biodegradable in nature. Vegetative/food waste is another global issue, evidenced by vastly populated countries such as China and India accounting for 91 and 69 tonnes of food wastage, respectively in 2019. The mitigation of plastic packaging issues has led to key scientific developments, one of which is biodegradable materials. However, there is a way that these two waste-related issues can be fronted as the analogy of "taking two shots with the same arrow". The presence of various bio-compounds such as proteins, cellulose, starch, lipids, and waxes, etc., in food and vegetative waste, creates an opportunity for the development of biodegradable packaging films. Although these flexible packaging films have limitations in terms of mechanical, permeation, and moisture absorption characteristics, they can be fine-tuned in order to convert the biobased raw material into a realizable packaging product. These strategies could work in replacing petrochemical-based non-biodegradable packaging plastics which are used in enormous quantities for various household and commercial packaging applications to combat the ever-increasing pollution in highly populated countries. This paper presents a systematic review based on modern scientific tools of the literature available with a major emphasis on the past decade and aims to serve as a standard resource for the development of biodegradable packaging films from food/vegetative waste.

Recent Advancements in Plant-Derived Nanomaterials Research for Biomedical Applications

Engineering, physics, chemistry, and biology are all involved in nanotechnology, which comprises a wide variety of multidisciplinary scientific field devices. The holistic utilization of metallic nanoparticles in the disciplines of bio-engineering and bio-medicine has attracted a great deal of attention. Medical nanotechnology research can offer immense health benefits for humans. While the advantages of developing nanomaterials have been well documented, it is precisely apparent that there are still some major issues that remain unattended to those need to be resolved immediately so as to ensure that they do not adversely affect living organisms in any manner. The existence of nanoparticles gives them particular value in biology and materials science, as an emerging scientific field, with multiple applications in science and technology, especially with numerous frontiers in the development of new materials. Presented here is a review of recent noteworthy developments regarding plant-derived nanomaterials and their use in the development of medicine and biomedical applications around the world.

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.

The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning

In this study, in order to develop zein-based, edible, functional food-contact materials in different forms incorporating sage extract (10, 20, and 30%), solvent casting and electrospinning were employed. The study aimed to assess the effects of the applied techniques and the extract’s incorporation on the materials’ properties. The solvent casting generated continuous and compact films, where the extract’s incorporation provided more homogenous surfaces. The electrospinning resulted in non-woven mats composed of ribbon-like fibers in the range of 1.275–1.829 µm, while the extract’s incorporation provided thinner and branched fibers. The results indicated the compatibility between the materials’ constituents, and efficient and homogenous extract incorporation within the zein matrices, with more probable interactions occurring during the solvent casting. All of the formulations had a high dry matter content, whereas the mats and the formulations incorporating the extract had higher solubility and swelling in water. The films and mats presented similar DPPH^• and ABTS^•+ radical scavenging abilities, while the influence on Staphylococcus aureus and Salmonella enterica subsp. enterica serovar Typhimurium bacteria, and the growth inhibition, were complex. The antioxidant and antibacterial activity of the materials were more potent after the extract’s incorporation. Overall, the results highlight the potential of the developed edible materials for use as food-contact materials with active/bioactive functionality.

Consumers' Attitudes toward the Use of an Edible Coating for Lamb Meat According to Label Information

The use of edible coatings in meat is currently being investigated in several studies. However, consumers’ attitudes toward this technology are not clear. This study evaluated consumers’ intention to purchase vacuum-packaged meat with a chitosan coating based on the label information. Three factors combined with different levels were considered: type of cut (“loin”, “French rack”, or “leg steak”), coating/information (no information, chitosan without information explained, and chitosan with information explained), and price (low or high). Consumers’ purchase intentions were evaluated using a 7-point structured scale (1 = certainly would not buy; 7 = certainly would buy). The data were analyzed by conjoint analysis and cluster analysis. The average purchase intention value was 4.3 ± 0.5. The “French rack” cut showed the highest value for purchase intention and a high price was also a relevant factor. The packaging with the label stating the presence of a “chitosan” coating without giving any further information obtained higher purchase intentions than the one with the more detailed information label. In the cluster analysis, the factor “type of cut” showed the highest relative importance in two groups, while “price” had a higher impact in another. The type of cut was the main factor affecting consumers’ purchase intentions. However, different attitudes were observed depending on the group.