Physical Characteristics, Release Properties, and Antioxidant and Antimicrobial Activities of Whey Protein Isolate Films Incorporated with Thyme (Thymus vulgaris L.) Extract-Loaded Nanoliposomes

Anise essential oil immobilized in chitosan microparticles: a novel bactericidal material for food protection

Foodborne infections in humans are one of the major concerns of the food industries, especially for minimally processed foods (MPF). Thereby, the packaging industry applies free chlorine in the sanitization process, ensuring the elimination of any fecal coliforms or pathogenic microorganisms. However, free chlorine's propensity to react with organic matter, forming toxic compounds such as trihalomethanes and haloacetic acid. Therefore, the present work aimed to synthesize a novel organic biomaterial as an alternative to free chlorine. Chitosan microparticles were produced, with Pimpinella anisum (anise) essential oil immobilized in the biopolymer matrix (MPsQTO). The characterization of this biomaterial was done through GC-MS/MS, FT-IR, and SEM. Antimicrobial assays proved that the MPsQTO presented antibacterial activity for Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, and Bacillus subtilis at 300 µL mL-1 of concentration. The fluorescence microscope also showed the MPsQTO targets the cytoplasmatic membrane, which is responsible for cell death in the first minutes of contact. Studies with the mutant B. subtilis (amy::pspac-ftsZ-gfpmut1) and the Saccharomyces cerevisiae D7 also proved that the biomaterial did not affect the genetic material and did not have any mutagenic/carcinogenic effect on the cells. The sanitization assays with pumpkin MPF proved that the MPsQTO is more effective than free chlorine, increasing the shelf-life of the MPF. Consequently, the novel biomaterial proposed in this work is a promising alternative to traditional chemical sanitizers.

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.

Autoxidation interference assay to evaluate the protection against lipid oxidation of antioxidant administration: Comparison of the efficiency of progressive release or total administration

Lipid oxidation is a cause of food spoilage, and antioxidants are used to retard it, but the timing of administration is important for this effect. The research aims to evaluate the protective efficiency against oxidative deterioration through the prolonged or complete addition of antioxidants without retention in the matrix. For this purpose, three modes of administration of the synthetic antioxidant BHT and oregano essential oil were evaluated: 100, 50, and 25 in which 100 % was incorporated at the beginning, 50 % in two aliquots, and 25 % in 4 aliquots. After adding the aliquots, all treatments reached 0.02 w/w of antioxidant in oil. An accelerated oxidation study was performed at 60 °C for 12 days, and chemical indicators (Peroxide and Conjugated Dienes value) along with volatiles (2-Heptenal and 2,4-Decadienal EE) were assessed. The order of protection shows that the initial addition of antioxidants yielded the highest efficiency.

Release kinetic modeling of Satureja Khuzestanica Jamzad essential oil from fish gelatin/succinic anhydride starch nanocomposite films: The effects of temperature and nanocellulose concentration

Fish gelatin (FG) and octenyl succinic anhydride starch (OSAS) composite films loaded with 1, 2, 3 and 4 wt% bacterial nanocellulose (BNC) and Satureja Khuzestanica Jamzad essential oil (SKEO) were achieved successfully and their physicochemical and release properties were investigated. The results revealed that incorporation of BNC improved the tensile strength which was associated with FE-SEM, FTIR and XRD. Moreover, this study focused on the release modeling of SKEO in 4, 25 and 37 °C from nanocomposite films using different release kinetic and Arrhenius models. Also, analysis of variance-simultaneous component analysis (ASCA) and exploratory data visualization by principal component analysis (PCA) were carried out to investigate the effects of two controlled factors. Consequently, the Peleg model showed the best fitting of experimental data. The activation energies decreased by increasing the BNC concentration. This research demonstrated the nanocomposite film containing SKEO would be a suitable candidate for active food packaging.

Zingiber officinale and thymus vulgaris extracts co-loaded polyvinyl alcohol and chitosan electrospun nanofibers for tackling infection and wound healing promotion

Infections are severe complications associated with chronic wounds and tardy healing that should be timely treated to achieve rapid and proper tissue repair. To hinder such difficulties, a nanofibrous mat composed of polyvinyl alcohol and chitosan (PVA/CS) was developed by electrospinning method, containing thyme (Thymus vulgaris) and ginger (Zingiber officinale) extracts. The mat containing 10 wt% of the extracts (at the ratio of 50:50) exposed the nanofibers (NFs) with the nanoscale diameter (average 382 ± 60 nm), smooth surface, and defect-free morphology. Likewise, the relevant analyses of the loaded mat displayed high wettability, porosity, and liquid absorption capacity without any adverse interaction. The obtained mat also provided a high antioxidant activity, and its release profile was continuous and sustained for nearly 72 h. Besides, it inhibited the growth of both Gram-positive S. aureus and Gram-negative E. coli strains. Furthermore, the proposed mat significantly accelerated cutaneous wound healing in bacterial-infected rats by preventing bacteria growth at the wound site. At last, histopathology analysis confirmed the ample regeneration of skin structures, forming collagen fibers and appendages. Overall, the proposed mat containing ginger-thyme extracts provides multiple therapeutic capabilities with promising solutions for inhibiting wound infection and accelerating the healing process.

Sodium alginate/carboxymethyl cellulose films embedded with liposomes encapsulated green tea extract: characterization, controlled release, application

To maintain the freshness of the fruit during storage, sodium alginate/carboxymethyl cellulose films embedded with pH-senstive liposomes encapsulated green tea extract were developed (SA/CMC/TP-Lip). An orthogonal design was used to optimise the preparation of TP-Lip and SA/CMC/TP-Lip was prepared through response surface. The stability of TP-Lip structure was measured. The morphology of SA/CMC/TP-Lip was characterised by SEM, and the mechanical properties and oxidation resistance of films were measured. Special attention was paid to the pH sensitivity of TP-Lip and the improvement of film properties. The zeta potential and encapsulation rate of TP-Lip were -45.85 ± 2.13 mV and 61.45 ± 0.23%. The average release rate of TP encapsulated into TP-Lip at pH 3 was 41.08%, an increase of 23.07% over pH 6 during 12 h. SEM and FTIR showed that TP-Lip was structurally stable and had good compatibility with SA/CMC. Tensile strength was increased by 30.55% and DPPH radical scavenging capacity was increased by 7.16% with the addition of TP-Lip. SA/CMC/TP-Lip is applied to blueberries to reduce their weight loss and improve the loss of freshness of blueberries during storage. Thus, SA/CMC/TP-Lip could provide a new way to extend active packaging materials and maintain fruit freshness during storage.

Multifunction smart nanocomposite film for food packaging based on carboxymethyl cellulose/Kombucha SCOBY/pomegranate anthocyanin pigment

Active packing systems employed to preserve food quality have gone through chains of sustainable development processes, reflecting the growth in consumer awareness of high-quality foods in eco-friendly packaging. Consequently, this study aims to develop antioxidant, antimicrobial, UV-shielding, pH-sensitive, edible, and flexible films from composites of carboxymethyl cellulose (CMC), pomegranate anthocyanin extract (PAE), and various fractions (1-15 %) of bacterial cellulose from the Kombucha SCOBY (BC Kombucha). Various analytical tools such as ATR-FTIR, XRD, TGA, and TEM were utilized to investigate the physicochemical characterization of BC Kombucha and CMC-PAE/BC Kombucha films. The DDPH scavenging test demonstrated the efficiency of PAE as a matrix with potent antioxidant properties, both as a solution and enclosed in composite films. The fabricated films of CMC-PAE/BC Kombucha showed antimicrobial activities against many pathogenic Gram-negative (Pseudomonas aeruginosa, Salmonella sp., and Escherichia coli), Gram-positive (Listeria monocytogenes and Staphylococcus aureus) bacteria, and Candida albicans, ranging from a 20 to 30 mm inhibition zone. The CMC-PAE/BC Kombucha nanocomposite has additionally been utilized to pack red grapes and plums. The results illustrated that CMC-PAE/BC Kombucha nanocomposite can increase red grapes and plums' shelf lives by up to 25 days while maintaining the fruits' quality better than those left unpacked.

Biodegradable Polymers and Polymer Composites with Antibacterial Properties

Antibiotic resistance is one of the greatest threats to global health and food security today. It becomes increasingly difficult to treat infectious disorders because antibiotics, even the newest ones, are becoming less and less effective. One of the ways taken in the Global Plan of Action announced at the World Health Assembly in May 2015 is to ensure the prevention and treatment of infectious diseases. In order to do so, attempts are made to develop new antimicrobial therapeutics, including biomaterials with antibacterial activity, such as polycationic polymers, polypeptides, and polymeric systems, to provide non-antibiotic therapeutic agents, such as selected biologically active nanoparticles and chemical compounds. Another key issue is preventing food from contamination by developing antibacterial packaging materials, particularly based on degradable polymers and biocomposites. This review, in a cross-sectional way, describes the most significant research activities conducted in recent years in the field of the development of polymeric materials and polymer composites with antibacterial properties. We particularly focus on natural polymers, i.e., polysaccharides and polypeptides, which present a mechanism for combating many highly pathogenic microorganisms. We also attempt to use this knowledge to obtain synthetic polymers with similar antibacterial activity.

Characterization of a Graphene Oxide-Reinforced Whey Hydrogel as an Eco-Friendly Absorbent for Food Packaging

This study presents a structural analysis of a whey and gelatin-based hydrogel reinforced with graphene oxide (GO) by ultraviolet and visible (UV-VIS) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results revealed barrier properties in the UV range for the reference sample (containing no graphene oxide) and the samples with minimal GO content of 0.66×10−3% and 3.33×10−3%, respectively, in the UV-VIS and near-IR range; for the samples with higher GO content, this was 6.67×10−3% and 33.33×10−3% as an effect of the introduction of GO into the hydrogel composite. The changes in the position of diffraction angles 2θ from the X-ray diffraction patterns of GO-reinforced hydrogels indicated a decrease in the distances between the turns of the protein helix structure due to the GO cross-linking effect. Transmission electron spectroscopy (TEM) was used for GO, whilst scanning electron microscopy (SEM) was used for the composite characterization. A novel technique for investigating the swelling rate was presented by performing electrical conductivity measurements, the results of which led to the identification of a potential hydrogel with sensor properties.

Ixiolirion tataricum mucilage/chitosan based antioxidant films activated by free and nanoliposomal fennel essential oil

Ixiolirion tataricum mucilage (ITM) was characterized and applied in fabrication of ITM/chitosan (CH) blend films activated by Foeniculum vulgare essential oil (FEO) in free and nanoliposomal forms. Uniform smooth surface structure, viscoelastic solid-like behavior and Newtonian nature of ITM were confirmed by morphological and rheological analyses. The prepared FEO nanoliposomes (FEO-NLPs) showed desirable properties in terms of particle size (57.2 nm), polydispersity index (0.243), zeta-potential (-17.6 mV), and encapsulation efficiency (85.2 %). The enhancing effects of FEO-NLPs and the adverse effects of free FEO on the crystalline, morphological and structural properties of films were confirmed by XRD, FE-SEM and ATR-FTIR tests. FEO-NLPs loaded films had better mechanical, thermal, water and gas barrier and antioxidant properties than neat film. Analysis also indicated the high controlled release of FEO from the films containing the nanoliposomal form of FEO. The films containing free FEO showed higher antibacterial activity against E. coli and S. aureus in comparison with FEO-NLPs loaded ones. The results showed the potential of FEO-NLPs loaded ITM/CH films for antioxidant food packaging applications.

Colorimetric porous microspheres of natural sodium alginate for chilled pork visual monitoring

Chilled meat is subject to deterioration by various factors during storage and distribution. Therefore, it is very important to monitor the quality of meat in real time. This study aims at preparing a natural, low-cost indicating microsphere to visualize the freshness of meat by the combination of sodium alginate (SA) and chitosan with 0-10 wt% anthocyanins derived from chokeberry as a colorant using ionic gelation method. Size-controlled porous SA microspheres with were further constructed by freeze-drying and their physicochemical properties were characterized by SEM, FTIR, DSC, and XRD. Results showed that microspheres with 1 wt% anthocyanin showed good responsiveness to different concentrations of ammonia and were able to effectively identify the freshness of chilled meat by color change. Principal component analysis showed that the color difference of the porous microspheres was highly significantly correlated with pH, TVB-N, total plate count and thiobarbituric acid active substance (p < 0.01), suggesting a visible satisfactory capability of the microspheres to identify the spoilage in pork. Principal component analysis showed that the color difference of the porous microspheres was highly significantly correlated with pH, TVB-N, total plate count and thiobarbituric acid active substance (P < 0.01), suggesting a visible satisfactory capability of the microspheres to identify the spoilage in pork.

Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films

To date, approximately 30-50% of food is wasted from post-harvesting to consumer usage. Typical examples of food by-products are fruit peels and pomace, seeds, and others. A large part of these matrices is still discarded in landfills, while a small portion is valorized for bioprocessing. In this context, a feasible strategy to valorize food by-products consists of their use for the production of bioactive compounds and nanofillers, which can be further used to functionalize biobased packaging materials. The focus of this research was to create an efficient methodology for the extraction of cellulose from leftover orange peel after juice processing and for its conversion into cellulose nanocrystals (CNCs) for use in bionanocomposite films for packaging materials. Orange CNCs were characterized by TEM and XRD analyses and added as reinforcing agents into chitosan/hydroxypropyl methylcellulose (CS/HPMC) films enriched with lauroyl arginate ethyl (LAE). It was evaluated how CNCs and LAE affected the technical and functional characteristics of CS/HPMC films. CNCs revealed needle-like shapes with an aspect ratio of 12.5, and average length and width of 500 nm and 40 nm, respectively. Scanning electron microscopy and infrared spectroscopy confirmed the high compatibility of the CS/HPMC blend with CNCs and LAE. The inclusion of CNCs increased the films' tensile strength, light barrier, and water vapor barrier properties while reducing their water solubility. The addition of LAE improved the films' flexibility and gave them biocidal efficacy against the main bacterial pathogens that cause foodborne illness, such as Escherichia coli, Pseudomonas fluorescens, Listeria monocytogenes, and Salmonella enterica.

Nanoliposomal delivery systems of natural antibacterial compounds; properties, applications, and recent advances

Todays, nanoliposomes (NLPs) are considered as one of the most efficient nanocarriers to deal with bacteria, practically in food products. These nanodelivery systems are able to be loaded with different bioactive compounds. The main aim of this review is investigating recent approaches (mostly from the years of 2018 to 2022) regarding development of nanoliposomal natural antibacterial compounds. In this regard, NLPs alone, combined with films, coatings, or fibers, and in coated forms are reviewed as advanced delivery systems of antibacterial substances. Moreover, a robust and comprehensive coverage of the morphological and physical properties of formulated NLPs as well as their interactions with antibacterial substances are discussed. The importance of NLPs to encapsulate antibacterial ingredients, advantages and drawbacks, antibacterial pathways of formulated NLPs, and comparison of them with pure antibacterial bioactive compounds are also explained.

Effect of excipient wall materials on the development of ginger oleoresin microcapsules: assessing the physicochemical, antioxidant and structural properties

BACKGROUND

Ginger oleoresin is prone to destruction from air, light and high temperatures and has a limited shelf life if kept improperly. Its viscous and sticky characteristics also make it difficult to handle and utilize. These issues can be solved via microencapsulation. The goal of this research was to evaluate how different wall materials affect the properties of microencapsulated ginger oleoresin powder.

RESULTS

Ginger oleoresin microcapsules were developed through spray drying technique using gum acacia (GA) and whey protein isolate (WPI) as wall materials. The characteristics of the obtained powder, including water activity, wettability and encapsulation efficiency, were evaluated, corresponded to values of 0.20, 90.54 s and 84.15% for whey protein isolate-based ginger oleoresin powder. Whey protein isolate microcapsules also exhibited higher phenolic content (27.26 mg gallic acid equivalents g-1 ), total flavonoid (2.94 mg quercetin equivalents g-1 ) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (68.71%) than GA microcapsules. Both WPI- and GA-based oleoresin microcapsules displayed poor flowability, but possessed a metastable amorphous state as indicated by X-ray diffraction. GA-encapsulated oleoresin microcapsules showed a significant increase in particle size (1983 nm) compared to WPI oleoresin microcapsules. Fourier transform infrared analysis of the developed oleoresin microcapsules indicated no change in molecular structure except for a variation in peak intensity.

CONCLUSION

Whey protein isolate proved to be more efficient in maintaining the physicochemical and antioxidant activity of spray-dried ginger oleoresin powder. The present study revealed whey protein-based oleoresin powder could be used as a therapeutic agent in various nutraceutical applications. © 2022 Society of Chemical Industry.

Thyme-Loaded Nanofibrous Dressing for Skin Wound Healing: A Combination of Chinese Traditional Medicine with Cutting-Edge Technology

The skin has vital functions and its defects and damages must be properly treated and healed. Chinese traditional herbal medicine has a long history in skin wound healing, and its merging with novel approaches (nanotechnology) has resulted in more promising results. The current study aimed to combine the biological properties of a long-lasting Chinese traditional herbal medicine (Thyme) with cutting-edge technology (electrospinning) to the fabricated interactive and bioactive wound dressing. The extract of Thyme was obtained and added into the polymeric solution and converted to the nanofibrous wound dressing. The SEM analysis revealed that the fabricated nanofibers were intact without deformity with an acceptable nanometric diameter. The release kinetics evaluation showed that 80±4% of the extract was released from the nanofibers during the first 24 h. Hemolysis lower than 8% for all nanofibers revealed hemocompatibility in the fabricated wound dressings. The in vitro studies confirmed the cytocompatibility of the nanofibers. The applied animal studies exhibited that the Thyme-loaded nanofibrous dressing enhanced the wound-healing process in a dose-dependent manner. These findings demonstrate the combination of Chinese traditional herbal medicine with modern cutting-edge technology, resulting in an interactive nanofibrous mat with promising potential as the wound dressing material.

Optimization of Biocomposite Film Based on Whey Protein Isolate and Nanocrystalline Cellulose from Pineapple Crown Leaf Using Response Surface Methodology

This study employed response surface methodology to optimize the preparation of biocomposites based on whey protein isolate, glycerol, and nanocrystalline cellulose from pineapple crown leaf. The effects of different concentrations of nanocrystalline cellulose as a filler and glycerol as a plasticizer on the thickness, the tensile strength, and the elongation at break on the resulting biocomposite films were investigated. The central composite design was used to determine the optimum preparation conditions for biocomposite films with optimum properties. The regression of a second-order polynomial model resulted in an optimum composition consisting of 4% glycerol and 3.5% nanocrystalline cellulose concentrations, which showed a desirability of 92.7%. The prediction of the regression model was validated by characterizing the biocomposite film prepared based on the optimum composition, at which the thickness, tensile strength, and elongation at break of the biocomposite film were 0.13 mm, 7.16 MPa, and 39.10%, respectively. This optimum composition can be obtained in range concentrations of glycerol (4–8%) and nanocrystalline cellulose (3–7%). Scanning electron microscope images showed that nanocrystalline cellulose dispersed well in the pure whey protein isolate, and the films had a relatively smooth surface. In comparison, a rough and uneven surface results in more porous biocomposite films. Fourier transform infrared spectroscopy revealed that nanocrystalline cellulose and glycerol showed good compatibility with WPI film by forming hydrogen bonds. The addition of nanocrystalline cellulose as a filler also decreased the transparency, solubility, and water vapor permeability and increased the crystallinity index of the resulting biocomposite film.

Active Composite Packaging Reinforced with Nisin-Loaded Nano-Vesicles for Extended Shelf Life of Chicken Breast Filets and Cheese Slices

To meet the demands for more effective and ecofriendly food packaging strategies, the potential of nisin-loaded rhamnolipid functionalized nanofillers (rhamnosomes) has been explored after embedding in hydroxypropyl-methylcellulose (HPMC) and κ-carrageenan (κ-CR)-based packaging films. It was observed that intrinsically active rhamnosomes based nanofillers greatly improved the mechanical and optical properties of nano-active packaging (NAP) films. Incorporation of rhamnosomes resulted in higher tensile strength (5.16 ± 0.06 MPa), Young’s modulus (2777 ± 0.77 MPa), and elongation (2.58 ± 0.03%) for NAP than active packaging containing free nisin (2.96 ± 0.03 MPa, 1107 ± 0.67 MPa, 1.48 ± 0.06%, respectively). NAP demonstrated a homogenous distribution of nanofillers in the biopolymer matrix as elucidated by scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) confirmed that NAP prepared with nisin-loaded rhamnosomes was thermally stable even above 200 °C. Differential scanning calorimetry (DSC) analyses revealed that addition of nisin in nanofillers resulted in a slight increase in Tg (108.40 °C), indicating thermal stability of NAP. Fourier transform infrared spectroscopy (FTIR) revealed slight shift in all characteristic bands of nano-active packaging, which indicated the embedding of rhamnosomes inside the polymer network without any chemical interaction. Finally, when tested on chicken breast filets and cheese slices under refrigerated storage conditions, NAP demonstrated broad-spectrum antimicrobial activity (up to 4.5 log unit reduction) and inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. These results suggest that HPMC and κ-CR-based NAP containing functionalized nanofillers can serve as an innovative packaging material for the food industry to improve the safety, quality, and shelf-life of dairy and meat products.

Application of Nanotechnology to Improve the Performance of Biodegradable Biopolymer-Based Packaging Materials

There is great interest in developing biodegradable biopolymer-based packaging materials whose functional performance is enhanced by incorporating active compounds into them, such as light blockers, plasticizers, crosslinkers, diffusion blockers, antimicrobials, antioxidants, and sensors. However, many of these compounds are volatile, chemically unstable, water-insoluble, matrix incompatible, or have adverse effects on film properties, which makes them difficult to directly incorporate into the packaging materials. These challenges can often be overcome by encapsulating the active compounds within food-grade nanoparticles, which are then introduced into the packaging materials. The presence of these nanoencapsulated active compounds in biopolymer-based coatings or films can greatly improve their functional performance. For example, anthocyanins can be used as light-blockers to retard oxidation reactions, or they can be used as pH/gas/temperature sensors to produce smart indicators to monitor the freshness of packaged foods. Encapsulated botanical extracts (like essential oils) can be used to increase the shelf life of foods due to their antimicrobial and antioxidant activities. The resistance of packaging materials to external factors can be improved by incorporating plasticizers (glycerol, sorbitol), crosslinkers (glutaraldehyde, tannic acid), and fillers (nanoparticles or nanofibers). Nanoenabled delivery systems can also be designed to control the release of active ingredients (such as antimicrobials or antioxidants) into the packaged food over time, which may extend their efficacy. This article reviews the different kinds of nanocarriers available for loading active compounds into these types of packaging materials and then discusses their impact on the optical, mechanical, thermal, barrier, antioxidant, and antimicrobial properties of the packaging materials. Furthermore, it highlights the different kinds of bioactive compounds that can be incorporated into biopolymer-based packaging.

Preparation and Properties of Fractionated Soybean Protein Isolate Films

Soybean protein isolate (SPI) and its four fractionated products (7S globulin, 11S globulin, upper soybean residue, and lower soybean residue) were compared by fabricating films and film liquids. The separation and grading effects, rheological properties of the film liquids, and difficulty in uncovering the films, in addition to the mechanical properties, water vapor permeability, oil permeability, and surface morphology of the films, were investigated. Results showed that the centrifugal precipitation method could be used to produce fractionated products. The 7S and 11S globulin films exhibited better hydrogels at lower shear rates than the other SPIs; however, they were more difficult to uncover. The tensile strength of the graded films decreased by varying degrees. However, the elongation at the break of the upper soybean residue film considerably increased, reaching 70.47%. Moreover, the permeability and surface morphology of the film were enhanced or weakened. The fractionated products, 7S and 11S globulin films, exhibited better performance. Overall, this study provides a basis for the improved development and use of fractioned SPI products.

Pullulan films loading saffron extract encapsulated in nanoliposomes; preparation and characterization

Nanoencapsulation of saffron extract (SE) components into the rapeseed lecithin nanoliposomes were performed by sonication of their aqueous dispersions as a green process. Dynamic light scattering (DLS) results exhibited that empty and SE loaded nanoliposomes (SENL) had average sizes in range of 118-138 nm, negative zeta potentials (-32.0 to -46.8 mV) and polydispersity index (PDI) less than 0.3 during storage for 28 days at 4 °C. Encapsulation efficiency of crocin was approximately 30%. The 70% of crocin released from SENLs within 5 h in PBS solution. Pullulan-based films were fabricated by incorporation of empty and SE loaded nanoliposomes into pullulan solution through casting method. The mechanical resistance and thermal stability of the films reduced by addition of nanoliposomes. FTIR and thermal characterizations indicated that SE was successfully encapsulated in the nanoliposomes and film matrix with high thermal stability. Incorporation of nanoliposomes enhanced the oxygen barrier properties of the films, while it didn't significantly affect the water vapor permeability (WVP) of the films. The obtained edible films or coatings can provide additional benefits due to unique flavor and color of saffron. In addition, the utilization of SE, can provide benefits for health-allegation from SE antioxidant capacity.

Carvacrol-loaded liposome suspension: optimization, characterization and incorporation into poly(vinyl alcohol) films

The purpose of this study was to encapsulate carvacrol into liposomes in order to promote its application in active food packaging. Response surface methodology was used to evaluate the effect of the concentration of the liposomal components on its characteristics. The optimum formulation for the preparation of liposomes with the highest encapsulation efficiency (59.0 ± 1.99%) was found to be 3000 μg mL^-1 of cholesterol and 4000 μg mL^-1 of carvacrol. Carvacrol reduced the polydispersity index and increased the zeta potential and the thermal stability of liposomes. Fourier-transform infrared spectroscopy indicated that the interaction of carvacrol with liposomes occurred probably through hydrogen-bonding. The incorporation into liposomes maintained the antibacterial effect of carvacrol, but when in the film, carvacrol liposomes were not effective against the microorganisms tested. Liposomes may offer a viable option for stabilizing carvacrol, however, more studies are necessary to enable its application in food packaging.

Recent Developments in Smart Food Packaging Focused on Biobased and Biodegradable Polymers

Food packaging has a crucial function in the modern food industry. New food packaging technologies seek to meet consumers and industrial's demands. Changes related to food production, sale practices and consumers' lifestyles, along with environmental awareness and the advance in new areas of knowledge (such as nanotechnology or biotechnology), act as driving forces to develop smart packages that can extend food shelf-life, keeping and supervising their innocuousness and quality and also taking care of the environment. This review describes the main concepts and types of active and intelligent food packaging, focusing on recent progress and new trends using biodegradable and biobased polymers. Numerous studies show the great possibilities of these materials. Future research needs to focus on some important aspects such as possibilities to scale-up, costs, regulatory aspects, and consumers' acceptance, to make these systems commercially viable.

Nanoliposomal thyme (Thymus vulgaris) essential oil: Effects of formulation parameters

Essential oils with antimicrobial or antioxidant activities have received extensive attention among customers, manufacturers, and food scientists, especially with rising worries about the safety of synthetic food preservatives. However, like other functional lipid compounds their incorporation into aqueous systems is challenging, due to their less water solubility. Furthermore, their susceptibility to light, moisture, heat, and oxygen origins their less chemical and structural stabilities. Consequently, the present research was aimed to encapsulate the thyme essential oil into nanoliposomes, using a thin layer hydration-sonication technique, which can be a proficient solution for revealed problems. The effects of phospholipid and stabilizing agents' concentrations, namely, lecithin, cholesterol, and glycerol, as main formulation parameters were investigated on characteristics of gained nanoliposomes, using a response surface method. Various empirical models were also developed to predict product characteristics by changing the formulation parameters. According to the numerical multiple optimizations, the best thyme oil nanoliposomes can be gained using equal concentrations of all three components as 1% with a mean particle size of 189.6 nm, PDI of 0.3487, the net zeta-potential of 42.48 mV, and DPPH radical scavenging of 12.72%. The prepared nanoliposomes had acceptable physical but limited chemical stabilities. The antibacterial action of manufactured essential oil nanoliposomes against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus has made them efficient candidates as natural food preservatives.

Development and characterization of active and pH-sensitive films based on psyllium seed gum incorporated with free and microencapsulated mulberry pomace extracts

Intelligent packaging with a pH indicator has been a hot research topic due to its extra active role compared with traditional ones. Considering the possible toxicity of synthetic pH sensitive pigments, natural pigments are promising alternative indicators. This work aimed to develop and characterize active and pH sensitive films based on psyllium seed gum (PSG) incorporated with free and microencapsulated mulberry pomace extracts (MPE). Compared with PSG control film, PSG-MPE films showed an increase in total phenolic content and DPPH scavenging activity, and decrease in surface hydrophobicity, lightness, and tensile strength. The molecular interactions between PSG and MPE were confirmed by thermal and microstructure analysis. Moreover, PSG-MPE films displayed wide color differences from red to blue at pH 2.0 - 12.0. PSG-based films containing 10% free and microencapsulated MPE demonstrated better overall performance and economy in packaging applications, which could be used as promising active and pH-sensitive food packaging materials.

Nanocomposite active packaging based on chitosan biopolymer loaded with nano-liposomal essential oil: Its characterizations and effects on microbial, and chemical properties of refrigerated chicken breast fillet

Biodegradable films reinforced with bio-nanomaterials are a solution for developing active packaging systems, shelf-life extension and protection of environment against conventional packaging. This study aimed to characterize the biocompatible chitosan (CS) films formulated with nano-liposomal garlic essential oil (NLGEO) and assess the physicho-mechanical, morphology properties and also microbial and chemical changes in chicken fillets during storage time at 4 °C. NLGEO was obtained by thin-layer hydration-sonication method using glycerol and tween 80 as plasticizer and emulsifier, respectively. Different levels (0, 0.5, 1 and 2%) of NLGEO with average size of ~101 nm were added into the chitosan matrix and films fabricated by casting method. The average size, polydispersity index and zeta potential were ~101 nm, 0.127 and -7.23, respectively. Control samples showed higher values for pH, total volatile nitrogen (TVN), peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), and microbial count including total viable count (TVC), coliforms, Staphylococcus aureus and psychrotroph bacteria than treated samples. The films with higher NLGEO content represented stronger inhibitory effects. The incorporation of NLGEO improved the mechanical properties and water resistance of active films. Microstructure analysis also showed a nearly smooth surface morphology and homogenous structure with a good dispersion for NLGEO films. Significant synergistic effects in chemical and bacterial preservation of chicken fillet samples were observed by NLGEO films. The optimal mechanical and barrier properties of chitosan-NLGEO films introduced it a potential active packaging to extend the shelf life of chicken fillet.

Biodegradable Antimicrobial Food Packaging: Trends and Perspectives

This review presents a perspective on the research trends and solutions from recent years in the domain of antimicrobial packaging materials. The antibacterial, antifungal, and antioxidant activities can be induced by the main polymer used for packaging or by addition of various components from natural agents (bacteriocins, essential oils, natural extracts, etc.) to synthetic agents, both organic and inorganic (Ag, ZnO, TiO2 nanoparticles, synthetic antibiotics etc.). The general trend for the packaging evolution is from the inert and polluting plastic waste to the antimicrobial active, biodegradable or edible, biopolymer film packaging. Like in many domains this transition is an evolution rather than a revolution, and changes are coming in small steps. Changing the public perception and industry focus on the antimicrobial packaging solutions will enhance the shelf life and provide healthier food, thus diminishing the waste of agricultural resources, but will also reduce the plastic pollution generated by humankind as most new polymers used for packaging are from renewable sources and are biodegradable. Polysaccharides (like chitosan, cellulose and derivatives, starch etc.), lipids and proteins (from vegetal or animal origin), and some other specific biopolymers (like polylactic acid or polyvinyl alcohol) have been used as single component or in blends to obtain antimicrobial packaging materials. Where the package's antimicrobial and antioxidant activities need a larger spectrum or a boost, certain active substances are embedded, encapsulated, coated, grafted into or onto the polymeric film. This review tries to cover the latest updates on the antimicrobial packaging, edible or not, using as support traditional and new polymers, with emphasis on natural compounds.