Preparation and functional properties of fish gelatin–chitosan blend edible films

Approaches in Animal Proteins and Natural Polysaccharides Application for Food Packaging: Edible Film Production and Quality Estimation

Natural biopolymers are an interesting resource for edible films production, as they are environmentally friendly packaging materials. The possibilities of the application of main animal proteins and natural polysaccharides are considered in the review, including the sources, structure, and limitations of usage. The main ways for overcoming the limitations caused by the physico-chemical properties of biopolymers are also discussed, including composites approaches, plasticizers, and the addition of crosslinking agents. Approaches for the production of biopolymer-based films and coatings are classified according to wet and dried processes and considered depending on biopolymer types. The methods for mechanical, physico-chemical, hydration, and uniformity estimation of edible films are reviewed.

Chitosan and Derivatives: Bioactivities and Application in Foods

Chitosan is a biodegradable, biocompatible, and nontoxic aminopolysaccharide. This review summarizes and discusses the structural modifications, including substitution, grafting copolymerization, cross-linking, and hydrolysis, utilized to improve the physicochemical properties and enhance the bioactivity and functionality of chitosan and related materials. This manuscript also reviews the current progress and potential of chitosan and its derivatives in body-weight management and antihyperlipidemic, antihyperglycemic, antihypertensive, antimicrobial antioxidant, anti-inflammatory, and immunostimulatory activities as well as their ability to interact with gut microbiota. In addition, the potential of chitosan and its derivatives as functional ingredients in food systems, such as film and coating materials, and delivery systems is discussed. This manuscript aims to provide up-to-date information to stimulate future discussion and research to promote the value-added utilization of chitosan in improving the safety, quality, nutritional value and health benefits, and sustainability of our food system while reducing the environmental hazards.

Circular Economy in Conjunction with Treatment Methodologies in the Biomedical and Dental Waste Sectors

In this review, life cycle assessment (LCA) principles are coupled with circular economy (CE) in order to address LCA examples in the biomedical sector worldwide. The objectives were (1) to explore the application of LCA in the medical, pharmaceutical, and dental fields; (2) to describe the ways of biomedical waste management; (3) to emphasize on the problem of dental waste in private and public dental sectors; and (4) to propose ways of “green circulation” of the dental waste. A literature search was performed using the Google Scholar, PubMed, and Scopus search engines covering the period from January 2000 until May 2020, corresponding to articles investigating the LCA and circular economy principles and legislation for biomedical and dental waste, their management options, and modern ways of recycling. The results showed that incineration seems to be the best management way option involved despite the mentioned drawbacks in this technology. Different adopted models are well defined for the dental field based on the 3Rs’ module (reduce, reuse, recycle). Replacing disposable products with reusable ones seems to be a good way to tackle the problem of waste in medical and dental sectors. Interventions on the selection and better biomedical and dental waste management will ensure eco-medicine and eco-dentistry of the future. These new terms should be the new philosophies that will change the way these fields operate in the future for the benefit of the professionals/patients and the community.

Preparation and Properties of Soy Protein Isolate/Cotton-Nanocrystalline Cellulose Films

This study was performed to estimate the effect of the incorporation of different cotton-nanocrystalline cellulose (C-NCC) contents with soy protein isolate (SPI) films. The results indicated that the C-NCC content had no effect on the thickness of the composite films ( $0.06\pm 0.01\text{mm}$ ), and the optical property of the composite films decreased as the C-NCC contents increased. Water vapor, carbon dioxide, and oxygen permeability decreased with the introduction of C-NCC and started to increase when the peak of 7% C-NCC was reached. Water solubility of the SPI/C-NCC films decreased from 44.46% of the SPI films to 35.36% of the SPI/C-NCC films with 5% C-NCC. The tensile strength (TS) of films increased from 4.25 MPa to 6.02 MPa by increasing the C-NCC content from 0 to 7%. Then, the TS decreased as the C-NCC content was further increased. The trend of the elongation at break was opposite to that of the TS. The results from FTIR and DSC indicated that the addition of C-NCC did not change functional groups of the SPI films, and the glass transition temperature shifted toward a higher temperature as the C-NCC content increased. Hence, the addition of C-NCC enhanced the barrier and mechanical properties of the SPI/C-NCC composite films.

Trends in Chitosan as a Primary Biopolymer for Functional Films and Coatings Manufacture for Food and Natural Products

Some of the current challenges faced by the food industry deal with the natural ripening process and the short shelf-life of fresh and minimally processed products. The loss of vitamins and minerals, lipid oxidation, enzymatic browning, and growth of microorganisms have been the main issues for many years within the innovation and improvement of food packaging, which seeks to preserve and protect the product until its consumption. Most of the conventional packaging are petroleum-derived plastics, which after product consumption becomes a major concern due to environmental damage provoked by their difficult degradation. In this sense, many researchers have shown interest in edible films and coatings, which represent an environmentally friendly alternative for food packaging. To date, chitosan (CS) is among the most common materials in the formulation of these biodegradable packaging together with polysaccharides, proteins, and lipids. The good film-forming and biological properties (i.e., antimicrobial, antifungal, and antiviral) of CS have fostered its usage in food packaging. Therefore, the goal of this paper is to collect and discuss the latest development works (over the last five years) aimed at using CS in the manufacture of edible films and coatings for food preservation. Particular attention has been devoted to relevant findings in the field, together with the novel preparation protocols of such biodegradable packaging. Finally, recent trends in new concepts of composite films and coatings are also addressed.

Characterization and antibacterial activity of edible films based on carboxymethyl cellulose, Dioscorea opposita mucilage, glycerol and ZnO nanoparticles

The edible films composed ofcarboxymethyl cellulose (CMC), glycerol, mucilage from Chinese yam (DOM)and ZnO nanoparticles (ZnO-NPs), were prepared by a casting method. To evaluate the applicability for food packaging, prepared films were characterised morphological, physical, rheological, mechanical and barrier properties, performed FT-IR, thermal analysis, and finally investigated the antibacterial activity and acute oral toxicity of films. The surface of films presented irregular arrangement with nanoparticles combined in the networks, suggesting the best "CMC to DOM weight ratio" of approximately 1:1 could provide a smooth surface. The films with 2.0 g ZnO-NPs presented antibacterial effects against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. With the increase of DOM, the antibacterial rate dropped at 400 and 450 μL/mL. The film-forming solutions with higher ZnO-NPs content display shear-thinning properties and liquid-like behaviour. The edible films have a great potential to be used in application in food packaging.

Chitosan-based nanocomposites: preparation and characterization for food packing industry

In the present work, Cerium (IV)-Zirconium (IV) oxide nanoparticles (CeO4ZrNPs) was successfully dispersed into Chitosan/15Gelatin nanocomposites with different quantities. The obtained chitosan-based nanocomposites represented remarkable improvements in structural, morphological, mechanical, and thermal properties. Roughness increased from 74 nm to 6.4 nm, Young’s Modulus enhanced from 1.36 GPa to 2.99 GPa. The influence of dispersed CeO4ZrNPs contents on the phase transition temperature (T g) and the non-isothermal degradation processes of chitosan-based nanocomposites were examined using Differential Scanning Galorimetry (DSC) with different heating rates. Kinetic parameters of the thermal degradation for chitosan-based nanocomposites were evaluated using Kissinger-Akahira-Sunose (KAS) and Kissenger (KIS) procedures. Chitosan-based nanocomposites showed an increase in the thermal degradation temperature with higher activation energies, indicating improved thermal stability. Thermal analysis demonstrated that chitosan-based nanocomposites became more ordered by increasing CeO4ZrNPs as inferred from the negative entropy increase. Moreover, the degradation of chitosan-based nanocomposites has been described as a non-spontaneous process. The resulting information is particularly important in applications in which there is a need to obtain chitosan nanocomposites with improved mechanical and thermal properties such as food packing industry.

Chitosan-based film incorporated with essential oil nanoemulsion foreseeing enhanced antimicrobial effect

Foodborne diseases are a huge problem that causes dramatic economic losses and threatens consumers' lives. Chitosan-based film incorporated with essential oil nanoemulsion would be an ideal solution to build smart food packaging. Thyme oil was formulated into nanoemulsion and checked for the droplet size, distribution, and physical stability. The prepared thyme oil nanoemulsion was incorporated with the chitosan-filmogenic mixture through continuous mixing. The filmogenic mixture was cast, dried, and assessed for their morphological, physical, mechanical, and molecular properties. In addition to investigating the antimicrobial activity against gram-negative (Escherichia coli spp.) and gram-positive (Bacillus subtilis spp.) bacteria. Thyme oil nanoemulsion showed a small droplet size (89-90 nm) with considerable stability. Incorporating thyme oil nanoemulsion with the chitosan-based film did not cause great change in the film appearance and transparency, while enhanced the light barrier property. It caused noticeable changes to the film physical (ex., moisture content, water vapor permeability, among others) and mechanical (Tensile strength and elongation at break) properties. On the other hand, it improved the film thermal stability without causing a structural alteration in the film matrix. Incorporation of chitosan-based film with thyme nanoemulsion remarkably improved the antimicrobial activity against foodborne pathogens. Chitosan-based film incorporated with thyme oil nanoemulsion would be considered a promising antimicrobial food packaging material with considerable packaging properties, and substantial growth inhibitor of foodborne pathogens.

Application of soymilk skin as sausage wrapping for improving lipid oxidation

Yuba, the soymilk skin, was developed as edible films for sausage. Yuba (Y) were prepared with added pine-needle extract (YP) and employed to wrap sausage. Physical and mechanical properties and lipid oxidation of sausages were compared to sausages made with commercial collagen casing (C). Y films showed better transparency, oxygen-barrier properties, and UV-light barrier properties than C films (p < .05). Particularly, the addition of pine-needle extract increased DPPH activities from 31 to 48% and total phenol content from 7.52 to 14.64 mg gallic acid/g. Regarding application for sausage wrapping, Y (2.35%) and YP (2.66%) wrapped sausages with better protection against water loss during cooking compared to sausages made from C (5.84%). Especially, YP (3.57 MDA mg/kg) showed better protection against lipid oxidation for sausages than Y (4 MDA mg/kg) and C (4.62 MDA mg/kg) on day 6 after refrigerated storage. Yuba films could be employed as potential alternatives to gelatin films for manufacturing sausages.

Effects of virgin olive oil and grape seed oil on physicochemical and antimicrobial properties of pectin-gelatin blend emulsified films

The active emulsified blend films based on gelatin-pectin (5% w/w) containing virgin olive oil (VOO) (0.1-0.3 g/g biopolymer) and grape seed oil (GSO) (0.1-0.3 g/g biopolymer) were prepared by casting method. GSO showed slightly more decreasing effect than VOO on ultimate tensile strength (UTS) and strain at break (SAB) of blend films however; VOO had more reducing effect than GSO on the water vapor permeability (WVP). The scanning electron microscopy (SEM) images showed that incorporating 0.3 g GSO and VOO oils had not considerable effect on the morphology of the emulsified films. Atomic force microscopy (AFM) topography images indicated that adding of oils considerably could increase roughness of emulsified film. Fourier transforms infrared (FTIR) revealed that no new chemical bond formed by adding oils into biopolymer matrix. The minimum inhibitory concentration (MIC) of VOO, GSO and Savory essential oil (SEO) against four important spoilage bacteria showed that GSO had higher antibacterial effect than VOO however; both showed very lower antimicrobial effect than SEO. All active films showed lower inhibitory zone for S. aureus than S. typhimurium and P. fluorescence. The chicken breast fillets wrapped in the films containing VOO-GSO-SEO (0.15-0.15-0.02 g/g polymer) showed considerably lower total viable count (TVC), Pseudomonas spp., Enterobacteriaceae, E. coli 157:H7 and S. typhimurium count than the control one during 12 days storage. Also, it caused significant decrease in peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N) of fillet samples.

An overview on plasticized biodegradable corn starch-based films: the physicochemical properties and gelatinization process

With increasing awareness of environmental protection, petroleum-based raw materials are continuously decreasing, which in turn necessitated the development of eco-friendly sustainable biomaterials, as alternative strategy. Starch could be an ideal substitute. Corn starch has been used as a renewable material for development of biodegradable packaging, owing to great varieties, low cost, large-scale industrial production, and good films forming properties. Unfortunately, its poor mechanical and barrier properties have limited the application of starch-based films. Thence, plasticizers were added to overcome the aforementioned pitfalls and improve the films elongation, distribution, flexibility, elasticity, and rigidity. Addition of plasticizers can change the continuity and therefore would enhance the properties of corn starch-based films. While plasticization can improve the tensile strength and percent elongation, it can reduce the water resistance in prepared films. Herein, we focused on changes of starch granules during gelatinization process, types of biodegradable films, as well as the types of modified starch with plasticizers. Furthermore, the influence of plasticizers on corn starch-based films and the physicochemical properties of various types of corn starch-based films were also addressed.

Enhanced physicochemical stability of ω-3 PUFAs concentrates-loaded nanoliposomes decorated by chitosan/gelatin blend coatings

To enhance the physicochemical stability of ω-3 PUFAs concentrates from fish oil, biopolymer coating based on chitosan (CH) and gelatin (GE) deposited on the surface of nanoliposomes (NLs) has been synthesized and characterized. The mean particle size of surface-decorated nanoliposomes (SDNLs) containing ω-3 PUFAs concentrates was found to be in the range of 209.5-454.3 nm. Scanning and transmission electron microscopy revealed the spherical shape and smooth surface of the nanovesicles. Fourier-transform infrared spectroscopy and X-ray diffraction observations confirmed that the NLs have been successfully coated by biopolymeric blends. The highest entrapment efficiency of 81.6% was obtained in polymer-stabilized NLs with a concentration ratio of 0.3:0.1 (CH:GE). Differential scanning calorimetry results revealed enhanced thermal stability of vesicles after polymeric blend desorption. Finally, the oxidative stability assays demonstrated that the ω-3 PUFAs concentrates entrapped in SDNLs was protected against oxidation in comparison to the free ω-3 PUFAs concentrates.

Characterization and antibacterial properties of biodegradable films based on CMC, mucilage from Dioscorea opposita Thunb. and Ag nanoparticles

The biodegradable films, composed of carboxymethyl cellulose (CMC), glycerol, mucilage from Dioscorea opposita (DOM) and Ag nanoparticles, were prepared by a casting method and characterised including colour measurement, solubility, mechanical and water barrier properties etc. to fit the requirements for food packaging. The films were also analysed by fourier transformed infrared spectroscopy, thermal analysis, scanning electron microscopy, and rheometer etc., meanwhile, the antimicrobial activities and acute toxicity of the films were investigated. The addition of Ag nanoparticles and DOM decreased the tensile strength, water solubility and transparency value, while increased the elongation at break. The functional groups and thermal analysis of films presented no significant differences, and the film-forming solutions showed similar shear-thinning properties. Antimicrobial evaluation revealed that the films achieved significant antibaterial effects against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. The biodegradable films presented a compact and uniform structure with antibacterial properties and without toxicological responses, which has excellent potential to be applied in food packaging.

Physicochemical properties and antibacterial activity of corn starch-based films incorporated with Zanthoxylum bungeanum essential oil

Herein, corn starch-based films were prepared by casting method and different concentrations of Zanthoxylum bungeanum essential oil (ZYO) were added to evaluate the morphological, optical, mechanical, and barrier properties of the resultant films. Additionally, structural analysis was carried out via atomic force microscopy and the antibacterial activities against Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes were assessed. We found that the elongation at break was significantly increased (P <  0.05), whereas tensile strength, moisture content, solubility in water, and water vapor permeability rate were significantly decreased (P <  0.05) in films incorporated with ZYO compared with oil-free films. Furthermore, incorporation of ZYO increased the opacity and decreased the gloss of films. Incorporation of ZYO appears to increase the surface roughness and the antibacterial activity of the films. In sum, ZYO can potentially be used in food packaging, particularly food intended to be protected from light and susceptible to spoilage by microorganisms.

Study on the stability and cellular affinity of gelatin-polysaccharide composite films

The gelatin film has great potential in biomedical applications, especially in wound healing. The combination of gelatin films and stem cells could further accelerate the skin regeneration. Although polysaccharide modification can improve the mechanical property and biological activity of gelatin films, information about the stability and cellular affinity is still limited. This study investigated the influence of polysaccharides on the stability and cellular affinity of gelatin films. Two kinds of gelatin-polysaccharide composite films, including gelatin-hyaluronic acid (G-HA) and gelatin-chitosan (G-CS), were prepared in this study. It was found that G-HA composite film had better short-term and long-term stability compared with G-CS composite film. And G-HA composite film also had better biological safety than G-CS film. Moreover, the surface of G-HA composite film supported the adhesion and growth of human umbilical cord Wharton's jelly-derived mesenchymal stem cells (WJ MSCs) better than G-CS film surface. These data illustrated that G-HA composite film has better stability and cellular affinity compared with G-CS film, which could be considered a promising delivery system of stem cells for further in vivo studies. Therefore, this work would be very helpful to optimize the preparation of gelatin-polysaccharide composite films.

Flexible translucent chitosan-glycerin/QD nanocomposite glue for anti-counterfeiting films with strong adhesion and stability

With the rapid development of commodity circulation, more attention has been paid to the anticounterfeiting technology of commodities, including stability, universality and ease of distinguishing. The authors report the use of gelatin-chitosan-glycerin/QD nanocomposite-functionalized glue for luminescent anti-counterfeiting labels. As the blend and plasticizer, the addition of chitosan and glycerin effectively improved the flexibility and formability of the gelatin-chitosan-glycerin/QD composite films, which show excellent mechanical properties, including high transparency, luminescence and flexibility, and they are easy to prepare on a large scale, providing certain reference values for new anticounterfeiting technology applying a variety of morphologies.

INVESTIGATION ON QUALITY PROPERTIES OF TRADITIONAL BULK BREAD COVERED WITH PROBIOTICS AND SOYBEAN OIL EDIBLE COATING

Probiotic food products are available at the supermarket commercially, but probiotic bakery products are much less in evidence. In the present study, methyl cellulose (2%), whey protein concentrate (2%), corn starch (1%), and soybean oil at 2, 4, and 6% were used for coating layer on the bulked bread surface, and then the quality properties were studied. The results showed that Lactobacillus rhamnosus GG, as probiotic component of the coating, immobilized in corn starch, whey protein, and methyl cellulose films had enhanced viability throughout shelf-life. The probiotics remained viable for 4 days, maintaining high viable cell number levels. Adding soybean oil at 6% concentration enhanced texture, sensory properties, and image index during storage.