The properties of chitosan and gelatin films incorporated with ethanolic red grape seed extract and Ziziphora clinopodioides essential oil as biodegradable materials for active food packaging

Development and characterization of a double-layer smart packaging system consisting of polyvinyl alcohol electrospun nanofibers and gelatin film for fish fillet

This study aimed to develop a double-layer film composed of an intelligent, gelatin-based film integrated with active polyvinyl alcohol electrospun nanofibers (PVANFs). Eggplant skin extract (ESE), a colorimetric indicator, was incorporated into the gelatin-based film at varying concentrations ranging from 0 % to 8 % w/w. The gelatin film containing 8 % ESE was identified as the optimal formulation based on its superior color indication, water barrier, and mechanical properties. Savory essential oil (SEO)-loaded PVANFs were electrospun onto the optimized gelatin film to fabricate the double-layer film. Analysis of the chemical and crystalline structures and the double-layer film's thermal properties confirmed the gelatin film's physical integration with PVANFs. Morphological examination revealed a smooth surface on the film and a uniform fibrillar structure within the PVANFs. Furthermore, the developed double-layer film effectively detected spoilage in trout fish while controlling pH, oxidation, and microbial changes during storage.

Antimicrobial Polymer Films with Grape Seed and Skin Extracts for Food Packaging

The development of antimicrobial food packaging is a very important and current goal, but it still difficult to implement in practice. Reducing microbial contamination and preserving food quality are very important tasks for food manufacturers as the use of antimicrobial packaging can preserve the health of consumers. On the other hand, the difficulty of degrading packaging materials, leading to environmental pollution, is also an important problem. These problems can be solved by using biodegradable biopolymers and antimicrobial agents in the production of food packaging. Very suitable antimicrobial agents are grape seed and skin extracts as they have high antioxidant and antimicrobial capacity and are obtained from grape pomace, a waste product of winemaking. The present review presents the valuable bioactive compounds contained in grape seeds and skins, the methods used to obtain the extracts, and their antimicrobial and antioxidant properties. Then, the application of grape seed and skin extracts for the production of antimicrobial packaging is reviewed. Emphasis is placed on antimicrobial packaging based on various biopolymers. Special attention is also paid to the application of the extract of grape skins to obtain intelligent indicator packages for the continuous monitoring of the freshness and quality of foods. The focus is mainly placed on the antimicrobial properties of the packaging against different types of microorganisms and their applications for food packaging. The presented data prove the good potential of grape seed and skin extracts to be used as active agents in the preparation of antimicrobial food packaging.

Biofilms from poly-vinyl alcohol/palmyra root sprout with Boswellia serrata, carbon dots and anthocyanin for sensing the freshness of sardine fish

One of the main issues that customers worldwide have is food adulteration. In commercial packages, freshness cannot always be determined visually. Here, we propose sensitive films for use in food packaging that could alter colour to indicate a change in freshness. Hybrid, multifunctional, and eco-friendly films were prepared from polyvinyl alcohol/palmyra root sprout (PVA/PRS), fused with soy protein isolate carbon dot (CD), Boswellia serrata (BS), and Clitoriaternatea anthocyanin (CTE). The films showed pH sensitivity, antioxidant, and UV barrier properties. By creating hydrogen bonds between PRS and the other fillers, adding these substances makes PVA less crystallized. These interactions were verified by infrared Fourier-transform analysis. When compared to PVA, PRS films had significantly lower moisture content and swelling ratios. The UV-blocking capabilities of the films were greatly improved by the addition of CD, BS, and CTE without compromising their mechanical, thermal, or water vapor barrier properties. The composite film PVA/PRS/CD/BS/CTE exhibited a maximum tensile strength value of 69.47 ± 1.49 MPa. The CT extract provides the film with superior antioxidant properties. The colorimetric films PVA/PRS/CTE and PVA/PRS/CD/BS/CTE showed distinct pH-responsive colour-change properties as well as good colour stability. The colorimetric films were used to test the freshness of sardine fish, and they revealed unique colour changes that indicated whether the fish sample was spoiled or not.

Free-standing carboxymethyl cellulose film incorporating nanoformulated pomegranate extract for meat packaging

This study aimed to explore an innovative approach to enhancing the shelf-life and quality of meat products through the application of an active packaging system. The study involved the development of new free-standing carboxymethyl cellulose (CMC) nanocomposite films incorporated with nanoencapsulated flavonoids derived from pomegranate extract. The loaded flavonoids, known for their antioxidant and antimicrobial properties, were nanoencapsulated via a self-assembly approach in a mixture of chitosan and sodium alginate to improve their stability, solubility, and controlled release characteristics. Chemical structure, size, and morphology of the obtained nanoparticles (Pg-NPs) were studied with FTIR, zeta-sizer, and TEM. The Pg-NPs showed particle size of 232 nm, and zeta-potential of -20.7 mV. Various free-standing nanocomposite films were then developed via incorporation of Pg-NPs into CMC-casted films. FTIR, SEM, thermal and mechanical properties, and surface wettability were intensively studied for the nanocomposite films. Barrier properties against water vapor were investigated at 2022 g·m-2d-1. The nanocomposite films possessed superior properties for inhibiting bacterial growth and extending the shelf-life of beef and poultry meat for 12 days compared with the Pg-NPs-free CMC films. This study presented a promising approach for development of active packaging systems with improved antimicrobial and antioxidant properties, and economic and environmental impacts.

Ziziphora clinopodioides extract-loaded chitosan/polyvinylpyrrolidone casting films for potential applications in wound dressings

Chitosan/polyvinylpyrrolidone composite films containing hydroalcoholic Ziziphora clinopodioides extract were developed and evaluated for their potential use as wound dressings. The physical and chemical properties of the films were extensively explored, including swelling capacity, mechanical properties, antimicrobial activity, and microstructural characteristics. The results showed that the addition of Ziziphora extract significantly increased the swelling capacity of the films by 561.24% to 1175% (p < 0.05). While tensile strength and Young's modulus were enhanced, elongation at the breaking point decreased with increasing volume percentages of Ziziphora extract. Variance analysis indicated no statistically significant effect on the tensile properties of the films with varying Ziziphora extract content (p < 0.05). Furthermore, films incorporated with Ziziphora extract demonstrated antimicrobial properties. Scanning electron microscopy (SEM) analysis revealed that samples lacking Ziziphora extract had a smooth surface, while those containing the extract displayed a rough texture that may potentially accelerate the wound healing process.

Chitosan/konjac glucomannan bilayer films: Physical, structural, and thermal properties

To overcome the limitations of chitosan (CS) and konjac glucomannan (KGM), the bilayer films of CS and KGM were prepared by layer-by-layer (LBL) casting method, and the effects of different mass ratios (i.e., C5: K0, C4:K1, C3:K2, C1:K1, C2:K3, C1:K4, and C0:K5) on the microstructures and physicochemical properties of bilayer films were examined to evaluate their applicability in food packaging. The results revealed that the bilayer films had uniform microstructures. When compared with pure films, the bilayer films displayed lower swelling degrees and water vapor permeability. However, the tensile tests revealed a reduction in the mechanical properties of the bilayer films, which was nonetheless superior to that of the pure KGM film. In addition, the intermolecular interactions between the CS and KGM layers were observed through FTIR and XRD analyses. Finally, TGA and DSC analyses demonstrated a decrease in the thermal stability of the bilayer films. Our cumulative results verified that CS-KGM bilayer films may be a promising material for use in food packaging and further properties of the bilayer films can be supplemented in the future through layer-by-layer modification and the addition of active ingredients.

Bioactive Components, Applications, Extractions, and Health Benefits of Winery By-Products from a Circular Bioeconomy Perspective: A Review

Significant waste streams produced during winemaking include winery by-products such as pomace, skins, leaves, stems, lees, and seeds. These waste by-products were frequently disposed of in the past, causing resource waste and environmental issues. However, interest has risen in valorizing vineyard by-products to tap into their latent potential and turn them into high-value products. Wine industry by-products serve as a potential economic interest, given that they are typically significant natural bioactive sources that may exhibit significant biological properties related to human wellness and health. This review emphasizes the significance of winery by-product valorization as a sustainable management resource and waste management method. The novelty of this review lies in its comprehensive analysis of the potential of winery by-products as a source of bioactive compounds, extraction techniques, health benefits, and applications in various sectors. Chemical components in winery by-products include bioactive substances, antioxidants, dietary fibers, organic acids, and proteins, all of which have important industrial and therapeutic applications. The bioactives from winery by-products act as antioxidant, antidiabetic, and anticancer agents that have proven potential health-promoting effects. Wineries can switch from a linear waste management pattern to a more sustainable and practical method by adopting a circular bioeconomy strategy. Consequently, the recovery of bioactive compounds that function as antioxidants and health-promoting agents could promote various industries concomitant within the circular economy.

Gelatin-sodium alginate packaging film with date pits extract: An eco-friendly packaging for extending raw minced beef shelf life

Gelatin-sodium alginate-based active packaging films were formulated by including date pits extracts (DPE), as bioactive compound, in raw minced beef meat packaging. The DPE effects at 0.37, 0.75 and 1.5% (w/w, DPE/ gelatin-sodium alginate) on physical, optical, antioxidant and antibacterial properties of established films were assessed. Findings showed that film lightness decreased with the incorporation of DPE. Physical, antioxidant and anti-food-borne pathogens capacities were enhanced by increasing DPE concentration in the films. For 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), the films with 1.5% DPE had the greatest levels (94 and 88%, respectively). DPE films (1.5%) also exhibited the highest anti-Listeria moncytogenes activity, with an inhibition zone of 25 mm. Moreover, during 14 days at 4 °C, the bio-preservative impact of gelatin-sodium alginate film impregnated with DPE at three levels on microbial, chemical, and sensory characteristics of meat beef samples was evaluated. By the end of the storage, DPE at 1.5% enhanced the instrumental color, delayed chemical oxidation and improved sensory traits. By chemometric techniques (principal component analysis (PCA) and heat maps), all data allowed to obtain helpful information by segregating all the samples at each storage time. PCA and heat maps could connect oxidative chemical changes, instrumental color parameters, and microbiological properties to sensory attributes. These data offer an approach to well interpreting the sensory quality and how they are affected by chemical and microbiological changes in the studied meat samples. Our findings indicated the potential of the gelatin-sodium alginate film incorporated with DPE for enhancing meat safety and quality.

Preparation, physicochemical and biological evaluation of chitosan Pleurotus ostreatus polysaccharides active films for food packaging

The aim of this study was to create CS-POP composite films by blending Pleurotus ostreatus stalk polysaccharides (POP) and chitosan (CS). The effects of adding different concentrations (0 %, 0.25 %, 0.5 %, 0.75 %, and 1 %) of POP on the mechanical, barrier, and optical properties of the CS films were investigated. When the POP content is at 0.5 %, the tensile strength of the composite film reaches its maximum value at 13.691 MPa, showing a significant improvement compared to the tensile strength of the pure CS film. The structure of the CS and CS-POP composite films was characterized by FT-IR spectroscopy, XRD, TGA and SEM. The results indicate that due to the interaction between the two types of CS and POP, the formation of Schiff base, and the intermolecular hydrogen bonds between CS and POP, the addition of POP to CS films can result in a smoother and more stable crystalline structure in the composite film. The CS-POP composite films exhibited enhanced antioxidant and antibacterial activity compared to the CS films alone, with the highest DPPH scavenging activity of 72.43 %. The composite films also showed significant inhibitory effects on the growth of E. coli.

Effects of filler type and content on mechanical, thermal, and physical properties of carrageenan biocomposite films

This study investigates the influence of various fillers on the properties of carrageenan, a natural polymer derived from red seaweed. Despite its potential for enhanced biocomposite film development, carrageenan faces challenges related to strength. The incorporation of nanoclay into the carrageenan film resulted in a significant increase in film thickness from 0.026 to 0.068 mm. The UV light transmission value for the carrageenan film alone was measured at 30.9 %, whereas films containing 5 wt% of Tetraethyl orthosilicate (TEOS), 3-Aminopropyltriethoxysilane (APTES), and nanoclay exhibited reduced transmission values of 23 %, 18 %, and 1 %, respectively. Notably, the tensile strength of the unfilled carrageenan film was 38.4 MPa, which increased to 38.6, 57, and 60 MPa upon the addition of 3 wt% of nanoclay, APTES, and TEOS fillers, respectively. All fillers contributed to improved tensile strength, with TEOS demonstrating the highest enhancement. The optimal filler content was determined to be 3 wt%. Regarding thermal properties, films containing TEOS displayed higher thermal stability compared to those with APTES, while films incorporating nanoclay exhibited the lowest stability. Findings provide insights into the effects of different fillers on the mechanical, physical and thermal properties of carrageenan films, supporting the development of improved biocomposite materials suitable for application in food packaging.

Combined Effect of Citric Acid and Polyphenol-Rich Grape Seed Extract towards Bioactive Smart Food Packaging Systems

Alginate films (2% w·v^-1) were prepared with varying concentrations (5-20% w/w) of citric acid and aqueous grape seed extract (GSE) filtrate (11.66 ± 1.32 g GAE/L) using the solvent-evaporation method. Crosslinking alginate via ester bonds (FTIR analysis) with citric acid up to 10% (w/w) led to a 33% increase in tensile strength, a 34% reduction in water vapor transmission rate (WVTR), and had no impact on elongation at break. Crosslinking alginate with citric acid in the presence of GSE increased the tensile strength by 17%, decreased WVTR by 21%, and significantly improved DPPH scavenging activity. Moreover, after incubation for 24 h at 37 °C, the film-forming solutions exhibited increased antimicrobial activity, resulting in 0.5- and 2.5-log reductions for Escherichia coli and Staphylococcus aureus, respectively, compared to the values obtained without the addition of GSE. The stronger inhibitory effect observed against Gram-positive bacteria can be attributed to the unique composition and structure of their cell walls, which creates a barrier that restricts the penetration of polyphenols into the cells. The pH adjustment of the GSE film-forming solution from 2.0 to 10.0 shifted the UV/VIS absorption spectra, resulting in a colour change from yellow to red. The findings of this study have showcased the potential of combining GSE and citric acid to enhance the functionality and bioactivity of alginate films for applications in smart food packaging.

Characterization of active Cerish fructan-sumac extract composite films: Physical, mechanical, and antioxidant properties

The biodegradable active films have the potential to increase the shelf life and safety of food products. In this study, the properties of Eremurus spectabilis (Cerish) root fructans (ESRF) film and its combination with Rhus coriaria L. (Sumac) extract (RCLE) at different concentrations (1%, 2%, 3%, and 4% w/w) were investigated. The Fourier transform infrared (FTIR) analysis determined the fingerprint region of fructans at 950-1150 cm^-1 in all spectrograms. RCLE increased the interactions between the hydroxyl groups and the formation of intermolecular bonds in composite films. Elongation-at-break (EAB) and tensile strength (TS) did not change significantly. However, RCLE increased Young's modulus (YM) (p ˂ .05), thermal stability, and crystallinity of composite films. RCLE also increased the film thickness and decreased the water content, solubility, and swelling degree significantly. RCLE improved the reducing ability and free radical-scavenging activity of composite films. Present results indicated that the ESRF/RCLE films were the protective barriers to the permeability of water vapor. The incorporation of RCLE increased the surface hydrophobicity and caused the composite film microstructure to become uniform and more compact. Overall, the Sumac extract at the specific concentration of 3% can be used to improve the Cerish fructans film properties and extend the product's shelf life in active food packaging.

Composite films based on carboxy methyl cellulose and sodium alginate incorporated Thymus vulgaris purified leaves extract for food application: Assessment, antimicrobial and antioxidant properties

The current study was conducted to develop biodegradable films with matrix composed from carboxymethyl cellulose (CMC), sodium alginate (SA) and different concentrations from Thymus vulgaris purified leaves extract (TVE). The color properties, physical properties, shape of surface, manners of crystallinity, mechanical properties and thermal properties of produced films were investigated. The continuous addition of TVE up to 1.6 % inside films matrix imparted the yellow color of extract that increased opacity to 2.98 and reduced moisture, swelling, solubility and water vapor permeability (WVP) of films up to 10.31 %, 30.17 %, 20.18 % and (1.12× 10^-10 g.m^-1 s^-1 pa^-1), respectively. Furthermore, the surface micrographs showed smoother surface after using small concentrations of TVE and turned to irregular with rough surface at higher concentrations. The FT-IR analysis indicated typically bands that demonstrated physical interaction between TVE extract and CMC/SA matrix. The fabricated films showed suitable thermal stability with decreasing trend by incorporation of TVE inside CMC/SA films. Furthermore, the developed CMC/SA/TVE2 showed significant effects on preserving the levels of moisture content, titrable acidity, force to puncture and sensory properties of cheddar cheese during cold storage days compared with commercial packaging materials.

Design of Biodegradable Films Using Pecan Nut Cake Extracts for Food Packing

The excessive consumption of plastic packaging and its consequent disposal and accumulation in the environment have aroused the interest of researchers in developing packaging that can cause less harm to nature. In this sense, this article presents research on the addition of antioxidant extracts from pecan nut cake in biodegradable packaging made with a polymeric mixture of gelatin and corn starch. The films produced were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thickness, mechanical properties, water vapor permeability (WVP), solubility, water contact angle, optical properties, in vitro bioactive activity, and biodegradability. A higher concentration of total phenolic compounds (101.61 mg GAE/g) was found for the condition where alcohol content and extraction time were 65% and 20 min, respectively. Pecan nut cake (PNC( extracts did not influence the film’s tensile strength, and elongation at break was tightly increased by adding 10–20% extracts. The film’s characterization pointed to more than 67% solubility, and adding PNC extract implied more hydrophilic surfaces (contact angles lower than 65°). Furthermore, the film opacity showed a linear relation with PNC extract concentration, and a higher luminosity (L*) was observed for the film without extract. Furthermore, the antioxidant activity of the films was enhanced with the addition of PNC extracts, and complete biodegradation was observed until the ninth day. Therefore, biodegradable films prepared from a mixture of gelatin starch and enriched with PNC extracts showed excellent mechanical properties and potential as carriers of antioxidant compounds, allowing us to propose their use as active packing.

Development of antimicrobial gelatin-ulvan-beeswax composite films: Optimization of formulation using mixture design methodology

A new generation of antimicrobial film was developed by incorporation of ulvan extracted from Ulva intestinalis into gelatin from common carp scale and its water sensitivity was reduced with addition of beeswax. Optimum composition of gelatin (0-100%w/w), ulvan (0-100%w/w) and beeswax (0-10%w/w) for achieving composite films with minimum water solubility (S) and water vapor permeability (WVP) and maximum tensile strength (TS), elongation at break point (EAB) and antibacterial effect on E. coli (EC) were investigated using mixture design methodology. Both pure gelatin and ulvan films and their composites had relatively good mechanical and optical properties. Addition of ulvan to gelatin produced composite films with good antibacterial properties but water resistance of all the films was weak. Addition of beeswax up to ∼5 % improved the water resistance and mechanical properties of the films without jeopardizing their antibacterial properties. The final optimum formulation with a desirability of 0.709 was achieved as 52.18 % of gelatin, 40.83 % of ulvan and 6.97 % of beeswax resulting in a minimum possible S (40 %) and WVP (1.86 10^-10 g/ms Pa) and maximum possible TS (6.23 MPa) and EAB (89 %) with good EC (7.66 mm). Finally, good mechanical, thermal and microstructural properties of the optimum composite film was confirmed. Altogether, a combination of ulvan and beeswax can be a promising solution for development of gelatin films with both antimicrobial properties and lower water sensitivity.

A Review on the Potential Bioactive Components in Fruits and Vegetable Wastes as Value-Added Products in the Food Industry

The food production industry is a significant contributor to the generation of millions of tonnes of waste every day. With the increasing public concern about waste production, utilizing the waste generated from popular fruits and vegetables, which are rich in high-added-value compounds, has become a focal point. By efficiently utilizing food waste, such as waste from the fruit and vegetable industries, we can adopt a sustainable consumption and production pattern that aligns with the Sustainable Development Goals (SDGs). This paper provides an overview of the high-added-value compounds derived from fruit and vegetable waste and their sources. The inclusion of bioactive compounds with antioxidant, antimicrobial, and antibrowning properties can enhance the quality of materials due to the high phenolic content present in them. Waste materials such as peels, seeds, kernels, and pomace are also actively employed as adsorbents, natural colorants, indicators, and enzymes in the food industry. Therefore, this article compiles all consumer-applicable uses of fruit and vegetable waste into a single document.

The use of essential oils in chitosan or cellulose-based materials for the production of active food packaging solutions: a review

In recent decades, interest in sustainable food packaging systems with additional functionality, able to increase the shelf life of products, has grown steadily. Following this trend, the present review analyzes the state of the art of this active renewable packaging. The focus is on antimicrobial systems containing nanocellulose and chitosan, as support for the incorporation of essential oils. These are the most sustainable and readily available options to produce completely natural active packaging materials. After a brief overview of the different active packaging technologies, the main features of nanocellulose, chitosan, and of the different essential oils used in the field of active packaging are introduced and described. The latest findings about the nanocellulose- and chitosan-based active packaging are then presented. The antimicrobial effectiveness of the different solutions is discussed, focusing on their effect on other material properties. The effect of the different inclusion strategies is also reviewed considering both in vivo and in vitro studies, in an attempt to understand more promising solutions and possible pathways for further development. In general, essential oils are very successful in exerting antimicrobial effects against the most diffused gram-positive and gram-negative bacteria, and affecting other material properties (tensile strength, water vapor transmission rate) positively. Due to the wide variety of biopolymer matrices and essential oils available, it is difficult to create general guidelines for the development of active packaging systems. However, more attention should be dedicated to sensory analysis, release kinetics, and synergetic action of different essential oils to optimize the active packaging on different food products. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Potato Starch-Based Film Incorporated with Tea Polyphenols and Its Application in Fruit Packaging

Effects of tea polyphenols (TP) on the physical properties, barrier properties and functionality of potato starch-based film were determined, while the interaction mechanism between TP and starch in film and the application of this film in fruit packaging were further evaluated. TP exhibited different effects on the physical properties of potato starch-based film, including thickness (0.083 to 0.087 mm), moisture content (9.27% to 9.68%), color (ΔE value: 5.41 to 10.55), light transmittance (51% to 62%), tensile properties and thermal properties, and improved its barrier properties, including water vapor permeability (9.68 to 11.84 × 10-11 g m-1 s-1 Pa-1),oxygen permeability (1.25 to 2.78 × 10-16 g m-1 s-1 Pa-1) and antioxidant activity. According to the determination of wide-angle X-ray diffraction, Fourier transform infrared and scanning electron microscope, TP could interact with starch chains via hydrogen bonds to form non-crystal complexes, thus affecting the cross-linking among starch chains and further changing the microstructure of film. Furthermore, film incorporated with TP could improve the storage quality (including weight and texture) of blueberries, and inhibit the enzymatic browning of fresh-cut bananas during storage. All present results suggested that tea polyphenols had potential to enhance the properties and function of potato starch-based film, and the film exhibited the application prospect in fruit packaging and preservation.

Chitosan Edible Films and Coatings with Added Bioactive Compounds: Antibacterial and Antioxidant Properties and Their Application to Food Products: A Review

Chitosan is the deacetylated form of chitin regarded as one of the most abundant polymers and due to its properties, both chitosan alone or in combination with bioactive substances for the production of biodegradable films and coatings is gaining attention in terms of applications in the food industry. To enhance the antimicrobial and antioxidant properties of chitosan, a vast variety of plant extracts have been incorporated to meet consumer demands for more environmentally friendly and synthetic preservative-free foods. This review provides knowledge about the antioxidant and antibacterial properties of chitosan films and coatings enriched with natural extracts as well as their applications in various food products and the effects they had on them. In a nutshell, it has been demonstrated that chitosan can act as a coating or packaging material with excellent antimicrobial and antioxidant properties in addition to its biodegradability, biocompatibility, and non-toxicity. However, further research should be carried out to widen the applications of bioactive chitosan coatings to more foods and industries as well was their industrial scale-up, thus helping to minimize the use of plastic materials.

Effects of Chitosan/Collagen Peptides/Cinnamon Bark Essential Oil Composite Coating on the Quality of Dry-Aged Beef

The aim of this study was to evaluate the effects of the chitosan/collagen peptides/cinnamon bark essential oil composite coating on dry-aged beef. Chitosan (2%, w/v), collagen peptides (1%, w/v), and cinnamon bark essential oil (1%, v/v) were homogenized to obtain the coating. Beef samples were divided into three groups (traditional dry-ageing, in-bag dry-ageing, and coating and then dry-ageing) and dry-aged for 42 days. Physiochemical, microbial, and sensorial parameters of samples were determined during the dry-ageing process. There were no significant differences (p > 0.05) in pH values, shear force values, cooking loss, color, juiciness, tenderness, and flavor across groups. The total volatile base nitrogen value of the coating group was lower than those of the other two groups. Compared to traditional dry-ageing, in-bag and coating dry-ageing reduced (p < 0.05) many volatile compounds such as alcohols, aldehydes, ketones, and acetate. In-bag and coating dry-ageing had no impact on the fungal community, but changed the bacterial community by inhibiting Pseudomonas. This study demonstrates that the chitosan/collagen peptides/cinnamon bark essential oil coating reduces microbial spoilage during dry-ageing, and has a small influence on product quality.

Biodegradable Active Packaging Material Containing Grape Seed Ethanol Extract and Corn Starch/κ-Carrageenan Composite Film

An active film composed of corn starch/κ-carrageenan and ethanolic grape seed extract (0, 1, 3, and 5 wt% of GSE on corn starch basis) were successfully prepared using the solvent casting technique. The effects of the different concentrations of ethanolic grape seed extract (GSE) on the physicochemical properties, antioxidant properties, and antibacterial properties of CS/κC films were analyzed. The results showed that the addition of GSE inhibited the recrystallization of starch in the composite film. The glass transition temperature of composite film is 121.65 °C. With the addition of GSE, the surface roughness of the composite film increased, and the cross-section displayed a stratification phenomenon. Meanwhile, when GSE was added to the composite film, the tensile strength of the composite film decreased (3.50 ± 0.27 MPa), the elongation at break increased (36.87 ± 2.08%), and the WVP increased (1.58 ± 0.03 g mm/m2·d· kPa). With the increase of the concentration of GSE in the composite film, the a* value and b* value of the composite film increase, the L* value decreases, and the opacity increases. The lipid oxidation test proved that the composite films containing 1% GSE has a significant inhibitory effect on the oxidation of lard (p < 0.05). The above results indicate that the GSE can be used as a food-grade packaging material and has a good application prospect in the food industry.

Influence of Ulluco Starch Modified by Annealing on the Physicochemical Properties of Biodegradable Films

This work aimed to evaluate the use of annealing (ANN) ulluco starch in the preparation of biodegradable films and its impact on the physicochemical properties of the materials. Three film samples (FS1, FS2, and FS3) were prepared at a fixed starch concentration (2.6% w/v) using glycerol as a plasticizer and then compared to a control sample (FSC) prepared with native ulluco starch. The physical, mechanical, and thermal properties of the films were evaluated. The use of ANN starch decreased the solubility (from 21.8% to 19.5%) and the swelling power (from 299% to 153%) of the film samples. In addition, an increase in opacity and relative crystallinity (from 7.54% to 10.5%) were observed. Regarding the thermal properties, all the samples presented high stability to degradation, with degradation temperatures above 200 °C. However, the samples showed deficiencies in their morphology, which affected the barrier properties. The use of ANN starch has some advantages over native starch in preparing films. However, more analysis is needed to improve the barrier properties of the materials. This work reveals the potential of the ANN ulluco starch for biodegradable film preparation. In addition, the use of modified ulluco starch is an alternative to add value to the crop, as well as to replace non-biodegradable materials used in the preparation of packaging.

Molecular Modeling Approaches Can Reveal the Molecular Interactions Established between a Biofilm and the Bioactive Compounds of the Essential Oil of Piper divaricatum

Molecular modeling approaches are used in a versatile way to investigate the properties of diverse organic and inorganic structures such as proteins, biomolecules, nanomaterials, functionalized nanoparticles, and membranes. However, more detailed studies are needed to understand the molecular nature of interactions established in gelatin biofilms impregnated with bioactive compounds. Because of this, we used computational methods to evaluate how the major compounds of Piper divaricatum essential oil can interact with the gelatin biofilm structure. For this, we used as inspiration the paper published, where various properties of the essential oil impregnated gelatin biofilm P. divaricatum are reported. After our computer simulations, we related our molecular observations to biofilm’s structural and mechanical properties. Our results suggest that the major compounds of the essential oil were able to interrupt intermolecular interactions between the chains of the biofilm matrix. However, the compounds also established interactions with the amino acid residues of these chains. Our molecular analyses also explain changes in the structural and mechanical properties of the essential oil-impregnated biofilm. These results can support the planning of functional packaging impregnated with bioactive compounds that can protect food against microorganisms harmful to human health.

Edible Polymers and Secondary Bioactive Compounds for Food Packaging Applications: Antimicrobial, Mechanical, and Gas Barrier Properties

Edible polymers such as polysaccharides, proteins, and lipids are biodegradable and biocompatible materials applied as a thin layer to the surface of food or inside the package. They enhance food quality by prolonging its shelf-life and avoiding the deterioration phenomena caused by oxidation, humidity, and microbial activity. In order to improve the biopolymer performance, antimicrobial agents and plasticizers are also included in the formulation of the main compounds utilized for edible coating packages. Secondary natural compounds (SC) are molecules not essential for growth produced by some plants, fungi, and microorganisms. SC derived from plants and fungi have attracted much attention in the food packaging industry because of their natural antimicrobial and antioxidant activities and their effect on the biofilm's mechanical properties. The antimicrobial and antioxidant activities inhibit pathogenic microorganism growth and protect food from oxidation. Furthermore, based on the biopolymer and SC used in the formulation, their specific mass ratio, the peculiar physical interaction occurring between their functional groups, and the experimental procedure adopted for edible coating preparation, the final properties as mechanical resistance and gas barrier properties can be opportunely modulated. This review summarizes the investigations on the antimicrobial, mechanical, and barrier properties of the secondary natural compounds employed in edible biopolymer-based systems used for food packaging materials.

Regulating the Physicochemical Properties of Chitosan Films through Concentration and Neutralization

Chitosan offers real potential for use in food preservation, biomedicine, and environmental applications due to its excellent functional properties, such as ease in the fabrication of large films, biocompatibility, and antibacterial properties. However, the production and application of chitosan films were limited by their strong residual acetic acid taste, weak mechanical properties, and poor water vapor barrier properties. In this study, the effects of the chitosan concentration in the film-forming solutions and the neutralization treatment on the physicochemical properties of chitosan films were examined. The results demonstrated that the chitosan concentration affected the mechanical and barrier properties of chitosan films without the neutralization treatment. This was mainly due to the low acetic acid contents in chitosan films after drying. Acetic acid acted as a plasticizer within chitosan films resulting in a looser network structure. After neutralization, the chitosan films showed improvements in properties, with little effect on the chitosan concentration in the film-forming solutions. Moreover, chitosan films after neutralization showed no residual acetic acid. Therefore, neutralization could effectively improve the performance of chitosan films.

Fabrication, characterization, and performance of antimicrobial alginate-based films containing thymol-loaded lipid nanoparticles: Comparison of nanoemulsions and nanostructured lipid carriers

Antimicrobial biopolymer films were prepared by incorporating thymol-loaded nanostructured lipid carriers (NLC) or nanoemulsions (NE) into Ca-alginate solutions. Thymol-loaded-NLCs with thymol/lipid mass ratios of 0.1 and 0.2 were prepared and then used to fabricate NLC/alginate films containing either 20% (NLC20 film) or 10% (NLC10 film) of NLCs. Consequently, these two films had the same total thymol mass fraction: R _{thymol/alginate} = 0.02. A nanoemulsion-loaded film (NE film) containing the same amount of thymol and a neat alginate film (control) were also prepared. Incorporation of the NLCs increased the porosity and surface roughness, thickness, water vapor permeability, and yellowness of the films, but decreased their water contact angle, mechanical strength, and swelling ratio. The release of thymol into the air and into water-ethanol solutions was slower for NLC-loaded than NE-loaded films, moreover being slower for the NLC20 than NLC10 films. The antimicrobial activity of the active films was tested on ground beef samples. Their antimicrobial activity was correlated to their release rates, with the NLC20 film giving the longest protection against the enumerated microorganisms. Our results show that encapsulating antimicrobial essential oils within NLCs was more effective at creating antimicrobial films with sustained release properties than encapsulating them within NEs.

Functional Properties and Preservative Effect of P-Hydroxybenzoic Acid Grafted Chitosan Films on Fresh-Cut Jackfruit

In the present study, p-hydroxybenzoic acid-grafted chitosan (PA-g-CS) conjugates with different grafting degrees were synthesized by a free radical-regulated grafting approach. The conjugates were further developed into films by casting, and their characteristics and preservative effects on fresh-cut jackfruit were evaluated. Compared to the CS film, the PA-g-CS film showed comprehensive performance improvements, including enhancements of water solubility, anti-ultraviolet capacity, antioxidation, and antibacterial activity. Moreover, compared with CS film, some appreciable and favorable changes of physical properties were observed in the PA-g-CS films, which included water vapor permeability, oxygen permeability, surface morphology, moisture content, and mechanical intensity. Furthermore, compared to CS alone, the application of PA-g-CS films to fresh-cut jackfruit exerted a beneficial effect on the quality of products, as indicated by the inhibition of weight loss, softening, and membrane damage, the maintenance of soluble solids and ascorbic acids contents, as well as a reduced bacterial count and a higher sensory score. Among these PA-g-CS films, the best preservation effect was achieved with the highest degree of grafting (PA-g-CS III). The results suggested that the PA-g-CS film has the potential to be explored as a new type of packaging material for the preservation of fresh-cut fruits and vegetables.

Physical and Mechanical Characteristics of Gelatin-Based Films as a Potential Food Packaging Material: A Review

This review discusses the potential application of gelatin-based film as biodegradable food packaging material from various types of gelatin sources. The exploitation of gelatin as one of the biopolymer packaging in the food industry has rising interest among researchers as the world becomes more concerned about environmental problems caused by petroleum-based packaging and increasing consumer demands on food safety. Single gelatin-based film properties have been characterized in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as thickness, color, and biodegradability were much influenced by total solid contents in each film. While, for mechanical and light barrier properties, poultry-based gelatin films have shown better properties compared to mammalian and marine gelatin films. This paper detailed the information on gelatin-based film characterization in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as color, UV-Vis absorption spectra, water vapor permeability, thermal, and moisture properties are discussed along with their mechanical properties, including tensile strength and elongation at break.

The Inhibitory Effect of Chitosan Based Films, Incorporated with Essential Oil of Perilla frutescens Leaves, against Botrytis cinerea during the Storage of Strawberries

Reduction in food waste, as well as non-invasive methods for extending the shelf-life of perishable fruits, are important global challenges. To achieve these objectives, in this paper, the use of natural compounds, chitosan films (CS) incorporated with essential oils from leaves, for postharvest fungal protection of strawberries is proposed. In the present study, the CS films incorporated with the essential oil from Perilla frutescens leaves (PFEO) at different concentrations were prepared and employed for packaging strawberries infected by B. cinerea during refrigerated storage at 4 °C for 10 days. Interestingly, the strawberries coated with CS films containing PFEO at 1.0% during this period possessed an effective antimicrobial effect against B. cinerea infection in potato dextrose agar (PDA). Moreover, the quality properties of the strawberries, (i.e., weight loss, firmness index, decay percentage, yeasts/molds, pH value, total soluble solids, titrable acidity, and maturity index), together with the sensory attributes (i.e., appearance, flavor, taste, and overall acceptability (p < 0.05 or p < 0.01)) were improved. These results demonstrated that (i) PFEO displayed a significant inhibitory effect against B. cinerea infection in strawberries, (ii) CS films containing PFEO at 1.0% could be a sustainable active food packaging for the refrigerated storage of strawberries.

Chitosan/zein bilayer films with one-way water barrier characteristic: Physical, structural and thermal properties

Chitosan (C) and zein (Z) were used to develop bilayer films with a characteristic one-way water barrier using a layer-by-layer (LBL) casting method. The effects of mass ratios (C:Z1:1, C:Z1:2, C:Z1:3, C:Z3:1, C:Z2:1) on the microstructure and physicochemical properties of bilayer films were investigated. Bilayer films had uniform microstructures, and C:Z = 1:3 showed a firmer structure as the Z aggregates were distributed in the continuous phase of C. The intermolecular interactions between the C and Z layers were observed using FTIR and XRD analysis. TGA demonstrated that adding Z layer enhanced the thermal stability of C films. LBL coating gave the C/Z bilayer film an increased elongation and tensile strength, as well as a decreased water vapor and oxygen permeability, especially for C:Z = 1:3 which had better properties. The results suggested that C and Z bilayer films may be a promising material for food packaging with the desired water resistance.

Fish Gelatin: Current Nutritional, Medicinal, Tissue Repair Applications and Carrier of Drug Delivery

Gelatin is obtained via partial denaturation of collagen and is extensively used in various industries. The majority of gelatin utilized globally is derived from a mammalian source. Several health and religious concerns associated with porcine/bovine gelatin were reported. Therefore, gelatin from a marine source is widely being investigated for its efficiency and utilization in a variety of applications as a potential substitute for porcine/bovine gelatin. Although fish gelatin is less durable and possesses lower melting and gelling temperatures compared to mammal-derived gelatin, various modifications are being reported to promote its rheological and functional properties to be efficiently employed. The present review describes in detail the current innovative applications of fish gelatin involving the food industry, drug delivery and possible therapeutic applications. Gelatin bioactive molecules may be utilized as carriers for drug delivery. Due to its versatility, gelatin can be used in different carrier systems, such as microparticles, nanoparticles, fibers and hydrogels. The present review also provides a perspective on the other potential pharmaceutical applications of fish gelatin, such as tissue regeneration, antioxidant supplementation, antihypertensive and anticancer treatments.

Natural Polymers Used in Edible Food Packaging—History, Function and Application Trends as a Sustainable Alternative to Synthetic Plastic

In this review, a historical perspective, functional and application trends of natural polymers used to the development of edible food packaging were presented and discussed. Polysaccharides and proteins, i.e., alginate; carrageenan; chitosan; starch; pea protein, were considered. These natural polymers are important materials obtained from renewable plant, algae and animal sources, as well as from agroindustrial residues. Historically, some of them have been widely used by ancient populations for food packaging until these were replaced by petroleum-based plastic materials after World War II. Nowadays, biobased materials for food packaging have attracted attention. Their use was boosted especially because of the environmental pollution caused by inappropriate disposal of plastic packaging. Biobased materials are welcome to the design of food packaging because they possess many advantages, such as biodegradability, biocompatibility and low toxicity. Depending on the formulation, certain biopolymer-based packaging may present good barrier properties, antimicrobial and antioxidant activities Thus, polysaccharides and proteins can be combined to form diverse composite films with improved mechanical and biological behaviors, making them suitable for packaging of different food products.

Active and Robust Composite Films Based on Gelatin and Gallic Acid Integrated with Microfibrillated Cellulose

BACKGROUND

Gelatin is a renewable, biodegradable, and inexpensive food polymer. The insufficient mechanical and functional properties of gelatin-based films (GBF) restrict their commercial application in food packaging. This work proposed a facile strategy to prepare an active and robust GBF that has the potential to be used in food packaging.

METHODS

A strong and active GBF was prepared based on the principle of supramolecular chemistry via the incorporation of gallic acid (GA) as an active crosslinking agent and of microfibrillated cellulose (MFC) as a reinforcing agent.

RESULTS

Under the appropriate concentration (1.0 wt%), MFC was evenly dispersed in a gelatin matrix to endow the film with low surface roughness and compact structure. Compared with the GF, the tensile strength and elongation at break of the resultant film reached 6.09 MPa and 213.4%, respectively, representing the corresponding improvement of 12.8% and 27.6%. Besides, a significantly improved water vapor barrier (from 3.985 × 10^-8 to 3.894 × 10^-8 g·m^-1·Pa^-1·s^-1) and antioxidant activity (from 54.6% to 86.4% for ABTS radical scavenging activity; from 6.0% to 89.1% for DPPH radical scavenging activity) of GBFs were also observed after introducing the aromatic structure of GA and nano-/microfibrils in MFC. Moreover, the UV blocking performance and thermal stability of GGF and GGCFs were also enhanced.

CONCLUSIONS

this work paves a promising way toward facile preparation of multifunctional GBFs that have great potential to be used in fabricating active and safe food packaging materials for food preservation.