A novel biopolymeric composite edible film based on sunnhemp protein isolate and potato starch incorporated with clove oil: Fabrication, characterization, and amino acid composition.

Composite edible films were developed by casting method using sunnhemp protein isolate (SHPI) and potato starch (PS) at various proportions (100:0, 90:10, 80:20; 70:30, 60:40, and 50:50) containing glycerol as a plasticizer and clove oil. All the edible films were evaluated for thickness, moisture content, solubility, swelling ratio, water activity. Further characterization of edible films was done on the basis of mechanical, optical, thermal and structural attributes along with morphology. Among all the films, composite film containing 50 % SHPI, 50 % PS and 1 % clove oil were having better characteristics. The solubility and WVP decreased, while the tensile strength and elongation at break of composite film increased with the inclusion of potato starch and clove oil. Intermolecular interactions in the composite film matrix were confirmed by FTIR and XRD analysis. SEM images confirmed the structural compactness and integrity of all the developed films. The amino acid composition of edible films indicated presence of most of the essential amino acids. The present finding of this research work shows that the utilization of sunnhemp protein in the development of biocomposite edible films represents an alternative opportunity of sustainable edible food packaging.

Antimicrobial activity of chitosan- edible films containing a combination of carvacrol and rosemary nano-emulsion against Salmonella enterica serovar Typhimurium and Listeria monocytogenes for ground meat.

This research aimed to assess the potential of active food packaging as an innovative approach to enhance the quality of fresh food products. Specifically, our focus was on developing chitosan edible films combined with rosemary nanoemulsion (Ch-RNE) and carvacrol nano-emulsion (Ch-CNE) as effective antibacterial food packaging solutions. The efficacy of these films against artificially inoculated L. monocytogenes (NCTC 13372\ ATCC® 7644) as a Gram-positive bacterium, and S. enterica serovar Typhimurium (ATCC 14028) as a Gram-negative bacterium, in ground meat was investigated. The size of the prepared nano-emulsions was characterized using zeta sizer, FTIR and HRTEM. The MIC of both nano-emulsions against both pathogens was found to be 0.78 % and 1.56 %. Filmogenic mixtures were casted using these concentrations, which were then dried and evaluated for their physical and mechanical properties.

Physicochemical and thermal characterization of the edible shellac films incorporated with oleic acid to enhance flexibility, water barrier and retard aging.

In this work, shellac plasticized with oleic acid was solvent cast to prepare the flexible and water-resistant film for packaging applications. The films were prepared with varying amounts of oleic acid and studied in detail for appearance, surface morphology, thermal, chemical, barrier, mechanical, and robustness. The surface morphology confirmed the smooth surface of films up to SH-OA20 (100:20 w/w; shellac: oleic acid). Fourier-transform infrared spectroscopy confirmed that oleic acid reduced the hydrogen bonding of the shellac matrix to provide a plasticization effect. Also, the thermal analysis showed a reduction in the melting enthalpy. Moreover, the plasticized films had a better barrier to water vapor due to increased smoothness and reduction in brittleness. Adding oleic acid also increased the elongation at break up to 40 % without any changes in tensile strength. The flexibility of the films increased with the oleic acid content, making them resistant to burst, crumbling, bending, rolling, and stretching. Oleic acid also showed the retardation of aging and thermal aging of shellac. In the future, the long-term stability and migration of the films can be investigated.

Fenugreek seed mucilage-based active edible films for extending fresh fruit shelf life: Antimicrobial and physicochemical properties.

Trigonella foenum-graecum, known as fenugreek, belongs to the leguminous family of wild growth in Western Asia, Europe, the Mediterranean, and Asia; its ripe seeds contain a pool of bioactive substances with great potential in the food industry and medicine. In this study, fenugreek seed mucilage (FSM) was extracted and characterized in its structural properties by X-ray diffraction, nuclear magnetic resonance, and high-performance liquid chromatography. Then, the applicability of FSM as an antimicrobial agent was demonstrated via the development of novel, active, edible FSM-based biofilms containing carboxymethyl cellulose and rosemary essential oil (REO). Incorporating REO in the biofilms brought about specific changes in Fourier-transform infrared spectra, affecting thermal degradation behavior. Scanning electron microscopy and atomic force microscopy morphography showed an even distribution of REO and smoother surfaces in the loaded films. Besides, the solubility tests evidenced a reduction in water solubility with increasing REO concentration from 1 to 3 wt%. The biological assay evidenced the antimicrobial activity of REO-loaded biofilms against Staphylococcus aureus and Escherichia coli. Finally, whole apples were dip-coated with FSM-based solutions to showcase future edible systems. The REO-loaded biofilms extended the shelf life of apples to 30 days, demonstrating their potential for sustainable and active coatings.

Biopolymer-based packaging films/edible coatings functionalized with ε-polylysine: New options for food preservation.

In light of the commendable advantages inherent in natural polymers such as biocompatibility, biodegradability, and cost-effectiveness, researchers are actively engaged in the development of biopolymer-based biodegradable food packaging films (BFPF). However, a notable limitation is that most biopolymers lack intrinsic antimicrobial activity, thereby restricting their efficacy in food preservation. To address this challenge, various active substances with antibacterial properties have been explored as additives to BFPF. Among these, ε-polylysine has garnered significant attention in BFPF applications owing to its outstanding antibacterial properties. This study provides a brief overview of the synthesis method and chemical properties of ε-polylysine, and comprehensively examines its impact as an additive on the properties of BFPF derived from diverse biopolymers, including polysaccharides, proteins, aliphatic polyesters, etc. Furthermore, the practical applications of various BFPF functionalized with ε-polylysine in different food preservation scenarios are summarized. The findings underscore that ε-polylysine, functioning as an antibacterial agent, not only directly enhances the antimicrobial activity of BFPF but also serves as a cross-linking agent, interacting with biopolymer molecules to influence the physical and mechanical properties of BFPF, thereby enhancing their efficacy in food preservation.

Milk-derived antimicrobial peptides incorporated whey protein film as active coating to improve microbial stability of refrigerated soft cheese.

Nisin is the first FDA-approved antimicrobial peptide and shows significant antimicrobial activity against Gram-positive bacteria, but only a weakly inhibitory effect on Gram-negative bacteria. The aim of this study was to prepare whey protein-based edible films with the incorporation of milk-derived antimicrobial peptides (αs2-casein151-181 and αs2-casein182-207) and compare their mechanical properties and potential application in cheese packaging with films containing nisin. These two antimicrobial peptides showed similar activity against B. subtilis and much higher activity against E. coli than bacteriocin nisin, representing that these milk-derived peptides had great potential to be applied as food preservatives. Antimicrobial peptides in whey protein films caused an increase in film opaqueness and water vapor barrier properties but decreased the tensile strength and elongation at break. Compared to other films, the whey protein film containing αs2-casein151-181 had good stability in salt or acidic solution, as evidenced by the results from scanning electron microscope and Fourier transform infrared spectroscopy. Whey protein film incorporated with αs2-casein151-181 could inhibit the growth of yeasts and molds, and control the growth of psychrotrophic bacteria present originally in the soft cheese at refrigerated temperature. It also exhibited significant inhibitory activity against the development of mixed culture (E. coli and B. subtilis) in the cheese due to superficial contamination during storage. Antimicrobial peptides immobilized in whey protein films showed a higher effectiveness than their direct application in solution. In addition, films containing αs2-casein151-181 could act as a hurdle inhibiting the development of postprocessing contamination on the cheese surface during the 28 days of storage. The films in this study exhibited the characteristics desired for active packaging materials.

Plant polysaccharide-derived edible film packaging for instant food: Rapid dissolution in hot water coupled with exceptional mechanical and barrier characteristics.

A comprehensive multiscale analysis was conducted to explore the effects of different ratios of these materials on its properties. The results show that KC played a crucial role in controlling solution viscosity and gel and sol temperatures. The dissolution time at high water temperatures primarily decreased with an increase in SA content. Higher KC and CS content increased tensile strength (TS) and elongation at break (ε), while also exhibiting better thermal stability. Water vapor transmission (WVT) and permeability (PV) initially decreased, then increased with the increase of SA and CS contents. Finally, an SA:KC:CS ratio of 1:3:2 showed optimal comprehensive properties, with a dissolution time of about 60.0 ± 3.8 s, TS of 23.80 ± 0.29 MPa, ε of 18.61 ± 0.34 %, WVT of 21.74 ± 0.62 g/m2·24h, and PV of 5.39 ± 0.17 meq/kg. Meanwhile, the SA:KC:CS edible food packaging only introduced minimal effects on food after dissolution, and the total bacterial count met regulatory standards.

Ozone-activated lignocellulose films blended with chitosan for edible film production.

This work focuses on the influence of ozone pretreatment on the fractionation and solubilization of sugarcane bagasse and soda bagasse pulp fibers in sodium hydroxide/urea solution, as well as the application of regenerated cellulose for producing edible films. The methodology involved pretreating lignocelluloses with ozone for 20 to 120 min before dissolving in sodium hydroxide/urea solution. The influence of the pretreatment conditions on cellulose dissolution yield was investigated. Regenerated cellulose films were then formed, with and without the addition of 2 % chitosan. Mechanical, physical, structural, thermal, and antimicrobial attributes were determined as a function of ozonation conditions of raw materials and chitosan content. The findings exhibited positive effects of short ozonation on enhancing mechanical strength, cohesion, and hydrophobicity. The prolonged ozonation of 120 min demonstrated optimal improvements in continuity, swelling, and antibacterial resistance of obtained films. Incorporating chitosan enhanced tensile performance, stiffness, and vapor barriers but increased moisture absorption. Tailoring the activation of biomass through ozone pretreatment and chitosan addition resulted in renewable films with adjustable properties to meet diverse packaging requirements, particularly for fruit protective coatings, ensuring the preservation of post-harvest quality.

Polysaccharide- and protein-based edible films combined with microwave technology for meat preservation.

To reduce food-borne bacterial infection caused by food spoilage, developing highly efficient food packing film is still an urgent need for food preservation. Herein, microwave-assisted antibacterial nanocomposite films CaO2@PVP/EA/CMC-Na (CP/EC) were synthesized using waste eggshell as precursor, egg albumen (EA) and sodium carboxymethylcellulose (CMCNa) as matrix by casting method. The size of CaO2@PVP (CP) nanoparticles with monodisperse spherical structures was 100-240 nm. When microwave and CP nanoparticles (0.05 mg/mL) were treated for 5 min, the mortality of E. coli and S. aureus could reach >97 %. Under microwave irradiation (6 min), the bactericidal rate of 2.5 % CP/EC film against E. coli and S. aureus reached 98.6 % and 97.2 %, respectively. After adding CP nanoparticles, the highest tensile strength (TS) and elongation at break (EB) of CP/EC film reached 19.59 MPa and 583.43 %, respectively. At 18 °C, the proliferation of bacterial colonies on meat can be significantly inhibited by 2.5 % CP/EC film. Detailed characterization showed that the excellent meat preservation activity was due to the synergistic effect of dynamic effect generated by ROS and thermal effect of microwave. This study provides a promising approach for the packaging application of polysaccharide- and protein-based biomass nanocomposite antibacterial edible films.

Properties of modified chitosan-based films and coatings and their application in the preservation of edible mushrooms: A review.

Edible mushrooms are prone to deteriorate during storage. A Single chitosan film or coating has limitations in preservation. Therefore, this article focused on the improvement of modified chitosan-based films and coatings on properties related to storage quality of edible mushrooms (e.g.: safety, barrier, mechanical, antioxidant and antibacterial properties). Besides, the application of chitosan-based materials in the preservation of mushrooms was also discussed. The modified chitosan film and coating can slow down the respiration of mushrooms, inhibit the growth of microorganisms, protect antioxidant compositions, and regulate the activity of related enzymes, thus improving the quality and prolonging the shelf life of mushrooms. Meanwhile, the added ingredients improve the water and gas barrier properties of chitosan through volume and group occupation, and reduce the light transmittance of chitosan through light transmission, scattering and absorption. Essential oils and polyphenolic compounds had a better enhancement of antioxidant and antimicrobial properties of chitosan.

UV blocking edible films based on corn starch/moringa gum incorporated with pine cone extract for sustainable food packaging.

Corn starch (CS) is a good alternative to synthetic polymers due to its sustainability; nevertheless, because of its weak tensile strength, the matrix requires another polymer. Therefore, 0.5 % (w/v) moringa gum (MG) was added. The purpose of this study was to assess how pine cone extract (PCE) affected the physiochemical and mechanical properties of corn starch and moringa gum (CS/MG) films and their use as UV-blocking composites. The findings suggest that the PCE improved the elongation at break from 3.27 % to 35.2 % while greatly reducing the tensile strength. The hydrogen bonding between CS/MG and PCE was visible in the FTIR spectra. The XRD graph indicated that the films were amorphous. In comparison to CS/MG films, PCE-incorporated edible films demonstrated significant UV-blocking ability indicating their potential as sustainable packaging material for light-sensitive food products.

Citric acid crosslinked carboxymethyl cellulose edible films: A case study on preserving freshness in bananas.

The study involves the preparation and characterization of crosslinked-carboxymethyl cellulose (CMC) films using varying amounts of citric acid (CA) within the range 5 %-20 %, w/w, relative to the dry weight of CMC. Through techniques such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, carbonyl content analysis, and gel fraction measurements, the successful crosslinking between CMC and CA is confirmed. The investigation includes an analysis of chemical structure, physical and optical characteristics, swelling behavior, water vapor transmission rate, moisture content, and surface morphologies. The water resistance of the cross-linked CMC films exhibited a significant improvement when compared to the non-crosslinked CMC film. The findings indicated that films crosslinked with 10 % CA demonstrated favorable properties for application as edible coatings. These transparent films, ideal for packaging, prove effective in preserving the quality and sensory attributes of fresh bananas, including color retention, minimized weight loss, slowed ripening through inhibiting amyloplast degradation, and enhanced firmness during storage.

Edible film preparation by anthocyanin extract addition into acetylated cassava starch/sodium carboxymethyl cellulose matrix for oxidation inhibition of pumpkin seeds.

In this study, an edible film was fabricated by incorporating anthocyanin extract from black rice (AEBR) into acetylated cassava starch (ACS)/carboxymethyl-cellulose (CMC) to enhance the shelf life of pumpkin seeds. The effects of AEBR on the rheological properties of film-forming solutions, as well as the structural characterization and physicochemical properties of the film, were evaluated. Rheological properties of solutions revealed that AEBR was evenly dispersed into polymer matrix and bound by hydrogen bonds, as confirmed by Fourier transform infrared spectroscopy analysis. The appropriate AEBR addition could be compatible with polymer matrix and formed a compact film structure, improving the mechanical properties, barrier properties, and opacity. However, with further addition of AEBR, the tensile strength and water vapor permeability decreased and the tight structure was destroyed. After being stored separately under thermal and UV light accelerated conditions for 20 days, the peroxide value and acid value of roasted pumpkin seeds coated with the AEBR film showed a significant reduction. Moreover, the storage stability of AEBR was improved through the embedding of ACS/CMC biopolymers. These results indicated that AEBR film could effectively delay pumpkin seeds oxidation and prolong their shelf life as an antioxidant material.

Innovative food-upcycling solutions: Comparative analysis of edible films from kimchi-extracted cellulose, sorbitol, and citric acid for food packaging applications.

In this study, kimchi-extracted cellulose was utilized to fabricate edible films using a hot synthetic approach, followed by solvent casting, and employing sorbitol and citric acid as the plasticizer and crosslinker, respectively. The chemical, optical, physical, and thermal properties of these films were explored to provide a comparative assessment of their suitability for various packaging applications. Chemical analyses confirmed that the kimchi-extracted cellulose comprised cellulose Iß and amorphous cellulose and did not contain any impurities. Optical analyses revealed that kimchi-extracted cellulose-containing films exhibited better-dispersed surfaces than films fabricated from commercial cellulose. Physical property analyses indicated their hydrophilic characteristics with contact angles <20°. In the thermal analysis, similar Tg results confirmed the comparable thermal stability between films containing commercial microcrystalline cellulose-containing films and kimchi-extracted cellulose-containing films. Edible films produced from kimchi-extracted cellulose through food-upcycling approaches are therefore promising for applications as packaging materials.

Valorization of edible films based on chitosan/hydroxyethyl cellulose/olive leaf extract and TiO2-NPs for preserving sour cream.

Biodegradable edible films for sour cream packaging were developed based on chitosan (CS), hydroxyethyl cellulose (HEC), Olive leaf extract (OE), and titanium dioxide nanoparticles (TiO2-NPs). The prepared CS/HEC/TiO2-OE bionanocomposite films were evaluated for their antimicrobial and antioxidant activities as well as using FT-IR, mechanical, permeability, and contact angle. The effect of developed films on the lipid oxidation, microbiological load, and chemical properties of sour cream was investigated. The fabricated films had an antimicrobial impact against all tested strains. The film containing 8 % OE showed effective protection against fat oxidation, with a peroxide value of 3.21 meq O2/kg, a para-anisidine value 5.40, and free fatty acids of 0.82 mg KOH/kg. The films with OE 4 % and 8 % have a good effect on the microbiological load of sour cream for 90 days. These films did not influence the chemical composition of sour cream and therefore can be used in this sort of dairy product.

Consumer perception and acceptance of edible packaging for various food products.

Excessive use of single-use plastic packaging presents an imminent threat to the environment. One of the emerging solutions is using edible food packaging. However, there is lack of consumer information toward edible packaging. This study evaluated consumer attitude, acceptability, and purchase intent of three types of edible food packaging: muffin liner, cranberry pomace fruit leather wrap, and powdered drink sachet. One hundred consumers who frequently consumed muffins, strawberry fruit leather, and powdered lemonade were selected from metropolitan area of Portland, Oregon to participate in the study. The panelists were presented with the edible films and the food products with the edible packaging, information card highlighting the environmental-friendly edible package, and were prompted with describing the sensory attributes, purchase intent, and qualities regarding the edible packaging with and without food. Overall, panelists liked the three foods with the edible packaging giving overall liking scores of 7.48, 8.06, and 7.48 for the muffin liners, edible fruit leather wraps, and powdered drink sachets, respectively, based on a 9-point hedonic scale where 1 = dislike extremely and 9 = like extremely. When asked about hypothetical purchase intent, 64%-68% of panelists positively reacted to purchase intent and would buy all three types of edible packaging products. Based on the positive reaction from panelists, edible packaging maybe a possible solution to reducing single-use plastic packaging in the food industry. This study can be the catalyst for further investigation of the efficacy of different applications of edible food packaging as well as consumer perceptions of eating their packaging. PRACTICAL APPLICATION: Edible food packaging is an emerging solution for reducing single-use plastic waste. This study investigated consumer attitude, acceptability, and purchase intent of edible food packaging for three food packaging applications, including edible muffin liner, fruit leather wrap, and powdered drink sachet. This study demonstrated that consumers strongly agree that edible packaging would serve as an environmentally sustainable solution to single-use plastics, and are willing to spend more to purchase these sustainable alternatives. This study provides new information toward the future development of edible packaging and consumer perceptions of eating their packaging.

Revolutionizing tropical fruits preservation: Emerging edible coating technologies.

Tropical fruits, predominantly cultivated in Southeast Asia, are esteemed for their nutritional richness, distinctive taste, aroma, and visual appeal when consumed fresh. However, postharvest challenges have led to substantial global wastage, nearly 50 %. The advent of edible biopolymeric nanoparticles presents a novel solution to preserve the fruits' overall freshness. These nanoparticles, being edible, readily available, biodegradable, antimicrobial, antioxidant, Generally Recognized As Safe (GRAS), and non-toxic, are commonly prepared via ionic gelation owing to the method's physical crosslinking, simplicity, and affordability. The resulting biopolymeric nanoparticles, with or without additives, can be employed in basic formulations or as composite blends with other materials. This study aims to review the capabilities of biopolymeric nanoparticles in enhancing the physical and sensory aspects of tropical fruits, inhibiting microbial growth, and prolonging shelf life. Material selection for formulation is crucial, considering coating materials, the fruit's epidermal properties, internal and external factors. A variety of application techniques are covered such as spraying, and layer-by-layer among others, including their advantages, and disadvantages. Finally, the study addresses safety measures, legislation, current challenges, and industrial perspectives concerning fruit edible coating films.

The dual function of calcium ion in fruit edible coating: Regulating polymer internal crosslinking state and improving fruit postharvest quality.

The edible coating is proved to be a convenient approach for fruit preservation. Among these published explorations, naturally sourced macromolecules and green crosslinking strategies gain attention. This work centers on edible coatings containing Ca2+ as crosslinker for the first time, delving into crosslinking mechanisms, include alginate, chitosan, Aloe vera gel, gums, etc. Additionally, the crucial functions of Ca2+ in fruit's quality control are also elaborated in-depth, involving cell wall, calmodulin, antioxidant, etc. Through a comprehensive review, it becomes evident that Ca2+ plays a dual role in fruit edible coating. Specifically, Ca2+ constructs a three-dimensional dense network structure with polymers through ionic bonding. Moreover, Ca2+ acts directly with cell wall to maintain fruit firmness and serve as a second messenger to participate secondary physiological metabolism. In brief, coatings containing Ca2+ present remarkable effects in preserving fruit and this work may provide guidance for Ca2+ related fruit preservation coatings.

Active whey protein/hydroxypropyl methylcellulose edible films incorporated with cinnamaldehyde: Characterization, release kinetics and application to Mongolian cheese preservation.

Edible films with modulated release of antimicrobial agents are important for food preservation. Herein, antimicrobial edible films were prepared using whey protein (WP) and hydroxypropyl methylcellulose (HM) as polymer matrix materials and cinnamaldehyde (CIN) as antimicrobial agent. The mass ratios of WP and HM were 100/0, 75/25, 50/50, 25/75 and 0/100. The release kinetics of CIN through the film was studied, applying the Fickian model, power law and Weibull model. The films were also characterized by physical and structural characteristics, and antibacterial activity. In comparison to other films, the CIN-loaded film with a WP/HM ratio of 50/50 had better moisture resistance, water vapor barrier properties and mechanical properties. High correlation factors were obtained by fitting the CIN release data with the power law (R2 > 0.96) and Weibull model (R2 > 0.97). The diffusion mechanism of CIN was pseudo-Fickian. The diffusion coefficients (D1 and D2) had a positive linear relationship with the HM ratio, suggesting that a high HM ratio was beneficial to the CIN release. Finally, the WH50-C film was successfully used to preserve Mongolian cheese. This research provides a new perspective on the design of active packaging film with sustained-release characteristics.

Fabrication and characterization of emulsion-based edible film containing cinnamon essential oil using chia seed mucilage.

Chia seed mucilage (CSM) film incorporated with 2, 4, and 6 % (w/w) nanoemulsion of cinnamon essential oil (CSM-2, CSM-4, CSM-6) were developed, and their physicochemical, mechanical, antioxidant, and antimicrobial properties were determined. According to the results, cinnamon EO nanoemulsion (CEN) had droplet size 196.07 ± 1.39 nm with PDI 0.47 ± 0.04. Moreover, CSM film had higher water solubility (99.37 ± 0.05 %) and WVP (8.55 ± 1.10 g/kPa h m2) than reinforced CSM films with CENCEN. The lowest water solubility (98.02 ± 0.01 %) and WVP (3.75 ± 0.80 g/kPa h m2) was observed in CSM-6 film. Moreover, the addition of CEN improved the homogeneity and density of films and the smoothness of the surface, being observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The Fourier transform infrared (FTIR) spectroscopy also confirmed the incorporation of CEN within the film matrix. The CSM films' antioxidant (DPPH radical scavenging power) and antimicrobial (against Escherichia coli and Staphylococcus aureus) properties of CSM films were notably enhanced with the inclusion of CEN in a dose-dependent manner. The mechanical (tensile strength and elongation at break) of CSM films also was affected by the addition of CEN, TS decreased, and EAB increased (p < 0.05). The lowest TS (20.63 ± 1.39 MPa) and highest EAB (3.36 ± 0.61 %) was observed in CSM-4 film. However, CSM film was relatively dark with low opacity, and adding CEN slightly increased lightness (L*) and yellowness (b*) parameters. The superior antioxidant and barrier characteristics of the CSM edible film incorporated with CEN make it a potential candidate for product packaging and shelf-life extension.