Characterization of edible film containing essential oils in hydroxypropyl methylcellulose and its effect on quality attributes of ‘Formosa’ plum (Prunus salicina L.)

Next-Generation Edible Packaging: Development of Water-Soluble, Oil-Resistant, and Antioxidant-Loaded Pouches for Use in Noodle Sauces

The development of sustainable biodegradable packaging materials is essential for enhancing food quality and shelf life while reducing plastic waste. This study explored polymer-based monolayer, composite, and bilayer films to produce water-soluble, oil-proof pouches. Single-serving seasoning oil pouches were prepared from bilayer films with polyvinyl alcohol (PVA) as the inner and sodium alginate (SA) as the outer layer. The PVA/SA films exhibited excellent UV protection, low oil permeability (0.18 × 10-6 g·mm/mm2·day), hydrophilic surface (water contact angle < 90°), and rapid solubility in hot water (87 ± 2 °C). Incorporating curcumin, a natural antioxidant, into PVA/SA films (Cur-PVA/SA) improved thermal stability, reduced light transmittance, and decreased water vapor permeability (0.28 × 10-10 g/m·Pa·s). Curcumin release followed a biphasic diffusion model, with 94.8% released at 96 h (diffusion coefficient: 1.30 × 10-11 m2/s), ensuring prolonged antioxidant activity. The Cur-PVA/SA pouches delayed lipid oxidation more effectively, with peroxide values of 6.48 and 10.35 meq/kg after 45 days at 35 °C, respectively. The Q10 model, which is commonly used to predict the shelf life of oils based on temperature-dependent oxidation rates, estimated that the oil packaged in Cur-PVA/SA pouches would remain stable for 12 months at 23 °C. This represents a 37% longer shelf life compared to oil packaged in PVA/SA pouches without curcumin. Cur-PVA/SA pouches also reduced noodle moisture migration, limiting weight loss to 2.73% over 14 days compared to 5.80% in controls. These findings highlight their potential as eco-friendly active packaging solutions.

Films of polylactic acid with graphene oxide-zinc oxide hybrid and Mentha longifolia essential oil: Effects on quality of refrigerated chicken fillet

This study was conducted to investigate the morphological, thermal, mechanical, FTIR, physicochemical (thickness, humidity, solubility in water and water vapor permeability) and antimicrobial properties of polylactic acid film (PLA) containing hybrid graphene oxide‑zinc oxide (GO-ZnO: 1.5 % w/v) and Mentha longifolia essential oil (ML:1 % v/v) on chicken fillet kept in the refrigerator. The studied groups were microbially (total count of mesophilic aerobic bacteria, psychrotrophic bacteria, Enterobacteriaceae, Staphylococcus aureus, and lactic acid bacteria), chemically (pH, TVB-N) and sensory (color, odor, and taste) evaluated at 8-day interval (0, 2, 5 and 8). In the examination of the morphological characteristics, the PLA film had a smooth and uniform surface and the addition of ML essential oil created a discontinuous structure and the addition of GO-ZnO led to the production of a denser and more homogeneous film. The presence of GO-ZnO increased the thickness, decreased moisture content and solubility in water, and added ML essential oil increased moisture content and decreased solubility in water (p˂0.05). The results of the mechanical evaluation showed that the addition of ML essential oil and GO-ZnO reduced elongation at break and tensile strength (p˂0.05). The addition of ML essential oil increased the thermal resistance and the addition of GO-ZnO decreased the thermal resistance compared to the film containing ML essential oil. The antimicrobial effect of films containing ML essential oil was confirmed in this study (p˂0.05). The addition of GO-ZnO did not change the count of any of the microbial groups. TVB-N showed that groups containing ML essential oil had lower levels of volatile nitrogenous bases than the control group (p˂0.05). Sensory evaluation of the studied groups showed that chicken fillets packed with films containing ML essential oil had the highest score in terms of color, smell and taste. The results of the present study showed that PLA film containing GO-ZnO and ML essential oil can be used to increase the shelf life and maintain the sensory characteristics of chicken fillets, and it can be used as a suitable packaging to increase the shelf life of food products.

Essential Oils as Alternative Green Broad-Spectrum Biocides

Natural compounds from plants represent suitable options to replace synthetic biocides when employed against microorganisms in various applications. Essential oils (EOs) have attracted increased interest due to their biocompatible and rather innocuous nature, and complex biological activity (fungicide, biocide and anti-inflammatory, antioxidant, immunomodulatory action, etc.). EOs are complex mixtures of derived metabolites with high volatility obtained from various vegetal parts and employed to a great extent in different healthcare (natural cures, nutrition, phyto- and aromatherapy, spices) and cosmetics applications (perfumery, personal and beauty care), as well as in cleaning products, agriculture and pest control, food conservation and active packaging, or even for restauration and preservation of cultural artifacts. EOs can act in synergy with other compounds, organic and synthetic as well, when employed in different complex formulations. This review will illustrate the employment of EOs in different applications based on some of the most recent reports in a systematic and comprehensive, though not exhaustive, manner. Some critical assessments will also be included, as well as some perspectives in this regard.

The physicochemical, mechanical, and antifungal properties of sodium alginate film containing Japanese rice vinegar and peppermint (Mentha piperita) oil as bio-composite packaging

Sodium Alginate has a high demand and is favored for food packaging; however, this film typically exhibits poor antimicrobial activity. In this study, sodium alginate film containing peppermint essential oil, Japanese rice vinegar, or a combination of both, is used to analyze antimicrobial, mechanical, structural, and optical properties. The scanning electron microscopy (SEM) technique is utilized to observe the film's surface and cross-section homogeneity. The addition of peppermint essential oil and Japanese rice vinegar to the alginate film solution improves fungal growth and spore germination prevention. Unlike the film containing vinegar, the film with peppermint essential oil shows the lowest transparency. It also has the lowest tensile strength and exhibits the highest elongation at break and water vapor permeability. Conclusively, the film containing a combination of vinegar and essential oil indicates moderate values. According to AFM topography, the film with a mix of essential oil and vinegar has a smoother, more homogeneous surface than other films. Our results prove that combining vinegar and oil with sodium alginate film is an ideal choice. This combination significantly improves the performance of food packaging.

Preserving plum perfection: Buckwheat starch edible coating with xanthan gum and lemongrass essential oil

The research focused on the fabrication of composite coatings using buckwheat starch (BS) and xanthan gum (XG) with incorporation of lemongrass (Cymbopogon citratus) essential oil (LEO) with varying concentration (0.75 %, 1.0 % and 1.25 % (w/v). BS was extracted from buckwheat groats (Fagopyrum esculentum) and its physico-chemical characteristics were determined. BS showed spherical and polygonal morphology and its XRD pattern was similar to starch extracted from other cereal sources. The amount of reducing sugar, starch and amylose content in extracted BS were 0.99 ± 0.33 %, 86.32 ± 0.22 % and 21.02 ± 1.89 % respectively, which indicates that BS is a suitable base material for the formation of edible coatings. XG was mixed with BS in different ratios (1:1, 2:1, 3:1 and 4:1) to optimize the best ratio of combination for composite coatings. The coating with a ratio of 2:1 was very smooth and was chosen for incorporation of LEO and the coatings physical, functional, mechanical, thermal and micro-structural characteristics were examined. The coating S5 with 1.25 % (w/v) concentration of LEO showed the best results with least moisture content (MC), minimum water vapor permeability (WVP) and maximum contact angle value. Moreover, the S5 formulation had the highest antioxidant (73.3 %) ability and maximum antimicrobial efficiency with inhibition zones of 22.09 ± 0.06 mm and 28.65 ± 0.14 mm against S. aureus and E. coli respectively. The coatings were then coated on plum fruit, and various parameters like weight loss, pH, shrinkage and TSS were calculated every 4th day during the 20 days of refrigeration period. The coated plums' ripening pace was delayed by the S5 formulation which improved moisture retention, maintained the plums' TSS value and overall pH. Therefore, composite coatings made up of BS, XG and 1.25 % (w/v) can be used as a cost-effective bio-active coating material for plum preservation under refrigeration conditions.

Global Research Network Analysis of Edible Coatings and Films for Preserving Perishable Fruit Crops: Current Status and Future Directions

Edible coatings and films have gained substantial attention as a promising and sustainable technology for fruit preservation. This study employed a bibliometric analysis to identify core research areas, research gaps, and emerging trends, thus providing a comprehensive roadmap for future research on the use of edible coatings and films for fruit quality preservation. The study involved 428 research articles related to edible coatings and films for fruit preservation published in the Scopus database before 06 October 2023. Utilizing Vosviewer and R for network analysis, we generated network visualization maps, research performance statistics, and identified key contributors and their collaborations. The results show the evolution of this field into three distinct phases: Initial Exploration (1998-2007), Growing Interest (2008-2015), and Rapid Expansion (2016-2023). The study revealed contributions from 1713 authors, with the first article appearing in 1998. Brazil and China emerged as the most productive countries in this domain. The core research areas focus on biomaterials, functional properties, and natural substances. Identified research gaps include pilot and industrial-scale applications, the lack of a regulatory framework and safety guidelines, and the application of artificial intelligence (AI), particularly deep learning and machine learning, in this field of edible coatings and films for fruit preservation. Overall, this study offers a scientific understanding of past achievements and ongoing research needs, thus aiming to boost a broader adoption of edible coatings and films by consumers and the food industry to preserve fruit quality, thereby enhancing their societal and environmental impact.

Chitosan/oxidized Konjac Glucomannan films incorporated with Zanthoxylum Bungeanum essential oil: A novel approach for extending the shelf life of meat

In this study, a novel edible composite film was prepared by chitosan, konjac glucomannan oxidized with ozone for 60 min (OKGM), and Zanthoxylum Bungeanum essential oil (ZEO). The chitosan/OKGM film was fortified with ZEO to assess the physical properties, structure, antioxidant and antibacterial abilities, and pork preservation systematically. Compared to the control group, the addition of 1 % ZEO increased tensile strength by 18.92 % and decreased water solubility, water vapor permeability, and moisture content by 10.05 %, 6.60 %, and 1.03 %, respectively. However, the treatment with ZEO (1.5 % and 2 %) decreased mechanical properties and increased the water vapor permeability. The ultraviolet barrier, antioxidant, and antibacterial abilities of composite films were enhanced by increasing the ZEO addition. Moreover, the COZ-1 film was used to protect the freshness of pork with slow-release behavior of ZEO. The results showed that addition of ZEO significantly decreased the pH value, total viable count, redness, total volatile basic nitrogen, and thiobarbituric acid and increased the hardness of pork after preservation for 10 days. Therefore, the chitosan/OKGM loaded with ZEO film can potentially be used as food packaging, providing new ideas for the research on active packaging materials.

Trends and challenges of fruit by-products utilization: insights into safety, sensory, and benefits of the use for the development of innovative healthy food: a review

A significant portion of the human diet is comprised of fruits, which are consumed globally either raw or after being processed. A huge amount of waste and by-products such as skins, seeds, cores, rags, rinds, pomace, etc. are being generated in our homes and agro-processing industries every day. According to previous statistics, nearly half of the fruits are lost or discarded during the entire processing chain. The concern arises when those wastes and by-products damage the environment and simultaneously cause economic losses. There is a lot of potential in these by-products for reuse in a variety of applications, including the isolation of valuable bioactive ingredients and their application in developing healthy and functional foods. The development of novel techniques for the transformation of these materials into marketable commodities may offer a workable solution to this waste issue while also promoting sustainable economic growth from the bio-economic viewpoint. This approach can manage waste as well as add value to enterprises. The goal of this study is twofold based on this scenario. The first is to present a brief overview of the most significant bioactive substances found in those by-products. The second is to review the current status of their valorization including the trends and techniques, safety assessments, sensory attributes, and challenges. Moreover, specific attention is drawn to the future perspective, and some solutions are discussed in this report.

The Potential of Edible Films, Sheets, and Coatings Based on Fruits and Vegetables in the Context of Sustainable Food Packaging Development

Several consumable substances, including fruit and vegetable purees, extracts, juices, and plant residue, were analyzed for their matrix-forming potential. These matrices serve as the basis for the production of edible films, sheets, and coatings that can be eaten as nutritional treats or applied to food products, thereby contributing to their overall good quality. Furthermore, this innovative approach also contributes to optimizing the performance of synthetic packaging, ultimately reducing reliance on synthetic polymers in various applications. This article explores the viability of incorporating fruits and vegetables as basic ingredients within edible films, sheets, and coatings. The utilization of fruits and vegetables in this manner becomes achievable due to the existence of polysaccharides and proteins that facilitate the formation of matrices in their makeup. Moreover, including bioactive substances like vitamins and polyphenols can impart attributes akin to active materials, such as antioxidants or antimicrobial agents. Advancing the creation of edible films, sheets, and coatings derived from fruits and vegetables holds great potential for merging the barrier and mechanical attributes of biopolymers with the nutritional and sensory qualities inherent in these natural components. These edible films made from fruits and vegetables could potentially serve as alternatives to seaweed in sushi production or even replace conventional bread, pancakes, tortillas, and lavash in the diet of people suffering from celiac disease or gluten allergy, while fruit and vegetable coatings may be used in fresh and processed food products, especially fruits and vegetables but also sweets.

Hydroxypropyl Methylcellulose and Gum Arabic Composite Edible Coatings Amended with Geraniol to Control Postharvest Brown Rot and Maintain Quality of Cold-Stored Plums

In this study, the effect of hydroxypropyl methylcellulose (HPMC) and gum Arabic (GA) edible coatings amended with 0.2% geraniol (GE) were evaluated for the control of brown rot, caused by Monilinia fructicola, on artificially inoculated plums (Prunus salicina Lindl., cv. Angeleno) stored for 5 weeks at 1 °C. Brown rot is the most important pre- and postharvest fungal disease of stone fruits, causing severe economic losses worldwide. Geraniol is an important constituent of many essential oils that can be obtained as a byproduct from different industrial procedures, such as those of the juice industry. Fruit postharvest quality was also evaluated after 5 and 8 weeks of storage at 1 °C, followed by 3 days at 7 °C plus 5 days at 20 °C, simulating packinghouse, transport, and retail shelf-life conditions, respectively. HPMC coatings containing 0.2% GE reduced the incidence and severity of brown rot by 37.5 and 64.8%, respectively, compared to uncoated fruit after 5 weeks of storage at 1 °C. HPMC-coated plums, with and without GE, showed the highest level of firmness, the lowest change in external peel color parameters (L*, a*, b*, C*, hue), and the lowest flesh bleeding compared to uncoated control and GA-coated samples throughout the entire storage period, which correlated with a higher gas barrier of these coatings without negatively affecting sensory quality. Furthermore, the HPMC-0.2% GE coating provided the highest gloss to coated plums, showing the potential of this coating as a safe and environmentally friendly alternative to conventional fungicides and waxes for brown rot control and quality maintenance of cold-stored plums.

Preparation and characterization of ultrasound-assisted essential oil-loaded nanoemulsions stimulated pullulan-based bioactive film for strawberry fruit preservation

Ultrasound is a high-energy approach that can help with homogenization and dispersion in cavitation. In this study, nanoemulsions of curcumin and orange essential oil were prepared with ultrasound treatment at different times. The ultrasound-treated nanoemulsions for 10 min exhibited the smallest droplet size, the best storage, and higher thermal stability. The pullulan-based film with ultrasound-assisted nanoemulsions exhibited improved water vapor permeability and moisture content and the highest tensile strength and elongation at break. The structural analysis showed that ultrasonic treatment enhanced the H-bond, resulting in a more orderly molecular arrangement and intermolecular compatibility. Furthermore, the bioactive film had the maximum oil retention time. It possessed excellent bacteriostatic properties against Escherichia coli and Staphylococcus aureus due to the smallest oil droplets and uniform distribution in the film matrix. Besides, the weight loss and deterioration of the strawberry fruit were effectively reduced, thus prolonging the shelf life.

Effect of adding nano-materials on the properties of hydroxypropyl methylcellulose (HPMC) edible films

The bio-composite films based on Hydroxypropyl methylcellulose (HPMC) reinforced with silver nanoparticles (AgNPs) and Titanium oxide nanoparticles (TiO₂-NPs) were developed. Some physical and mechanical properties: Tensile strength (TS), elongation (E), Young's elastic modulus (EM), water vapor permeability (WVP) and transparency were determined. Antibacterial properties of these films were also studied. The tensile strength values of HPMC film reinforced with Ag NPs and TiO₂-NPs and HPMC without nanoparticles were 39.24, 143.87 and 157.92 MPa, respectively. Elongation of the HMPC film was less than the HPMC film reinforced with AgNPs and TiO₂-NPs, the results were 2, 35 and 42%, respectively. Additionally, Young's elastic modulus of HMPC film was determined to be 19.62 MPa and the HPMC film reinforced with AgNPs and TiO₂-NPs were 4.11 and 3.76 MPa, respectively. The values of WVP of HMPC film was higher than the HMPC film reinforced with AgNPs and TiO₂-NPs, where they were 0.5076 × 10^-3, 0.4596 × 10^-3 and 0.4504 × 10^-3 (g/msPa), respectively. Nano-composite films demonstrated strong antibacterial activity against tested pathogen bacteria in the contact surface zone. The antibacterial activites of AgNPs (~ 10 nm) at 80 ppm were more active than 20 and 40 ppm against foodborne pathogen i.e. Bacillus cereus and Escherichia coli, the inhibition zone diameters were 9 and 10 mm, respectively. As well, TiO₂-NPs (~ 50 nm) at 80 ppm were more active than 20 and 40 ppm against B. cereus and Salmonella Typhimurium, the inhibition zone diameters were11 and 10 mm, respectively.

HPMC films functionalized by zein/carboxymethyl tamarind gum stabilized Pickering emulsions: Influence of carboxymethylation degree

Pickering emulsions are promising systems to act as carriers of active hydrophobic components, and to improve compatibility and the water vapor barrier properties of bio-based films. This study aimed to investigated the effects of cinnamon essential oil Pickering emulsions (CEOEs) using zein/carboxymethyl tamarind gum as stabilizers on the mechanical, barrier, antibacterial and antioxidant properties of Hydroxypropyl methyl cellulose (HPMC) films, and assessed the influence of carboxymethylation degree. In addition, the effect of the packaging was studied on the shelf life of cherry tomatoes. Results showed that the droplet size reduced approximately from 93.03 to 10.59 μm with the increasing degree of substitution (DS), greatly facilitating the droplet uniform distribution in film matrix. Moreover, with the addition of CEOEs, significant increase was observed with the tensile strength from 8.46 to 25.41 MPa, and the water vapor permeability decreased from 6.18 × 10^-10 to 4.24 × 10^-10 g·m^-1·s^-1·Pa^-1. The films exhibited good UV barrier properties without sacrificing the transparency after adding CEO. Furthermore, the antibacterial and antioxidant activities of the prepared films have also been greatly improved. Consequently, the CEOEs was an ideal alternative for incorporation with HPMC based films for increasing the shelf life of cherry tomatoes.

Design and development of orally disintegrating films: A platform based on hydroxypropyl methylcellulose and guar gum

From a design of experiments (DOE) performed under four independent variables, with the filmogenicity conditions and shortest disintegration time as the answers, a new oral disintegrating film (ODF) based on hydroxypropyl methylcellulose (HPMC) and guar gum (GG) with the essential oil of Plectranthus amboinicus L. (EOPA) was developed. Sixteen formulations were tested for filmogenicity, homogeneity, and viability. The better selected ODF required 230.1 s for complete disintegration. The retention rate of the EOPA was quantified using the nuclear magnetic resonance hydrogen technique (H¹ NMR), which identified the presence of 0.14 % carvacrol. The scanning electron microscopy showed a smooth and homogeneous surface with the presence of small white dots. Through the disk diffusion test, the EOPA was able to inhibit the growth of clinical strains of the Candida genus and gram-positive and gram-negative bacterial strains. This work opens new perspectives for the development of antimicrobial ODFS used in clinical practice.

Novel Features of Cellulose-Based Films as Sustainable Alternatives for Food Packaging

Packaging plays an important role in food quality and safety, especially regarding waste and spoilage reduction. The main drawback is that the packaging industry is among the ones that is highly dependent on plastic usage. New alternatives to conventional plastic packaging such as biopolymers-based type are mandatory. Examples are cellulose films and its derivatives. These are among the most used options in the food packaging due to their unique characteristics, such as biocompatibility, environmental sustainability, low price, mechanical properties, and biodegradability. Emerging concepts such as active and intelligent packaging provides new solutions for an extending shelf-life, and it fights some limitations of cellulose films and improves the properties of the packaging. This article reviews the available cellulose polymers and derivatives that are used as sustainable alternatives for food packaging regarding their properties, characteristics, and functionalization towards active properties enhancement. In this way, several types of films that are prepared with cellulose and their derivatives, incorporating antimicrobial and antioxidant compounds, are herein described, and discussed.

3D Printed gelatin film with Garcinia atroviridis extract

Active packaging, such as edible film with antibacterial properties, can help extend the shelf life of food. The research aimed to develop a 3D printed gelatin edible film by using glycerol and Garcinia atroviridis extract (GAE). Mechanical properties of gelatin gel, physical, mechanical, and antimicrobial properties of edible film with glycerol and GAE were determined. Water solubility, total colour difference, and elongation of break of gelatin edible film increased as glycerol concentration increased (0-25% w/w), whereas tensile strength and Young's modulus value decreased from 26.5 to 4.64 MPa and 3.04 to 0.13 MPa, respectively. On the other hand, increasing GAE from 1 to 4% (w/w) increases elongation at break from 40.83 to 98.27%, while decreasing edible film tensile strength and gelatin gel hardness value from 8.94 to 6.21 MPa and 1848.67 to 999.67 g, respectively. Using 20% (w/w) glycerol and 4% (w/w) GAE, the best 3D printed film with low tensile strength (6.21 MPa), high elongation at break (98.27%), and antibacterial activity against S. aureus with 7.23 mm zone of inhibition was developed. It seems to have a great potentiality as an active packaging material for 3D printed gelatin edible film.

Chitosan-Based Edible Coatings Containing Essential Oils to Preserve the Shelf Life and Postharvest Quality Parameters of Organic Strawberries and Apples during Cold Storage

Edible coatings and films have been researched for more than three decades due to their ability to be incorporated with different functional ingredients or compounds as an option to maintain the postharvest quality of fruits and vegetables. The aim of this study was to evaluate the effect of three types of chitosan-based (CH) edible coatings obtained from medium and high molecular weight chitosan, containing ascorbic or acetic acid and sea buckthorn or grape seed essential oils on the physical-chemical and microbiological properties of organic strawberries and apple slices during cold storage at 4 °C and 8 °C. Scanning electron microscope images showed both a smooth structure and a fracture and pore structure on strawberry coatings and a dense and smooth structure on the apple slices coatings. Further, the edible coatings managed to reduce the microbial load of yeasts and molds of the coated strawberries during the storage period. Overall, the treatments preserved the ascorbic acid, total polyphenol content, and antioxidant activity for all the tested samples compared to the control sample, throughout the storage period. In addition, the water activity (a_w) of the coated samples presented lower values (0.96-0.98) than the control samples. The obtained results indicate that the developed chitosan-based edible coatings could maintain the postharvest parameters of the tested samples, also leading to their shelf-life prolongation.

Natural Plant Extracts: An Update about Novel Spraying as an Alternative of Chemical Pesticides to Extend the Postharvest Shelf Life of Fruits and Vegetables

Fresh fruits and vegetables, being the source of important vitamins, minerals, and other plant chemicals, are of boundless importance these days. Although in agriculture, the green revolution was a milestone, it was accompanied by the intensive utilization of chemical pesticides. However, chemical pesticides have hazardous effects on human health and the environment. Therefore, increasingly stimulating toward more eco-friendly and safer alternatives to prevent postharvest losses and lead to improving the shelf life of fresh fruits and vegetables. Proposed alternatives, natural plant extracts, are very promising due to their high efficacy. The plant-based extract is from a natural source and has no or few health concerns. Many researchers have elaborated on the harmful effects of synthetic chemicals on human life. People are now much more aware of safety and health concerns than ever before. In the present review, we discussed the latest research on natural alternatives for chemical synthetic pesticides. Considering that the use of plant-based extracts from aloe vera, lemongrass, or neem is non-chemical by-products of the fruits and vegetable industry, they are proved safe for human health and may be integrated with economic strategies. Such natural plant extracts can be a good alternative to chemical pesticides and preservatives.

Antimicrobial packaging film from cactus (Cylindropuntia fulgida) mucilage and gelatine

Gelatine is an excellent substitute for biodegradable packaging materials; nevertheless, it is necessary to mix it with other polymers due to its poor mechanical and high hydrophilicity. In the present study, we used Cylindropuntia fulgida mucilage (CF) as main constituent and gelatine (GTN). The Euphorbia caducifolia extract (ECE) was incorporated in concentrations of 0, 1, 5, 10, 20 %, and its influence on the film's morphological, thermal, mechanical, and water vapor barrier properties was assessed. The surface of fabricated CF/GTN/ECE biocomposite films was more homogeneous and smoother with the high concentration of in ECE. The elongation at break improved from 2 to 60.59 %, and WVP enhanced from 3.34 to 2.59 10^-4 g mm/mm² day kPa and highest antimicrobial activity of 3.62 ± 0.71 Log CFU g^-1 when CF/GTN was incorporated with 20 % ECE. Incorporating CF and ECE 10 to 20 % makes these films a good substitute for the packaging of food products.

Preparation and characterization of oregano essential oil-loaded Dioscorea zingiberensis starch film with antioxidant and antibacterial activity and its application in chicken preservation

In this study, abundant starch was separated from the industrial crop Dioscorea zingiberensis C.H. Wright (DZW), and a novel bioactive packaging film loaded with oregano essential oil (OEO) was prepared and characterized. NaClO solution worked as a bleacher to prepare uniform starch powder from DZW tubers. OEO was selected from among three essential oils of Labiatae family plants for its strongest antibacterial activity. After the addition of OEO into the starch-based film, the UV-vis shielding property and antioxidant activity were enhanced. Meanwhile, the films still have a considerable performance in transparency, mechanical strength and water vapor permeability after incorporated with OEO. Furthermore, the 3% OEO-loaded starch film exhibited the strongest antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. It effectively lowered the total viable count of fresh chicken under 4 °C preservation conditions. These results revealed that the OEO-loaded DZW starch film can exert a positive effect on maintaining the quality and extending the shelf life of fresh meat. Therefore, readily accessible DZW tubers and oregano are very promising resources for application in degradable bioactive packaging film.

Calcium Ascorbate Coating Improves Postharvest Quality and Storability of Fresh-Cut Slices of Coscia and Abate Fétel Pears (Pyrus communis L.)

Flesh firmness is closely related to fruit ripeness and is typically a reliable indicator of shelf-life potential so it could be considered a crucial quality index for the determination of pear quality. Flesh softening after cutting could considerably affect consumer acceptance of fresh-cut pears (Pyrus communis L.). Indeed, mechanical stress (cutting, peeling, etc.) could lead to ethylene production that results in the hydrolysis of pectic substances in the cell walls. The effectiveness of an edible coating treatment on the physical-chemical, nutraceutical, and sensorial analysis was evaluated on two pear cultivars: the summer-ripening ‘Coscia’ and the late-ripening ‘Abate Fétel’, both harvested at their commercial ripening stage. Pear fruit slices were treated with calcium ascorbate, xanthan gum or HPMC coating and stored at 4 °C for 12 days. Weight loss, flesh firmness, soluble solid content, titratable acidity, ΔE color, browning surface, total polyphenol content, and antioxidant capacity were measured. Sensory analysis was carried out. Results showed that calcium ascorbate treatment applied to fruit slices significantly extended their shelf-life because it considerably inhibited browning and color changes in fresh-cut slices of both pear cultivars over seven days of storage. Furthermore, pear slices treated with calcium ascorbate revealed a higher antioxidant capacity and a lower content of total phenols during cold storage.

Impact of Biodegradable Materials on the Quality of Plums

Edible starch-based materials have shown a positive impact on quality parameters. In this study, plums (Prunus domestica cv. Jojo) were divided into five groups: a control, two coating treatments (starch and starch-whey protein (80–20%), and two film systems (starch and starch-whey protein (80–20%). Biodegradable packaging, particularly the coating treatment, had no negative effect on color parameters. After 28 days of performed tests, firmness was boosted with starch and starch-whey protein (80–20%) films. With the coated materials, there was no significant difference compared to control group. The lowest transpiration velocity was of plums wrapped in starch films. In the case of respiration rate, no significant difference was observed between the packaging and control samples. After the conducted trials, the weight loss of untreated plums was at 10%, while 5% of weight loss was noticed for plums wrapped in starch materials, and around 6% was noticed for the other materials. Oxygen permeability was higher for S-WP films, the thickness of S and S-WP films were comparable and thickness of starch coating was around 60% higher than S-WP. Both films have an affinity to water and both show typical behavior of water vapor sensitive hydrophilic biopolymers. The starch film with the addition of 20% of proteins increased the resistance of gas exchanges, which represents one of its great benefits.

Recent advances and future perspective of essential oils in control Colletotrichum spp.: A sustainable alternative in postharvest treatment of fruits

The world population growth has raised concerns about food security. Agricultural systems are asked to satisfy a growing demand for food with increasingly limited resources, and simultaneously still must reduce the impacts on the environment. This scenario encourages the search for safe and sustainable production strategies. Reducing losses in the production process can be one of the main ways to guarantee food safety. In fruticulture, it is estimated that more than 50% of the production can be lost between harvest and the final consumer due to postharvest diseases caused by phytopathogenic fungi. The fungi of the genus Colletotrichum are opportunistic and are associated with several diseases, being the anthracnose the most relevant in terms of the quality and yield losses in fruit species around worldwide. To control these diseases, the use of synthetic fungicides has been the main instrument utilized, however, because of their phytotoxicity to human health, the environment, and strong selection pressure imposed by continuous applications, the fungicides have caused resistance in the pathogen populations. So reducing the excessive application of these products is indispensable for human health and for sustainable Agriculture. Towards this purpose, research has been carried out to identify the phytopathological potentiality of essential oils (EOs) extracted from plants. Therefore, this review aims to contribute to the formation of knowledge bases, about the discoveries, recent advances, and the use of EOs as a strategy to alternatively control fungal disease caused by Colletotrichum spp. in postharvest fruits. Here, we provide valuable information exploring the application potential of essential oils as commercially useful biorational pesticides for food preservation, contributing to sustainable production and global food security.

Polyphenolic Antibacterials for Food Preservation: Review, Challenges, and Current Applications

Natural alternatives replacing artificial additives have gained much attention in the consumer’s view because of the growing search for clean label products that are devoid of carcinogenic and toxic effects. Plant polyphenols are considered as suitable alternative natural preservatives with antioxidant and antimicrobial properties. However, their uses in the food industry are undermined by a series of limitations such as low solubility and stability during food processing and storage, lack of standardization, and undesirable organoleptic properties. Different approaches in the use of polyphenols have been proposed in order to overcome the current hurdles related to food preservation. This review article specifically focuses on the antibacterial activity of plant-derived polyphenols as well as their applications as food preservatives, main challenges, and other trends in the food industry.

An Extensive Review of Natural Polymers Used as Coatings for Postharvest Shelf-Life Extension: Trends and Challenges

Global demand for minimally processed fruits and vegetables is increasing due to the tendency to acquire a healthy lifestyle. Losses of these foods during the chain supply reach as much as 30%; reducing them represents a challenge for the industry and scientific sectors. The use of edible packaging based on biopolymers is an alternative to mitigate the negative impact of conventional films and coatings on environmental and human health. Moreover, it has been demonstrated that natural coatings added with functional compounds reduce the post-harvest losses of fruits and vegetables without altering their sensorial and nutritive properties. Furthermore, the enhancement of their mechanical, structural, and barrier properties can be achieved through mixing two or more biopolymers to form composite coatings and adding plasticizers and/or cross-linking agents. This review shows the latest updates, tendencies, and challenges in the food industry to develop eco-friendly food packaging from diverse natural sources, added with bioactive compounds, and their effect on perishable foods. Moreover, the methods used in the food industry and the new techniques used to coat foods such as electrospinning and electrospraying are also discussed. Finally, the tendency and challenges in the development of edible films and coatings for fresh foods are reviewed.

The impact of essential oils on the qualitative properties, release profile, and stimuli-responsiveness of active food packaging nanocomposites

Food industries attempt to introduce a new food packaging by blending essential oils (EOs) into the polymeric matrix as an active packaging, which has great ability to preserve the quality of food and increase its shelf life by releasing active compounds within storage. The main point in designing the active packaging is controlled-release of active substances for their enhanced activity. Biopolymers are functional substances, which suggest structural integrity to sense external stimuli like temperature, pH, or ionic strength. The controlled release of EOs from active packaging and their stimuli-responsive properties can be very important for practical applications of these novel biocomposites. EOs can affect the uniformity of the polymeric matrix and physical and structural characteristics of the composites, such as moisture content, solubility in water, water vapor transmission rate, elongation at break, and tensile strength. To measure the ingredients of EOs and their migration from food packaging, chromatographic methods can be used. A head-space-solid phase micro-extraction coupled to gas chromatography (HS-SPME-GC-MS) technique is as a good process for evaluating the release of Eos. Therefore, the aims of this review were to evaluate the qualitative characteristics, release profile, and stimuli-responsiveness of active and smart food packaging nanocomposites loaded with essential oils and developing such multi-faceted packaging for advanced applications.

Extraction of Nicotine from Tobacco Leaves and Development of Fast Dissolving Nicotine Extract Film

Nicotine (NCT), administered in the form of a fast dissolving oral delivery system, can be a potential alternative to nicotine replacement therapy. NCT was extracted by maceration and acid-base extraction methods from Burley tobacco leaves with different stalk positions and extraction yield and NCT content were further determined. The extract with the highest nicotine content was selected for incorporation into a fast dissolving film formulation. The optimized film was evaluated for its physical and mechanical properties, in vitro disintegration, and drug release profile. The results demonstrated that the extract from the upper part of tobacco leaves using the acid-base extraction method had the highest amount of NCT. NCT fast dissolving film consisting of this extract as the active ingredient and HPMC E15 as a film polymer resulted in a homogeneous translucent film with a light brown color. The addition of NCT significantly affected the film properties in terms of weight, disintegration time, tensile strength, percentage elongation at break, and Young's modulus values. The drug release of NCT fast dissolving film showed a rapid initial release of 80% within three minutes, and its kinetics followed the Higuchi matrix model. The results suggest that these NCT films can be employed in the development of NCT fast dissolving films for clinical use.

Combining edible coatings technology and nanoencapsulation for food application: A brief review with an emphasis on nanoliposomes

The use of bioactive compounds within the biopolymer-based Edible Coatings (EC) matrices has certain limitations for their application at the food industry level. Encapsulation has been considered as a strategy that enables protecting and improving the physical and chemical characteristics of the compounds; as a result, it extends the shelf life of coated foods. This review discusses recent progress in combining edible coatings with nanoencapsulation technology. We also described and discussed various works, in which nanoliposomes are used as encapsulation systems to prepare, and subsequently apply the edible coatings in plant products and meat products. The use of nanoliposomes for the encapsulation of phenolic compounds and essential oils provides an improvement in the antioxidant and antimicrobial properties of coatings by extending the shelf life of food matrices. However, when liposomes are stored for a long period of time, they may present some degree of instability manifested by an increase in size, polydispersity index, and zeta potential. This is reflected in an aggregation, fusion, and rupture of the vesicles. This investigation can help researchers and industries to select an appropriate and efficient biopolymer to form EC containing nanoencapsulated active compounds. This work also addresses the use of nanoliposomes to create EC extending markedly the shelf life of fruit, reducing the weight loss, and deterioration due to the action of microorganisms.

Investigating the properties of PLA-nanochitosan composite films containing Ziziphora Clinopodioides essential oil and their impacts on oxidative spoilage of Oncorhynchus mykiss fillets

The present study aimed to investigate the impact of polylactic acid (PLA) integrated with nanochitosan (NC) composite film and Ziziphora Clinopodioides essential oil (ZCEO) on oxidative spoilage of rainbow trout fillets during a 9-day refrigeration period. For this purpose, first, six degradable films including T1: PLA, T2: PLA + NC, T3: PLA + NC + 1% ZCEO, T4: PLA + NC + 1.5% ZCEO, T5: PLA + 1% ZCEO, and T6: PLA + 1.5% ZCEO were prepared. Next, the properties of the films were investigated. The results of the mechanical tests showed that ZCEO decreased the tensile strength and increased the elongation at the break of the PLA films. However, adding NC improved the mechanical characteristics of the PLA film. The outcomes of physical tests including moisture content (14.02%), solubility (17.41%), water vapor permeability (1.14 × 10-7 g s-1 m-1 Pa-1), and oxygen transmission rate (21.54 cm3.mm/m2.24 hr) showed that adding 1% ZCEO improved the film physical characteristics. Nevertheless, by adding 1.5% concentration EO to the PLA film, the values of water vapor permeability, porosity (according to the scanning electron microscopy), and turbidity increased and cross-sectional pores were observed. Moreover, the films had high antioxidant properties (84.33%). In the next step, the effects of the mentioned films on the oxidative spoilage of rainbow trout fillets were investigated. The results of the chemical analysis in PLA film with the EO compared with the control treatment revealed the increasing trend of oxidation indices, in general. Moreover, increasing the concentration yielded better results such that all treatments containing EO showed satisfactory results up until the storage period ends. In most cases, adding NC affected the mentioned characteristics positively, and the best results were observed in T4 and then in T3. However, based on economics and the better mechanical and physical properties of T3, the film can be applied as an active packaging in fishery products.

Essential Oil-Containing Polysaccharide-Based Edible Films and Coatings for Food Security Applications

The wastage of food products is a major challenge for the food industry. In this regard, the use of edible films and coatings have gained much attention due to their ability to prevent the spoilage of the food products during handling, transport, and storage. This has effectively helped in extending the shelf-life of the food products. Among the various polymers, polysaccharides have been explored to develop edible films and coatings in the last decade. Such polymeric systems have shown great promise in microbial food safety applications. The inclusion of essential oils (EOs) within the polysaccharide matrices has further improved the functional properties of the edible films and coatings. The current review will discuss the different types of polysaccharides, EOs, methods of preparing edible films and coatings, and the characterization methods for the EO-loaded polysaccharide films. The mechanism of the antimicrobial activity of the EOs has also been discussed in brief.

Corn Starch/Chitosan Nanoparticles/Thymol Bio-Nanocomposite Films for Potential Food Packaging Applications

This work aims to develop corn starch/chitosan nanoparticles/thymol (CS/CNP/Thy) bio-nanocomposite films as potential food packaging materials that can enhance the shelf life of food. CS/CNP/Thy bio-nanocomposite films were prepared by the addition of different concentrations of thymol (0, 1.5, 3.0, 4.5 w/w%) using a solvent casting method. The resulting films were characterized in terms of optical, mechanical, and water vapor permeability (WVP) properties. The addition of thymol was found to reduce the tensile strength (TS), elongation at break (EAB), and Young’s modulus (YM) of the films. Generally, the increment in the concentration of thymol did not significantly affect the TS, EAB, and YM values. The addition of 1.5 w/w% thymol increased the WVP of the films but the WVP reduced with the increase in thymol concentrations. CS/CNP/Thy-3% bio-nanocomposite films demonstrated the potential to lengthen the shelf life of cherry tomatoes packed with the films, whereby the cherry tomatoes exhibited no significant changes in firmness and the lowest weight loss. In addition, no mold growth was observed on the sliced cherry tomatoes that were in direct contact with the films during 7 days of storage, proving the promising application of the films as active food packaging materials.

Shelf life extension of apricot fruit by application of nanochitosan emulsion coatings containing pomegranate peel extract

The effect of nanochitosan coating containing pomegranate peel extract (PPE) at concentrations 0.5, 0.75 and 1% (w/v) on postharvest quality of apricot fruit was studied during storage at 4 °C for 30 days. Nanoemulsions showed significant increase in droplet diameter 275-400 nm, decrease in zeta potential -30-23 mV and viscosity 90-76 mPas^-1 with increase in PPE concentration. Results confirmed that apricot fruit treated with chitosan and 1% PPE showed significantly reduced decay percentage, weight loss, effectively retained DPPH radical scavenging activity, ascorbic acid, kept titratable acidity and firmness at high level than untreated fruit. Color attributes showed decrease in L*, a* values and significant increase in b* value. Nanochitosan containing 1% PPE significantly inhibited total psychrophilic bacterial count, yeast and mold count during storage. Our results suggest that chitosan coatings enriched with pomegranate peel extract has the potential to preserve the quality and extend shelf life of apricot.

Modern technologies for extraction of aroma compounds from fruit peels: a review

Fruit peel is an agricultural by-product and potential source to extract natural aroma compounds with low cost. In the past few decades, the extraction of plant aroma volatiles experienced a transition from traditional to modern technologies. This review summarizes the main aroma compounds in different fruit peels, evaluates modern extraction techniques applicable for these aroma compounds in terms of mechanism, procedure, merits and demerits, and practice. Additionally, the applications of fruit peel aroma extract in food, pharmaceutical and cosmetic industries are also discussed. This review provides comprehensive information for extraction and application of aroma compounds from fruit peels, which could facilitate the valorization of the agricultural by-products and reduce environmental impacts.

Antimicrobial Activities of Starch-Based Biopolymers and Biocomposites Incorporated with Plant Essential Oils: A Review

Recently, many scientists and polymer engineers have been working on eco-friendly materials for starch-based food packaging purposes, which are based on biopolymers, due to the health and environmental issues caused by the non-biodegradable food packaging. However, to maintain food freshness and quality, it is necessary to choose the correct materials and packaging technologies. On the other hand, the starch-based film’s biggest flaws are high permeability to water vapor transfer and the ease of spoilage by bacteria and fungi. One of the several possibilities that are being extensively studied is the incorporation of essential oils (EOs) into the packaging material. The EOs used in food packaging films actively prevent inhibition of bacteria and fungi and have a positive effect on food storage. This work intended to present their mechanical and barrier properties, as well as the antimicrobial activity of anti-microbacterial agent reinforced starch composites for extending product shelf life. A better inhibition of zone of antimicrobial activity was observed with higher content of essential oil. Besides that, the mechanical properties of starch-based polymer was slightly decreased for tensile strength as the increasing of essential oil while elongation at break was increased. The increasing of essential oil would cause the reduction of the cohesion forces of polymer chain, creating heterogeneous matrix and subsequently lowering the tensile strength and increasing the elongation (E%) of the films. The present review demonstrated that the use of essential oil represents an interesting alternative for the production of active packaging and for the development of eco-friendly technologies.

Preparation and characterization of β-cyclodextrin-oregano essential oil microcapsule and its effect on storage behavior of purple yam

BACKGROUND

Natural plant essential oils have antimicrobial properties; however, essential oils are difficult to maintain in a system because of their volatile nature. First, we prepared microcapsules from β-cyclodextrin and oregano essential oil and characterized their properties. Second, the effect of microcapsules on the preservation of freshly cut purple yam was studied using an edible coating technique. Purple yams immersed in distilled water were used as control, and their characteristics were compared with yams coated with citric acid, citric acid + sodium alginate, and citric acid + sodium alginate + β-cyclodextrin-oregano essential oil microcapsules (CA-SA-MC) and stored at 4 °C for 5 days.

RESULTS

Microcapsules of oregano essential oil and β-cyclodextrin solution were successfully prepared via the inclusion method, with an optimal encapsulation efficiency of 55.14%. Scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis showed strong bonds between β-cyclodextrin and oregano essential oil. All edible coatings, particularly CA-SA-MC, significantly (P ≤ 0.05) maintained firmness, total soluble solids, ascorbic acid content, and anthocyanin content compared with control treatment. This treatment also prevented browning and extended the shelf life of purple yam.

CONCLUSION

Oregano essential oil can be successfully encapsulated into cyclodextrin microcapsules. It has a great impact on the shelf life extension of purple yam and could be successfully applied to other fresh produce. © 2020 Society of Chemical Industry.