Edible coatings for enhancing safety and quality attributes of fresh produce: A comprehensive review

Nano-edible coatings for quality enhancement and shelf-life extension of fruits and vegetables

In developing countries, significant fruit and vegetable losses stem from inadequate storage and mishandling during harvest. Employing edible coatings on agricultural products offers an alternative method to reduce these losses as it aids in controlling the flow of moisture and gases between the product and its immediate environment. A significant benefit of applying edible films and coatings to agricultural produce is the incorporation of active components to the biopolymer matrix, which can be consumed together with the food, improving its nutritional and sensory appeal as well as its safety. Producing edible coatings at the nanoscale level has become more prevalent since the introduction of nanotechnology. By decreasing the coating particles to a nanometric scale of 1 to 100 nanometers, nanotechnology offers an innovative approach for producing new edible coatings. Such nanomaterials exhibit unique and improved characteristics of slowing ripening and decay of fruit and have additional advantages like affordability, convenience of application, and use of natural ingredients. The primary objective of incorporating edible coatings with nanoparticles is to improve the mechanical and barrier qualities of the biopolymer. Despite the tremendous advancements in nutritional nanotechnology, little is known about the toxicity of nanomaterials and due to their potential for toxicity, nanomaterials require more characterization and strict regulations to be incorporating them along with food. This review provides a comprehensive understanding of nanocoatings, including its synthesis and application for fruits and vegetables quality enhancement and shelf-life extension.

Fabrication and Characterization of Pectin-Chitosan Edible Coatings with a Cosmos caudatus Leaf Extract for Tomato Preservation

An edible coating based on pectin-chitosan and Cosmos caudatus leaf extract has been created. Cosmos caudatus leaf extract, which contains several bioactive compounds, aims to produce an edible coating with antibacterial properties. C. caudatus extract was incorporated at concentrations of 1, 2, and 3 g into a mixture of 1.5 g of pectin and 1 g of chitosan. The edible coating was applied to the tomatoes using the dipping method. The coated tomatoes were analyzed for 21 days at room temperature to determine the weight loss value. The edible coating was characterized, including FTIR analysis, X-ray diffraction, surface morphology, thermal stability, viscosity, and antibacterial activity. The research results reveal that C. caudatus extract contains anthocyanins with antibacterial properties, has an amorphous crystalline structure, and has a textured surface with partial aggregation. Thermal stability analysis using differential scanning calorimetry (DSC) shows a decrease in thermogravimetric (TG) values with increasing extract concentration. The optimal weight loss (6.18%) was found in the pectin-chitosan composition containing 3 g of C. caudatus extract. At this concentration, the inhibition zones against Escherichia coli and Staphylococcus aureus were 16.4 and 15.6 mm, respectively. These findings indicate that the C. caudatus leaf extract, particularly at 3 g, enhances the antibacterial properties of the edible pectin-chitosan coating, demonstrating its potential to extend the shelf life of tomatoes safely.

Chitosan-gallic acid conjugate edible coating film for perishable fruits

Approximately 30 % of global agricultural land is used to produce food that is ultimately lost or wasted, making it imperative to explore strategies for mitigating this waste. This study explored the potential of chitosan (CS) derivatives as edible coatings to extend food shelf life. Although soluble CS derivatives such as glycol CS are suitable coatings, their antimicrobial properties often diminish with increased solubility. To address this issue, gallic acid (GA), a polyphenol, was conjugated with CS using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) chemistry to create edible coating solutions. The resulting CS-GA films exhibited remarkable solubility, mechanical strength, UV-blocking properties, and superior antioxidant and antimicrobial properties. Furthermore, these films exhibited a high affinity for hydrophobic fruit surfaces while also facilitating easy washing, making them an alternative for consumers who are averse to film-coated products. The CS-GA-coated fruits exhibited minimal surface spoilage, decreased mass loss, and increased firmness. Therefore, these CS-GA conjugate coatings hold significant potential as eco-friendly, edible, and washable food packaging coatings.

Natural biopolymers in edible coatings: Applications in food preservation

Edible coatings are revolutionizing food preservation by offering a sustainable and effective solution to key industry challenges. Made from natural biopolymers such as proteins, polysaccharides, and lipids, these coatings form a thin, edible layer on food surfaces. This barrier reduces moisture loss, protects against oxidative damage, and limits microbial growth, thereby extending shelf life while preserving food quality. Enhanced with natural additives like essential oils and antioxidants, these coatings offer antimicrobial benefits and contribute to health. Applications span from fresh produce, where they control respiration and moisture, to meat, dairy, and bakery products, maintaining sensory and nutritional properties. Innovations in coating technologies-such as composite materials, nano-emulsions, and bio-nanocomposites-are improving their mechanical strength, barrier properties, and compatibility with other preservation methods like modified atmosphere packaging. Although challenges remain in cost, consumer acceptance, and regulation, edible coatings represent a significant stride towards sustainable food systems and reduced dependence on synthetic packaging.

Global insights and advances in edible coatings or films toward quality maintenance and reduced postharvest losses of fruit and vegetables: An updated review

Transitioning to safe, nonthermal, and edible strategies for maintaining fruit and vegetable (F&V) quality, reducing postharvest losses (up to 55% annually), and ensuring food security requires extensive research and innovation in postharvest technologies. This review aims to provide an updated understanding of edible coatings or films (ECF), focusing on their role in reducing F&V postharvest losses, based on data from the last 40 years retrieved from the Web of Science database. The global ECF research network is represented by publication trends, majorly researched F&V, key research areas, influential and emerging authors, and global research ranking. The role of ECF in preserving F&V quality has been assessed by examining critical quality parameters, including weight loss, total soluble solids, titratable acidity, ripening, softening, sensory and organoleptic characteristics, browning, chilling injury, and microbial safety. Furthermore, recent advancements in ECF formulations, including nanoscale ingredients and application methodologies, have been critically discussed. Sources, categorization, application strategies, mode of action, functional properties, sustainable development goals (SDGs), challenges, safety, legislations, and future perspectives in ECF research have also been discussed. The key findings indicate that China (20.34%) and the USA (9.94%) are the leading countries in ECF research. Studies have demonstrated ECF's potential in reducing F&V postharvest losses by maintaining quality parameters through advanced nanoscale compositions and methodologies. Notably, ECF research supports multiple SDG targets, including SDGs 2, 3, 8, 9, 12, 13, and 15. Future ECF research should explore 3D-printed coatings, nonflavor-altering components, and potential crosslinking agents to enhance F&V quality and reduce postharvest losses.

Role of irradiated and un-irradiated alginate as edible coating in physicochemical and nutritional quality of cherry tomato

BACKGROUND

Fresh vegetables are commodities that have a high tendency to deteriorate after harvest, causing significant losses in economic and environmental costs associated with plant food loss. Therefore, this study was carried out to evaluate the effects of both un-irradiated (UISA) and irradiated sodium alginate (ISA) as an edible coating for preserving cherry tomato fruits under storage conditions. The FTIR, XRD, TGA, SEM, and TEM were used to characterize the UISA and ISA (25, 50, 75, and 100 kGy), which demonstrated that the alginate polymer was degraded and low molecular-weight polysaccharides were formed as a result of irradiation, particularly with the 100 kGy dose level. Sodium alginate irradiated at 100 kGy was used for the coating process, and the physico-chemical and nutritional quality of cherry tomatoes were analyzed.

RESULTS

The results demonstrated that UISA and ISA treatments delayed changes in most of the ripening characteristics; weight and acidity losses, decay, and softening. The weight loss of the control was observed to be greater at the two keeping temperatures (4 and 25 °C) comparison with tomatoes coated with UISA. The ISA coatings gave the least weight loss at the two keeping temperatures (4 and 25 °C) (5.46 and 14.72%), respectively compared to the control (8.77 and 18.93%), respectively at the end of the storage period. In terms of antioxidant properties, significant results were obtained with the use of the alginate coating, specially irradiated sodium alginate. Over time, the majority of water-soluble vitamins in cherry tomatoes decreased, especially vitamin C, and the alginate-coated tomatoes showed the least decrease in vitamin C content, especially ISA.

CONCLUSIONS

The current findings suggest that ISA treatment efficiently extends the storage period of tomato fruits and maintains their quality through preservation and offers promising potential for successful commercialization of this eco-friendly eatable coating for fruit and vegetable growers and industries.

A Current Trend in Efficient Biopolymer Coatings for Edible Fruits to Enhance Shelf Life

In recent years, biopolymer coatings have emerged as an effective approach for extending the shelf life of edible fruits. The invention of biopolymer coverings has emerged as an innovation for extending fruit shelf life. Natural polymers, like chitosan, alginate, and pectin, are used to create these surfaces, which have several uses, including creating a barrier that prevents water evaporation, the spread of living microbes, and respiratory movement. These biopolymer coatings' primary benefits are their environmental friendliness and lack of damage. This study highlights the advancements made in the creation and usage of biopolymer coatings, highlighting how well they preserve fruit quality, reduce post-harvest losses, and satisfy consumer demand for natural preservation methods. This study discusses the usefulness of the biopolymer coating in terms of preserving fruit quality, reducing waste, and extending the product's shelf life. Biopolymer coatings' potential as a sustainable solution for synthetic preservatives in the fruit sector is highlighted as are formulation process advances that combine natural ingredients and environmental implications. This essay focuses on the essential methods, such as new natural additives, as well as the environmental effect of biopolymer coatings, which are safe and healthy commercial alternatives.

Application of seed mucilage as functional biopolymer in meat product processing and preservation

Meat products consumption is rising globally, but concerns about sustainability, fat content, and shelf life. Synthetic additives and preservatives used for extending the shelf life of meat often carry health and environmental drawbacks. Seed mucilage, natural polysaccharides, possesses unique functional properties like water holding, emulsifying, and film forming, offering potential alternatives in meat processing and preservation. This study explores the application of seed mucilage from diverse sources (e.g., flaxseed, psyllium, basil) in various meat and meat products processing and preservation. Mucilage's water-holding and emulsifying properties can potentially bind fat and decrease the overall lipid content in meat and meat-based products. Moreover, antimicrobial and film-forming properties of mucilage can potentially inhibit microbial growth and reduce oxidation, extending the shelf life. This review emphasizes the advantages of incorporating mucilage into processing and coating strategies for meat and seafood products.

Review on the extension of shelf life for fruits and vegetables using natural preservatives

Fruits and vegetables are important for the nutrition and health of individuals. They are highly perishable in nature because of their susceptibility to microbial growth. Foodborne pathogens create a significant problem for consumers, food businesses, and food safety. Postharvest factors, including transportation, environment, and preservation techniques, cause a reduction in product quality. The present world is using synthetic preservatives, which have negative impacts on consumer health. Food safety and demand for healthy foods among consumers, the scientific community, and the food industry resulted in the exploitation of natural preservatives, which play an important role in their effectiveness, prolonged shelf life, and safety. Natural preservatives include plants, animals, and microbiological sources with polymers to extend shelf life, improve quality, and enhance food safety. This review specifically focuses on mechanism of action of natural preservatives, spoilage of fruit and vegetables, the importance of edible film and coating on fruits and vegetables.

Fast detection of moisture content and freshness for loquats using optical fiber spectroscopy

Detection of the moisture content (MC) and freshness for loquats is crucial for achieving optimal taste and economic efficiency. Traditional methods for evaluating the MC and freshness of loquats have disadvantages such as destructive sampling and time-consuming. To investigate the feasibility of rapid and non-destructive detection of the MC and freshness for loquats, optical fiber spectroscopy in the range of 200-1000 nm was used in this study. The full spectra were pre-processed using standard normal variate method, and then, the effective wavelengths were selected using competitive adaptive weighting sampling (CARS) and random frog algorithms. Based on the selected effective wavelengths, prediction models for MC were developed using partial least squares regression (PLSR), multiple linear regression, extreme learning machine, and back-propagation neural network. Furthermore, freshness level discrimination models were established using simplified k nearest neighbor, support vector machine (SVM), and partial least squares discriminant analysis. Regarding the prediction models, the CARS-PLSR model performed relatively better than the other models for predicting the MC, with R 2 P and RPD values of 0.84 and 2.51, respectively. Additionally, the CARS-SVM model obtained superior discrimination performance, with 100% accuracy for both calibration and prediction sets. The results demonstrated that optical fiber spectroscopy technology is an effective tool to fast detect the MC and freshness for loquats.

Recent Approaches to the Formulation, Uses, and Impact of Edible Coatings on Fresh Peach Fruit

Peaches are among the most well-known fruits in the world due to their appealing taste and high nutritional value. Peach fruit, on the other hand, has a variety of postharvest quality issues like chilling injury symptoms, internal breakdown, weight loss, decay, shriveling, and over-ripeness, which makes a challenging environment for industries and researchers to develop sophisticated strategies for fruit quality preservation and extending shelf life. All over the world, consumers prefer excellent-quality, high-nutritional-value, and long-lasting fresh fruits that are free of chemicals. An eco-friendly solution to this issue is the coating and filming of fresh produce with natural edible materials. The edible coating utilization eliminates the adulteration risk, presents fruit hygienically, and improves aesthetics. Coatings are used in a way that combines food chemistry and preservation technology. This review, therefore, examines a variety of natural coatings (proteins, lipids, polysaccharides, and composite) and their effects on the quality aspects of fresh peach fruit, as well as their advantages and mode of action. From this useful information, the processors could benefit in choosing the suitable edible coating material for a variety of fresh peach fruits and their application on a commercial scale. In addition, prospects of the application of natural coatings on peach fruit and gaps observed in the literature are identified.

Nanoemulsion based edible coatings for quality retention of fruits and vegetables-decoding the basics and advancements in last decade

Fruits and vegetables (F&V) are highly perishable and have important contributions to nutritional and economic sustainability. Although the developing nations have shown an immense increase in the production of horticultural commodities, the post-harvest losses are significant and have an adverse impact on the resources, economy, and environment as well. Nanoemulsion-based carriers are recognized for their diversity, natural origin, and immense potential to restrict losses while boosting the functional attributes of produce. The recent findings attest to nanoemulsions potential for extending the shelf life, managing quality, and reducing the losses of the perishables for sustainable livelihood of the farmers. However, further studies are required to evaluate the biological fate, safety, or potential toxicity of the nanoemulsion-based edible coatings. This review precisely focuses on various matrices used in the production of nanoemulsions, fabrication methods, characterization techniques, and the use of natural emulsifiers instead of chemicals. The future research focus stresses on developing low-cost fabrication techniques for nanoemulsion, improvement of the transmission properties i. e gas transmission rate (GTR), water vapor transmission rate (WVTR), and enhancing the performance of monolayer, bilayer, and other composite nanoemulsion base films. This beyond reducing the postharvest losses shall also restrict burden of the food waste management and related environmental issues at the same time.

Review of postharvest processing of edible wild-grown mushrooms

Edible wild-grown mushrooms, plentiful in resources, have excellent organoleptic properties, flavor, nutrition, and bioactive substances. However, fresh mushrooms, which have high water and enzymatic activity, are not protected by cuticles and are easily attacked by microorganisms. And wild-grown mushroom harvesting is seasonal the harvest of edible wild-grown mushrooms is subject to seasonality, so their market availability is challenging. Many processing methods have been used for postharvest mushroom processing, including sun drying, freezing, packaging, electron beam radiation, edible coating, ozone, and cooking, whose effects on the parameters and composition of the mushrooms are not entirely positive. This paper reviews the effect of processing methods on the quality of wild and some cultivated edible mushrooms. Drying and cooking, as thermal processes, reduce hardness, texture, and color browning, with the parallel that drying reduces the content of proteins, polysaccharides, and phenolics while cooking increases the chemical composition. Freezing, which allows mushrooms to retain better hardness, color, and higher chemical content, is a better processing method. Water washing and ozone help maintain color by inhibiting enzymatic browning. Edible coating facilitates the maintenance of hardness and total sugar content. Electrolytic water (EW) maintains total phenol levels and soluble protein content. Pulsed electric field and ultrasound (US) inhibit microbial growth. Frying maintains carbohydrates, lipids, phenolics, and proteins. And the mushrooms processed by these methods are safe. They are the focus of future research that combines different methods or develops new processing methods, molecular mechanisms of chemical composition changes, and exploring the application areas of wild mushrooms.

Recent advances in edible coatings and their application in food packaging

The food packaging industries are facing the challenge of food waste generation. This can be addressed through the use of edible coating materials. These coatings aid in extending the shelf life of food products, reducing waste. The key components of these coatings include food-grade binding agents, solvents, and fillers. The integration of polysaccharide, protein, lipids, bioactive and composite-based materials with edible coating matrix aids to combat substantial post-harvest loss of highly perishable commodities and elevates the quality of minimally processed food. The aim of this review is to introduce the concept of edible coatings and discuss the different coating materials used in the food industry, along with their properties. Additionally, this review aims to classify the coating types based on characteristic features and explore their application in various food processing industries. This review provides a comprehensive overview of edible coatings, including the integration of polysaccharides, proteins, lipids, bioactive, and composite-based materials into the coating matrix. This review also addresses the significant post-harvest loss of highly perishable commodities and emphasizes the enhancement of quality in minimally processed food. Furthermore, the antimicrobial, anti-corrosive, and edible characteristics are highlighted, showcasing their potential applications in different food packaging industries. Moreover, it also discusses the challenges, safety and regulatory aspects, current trends, and future perspectives, aiming to shed light on the commercialization and future investigation of edible coatings.

Soil-Borne Neosartorya spp.: A Heat-Resistant Fungal Threat to Horticulture and Food Production-An Important Component of the Root-Associated Microbial Community

Soil-borne Neosartorya spp. are the highly resilient sexual reproductive stage (teleomorph) of Aspergillus spp. Fungi of this genus are relevant components of root-associated microbial community, but they can also excrete mycotoxins and exhibit great resistance to high temperatures. Their ascospores easily transfer between soil and crops; thus, Neosartorya poses a danger to horticulture and food production, especially to the postharvest quality of fruits and vegetables. The spores are known to cause spoilage, mainly in raw fruit produce, juices, and pulps, despite undergoing pasteurization. However, these fungi can also participate in carbon transformation and sequestration, as well as plant protection in drought conditions. Many species have been identified and included in the genus, and yet some of them create taxonomical controversy due to their high similarity. This also contributes to Neosartorya spp. being easily mistaken for its anamorph, resulting in uncertain data within many studies. The review discusses also the factors shaping Neosartorya spp.'s resistance to temperature, preservatives, chemicals, and natural plant extracts, as well as presenting novel solutions to problems created by its resilient nature.

Phytochemicals-based edible coating for photodynamic preservation of fresh-cut apples

Nature-derived chemicals have recently gained increased attention to settle down the challenges in the food industry. Quercetin has long been used as a natural medicine but its photoactivity has been neglected. In this work, by combining photodynamic bacteria inactivation (PDI) with an edible coating (Pectin/Quercetin) derived from FDA-approved chemicals, extend shelf-life and protected commercial quality of fresh-cut apples were achieved. Firstly, the potential photoactivated antibacterial performance of Quercetin (a natural plant flavonoid) was clarified with the treatment of a simulated sunlight lamp, realizing antibacterial efficacy of 100 % towards S. aureus (50 min) and L. monocytogenes (80 min) with light treatment. To develop safe and effective preservation of fresh-cut apples, Pectin/Quercetin edible coatings with 100 μmol/L quercetin were adopted. The results showed that the prepared edible coatings form a protective barrier over the surface of apples, effectively resisting bacterial infection and extending shelf life to 10 days while maintaining good commercial quality (including preferable color, keeping 100 % hardness, 80 % sugar content and 17.3 % weightlessness rate). Therefore, the prepared light-driven Pectin/Quercetin in this work has the potential to develop as fresh-cut fruit preservation technology.

Investigation on the potential of applying bio-based edible coatings for horticultural products exemplified with cucumbers

Plastic packaging for fresh horticultural produce has many advantages but generates plastic waste and ecological alternatives are required. Edible coatings can retard many processes related to loss of quality. Hydrophobic lipid-based coatings are preferably applied for fresh fruits and vegetables. The approval of such coatings for products with edible peels in EU is increasingly under discussion. However, investigations on the efficiency of various edible coatings on soft-skinned fruit and vegetables are rare and it is currently unclear whether the consumer will accept them. Therefore, this study investigates (1) important characteristics of a lipid-based coating and (2) its ability to maintain the post-harvest quality of fresh cucumbers. This was evaluated by a comparative storage test under common suboptimal retail conditions (20 °C; 65% RH). The study also evaluates (3) the general perception of consumers about and their acceptance of the application of edible coatings on fresh fruit and vegetables with edible peels. The investigated coating was able to drastically reduce water loss (54-68%) and fruit respiration (approx. 33%) of fresh cucumber. The reduction of tissue stiffness was delayed by 2 days, thus, prolonged shelf life. Majority of consumer (77%) endorse the application of edible coatings as an alternative to plastic packaging, but emphasized important requirements for them.