Edible Coatings Research Articles

Fabraction of edible bio-nanocomposite coatings from pectin-containing lignocellulosic nanofibers isolated from apple pomace

Minimally processed fruits are increasingly demanded in modern society, but the management of perishable waste pomaces (WPs) and the products' short shelf-life are still big issues. Here, a facile approach of reconstruing apple pomace (AP) into edible bio-nanocomposite coatings of fresh-cutting apple slices was successfully developed through alkaline demethylation followed by high-pressure homogenization. The fibrillation of AP fibers is largely improved by -COO− at a concentration of 1.23 mmol g−1, which is released through alkaline demethylation of pectin, instead of relying on intricated or costly cellulose modifications. The average width of AP nanofibers (AP-NFs) downsizes to 18 nm. By casting, AP-NFs fabricate homogeneous films with comparable transparency (56 % at 600 nm), superior mechanical strength (6.4 GPa of Young modulus and 81.7 MPa of strength) and oxygen barrier properties (79 mL μm m−2 day−1 bar−1), and non-toxicity. Moreover, the AP-NF coatings effectively extend shelf life of apple slices by inhibiting browning and respiration, and retain firmness. This research demonstrates a way to valorize WPs as edible coatings for fruit packaging.

Impact of Antioxidant-Enriched Edible Gel Coatings and Bio-Based Packaging on Cherry Tomato Preservation.

This research investigates the effects of using edible gel coatings and bio-based packaging materials on extending the shelf life of cherry tomatoes. Two edible gel coatings (guar gum and guar gum +5% of a lemon (Citrus limon (L.) Osbeck pomace extract obtained in the research laboratory) were applied on cherry tomatoes, then they were packaged in bio-based materials (cellulose tray + PLA lid). Guar gum, glycerol, sorbitol, extra virgin olive oil, and tween 20 were used in coating formulation. Uncoated tomatoes packed in bio-based materials and conventional plastic (PET trays + lid) were tested as a control. Samples were stored for 45 days at 20 °C and their quality parameters were evaluated. Coated tomatoes maintained firmness and weight, and the enriched coated samples showed a significant increase in phenol content, derived from the antioxidant extract. Samples packed in PET showed a sensory unacceptability (<4.5) after 45 days correlated with a greater decline in firmness (from 10.51 to 5.96 N) and weight loss (from 7.06 to 11.02%). Therefore, edible gel coating and bio-based packaging proved to be effective in maintaining the overall quality of cherry tomatoes for 45 days, offering a promising approach to reduce plastic polymer use and food waste.

Appraisal of cutting-edge techniques for prolonging fresh berries shelf life: innovations in essential oil nanoemulsion-based edible coatings

The high susceptibility of berries to fungal contamination during the postharvest phase and increasing demand from consumers for a safe preservative have prompted the need for a potential substitute. In this context, beyond their conventional use as flavouring agents, essential oils have been investigated for their preservative actions in berries to supplant traditional synthetic preservatives. However, high volatility, poor environmental stability, intense organoleptic properties, and low aqueous solubility limit their use as natural preservatives. To circumvent this problem, nanoemulsion has evolved as a feasible strategy. Incorporating essential oil nanoemulsion into a biopolymer matrix of an edible coating ameliorates the postharvest deterioration of berries. Nanoemulsions improve the functional properties of essential oil-incorporated edible coatings by creating an effective barrier that improves antimicrobial properties, decreases water loss, reduces the rate of respiration and loss of firmness, and subsequently enhances the shelf life of berries. This paper summarizes how the physiological characteristics of fresh berries are affected by essential oil-based nanoemulsions integrated into edible coatings and recommends using these nanoemulsions to preserve berries.

Carbon dots as a distinctive platform fabricated through a sustainable approach for versatile applications

Red-emitting carbon dots (R-CDs) have garnered significant interest owing to its exceptional fluorescence (FL) characteristics. In this study, we present a one-pot solvothermal synthesis for producing biomass-derived R-CDs, utilizing Birch leaves as the primary raw material. The R-CDs display high solubility in ethanol and demonstrate deep-red emission at 625 nm with narrowband characteristics. After conducting a selectivity assessment with different metal ions, it is observed that R-CDs demonstrate exceptional sensitivity and specificity specifically to Fe3+. This demonstrates a linear relationship up to a concentration of 500 μM, with a detection limit of 0.302 μM (S/N=3). In this research, we created photoluminescent and transparent composites made from polyvinyl alcohol (PVA) with embedded fluorescent R-CDs, using the solution casting method for fabrication. The synthesized R-CDs exhibit robust and consistent FL in solution, whereas, the R-CDs@PVA nanocomposites (NCs) films are transparent and exceptionally flexible. The optimized 0.08 wt% R-CDs demonstrated the most effective ultra violet (UV) blockage across the UV-A (76.84 %), UV-B (74.86 %), and UV-C (78.46 %) region. However, PVA alone absorbed < 25 % of the light in all UV regions. The study explored the shape memory and FL characteristics of the R-CDs@PVA NCs changed under varying conditions such as water, temperature and pH. In alkaline conditions, the FL intensity of the R-CDs@PVA NCs increased due to the deprotonation of the R-CDs surface. In addition, R-CDs dispersed within PVA exhibit superior ink-free patterned substrates, proving to be advantageous for non-destructive template relief printing. Furthermore, R-CDs serve as effective anti-oxidants, combating 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and mitigating the oxidative stress (OS) in red blood cells (RBCs) induced by sodium nitrite (NaNO2). They aid in the restoration of essential stress indicators, encompassing lipid peroxidation (LPO), protein carbonyl content (PCC), total thiol (TT), superoxide dismutase (SOD), and catalase (CAT). Furthermore, R-CDs restored the damaged liver, kidney, heart, and pancreas by regulating biochemical parameters. Furthermore, incorporated R-CDs into red light-emitting diodes (R-LEDs) and white light-emitting diodes (W-LEDs), thereby enhancing plant growth efficiency. The results of this study highlight the possible of R-CDs as non-toxic, UV blocking agents suitable for developing edible coatings and packaging. These properties suggest their applicability in the food industry, anti-counterfeiting (AC) measures, and biomedical applications.

Extending the postharvest shelf life of sweet orange (Citrus sinensis L.) fruits using muskmelon seeds flour based edible coatings functionalized with oregano essential oil

Extending the postharvest shelf life of sweet orange (Citrus sinensis L.) fruits using muskmelon seeds flour based edible coatings functionalized with oregano essential oil

Effect of basil seed gum coating and ultrasound pretreatment on frying time, oil uptake, hardness, color indexes, and sensory properties of potato slices

Fried food products have low oil content with improved nutritional quality, higher crispiness, and better sensory attributes. Edible coatings can decrease the excessive oil uptake in deep-fat fried food products. Furthermore, ultrasound treatment before frying process decreased oil uptake of food products. So, in this study, the impact of gum edible coating and ultrasonic pretreatment (at two different power levels of 75 and 150 W) on the frying time of potato slices, and moisture percent, oil uptake, texture hardness, surface area change, color parameters (lightness, redness, yellowness, and total color change), and sensory attributes of fried potato slices were examined. Edible coating with basil seed gum (BSG) and ultrasonic pretreatment significantly increased the frying time of the slices (p < 0.05). The average moisture content of the fried slices changed from 49.48 % to 60.55 %, and was further increased by edible coating and ultrasonic treatment. The highest (26.92 %) and lowest (14.56 %) oil uptake were for the uncoated and coated-sonicated (150 W) fried potato slices, respectively. The ultrasound pretreatment significantly increased the hardness of fried potato slices (p < 0.05). The low and high intensity ultrasonic pretreatment (75 W and 150 W, respectively) significantly decreased the crust area change of fried potato slices (p < 0.05). The average lightness index of the fried samples changed from 63.30 to 71.58, and increased with increasing ultrasonic power. The minimum redness, yellowness, and total color change indexes were for the coated and high-power sonicated (150 W) samples, respectively. The highest appearance, odor, texture, flavor, and overall acceptance were for the coated and high-power sonicated (150 W) sample.

Effect of water chestnut based edible coating on the physicochemical quality and shelf life of apples

Preservation of perishable fruits and vegetables through edible coatings having functional roles, has gained importance now a days. The present study was designed to investigate the effect of water chestnut powder-based edible coatings on the quality and shelf life of apples (Kala kullu). Two treatments, T1 and T2, were developed by utilizing two different concentrations of heated water chestnut powder (2% and 2.5%, respectively). Whereas, 2% guar gum (T0+) was accustomed as positive control, and uncoated apples as negative control (T0−). Before developing emulsions, water chestnut powder was subjected to chemical, functional and structural analysis, after that emulsions developed were used to coat apples, which were investigated for physicochemical and sensory parameters, during 80 days storage at 20 °C. The findings indicated that emulsion capacity, emulsion stability, foaming capacity and viscosity of the coatings was significantly high (p ≤ 0.05) for T2, as compared to T1. During the storage of apples, significant (p ≤ 0.05) decrease in the weight loss and decay percentage was observed in T2. Increased pH and decrease in titratable acidity were also noted in T2. Coated apples (both T2 and T1) maintained the firmness of apples during storage duration, as compared to the uncoated ones. Significantly high (p ≤ 0.05) total phenolic contents and antioxidant capacity was shown by T2 as compared to other treatments, as during storage a comparatively lesser decrease in the values of these parameters was observed for T2. Sensory analysis results showed that T2 was given high scores for color, texture, taste, flavor and overall acceptability, as compared to other treatments. It was noted that T2 showed better outcomes in terms of sensory and physiochemical attributes, thus edible coatings having 2.5% water chestnut powder could be used to increase the shelf life of fruits.Graphical abstract

Alginate coatings applied on apple cubes as a vehicle for Lacticaseibacillus casei: probiotic viability and overall quality of a new functional product.

Worldwide, vegan and vegetarian lifestyles, as well as food allergies and intolerance (e.g. lactose intolerance and milk protein allergy) demand the development of alternatives to dairy-based probiotic foods. In the present study, probiotic Lacticaseibacillus casei CECT 9104 was added to alginate-based edible coatings enriched with inulin and oligofructose and applied to fresh-cut apple. Microbiological, physicochemical and sensory quality parameters of the apple cubes were monitored during 8 days of refrigerated storage. Lacticaseibacillus casei was tested for its antagonistic effect against inoculated Listeria innocua and Escherichia coli O157:H7. The viability of the probiotic strain during refrigerated storage and after simulated gastrointestinal digestion (GID) was evaluated. After 8 days of storage, 9.52-9.64 log colony-forming units (CFU) g-1 of L. casei were detected in apple samples. The functional apple cubes retained 8.31-8.43 log CFU g-1 of the probiotic after GID, without a significant effect of prebiotic addition. The microbiological quality and nutritional properties were maintained by the use of active coatings, whereas the sensory quality decreased after 8 days of storage. A bactericidal effect was exerted by the probiotic strain loaded in the coating against L. innocua artificially inoculated on apple cubes. Escherichia coli O157:H7 counts were reduced by 2.5 log after 8 days. This study has demonstrated the suitability of apple cubes as an alternative matrix to milk for carrying probiotic L. casei CECT 9104 and prebiotics, offering a promising alternative for the development of plant-based functional foods. © 2024 Society of Chemical Industry.

Applications of biotechnology for enhancing the shelf life of horticultural crops

AbstractHorticultural crops, encompassing fruits, vegetables, spices and herbs, play a critical role in providing nutrition and health‐promoting compounds. However, their limited storability challenges producers and exporters, resulting in significant postharvest losses. Traditional preservation methods like cold storage, controlled atmosphere storage and packaging techniques have been employed to prolong shelf life, but they have their constraints. Biotechnological interventions, notably genetic engineering, offer promising avenues to address these limitations. Genetic modifications target physiological processes such as ripening and ethylene production, enhancing resistance to postharvest diseases and improving nutritional profiles. For instance, genetically modified tomatoes with prolonged shelf life and reduced susceptibility to fungal infections showcase the potential of genetic engineering. Similarly, genetic modification has been successfully applied to various horticultural crops like apples, bananas and mushrooms, resulting in decreased browning and heightened disease resistance. Emerging technologies such as modified atmosphere packaging, edible coatings and nanoparticle treatments further augment efforts to extend shelf life. Despite their benefits, the debate surrounding genetically modified fruits and vegetables persists due to concerns regarding environmental impact, health implications and ethical considerations. This review offers insights into current practices and research endeavours aimed at enhancing the shelf life of horticultural crops through both traditional and biotechnological means, shedding light on opportunities and hurdles in this domain. Future directions include intensifying basic research to unravel molecular processes in harvested tissues, prioritising investigations that directly benefit consumers and developing sustainable and cost‐effective approaches for emerging technologies like modified atmosphere packaging, edible coatings and postharvest treatments.

Xanthan/ carboxymethyl cellulose-based edible coatings enriched with greenly synthesized ZnO-NPs for active packaging applications

The limited use of xanthan (Xa) and carboxymethyl cellulose (CMC) in the food packaging industry is due to their poor barrier and antimicrobial properties. The objective of this work was to enhance the characteristics of the CMC/Xa composite coating by incorporating ZnO nanoparticles (ZnO-NPs) that were prepared through a green method through Coriandrum sativum extract. FTIR and XRD confirmed the successful preparation of the coating and verified the interactions between its components. Compared to the neat CMC/Xa system, systems incorporated with ZnO-NPs exhibited excellent water barrier, mechanical, thermal, and antimicrobial characteristics. The CMC/Xa/ZnO-NP systems effectively prolonged the shelf life of tomatoes for a storage period of 20 days without any significant indications of spoilage or mass loss of the coated tomatoes. The obtained results indicated that the developed coating has the potential to replace traditional plastic packaging and effectively preserve food products.

Development of Functional Composite Edible Films or Coatings for Fruits Preservation with Addition of Pomace Oil-Based Nanoemulsion for Enhanced Barrier Properties and Caffeine for Enhanced Antioxidant Activity.

The aim of this study was to develop functional composite edible films or coatings for fruit preservation by the addition of bioactive components in combinations that have not yet been thoroughly studied, according to the relevant literature. Edible films were initially composed of (i) chitosan (CH), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio), and (ii) hydroxypropyl methylcellulose (HPMC), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio). The bioactive components incorporated (5, 10 and 15% v/v) were as follows: (i) pomace oil-based nanoemulsion (NE) aiming to enhance barrier properties, and (ii) caffeine (C), aiming to enhance the antioxidant activity of films, respectively. Indeed, NE addition led to very high barrier properties (low oxygen and water vapor permeability), increased flexibility and reduced color. Furthermore, the contribution of these coatings to fresh strawberries' preservation under cold storage was investigated, with very promising results concerning weight loss, color difference, and preservation of fruit moisture and quantity of O2 and CO2 inside the packages. Additionally, C addition led to very high antioxidant activity, reduced color and improved barrier properties. Finally, the contribution of these coatings to avocado's preservation under cold storage was investigated, with very encouraging results for color difference, hardness and peroxide value of the fruit samples.

Advances in biomaterials based food packaging systems: Current status and the way forward

World hunger is getting worse, while one-third of food produced around the globe is wasted and never consumed. It is vital to reduce food waste to promote the sustainability of food systems, and improved food packaging solutions can augment this effort. The utilization of biomaterials in smart food packaging not only enhances food preservation and safety but also aligns with current demands for eco-friendly technologies to mitigate the impacts of climate change. This review provides a comprehensive overview of the developments in the field of food packaging based on the innovative use of biomaterials. It emphasizes the potential use of biomaterials derived from nature including cellulose, chitosan, keratin, etc. for this purpose. Various smart food packaging technologies such as active and intelligent packaging are discussed in detail including scavenging additives, colour-changing environment indicators, sensors, RFID tags, etc. The article also delves into the utilization of edible films and coatings, nanoparticle fillers and 2D materials in food packaging systems. Furthermore, it outlines the challenges and opportunities in this dynamic domain, emphasizing the ongoing need for research and innovation to shape the future of sustainable and smart food packaging solutions to enhance and monitor the shelf-life of food products.

Exploring the Potential of Anthocyanin-Based Edible Coatings in Confectionery-Temperature Stability, pH, and Biocapacity.

This study aims to develop purple-coloured polymeric coatings using natural anthocyanin and desoxyanthocianidins (3-DXA) colourants for application to chocolate almonds. The objective is to achieve a stable and uniform colour formulation throughout processing and storage, enhancing the appearance and durability of the almonds to appeal to health-conscious consumers and align with market demands. Plant materials like sweet potato pulp, sweet potato peel, radish peel, black carrot, and sorghum were employed to obtain the desired purple hue. Anthocyanidins and 3-DXA were extracted from the matrices using solvent extraction and ultrasound-assisted methods at different pH values. High-performance liquid chromatography with diode array detection (HPLC-DAD) and high-resolution tandem mass spectrometry (HRMS/MS) were used to identify the compounds in the extracts. The highest antioxidant capacities, as measured by the DPPH• and FRAP methods, were observed in purple sweet potato and dye factory extracts, respectively; meanwhile, sorghum extract inhibited both α-amylase and α-glucosidase, indicating its potential for managing postprandial hyperglycemia and type 2 diabetes. The degradation kinetics of coloured coatings in sugar syrup formulations with anthocyanins and 3-DXA revealed that locust bean gum offered the best colour stabilization for plant extracts, with sorghum extracts showing the highest and black carrot extracts the lowest colour variation when coated with Arabic gum. Sweet potato pulp extracts exhibited less colour variation in sugar pastes, both with and without blue spirulina dye, compared to factory dye, highlighting their potential as a more stable and suitable alternative for colouring purple almonds, particularly over a five-month storage period. This study supports sustainable practices in the confectionery industry while aligning with consumer preferences for healthier and environmentally friendly products.

Application of Edible Coating from Beneng Taro Starch, Chitosan and Ginger Essential Oil to Maintain the Quality of Mango

Application of Edible Coating from Beneng Taro Starch, Chitosan and Ginger Essential Oil to Maintain the Quality of Mango

Maintenance of postharvest quality of ‘Palmer’ mango coated with biodegradable coatings based on cassava starch and emulsion of lemongrass essential oil

This study aimed to evaluate the effect of applying oxidized cassava starch-based edible coatings with addition of lemongrass essential oil emulsion on ‘Palmer’ mangoes stored under refrigeration. A completely randomized design was used, arranged in a 5 × 3 factorial scheme, with five types of coatings and three evaluation times. The evaluated postharvest quality parameters consisted of weight loss, pulp and peel firmness, biochemical transformations related to pigments, and pulp and peel coloration of mango. The application of edible coatings with a 0.9 % EO concentration resulted in delayed fruit ripening, evidenced mainly by a 7.25 % reduction in weight loss, a 29.23 % increase in soluble solids content, and a 24.15 % decrease in total chlorophyll, when compared to uncoated fruits, which showed 19.8 %, 48.66 %, and 82.00 %, respectively, over the storage period. This effect was also evident in the angle Hue (°h) measurement, with uncoated fruits showing a decrease of 32.2 %. The antimicrobial effect and absence of anthracnose symptoms were observed in the fruits in which the coating with 0.9 % EO was applied. Therefore, biodegradable coating with the addition of 0.9 % emulsion EO, can be used as postharvest treatments for maintenance quality of ‘Palmer’ mangoes during refrigerated storage.

Edible Oil-Based Coatings Preserve Quality of Organic Apple cv. ‘Golden Delicious’ during Storage

Edible Oil-Based Coatings Preserve Quality of Organic Apple cv. ‘Golden Delicious’ during Storage

Encapsulation of Peperomia pellucida (L.) kunth leaf extract for postharvest preservation of Malang apple (Malus sylvestris) at ambient storage

This study investigated the efficacy of edible coatings based on encapsulated Peperomia pellucida leaf extract to extend the shelf life of Malang apples. An edible coating was developed by encapsulating P. pellucida leaf extract using a chitosan-STPP matrix. The optimum encapsulation efficiency observed of polyphenols and flavonoids retention was 86.25% ± 0.02 and 83.30% ± 0.04, respectively. It achieved by 2.5% chitosan, 2% STPP, and 3.5% extract in formula. The encapsulated extract was further applied to Malang apples as edible coated using varying dipping times and stored for 15 days at ambient temperature. Evaluation parameters on coated Malang apples included hardness, weight loss, pH, moisture content, and color change. A 1-min dipping time of the encapsulated extract was found to be optimal, effectively reducing physical and chemical alterations and enhancing the shelf-life quality of the apples. Therefore, the edible coating derived from encapsulated P. pellucida leaf extract presents a promising alternative for preserving Malang apples.

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.

Enhancing postharvest quality of sapota fruit using edible coatings and malic acid

Sapota is a tropical fruit that grows in tropical regions and is highly perishable and sensitive to low temperatures. The main problem with sapota marketing is that it is ripe in less than a week after harvest and has a short storage life. Therefore, this study was conducted to investigate the effect of edible coatings containing 2% sodium alginate (AL), 2% carboxymethyl cellulose (CMC), 10% gum Arabic (GA) and 1% oleic acid (OL) in combination with malic acid (MA) to improve the postharvest quality of sapota during 32 days of storage at 10 °C and 90% relative humidity. The results showed that the least weight loss was observed in coated fruits. In addition, the treatments resulted in more firmness and reduced electrolyte leakage. The best treatments for delaying malondialdehyde production were MA and CMC/MA, and MA was the most effective treatment for increasing catalase activity. According to the results, all treatments showed more significant bioactive compounds than untreated fruit. Application of GA/MA and AL/MA resulted in more phenol and flavonoid content, respectively. This study showed the positive effect of edible coatings and MA on improving the postharvest quality of sapota fruit.

Essential oil-nanoemulsion based edible coating: Innovative sustainable preservation method for fresh/fresh-cut fruits and vegetables

Utilizing plant-based sources for the preservation of fresh and fresh-cut fruits and vegetables offers a natural and chemical-free method. However, the inherent instability of plant bioactive compounds underscores the necessity for encapsulation techniques. Essential oil-based nanoemulsions (EO-NEs) stand out among food additives due to their distinctive antibacterial and antioxidant properties. This review delves into recent advancements in the application of EO-NEs as edible coatings for fresh and fresh-cut produce. It examines the efficacy of EO-NEs in enhancing the preservation of fruits and vegetables by harnessing their bioactive compounds for antibacterial, antifungal, and antioxidant activities. Additionally, the review accentuates the efficacy of EO-NEs in inhibiting biofilm formation on fruits and vegetables. It reveals that coatings derived from plant-source nanoemulsions exhibit exceptional mechanical, optical, and microstructural qualities, as well as superior water barrier properties. In contrast to conventional emulsions, nanocoatings facilitate the gradual and controlled release of antimicrobial and antioxidant compounds during food storage. This feature enhances bioactivity, extends shelf life, and enhances the nutritional profile of products. By preserving and protecting shelf stability, EO-NEs contribute to the maintenance of vegetable freshness. Nonetheless, ensuring their commercial viability necessitates additional research into the toxicity of EO-based nanoemulsions.