Use of biopolymeric coating hydrophobized with beeswax in post-harvest conservation of guavas

Revolutionizing tropical fruits preservation: Emerging edible coating technologies

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

Recent advances in starch-based coatings for the postharvest preservation of fruits and vegetables

Efficient and low-cost postharvest preservation of fruits and vegetables has always been one of the urgent problems to be solved in the food field. Due to the wide sources, good environmental and human safety, and high biodegradability, starch-based coating preservation method has great application prospects in the postharvest preservation of fruits and vegetables. However, starch materials also have the disadvantages of poor mechanical properties and easy water absorption performance, which makes it difficult to fully meet the requirements in practical production. Therefore, starch is often used in combination with other components to form composite materials. This paper began with an introduction to the preservation principles of edible starch-based coatings, including inherent properties and extra functional properties. Besides, the preservation principles of edible coatings and the recent advances in the field of fruit and vegetable preservation were also comprehensively reviewed, focusing on the preparation and application of starch-based coatings. The information will contribute to the further development of starch-based coatings to improve the postharvest preservation effect of fruits and vegetables.

Lipid incorporated biopolymer based edible films and coatings in food packaging: A review

In the evolving landscape of food packaging, lipid-based edible films and coatings are emerging as a sustainable and effective solution for enhancing food quality and prolonging shelf life. This critical review aims to offer a comprehensive overview of the functional properties, roles, and fabrication techniques associated with lipid-based materials in food packaging. It explores the unique advantages of lipids, including waxes, resins, and fatty acids, in providing effective water vapor, gas, and microbial barriers. When integrated with other biopolymers, such as proteins and polysaccharides, lipid-based composite films demonstrate superior thermal, mechanical, and barrier properties. The review also covers the application of these innovative coatings in preserving a wide range of fruits and vegetables, highlighting their role in reducing moisture loss, controlling respiration rates, and maintaining firmness. Furthermore, the safety aspects of lipid-based coatings are discussed to address consumer and regulatory concerns.

Postharvest Physiology and Handling of Guava Fruit

Guavas are typical tropical fruit with high nutritional and commercial value. Because of their thin skin and high metabolic rate, guavas are highly susceptible to water loss, physical damage, and spoilage, severely limiting their shelf-life. Guavas can typically only be stored for approximately one week at room temperature, making transportation, storage, and handling difficult, resulting in low profit margins in the industry. This review focuses on the physiological and biochemical changes and their molecular mechanisms which occur in postharvest guavas, and summarizes the various management strategies for extending the shelf-life of these sensitive fruits by means of physical and chemical preservation and their combinations. This review also suggests future directions and reference ideas for the development of safe and efficient shelf-life extension techniques.

Recent advancements in polysaccharides, proteins and lipids based edible coatings to enhance guava fruit shelf-life: A review

Fresh fruits are highly needed for the health benefits of human beings because of the presence of high content of natural nutrition in the form of vitamins, minerals, antioxidants, and other phenolic compounds. However, some nutritional fruits such as guava are climacteric in nature with very less post-harvest shelf-life because of the ripening in a very short period and possibility of microbial infections. Thus security of natural nutrients is a serious concern in order to properly utilize guava without generating a huge amount of waste. Among reported various methods for the enhancement of fruits shelf-life, the application of edible coatings with antimicrobial activities on the outer surface of fruits have attracted significant attention because of their eco-friendly nature, easy applicability, high efficacy, and good durability. In recent years, researchers are paying more and more attention in the development of antimicrobial edible coatings to enhance the post-harvest shelf-life of guava using polysaccharides, protein and lipids. In this review, basic approaches and recent advancements in development of antimicrobial and edible coatings on guava fruit by the application of polysaccharides and protein and lipids along with the combination of nanomaterials are summarized. In addition, improvements in basic properties of edible coatings to significantly control the permeation of gases (O2/CO2) by the optimization of coating components as well as delay in ripening process are reviewed and discussed.

TiO2 incorporated into a blend of biopolymeric matrices improves film properties and affects the postharvest conservation of papaya fruits under UV light

This work investigated the properties of chitosan-cassava starch biopolymeric films containing nanometric photoactive TiO2 particles for use in postharvest conservation of papaya fruits under UV light at a temperature of 15 ± 1 °C and a relative humidity of 90 ± 1 % for 24 days. Starch-chitosan blend films showed intermediate hydrophobicity and improved mechanical properties. The addition of 1 % TiO2 into the polymeric matrix of starch/chitosan (1:1) further improved the mechanical properties with solubility of 16.04 ± 0.41 %, visible transmittance of 31.76 ± 1.58 %, and reduced UV transmittance of more than 97 %. However, the addition of TiO2 exceeding 1 % led to the formation of agglomerates and excessive reduction in film transparency. UV exposure damaged the fruit peel and resulted in a higher weight loss. In contrast, the addition of 1 % TiO2 to the blend reduced the weight loss in light and dark by 7.12 ± 1.57 % and 5.27 ± 0.31 % respectively, and delayed fruit ripening.

Effect of coating using beeswax and sodium nitroprusside on chlorophyll stability and quality factors of lime during cold storage

Lime (Citrus floridana) is a quickly perishable fruit, limiting its shelf life because of reduced chlorophyll content and post-harvest quality under different storage conditions. To increase chlorophyll stability as well as other quality factors of limes, they were coated with beeswax in 0.1 wt.% and sodium nitroprusside in three various concentrations (0.1, 0.2, and 0.4 mM) at 25 °C for 3 min and then stored at 8 °C for 60 days. In this research, changes in weight loss, juice content, firmness (F), chlorophyll, chlorophyllase activity, polyphenol oxidase activity, color, total acidity (titratable acidity), ascorbic acid (ASA) and sensory evaluation were studied. During storage at low temperatures, BW surface coating (0.1%) alone, sodium nitroprusside alone, and also in combination with each other and a double layer were effective in maintaining chlorophyll and the qualitative characteristics of limes. In our observations, the best treatment was the treatment where the limes were coated by beeswax enriched by sodium nitroprusside coating. This treatment contained the highest content of lime juice and the highest chlorophyll plus the lowest activity of chlorophyllase and polyphenol oxidase, while the amount of green color was maintained to a large extent. As a result, it is possible to use beeswax enriched by sodium nitroprusside coating method to maintain the quality and chlorophyll of cold-stored lime fruits.

Enhancing the Properties of Polyvinyl Alcohol Films by Blending with Corn Stover-Derived Cellulose Nanocrystals and Beeswax

Coating is a technique to surround a target substance with a thin layer to obtain desirable properties. Polyvinyl alcohols (PVAs) are biodegradable plastics and have shown good applicability as a coating or film material. Cellulose nanocrystals are a promising green nanomaterial that has been shown to enhance the properties of PVA after blending. However, these PVA/CNC films have concerns in a moist environment due to high hydrophilicity. To overcome this issue, the current study incorporated beeswax into PVA/CNC films and investigated the effect of CNC and beeswax on the properties of the coatings and films. Results showed that the addition of corn stover-derived CNCs to PVA films increased tensile strength (from 11 to 25 MPa) and Young's modulus (from 32 to 173 MPa) and reduced water vapor transmission rate (from 25 to 20 g h-1 m-2). Beeswax added to PVA/CNC films further improved water vapor barrier properties (from 20 to 9 g h-1 m-2) and maintained Young's modulus (from 173 to 160 MPa), though it caused a reduction in the tensile strength (from 25 to 11 MPa) of the films. This information can help to select materials for blending with PVAs by obtaining the desirable endmost properties depending on applications.

Beeswax: A review on the recent progress in the development of superhydrophobic films/coatings and their applications in fruits preservation

Recently, the design and fabrication of bio-inspired superhydrophobic materials using natural lipid additives such as beeswax (BW) have aroused great attention in food packaging as they can minimize the transfer rate of water molecules and have effective moisture barriers. This review discusses the recent progress in the design and fabrication of BW-containing edible films/coatings (e.g., emulsion and blend films, bilayer materials, bionanocomposites, and antimicrobial materials) and their potential applications on the postharvest life and quality attributes of various fruits. Incorporation of BW into polysaccharides- and proteins-based emulsion films effectively improved their hydrophobicity, water vapor, and UV/visible light barrier properties, as well as the film tensile properties. The addition of nanoparticles to BW-based polymeric matrices often results in improved physico-mechanical properties. BW coatings have been also applied to prolong the shelf-life of various climacteric fruits, however, optimization of the wax concentration can be further investigated to develop targeted food storage systems.

Biodegradable active packaging: Components, preparation, and applications in the preservation of postharvest perishable fruits and vegetables

The consumption of fresh fruits and vegetables is restricted by the susceptibility of fresh produce to deterioration caused by postharvest physiological and metabolic activities. Developing efficient preservation strategies is thus among the most important scientific issues to be urgently addressed in the field of food science. The incorporation of active agents into a polymer matrix to prepare biodegradable active packaging is being increasingly explored to mitigate the postharvest spoilage of fruits and vegetables during storage. This paper reviews the composition of biodegradable polymers and the methods used to prepare biodegradable active packaging. In addition, the interactions between bioactive ingredients and biodegradable polymers that can lead to plasticizing or cross-linking effects are summarized. Furthermore, the applications of biodegradable active (i.e., antibacterial, antioxidant, ethylene removing, barrier, and modified atmosphere) packaging in the preservation of fruits and vegetables are illustrated. These films may increase sensory acceptability, improve quality, and prolong the shelf life of postharvest products. Finally, the challenges and trends of biodegradable active packaging in the preservation of fruits and vegetables are discussed. This review aims to provide new ideas and insights for developing novel biodegradable active packaging materials and their practical application in the preservation of postharvest fruits and vegetables.

A comprehensive review on clove (Caryophyllus aromaticus L.) essential oil and its significance in the formulation of edible coatings for potential food applications

Many studies have demonstrated the use of synthetic preservatives and chemical additives in food is causing poisoning, cancer, and other degenerative disorders. New solutions for food preservation with quality maintenance are currently emerging. As a result, public concern has grown, as they desire to eat healthier products that use natural preservatives and compounds rather than synthetic ones. Clove is a highly prized spice used as a food preservative and for a variety of therapeutic reasons. Clove essential oil and its principal active component, eugenol, indicate antibacterial and antifungal action, aromaticity, and safety as promising and valuable antiseptics in the food sector. Clove essential oil and eugenol are found to have strong inhibition effects on a variety of food-source bacteria, and the mechanisms are linked to lowering migration and adhesion, as well as blocking the creation of biofilm and various virulence factors. This review emphasizes the importance of CEO (clove essential oil) in the food industry and how it can be explored with edible coatings to deliver its functional properties in food preservation.

Recent Advances in Novel Packaging Technologies for Shelf-Life Extension of Guava Fruits for Retaining Health Benefits for Longer Duration

Guava (Psidium guajava L.) fruit is also known as the apple of tropics, belongs to the family of genus Psidium, and is widely cultivated in tropical zones of the world. Recently, the importance of guava fruit has increased due to its inherent nutritional content, pleasant aroma, excellent flavor, and delicious taste. It is considered an excellent source of nutrients and phytochemicals. Guava is a climacteric fruit that continues to mature or ripen even after harvest, showing an increase in the rate of respiration and metabolic activities within a short period, leading to rapid senescence or spoilage of fruit. It has limitations in terms of commercialization due to short storage life after harvest and sensitivity to diseases and chilling injury during the storage period. Many postharvest technologies such as edible packaging, modified atmosphere packaging (MAP), composite packaging, controlled atmosphere packaging (CAP), antimicrobial/antifungal packaging, and nano packaging have been used to retard the chilling injury and enhance the keeping quality of guava fruits during the storage period to control respiration rate, reduce weight loss, minimize lipid oxidation, and maintain organoleptic properties. However, these packaging technologies have varied effects on the internal and external quality attributes of guava fruits. This review, therefore, discusses the physiology, mechanism of ripening, oxidation, and ethylene production of guava fruits. The review also discusses the packaging technologies and their effect on the postharvest characteristics of guava fruits during the storage period.

Production of mycosporine-like amino acid (MAA)-loaded emulsions as chemical barriers to control sunscald in fruits and vegetables

BACKGROUND

Sunscald is a physiological disorder that occurs in many horticultural products when exposed to excessive solar radiation and high temperatures. Traditionally, sunscald is controlled using physical barriers that reflect radiation, however this practice is not always efficient. A possible alternative would be the use of chemical barriers, such as mycosporine-like amino acids (MAAs), which protect aquatic organisms against ultraviolet (UV) radiation. Thus, this study aimed to develop a lipid-based emulsion containing MAAs for using in the preharvest of horticultural products.

RESULTS

Emulsions were developed using 10% (w/v) of corn oil (CO) and soybean oil (SO), carnauba wax (CW), and beeswax (BW) as lipid bases (LBs). The emulsion containing CW and ammonium hydroxide was the most stable, resembling commercial wax. Therefore, this formulation was used as the basis for the incorporation of the commercial product Helioguard™ 365, a source of MAA, in concentrations of 0%, 1%, 2%, and 4% (v/v). The MAA incorporation resulted in little modifications in the stability of the emulsion, providing an increase in the absorbance with peaks in the UV-B ranging from 280 to 300 nm.

CONCLUSION

The lipid-base emulsion containing MAAs could be used as a chemical barrier to control sunscald in horticultural products. © 2021 Society of Chemical Industry.

Application of Potentially Probiotic Fruit-Derived Lactic Acid Bacteria Loaded into Sodium Alginate Coatings to Control Anthracnose Development in Guava and Mango During Storage

This study evaluated the efficacy of potentially probiotic fruit-derived lactic acid bacteria (LAB) strains loaded into sodium alginate (SA) coatings to control the anthracnose development in guava cv. Paluma and mango cv. Palmer caused by distinct pathogenic Colletotrichum species (C. asianum, C. fructicola, C. tropicale, C. siamense, C. karstii, and C. gloeosporioides) during 15 days of room temperature storage (25 ± 0.5 °C). The effects of the formulated coatings on physicochemical parameters indicative of overall postharvest quality of guava and mango were evaluated. The eight examined LAB strains caused strong inhibition on the mycelial growth of all target Colletotrichum species in vitro. LAB strains with the highest inhibitory effects (Levilactobacillus brevis 59, Lactiplantibacillus pentosus 129, and Limosilactobacillus fermentum 263) on the target Colletotrichum species were incorporated into SA coatings. These strains had viable counts of > 6 log CFU/mL in SA coatings during 15 days of room temperature storage. Application of coatings with SA + L. brevis 59, SA + L. pentosus 129, and SA + L. fermentum 263 delayed the development and decreased the severity of anthracnose lesions in guava and mango artificially contaminated with either of the tested Colletotrichum species. These coatings impacted positively on some physicochemical parameters indicative of postharvest quality and more prolonged storability of guava and mango. The formulated SA coatings loaded with tested fruit-derived potentially probiotic LAB strains could be innovative and effective strategies to control postharvest anthracnose and extend the storability of guava and mango.

Improvement of the Performance of Chitosan-Aloe vera Coatings by Adding Beeswax on Postharvest Quality of Mango Fruit

The effect of the application of chitosan–Aloe vera coatings emulsified with beeswax (0, 0.5, 1, 1.5 and 2%) during storage of Mangifera indica L. (cv Anwar Ratol) was investigated. Particle size of emulsions was reduced significantly with an increase in beeswax concentration. Water vapor permeability of the coatings was reduced by 43.7% with an increase in concentration of beeswax to 2%. The coated mangoes (at all concentrations of beeswax) exhibited reduced weight loss, delayed firmness loss, minimized pH change, maintained the total soluble solid contents, and retained free radical scavenging activity and total phenolic contents when stored at 18 °C and 75 ± 5% R.H. The best results were produced with a formulation containing 2.0% beeswax. Antimicrobial properties of chitosan and Aloe vera coatings were also improved with an increase in beeswax concentration and remarkably reduced the disease incidence in mangoes. In conclusion, beeswax-emulsified chitosan–Aloe vera coatings can be effectively used to increase the shelf life and marketable period of mangoes.

Potentials of polysaccharides, lipids and proteins in biodegradable food packaging applications

Bio-based packaging materials are gaining importance due to their biodegradability, sustainability and environmental friendliness. To control the food quality and improve the food safety standards, proteins polysaccharide and lipid-based packaging films are enriched with bioactive and functional substances. However, poor permeability and mechanical characteristics are the challenging areas in their commercialization. Scientists and researchers are using a combination of techniques i.e. hydrogels, crosslinking, etc. to improve the intermolecular forces between different components of the film formulation to counter these challenges More recently, biodegradable packaging materials, sometimes edible, are also used for the delivery of functional ingredients which reveals their potential for drug delivery to counter the nutrient deficiency problems. This study highlights the potentials of bio-based materials i.e. proteins, polysaccharides, lipids, etc. to develop biodegradable packaging materials. It also explores the additives used to improve the physicochemical and mechanical properties of biodegradable packaging materials. Furthermore, it highlights the novel trends in biodegradable packaging from a food safety and quality point of view.

Characterization of Beeswax, Candelilla Wax and Paraffin Wax for Coating Cheeses

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.

Effects of edible coatings of Chlorella sp. containing pomegranate seed oil on quality of Spondias tuberosa fruit during cold storage

Spondias tuberosa is a highly perishable fruit that is difficult to transport, which limits its consumption in local areas. Thus, for economic reasons, there is a need for technologies to extend post-harvest shelf life of these fruits. The aim of this study was to evaluate the life of Spondias tuberosa fruit using edible coatings composed of Chlorella sp. and pomegranate seed oil (PSO) during cold storage. Coated and uncoated S. tuberosa fruits were stored for 12 days at 14 ± 2 °C and 85 ± 5% RH and evaluated every 3 days. Chlorella sp. + PSO coatings retarded ripening, maintained firmness, mass, and a greener color when compared to control treatment - since by default controls are not treated. Coatings in association with the best quality fruit presented 2.0% of Chlorella sp.

Chitosan-citric acid edible coating to control Colletotrichum gloeosporioides and maintain quality parameters of fresh-cut guava

This study aimed to verify the action of edible chitosan-citric acid (CHI-CA) coating to control Colletotrichum gloeosporioides and maintain quality parameters of fresh-cut guava. Chitosan was obtained from Litopenaeus vannamei shells using high temperature and short exposure times. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of CHI-CA against C. gloeosporioides were determined by macrodilutions at 28 °C/120 h in the absence/presence of CHI-CA (0-10 mg/mL). Scanning electron microscopy was used to evaluate morphological changes in the fungus. Guava slices were coated with CHI-CA (MIC) or 5 mg/mL glycerol (control). Rot incidence and physicochemical, physical, and microbiological factors were determined at 0, 3, 7, and 14 days at 24 °C and 4 °C. Chitosan presented typical structural characterization, 64% deacetylation, and a molecular weight of 1.6 × 10⁴ g/mol. CHI-CA exhibited MIC and MFC values of 5 mg/mL and 10 mg/mL, respectively, and promoted changes in the morphology and cell surface of fungal spores. The fresh-cut guava coated with CHI-CA maintained quality parameters during storage and preserved their sensorial characteristics. Therefore, the use of CHI-CA as a coating is a promising strategy for improving postharvest quality of fresh-cut fruits.

Trends and advances in edible biopolymer coating for tropical fruit: A review

Nowadays, many of the tropical fruits have been commercialized worldwide due to increasing demand. In 2018, global tropical fruit has reached an unprecedented peak of 7.1 million tonnes. As such, a lot of large scale farming has been initiated to cultivate the fruit for commercialization. The nature of tropical fruit is perishable make the fruit easily undergo post-harvest losses especially when the fruit travels in a long distance for distribution. Losses of tropical fruit is estimated around 18-28% after harvesting. Then, the losses will continually develop during the trading process. Applying fruit coating on the fruit can minimize substantial privation. This article compendiously reviews the needs of coating and discuss different types of coating materials. The efficiency of different coating materials; polysaccharide, protein, lipid and composite based coating on tropical fruit is highlighted. There are various types of coating available for major fruit such as banana, mango, pineapple and avocado that can effectively extend the post-harvest life, minimize water loss, reduce chilling injuries and fight against post-harvest disease. Coating from minor fruit such as durian, rambutan, passion-fruit and mangosteen are still limited especially made from lipid and protein coating. In choosing the most appropriate coating for tropical, the nature of fruit needs to be understood. In addition, the chemistry of coating components and techniques of application is important in modulating the fruit quality.

Acetonitrile-Ethyl acetate based method for the residue analysis of 373 pesticides in beeswax using LC-MS/MS and GC-MS/MS

In the current study, Pesticide residue extraction in beeswax was carried out using a mixture of acetonitrile-ethyl acetate (1:3, v/v). This mixture of solvents not only enables the melting of beeswax sample at a lower temperature than when using acetonitrile only but also introduces one phase solution. The sample extract was directly injected into both GC-MS/MS, of the commonly used split-less inlets, and into LC-MS/MS. Sample preparation and clean-up were also optimized. The developed method was validated according to SANTE/11813/2017 European Union guidelines. Three spiking levels of low concentrations 20, 50, 100 µg/kg were studied for the analysis of a total of 373 pesticides. Most of the studied pesticides have acceptable recovery between 80 and 110% with good reproducibility <10. There are 265 and 139 pesticides having a lower limit of quantifications equal 20 µg/kg using LC-MS/MS and GC-MS/MS, respectively. Finally, the developed method was successfully applied for the analysis of real beeswax samples.