Spray technology applications of xanthan gum-based edible coatings for fresh-cut lotus root (Nelumbo nucifera)

Improving fresh-cut fruit salad quality and longevity with chitosan coating enriched with poppy seed phenolics

This innovative study introduces the application of a 5% (v/v) poppy seed phenolic extract-infused edible chitosan coating on fresh-cut fruit salads (comprising apple, pineapple, pomegranate, and kiwi) stored at +4°C for 12 days. Non-coated samples experienced notable changes: 4.30% weight loss, 25% decay, pH level at 3.59, titratable acidity of 0.18%, and browning index of 1.71. In contrast, fruit salads coated with chitosan-poppy seed phenolic extract exhibited significant improvements: weight loss reduced to 3.10%, decay limited to 3.13%, pH increased to 3.76, titratable acidity enhanced to 0.20%, and browning index notably decreased to 0.33. Soluble solids ranged from 11.83 to 14.71, L* from -8.13 to 18.64, a* from -1.85 to 22.35, and b* from 8.26 to 27.89 in non-coated salads. Adding poppy seed phenolic extract to the coated fruits slightly expanded these ranges. Sensory evaluations consistently rated non-coated samples between 1 and 3, while the coated samples received higher ratings between 6 and 7. These assessments consistently highlighted enhanced attributes, including intensified aroma, enriched color, improved taste, texture, and overall acceptability. Moreover, incorporating poppy seed phenolic extract amplified sensory qualities and significantly improved microbial safety (<106 CFU/g). In summary, the chitosan-based coating, enriched with poppy seed phenolic extract, effectively extended the shelf life of fresh-cut fruit salads. This integrated approach preserves key attributes, ensures microbial quality, and enhances the sensory characteristics of these products. The study's results emphasize its potential as a pivotal innovation in food preservation by providing specific and tangible outcomes.

Applications and characterization of anti-browning enzymatically modified potato starch (EPS) film associated with chitosan (CTS)/L-Cys/citric acid (CA) on fresh-cut potato slices

This study explores the influence of incorporating L-cysteine (L-Cys), chitosan (CTS), and citric acid (CA) on the enzymatic modification of potato starch (EPS) films to enhance anti-browning properties. Four types of EPS composite films were evaluated for preserving fresh-cut potato slices at low temperatures to inhibit browning. Their thermal, physiochemical, mechanical, and digestibility properties were assessed. Results indicate that the addition of CTS, CA, and L-Cys improved the anti-browning activity of the EPS films by increasing film thickness and reducing water vapor permeability (WVP), oxygen transmission rate (OTR), ultraviolet (UV) transmittance, and tensile strength (TS). Furthermore, these additives improved the film's microstructure, resulting in reinforced intermolecular interactions, increased elongation at break, heightened crystallinity, enhanced thermal stability, and favorable gastrointestinal digestibility. Overall, EPS/CTS/L-Cys/CA composite films show promise as edible packaging materials with effective anti-browning properties.

Review on emerging trends and challenges in the modification of xanthan gum for various applications

This review explores the realm of structural modifications and broad spectrum of their potential applications, with a special focus on the synthesis of xanthan gum derivatives through graft copolymerization methods. It delves into the creation of these derivatives by attaching functional groups (-OH and -COOH) to xanthan gum, utilizing a variety of initiators for grafting, and examining their diverse applications, especially in the areas of food packaging, pharmaceuticals, wastewater treatment, and antimicrobial activities. Xanthan gum is a biocompatible, biodegradable, less toxic, bioactive, and cost-effective natural polymer derived from Xanthomonas species. The native properties of xanthan gum can be improved by cross-linking, grafting, curing, blending, and various modification techniques. Grafted xanthan gum has excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing ability. Owing to its remarkable properties, such as biocompatibility and its ability to form gels resembling the extracellular matrix of tissues, modified xanthan gum finds extensive utility across biomedicine, engineering, and the food industry. Furthermore, the review also covers various modified derivatives of xanthan gum that exhibit excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing abilities. These applications could serve as important resources for a wide range of industries in future product development.

Xanthan gum coatings augmented with lemongrass oil preserve postharvest quality and antioxidant defence system of Kinnow fruit under low-temperature storage

Kinnow mandarin is an important citrus fruit that undergoes various postharvest qualitative losses. Therefore, the present study aimed to investigate the effect of polysaccharide-based xanthan gum (XG) coatings and lemongrass essential oil (LG) on the nutritive quality of Kinnow mandarins stored at 5-7 °C, 90-95 % RH for 75 days. The results revealed that in comparison to control the coatings maintained the fruit titratable acidity (TA), soluble solid content (SSC), ascorbic acid (AsA) content, total flavonoid content (TFC), and juice content, along with reduced weight loss and spoilage incidence. The coated fruits also exhibited higher sensory quality, total antioxidant activity (TAA), and activities of enzymes; catalase (CAT), peroxidase (POD), and phenylalanine ammonia-lyase (PAL). At the end of storage, the fruits coated with XG 1.0 % + LG 1.0 % exhibited maximum TA (0.69 %), AsA content (203.5 mg L-1), and TFC (0.21 mg g-1) with minimum weight loss (7.57 %) and spoilage (3.01 %) and SSC (11.87 %). The scanning electron microscopic (SEM) images of the coated fruits also exhibited smooth surfaces with closed stomata pores. Overall, XG 1.0 % + LG 1.0 % proved as a potential postharvest treatment for maintaining the nutritive quality of Kinnow under low-temperature storage.

Recent Highlights in Sustainable Bio-Based Edible Films and Coatings for Fruit and Vegetable Applications

The present review paper focuses on recent developments in edible films and coatings made of base compounds from biological sources, namely plants, animals, algae, and microorganisms. These sources include by-products, residues, and wastes from agro-food industries and sea products that contribute to sustainability concerns. Chitosan, derived from animal biological sources, such as crustacean exoskeletons, has been the most studied base compound over the past three years. Polysaccharides typically constitute no more than 3-5% of the film/coating base solution, with some exceptions, like Arabic gum. Proteins and lipids may be present in higher concentrations, such as zein and beeswax. This review also discusses the enrichment of these bio-based films and coatings with various functional and/or bioactive compounds to confer or enhance their functionalities, such as antimicrobial, antioxidant, and anti-enzymatic properties, as well as physical properties. Whenever possible, a comparative analysis among different formulations was performed. The results of the applications of these edible films and coatings to fruit and vegetable products are also described, including shelf life extension, inhibition of microbial growth, and prevention of oxidation. This review also explores novel types of packaging, such as active and intelligent packaging. The potential health benefits of edible films and coatings, as well as the biodegradability of films, are also discussed. Finally, this review addresses recent innovations in the edible films and coatings industry, including the use of nanotechnologies, aerogels, and probiotics, and provides future perspectives and the challenges that the sector is facing.

Advanced biopolymer-based edible coating technologies for food preservation and packaging

Along with the growth of the world's population that reduces the accessibility of arable land and water, demand for food, as the fundamental element of human beings, has been continuously increasing each day. This situation not only becomes a challenge for the modern food chain systems but also affects food availability throughout the world. Edible coating is expected to play a significant role in food preservation and packaging, where this technique can reduce the number of food loss and subsequently ensure more sustainable food and agriculture production through various mechanisms. This review provides comprehensive information related to the currently available advanced technologies of coating applications, which include advanced methods (i.e., nanoscale and multilayer coating methods) and advanced properties (i.e., active, self-healing, and super hydrophobic coating properties). Furthermore, the benefits and drawbacks of those technologies during their applications on foods are also discussed. For further research, opportunities are foreseen to develop robust edible coating methods by combining multiple advanced technologies for large-scale and more sustainable industrial production.

Continuous roller nanoimprinting: next generation lithography

Nanoimprint lithography (NIL) is a cost-effective and high-throughput technique for replicating nanoscale structures that does not require expensive light sources for advanced photolithography equipment. NIL overcomes the limitations of light diffraction or beam scattering in traditional photolithography and is suitable for replicating nanoscale structures with high resolution. Roller nanoimprint lithography (R-NIL) is the most common NIL technique benefiting large-scale, continuous, and efficient industrial production. In the past two decades, a range of R-NIL equipment has emerged to meet the industrial needs for applications including biomedical devices, semiconductors, flexible electronics, optical films, and interface functional materials. R-NIL equipment has a simple and compact design, which allows multiple units to be clustered together for increased productivity. These units include transmission control, resist coating, resist curing, and imprinting. This critical review summarizes the hitherto R-NIL processes, their typical technical problems, and corresponding solutions and gives guidelines for developing advanced R-NIL equipment.

Comparative Analysis of the Physicochemical Properties and Metabolites of Farinose and Crisp Lotus Roots (Nelumbo nucifera Gaertn.) with Different Geographical Origins

Lotus roots are widely consumed vegetables because of their great taste and abundant nutrients, but their quality varies with the environments and cultivar. This study systematically compared farinose (Elian No. 5) and crisp (Elian No. 6) lotus root cultivars from three geographical origins. Pasting and texture characteristics verified that Elian No. 5 possessed lower hardness and lower ability to withstand shear stress and heating during cooking compared with Elian No. 6. Untargeted metabolite profiling was first performed using ultrahigh-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) combined with a Zeno trap. In total, 188 metabolites were identified based on the matching chemistry database. Multivariate analysis demonstrated that lotus roots from different cultivars and origins could be adequately distinguished. Sixty-one differential metabolites were identified among three Elian No. 5 samples, and 28 were identified among three Elian No. 6 samples. Isoscopoletin, scopoletin, and paprazine were the most differential metabolites between Elian No. 5 and Elian No. 6. These results can inform future research on the discrimination and utilization of lotus roots.

Effects of grape seed extract on the properties of pullulan polysaccharide/xanthan gum active films for apple preservation

Grape seed extract (GSE) was added to pullulan polysaccharide (PP)/xanthan gum (XG) as composite film (PP/XG/GSE or PXG). The observed composite morphology indicated their biocompatibility. Sample PXG100 (contain 100 mg/L GSE) demonstrated the best mechanical properties, with tensile strength of 16.62 ± 1.27 MPa, and the elongation at break of (22.60 ± 0.48)%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity of PXG150 were the highest at (81.52 ± 1.57)% and (90.85 ± 1.54)%, respectively. PXG films also demonstrated inhibitory effects on Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. The PXG films could also prolong the shelf life of fresh-cut apples because it could decrease the rate of weight loss and retain more vitamin C and total polyphenol even on the 5th day. The weight loss rate of PXG150 was decreased from (8.58 ± 0.6)% (control) to (4.15 ± 0.19)%. It was able to achieve vitamin C and total polyphenol retention rate of 91 % and 72 %, respectively, which was significantly higher that the control sample. Therefore, GSE had contributed in enhancing the antibacterial, antioxidant properties, mechanical strength, UV protection and water resistance in PXG composite films. This effectively extend the shelf life of fresh-cut apples, which it will be an excellent food packaging material.

Advances in the Role and Mechanisms of Essential Oils and Plant Extracts as Natural Preservatives to Extend the Postharvest Shelf Life of Edible Mushrooms

China has a large variety of edible mushrooms and ranks first in the world in terms of production and variety. Nevertheless, due to their high moisture content and rapid respiration rate, they experience constant quality deterioration, browning of color, loss of moisture, changes in texture, increases in microbial populations, and loss of nutrition and flavor during postharvest storage. Therefore, this paper reviews the effects of essential oils and plant extracts on the preservation of edible mushrooms and summarizes their mechanisms of action to better understand their effects during the storage of mushrooms. The quality degradation process of edible mushrooms is complex and influenced by internal and external factors. Essential oils and plant extracts are considered environmentally friendly preservation methods for better postharvest quality. This review aims to provide a reference for the development of new green and safe preservation and provides research directions for the postharvest processing and product development of edible mushrooms.

Natural Gum-Based Functional Bioactive Films and Coatings: A Review

Edible films and coatings are a current and future food packaging trend. In the food and envi-ronmental sectors, there is a growing need to understand the role of edible packaging and sus-tainability. Gums are polysaccharides of natural origin that are frequently utilized as thickeners, clarifying agents, gelling agents, emulsifiers, and stabilizers in the food sector. Gums come in a variety of forms, including seed gums, mucilage gums, exudate gums, and so on. As a biodegradable and sustainable alternative to petrochemical-based film and coatings, gums could be a promising option. Natural plant gum-based edible packaging helps to ensure extension of shelf-life of fresh and processed foods while also reducing microbiological alteration and/or oxidation processes. In this review, the possible applications of gum-based polymers and their functional properties in development of edible films and coatings, were comprehensively dis-cussed. In the future, technology for developing natural gum-based edible films and coatings might be applied commercially to improve shelf life and preserve the quality of foods.

Encapsulation of Bioactive Compounds for Food and Agricultural Applications

This review presents an updated scenario of findings and evolutions of encapsulation of bioactive compounds for food and agricultural applications. Many polymers have been reported as encapsulated agents, such as sodium alginate, gum Arabic, chitosan, cellulose and carboxymethylcellulose, pectin, Shellac, xanthan gum, zein, pullulan, maltodextrin, whey protein, galactomannan, modified starch, polycaprolactone, and sodium caseinate. The main encapsulation methods investigated in the study include both physical and chemical ones, such as freeze-drying, spray-drying, extrusion, coacervation, complexation, and supercritical anti-solvent drying. Consequently, in the food area, bioactive peptides, vitamins, essential oils, caffeine, plant extracts, fatty acids, flavonoids, carotenoids, and terpenes are the main compounds encapsulated. In the agricultural area, essential oils, lipids, phytotoxins, medicines, vaccines, hemoglobin, and microbial metabolites are the main compounds encapsulated. Most scientific investigations have one or more objectives, such as to improve the stability of formulated systems, increase the release time, retain and protect active properties, reduce lipid oxidation, maintain organoleptic properties, and present bioactivities even in extreme thermal, radiation, and pH conditions. Considering the increasing worldwide interest for biomolecules in modern and sustainable agriculture, encapsulation can be efficient for the formulation of biofungicides, biopesticides, bioherbicides, and biofertilizers. With this review, it is inferred that the current scenario indicates evolutions in the production methods by increasing the scales and the techno-economic feasibilities. The Technology Readiness Level (TRL) for most of the encapsulation methods is going beyond TRL 6, in which the knowledge gathered allows for having a functional prototype or a representative model of the encapsulation technologies presented in this review.

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.

Recent Advancements of Polysaccharides to Enhance Quality and Delay Ripening of Fresh Produce: A Review

The freshness of fruits and vegetables plays a significant role in consumers' decision to purchase a product at the supermarket. Fresh-cut products are the latest trend in fulfilling society's restless needs, and the food industry is faced with the challenge of maintaining the quality of fresh produce. The food industry is concerned with the natural maturation and degradation of fruits and vegetables, primarily due to enzymatic reactions. It has been demonstrated that polysaccharide coatings effectively preserve the freshness of these products, extending their shelf life depending on the preservation method used. This review informs readers about the different types of polysaccharides and their novel applications as natural food preservatives in the past five years (2018-2022). The key findings summarized the properties of the antimicrobial agent, the molecular mechanism of action, coating methods, and formulation for the preservation approach. Additionally, we discuss the scientific factors influencing polysaccharide processing and preservation efficacy, allowing it to be used in post-harvest management.

Latest Developments in Edible Coatings on Minimally Processed Fruits and Vegetables: A Review

The food industry nowadays is facing new challenges in terms of sustainability and health implications of packaging and processing techniques. Due to their desire for new and natural products coupled with changes in lifestyle, consumers are looking for food products that have been less processed but possess longer shelf life and maintain nutritional and sensorial proprieties during storage. These requirements represent real challenges when dealing with highly perishable food products, such as fruits and vegetables. Thus, in recent years, edible coatings have been intensively developed and studied because of their capacity to improve the quality, shelf life, safety, and functionality of the treated products. Edible coatings can be applied through different techniques, like dipping, spraying, or coating, in order to control moisture transfer, gas exchange, or oxidative processes. Furthermore, some functional ingredients can be incorporated into an edible matrix and applied on the surface of foods, thus enhancing safety or even nutritional and sensory attributes. In the case of coated fruits and vegetables, their quality parameters, such as color, firmness, microbial load, decay ratio, weight loss, sensorial attributes, and nutritional parameters, which are very specific to the type of products and their storage conditions, should be carefully monitored. This review attempts to summarize recent studies of different edible coatings (polysaccharides, proteins, lipids, and composites) as carriers of functional ingredients (antimicrobials, texture enhancers, and nutraceuticals) applied on different minimally processed fruits and vegetables, highlighting the coating ingredients, the application methods and the effects on food shelf life and quality.

Approaches in Animal Proteins and Natural Polysaccharides Application for Food Packaging: Edible Film Production and Quality Estimation

Natural biopolymers are an interesting resource for edible films production, as they are environmentally friendly packaging materials. The possibilities of the application of main animal proteins and natural polysaccharides are considered in the review, including the sources, structure, and limitations of usage. The main ways for overcoming the limitations caused by the physico-chemical properties of biopolymers are also discussed, including composites approaches, plasticizers, and the addition of crosslinking agents. Approaches for the production of biopolymer-based films and coatings are classified according to wet and dried processes and considered depending on biopolymer types. The methods for mechanical, physico-chemical, hydration, and uniformity estimation of edible films are reviewed.