Effect of chitosan coatings supplemented with chitosan-montmorillonite nanocomposites on postharvest quality of 'Hom Thong' banana fruit

Fruit quality retention and shelf-life extension of papaya through organic coating

Papaya (Carica papaya L.) is a climacteric fruit which lose quality and shelf life quickly due to physiological decay and microbial infection after harvest. The study was conducted to evaluate newly applied clybio formulation (0.2 %) along with the existing effective concentration of chitosan (1 %), aloevera gel (50 %), seaweed extract (1 %) and uncoated papaya (control) fruits on post-harvest physicochemical properties and disease incidence when stored at 25 ± 1 °C and 85-90 % relative humidity. Quality parameters were available up to 12 days of storage (DAS) for chitosan and clybio treated papaya where it was 9 DAS for aloevera gel and seaweed treated papaya and 6 DAS for control papaya. Before decay of all the coated papaya at 9 DAS, chitosan (1 %) performed superior in retaining maximum reducing sugar (0.77 %, 1.41 % and 3.85 % more than aloevera, seaweed and clybio application, respectively), β-carotene (10.94 %, 12.5 % and 9.89 % greater than aloevera, seaweed and clybio coatings, respectively), total flavonoids content (18.36 %, 29.81 % and 25.29 % better than aloevera, seaweed and clybio treatments, respectively), total antioxidant activity (21.85 %, 68.2 % and 47.91 % than noted in aloevera, seaweed and clybio formulations, respectively) and potassium content (3.14 % and 9.32 % than aloevera and clybio treatments, respectively). In addition, clybio gave better results over chitosan up to completion of shelf life (12 DAS) such as retention of ascorbic acid (6.21 %), non-reducing sugar (13.48 %), magnesium content (8.31 %) and disease incidence (20 %). Thus, besides preserving nutraceutical property, chitosan and clybio coated papaya remained edible for further 6 days compared to control, and 3 days over aloevera gel and seaweed extract treatment. These findings suggest the use of chitosan and clybio formulation for preserving quality parameters and extending the storage life of papaya.

Effect of High CO2 Controlled Atmosphere Storage on Postharvest Quality of Button Mushroom (Agaricus bisporus)

The Agaricus bisporus (Button mushroom) stands out as one of the most prolific edible fungi which offers robust flavor and nutrition. Nonetheless, this mushroom contains high moisture levels and intense respiration. Without appropriate postharvest preservation techniques, the button mushroom readily experiences browning and senescence. To ensure optimum quality, prompt cooling and appropriate storage conditions are essential. This present research investigated the postharvest quality of button mushrooms stored in a controlled atmosphere (CA) with different initial gas compositions. The findings revealed that button mushrooms in the CA group demonstrated considerable enhancements in appearance and overall quality, effectively delaying browning and senescence compared to those in the control group. The optimal gas composition is 1-3% O2 and 15-17% CO2 (CAII), which effectively inhibited the expression of polyphenol oxidase (PPO)- and lactase (LAC)-related genes in the button mushroom, maintaining a high L* value. Furthermore, the application of 1-3% O2 and 15-17% CO2 (CAII) not only preserved visual quality but also extended the postharvest shelf life of the button mushroom by minimizing metabolic activities that contribute to senescence. Moreover, 1-3% O2 and 15-17% CO2 (CAII) storage also reduced the expression levels of genes associated with ethylene synthesis, which is reflected in the gradual decrease in cell membrane permeability. Consequently, this research underscores the critical importance of controlled atmosphere storage in improving the marketability and sustainability of this widely consumed mushroom.

Fatty-acid incorporation improves hydrophobicity of pea protein based films towards better oxygen/water barrier properties and fruit protecting ability

The current study was undertaken to synthesize pea protein based films containing fatty acids with various chain lengths. Films namely PFAF1, PFAF2, and PFAF3 were fabricated in the presence of pelargonic acid, margaric acid, and pentacosanoic acid, respectively. Also, negative (PF: film formulated using protein alone) and positive control (PCF: film formulated using mixture of protein and chitosan) control were prepared. Interactions occurring within films were clarified by FTIR. Moreover, morphology and thermal behavior of samples were evaluated by SEM and TGA. Variations in thickness (PF: 0.03 mm, PFAF1: 0.03 mm, PFAF2: 0.04 mm, PFAF3: 0.04 mm, PCF: 0.06 mm) and water content (PF: 28.85 %, PFAF1: 16.20 %, PFAF2: 14.51 %, PFAF3: 12.04 %, PCF: 13.83) were obvious. Superior opacity was identified in PCF, followed by PFAF3, PFAF2, PFAF1, and PF. PFAF3 together with PCF were more successful than others in reducing/protecting oxygen and water permeation. Adding fatty acid or chitosan to protein films led to the decline in tensile strength (TS) and increment in elongation at break (E). As for preservation performances, maximum limitations against shifts in weight and color of bananas during 7-day storage were provided by PFAF3. Also, except for PF, all coatings (especially PFAF3) postponed the rotting of fruits.

Development of packaging films based on UiO-66 MOF loaded melatonin with antioxidation functions for spinach preservation

Spinach tends to deteriorate after harvest due to physiological metabolic activities. As a natural, pollution-free, and environmentally friendly preservative, melatonin (MT) can effectively maintain the quality of fruits and vegetables after harvest and delay senescence. To enhance the preservation effect of MT, this study developed antioxidant films using MT-loaded UiO-66 metal-organic framework (MOF) nanoparticles. This approach effectively extends the shelf life of spinach while preserving its quality. The underlying mechanism involves leveraging the microporous structure and stability of UiO-66 MOF. Experimental results obtained from the packaging films demonstrated significant improvements in both mechanical strength and antioxidant properties when UiO-66 was loaded with MT at a concentration of 0.20 mg/mL and combined with sodium alginate. Freshness preservation experiments also indicated the effective preservation effect of these films on spinach. In conclusion, the results of this study suggest that MT-loaded UiO-66 MOF is a promising active packaging material for spinach preservation.

Facile Preparation of Lightweight Natural Rubber Nanocomposite Foams with High Wear Resistance

The light weight and excellent mechanical properties of rubber foam means that it is widely applied in the aerospace, automobile, and military industries. However, its poor wear resistance contributes directly to a short service life and a waste of resources. Therefore, the design and development of high-wear-resistance rubber foam are of great importance. In this work, some nanoclay/rubber composite foams were prepared by blending NR/EPDM with different kinds of nanoclays containing layered double hydroxide (LDH), montmorillonite (MMT), and attapulgite (ATP) to indicate the effects of the kinds of nanoclays on the wear resistance and mechanical properties of nanoclay/rubber composite foams. The kinds of nanoclay/rubber composite foams were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The results showed that nanoclay has heterogeneous nucleation in composite foamed materials. The wear resistance of the composite foam materials with added nanoclay was significantly improved, and the MMT of the lamellar structure (increased by 43.35%) and LDH (increased by 38.57%) were significantly higher than the ATP of the rod-like structure (increased by 13.04%). The improvement in the wear resistance of the matrix was even higher. Compared with other foams, the wear resistance of the OMMT-NR/EPDM foam (increased by 58.89%) with a lamellar structure had the best wear resistance. Due to the increase in the lamellar spacing of the modified OMMT, the exfoliation of worn rubber molecular chains has little effect on the adjacent molecular chains, which prevents the occurrence of crimp wear and further improves the wear resistance of composite foaming materials. Therefore, this work lays the foundation for the manufacturing of rubber foams for wear-resistant applications.

Enhancing Postharvest Quality and Shelf Life of Strawberries through Advanced Coating Technologies: A Comprehensive Investigation of Chitosan and Glycine Betaine Nanoparticle Treatments

The application of natural polymer-based coatings presents a viable approach to prolong the longevity of fruits and tissue damage. This study investigates the impact of treatments involving glycine betaine (GB), chitosan (CTS), and chitosan-coated glycine betaine nanoparticles (CTS-GB NPs) on preserving the quality and reducing decay in strawberry fruits. The fruits were subjected to treatments with GB (1 mM), CTS (0.1%), CTS-GB NPs (0.1%), or distilled water at 20 °C for 5 min, followed by storage at 4 °C for 12 days. The results indicate that CTS and CTS-GB NPs treatments resulted in the highest tissue firmness, total anthocyanin content, and ascorbate peroxidase activity, while exhibiting the lowest decay percentage and weight loss, as well as reduced malondialdehyde levels at the end of storage. GB, CTS, and CTS-GB NPs treatments demonstrated elevated catalase activity and antioxidant capacity, coupled with lower electrolyte leakage and hydrogen peroxide levels. These treatments did not significantly differ from each other but were markedly different from the control. The results substantiate that CTS and CTS-GB NPs treatments effectively preserve strawberry quality and extend storage life by bolstering antioxidant capacity and mitigating free radical damage.

Effect of EVA film and chitosan coating on quality and physicochemical characteristics of mango fruit during postharvest storage

Mango (Mangifera indica L.) is a major tropical fruit, but a short postharvest life hampers marketing. The objective of this work is to assess the influence of a novel nanocomposite poly (ethylene-co-vinyl acetate) (EVA) film and Chitosan (CTS) affect on mango postharvest quality while stored at 20 °C. The results showed that the film coating treatment reduced the decay rate and weight loss of mangoes, maintaining good postharvest quality of mango fruit. The film coating treatment increased the antioxidant capacity of mangoes by inhibiting PPO activity and increasing the activity of antioxidant enzymes. ACS, ACO, and ethylene release were all suppressed, as well as the expression of the ethylene receptors genes ETR1, ETR2, and ERS2, thus delaying mango aging. After harvest, the EVA treatment was superior to the CTS treatment in mango preservation.

Interaction mechanisms of edible film ingredients and their effects on food quality

Traditional food packaging has problems such as nondegradable and poor food safety. Edible films play an important role in food packaging, transportation and storage, having become a focus of research due to their low cost, renewable, degradable, safe and non-toxic characteristics. According to the different materials of edible films substrate, edible films are usually categorized into proteins, polysaccharides and composite edible films. Functional properties of edible films prepared from different substrate materials also vary, single substrate edible films are defective in some aspects. Functional ingredients such as proteins, polysaccharides, essential oils, natural products, nanomaterials, emulsifiers, and so on are commonly added to edible films to improve their functional properties, extend the shelf life of foods, improve the preservation of sensory properties of foods, and make them widely used in the field of food preservation. This paper introduced the classification, characteristics, and modification methods of common edible films, discussed the interactions among the substrate ingredients of composite edible films, the influence of functional ingredients on the properties of edible films, and the effects of modified edible films on the quality of food, aiming to provide new research ideas for the wide application and further study of edible films.

Enhancing Postharvest Quality and Antioxidant Capacity of Blue Honeysuckle cv. 'Lanjingling' with Chitosan and Aloe vera Gel Edible Coatings during Storage

This study investigated the impact of chitosan (CH, 1%) and aloe vera gel (AL, 30%) edible coatings on the preservation of blue honeysuckle quality during a 28-day storage at -1 °C. Coating with CH, AL, and CH+AL led to notable enhancements in several key attributes. These included increased firmness, total soluble solids, acidity, pH, and antioxidant capacity (measured through DPPH, ABTS, and FRAP assays), as well as the preservation of primary (ascorbic acid) and secondary metabolites (TPC, TAC, and TFC). The TAC and TFC levels were approximately increased by 280% and 17%, respectively, in coated blue honeysuckle after 28 d compared to uncoated blue honeysuckle. These coatings also resulted in reduced weight loss, respiration rate, color, abscisic acid, ethylene production, and malondialdehyde content. Notably, the CH+AL treatment excelled in preserving secondary metabolites and elevating FRAP-reducing power, demonstrating a remarkable 1.43-fold increase compared to the control after 28 days. Overall, CH+AL exhibited superior effects compared to CH or AL treatment alone, offering a promising strategy for extending the shelf life and preserving the quality of blue honeysuckle during storage.

Efficacy of chitosan nanoparticles and wax coatings on maintaining post-harvest quality of "Murcott" mandarins

Because of its high degree of biodegradability, chitosan is widely used as a component in food packaging. However, its poor physical properties, such as permeability, limit its applicability. Consequently, applying nano chitosan is regarded as the most effective solution to this issue. In the current study, we studied the effect of using different materials in the coating process on the quality of "Murcott" mandarin during cold storage. We used different concentrations of nano chitosan (50 and 100 ppm) without wax and 100 ppm nano chitosan with wax. We investigated the impact of these compounds on the chemical composition and quality of fruits. The most successful treatment for preventing weight loss from discarded fresh fruit was a combination of wax and 100 ppm nano chitosan. This combination also prevented the deterioration of vitamin C, maintained the fruit pulp, and preserved the fruit's superior taste during cold storage and shelf life. It also maintains a better total soluble solids and total acidity level than other treatments. In addition, the activity of antioxidant enzymes and the total number of antioxidants indicates no degradation of plant tissues compared to those not coated with nano chitosan. It also reduces the microbial load on the coated fruits. Consequently, this coating combination could suggest prolonging post-harvest life and increasing the marketing period of mandarin fruits.

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.

Chitosan coating enriched with biosynthetic CuO NPs: Effects on postharvest decay and quality of mango fruit

A chitosan-based nanocomposite film (CSC) was developed by mixing chitosan (CS, 2 %, v/v) and copper oxide nanoparticles (CuO NPs, 500 μg∙mL-1) synthesized using Alpinia officinarum extract for the safe storage of mango fruit. The effects of CuO NPs on the morphological, mechanical, thermal, physical and antifungal properties of the CS films and postharvest quality of mango fruit were determined. Scanning electron microscopy (SEM) analysis confirmed that CuO NPs were uniformly dispersed into the CS matrix. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) profiles showed that intermolecular H-bondings occurred between CS and CuO NPs, accompanied by decreased crystallinity and increased amorphous structure. In comparison to the pure CS film, addition of CuO NPs obviously improved the morphological, mechanical, thermal, physical and antifungal properties of CSC film. CSC coating treatment obviously delayed the fruit decay and yellowing, as well as reduced losses of weight and firmness of mango (Mangifera indica L.) fruit during the storage, when compared with the control and CS coating treatment. Meanwhile, it significantly decreased the respiration rate and ethylene generation and maintained high level of ascorbic acid (AsA), titratable acid (TA) and soluble sugar content (SSC) of the fruit during the storage. Notably, Cu presented in the CSC film was restrained to the peel, indicating that the CSC coated mango fruit had good edible safety. Principal component analysis (PCA) confirmed that CSC coating played a positive role in mango preservation. Therefore, CSC coating can be considered a potential application for successfully controlling of postharvest disease and prolonging the shelf life for mango fruit.

Exogenous glutathione maintains the postharvest quality of mango fruit by modulating the ascorbate-glutathione cycle

Background

Mango fruit is prone to decay after harvest and premature senescence, which significantly lowers its quality and commercial value.

Methods

The mango fruit (Mangifera indica L.cv. Guixiang) was treated with 0 (control), 2, 5, and 8 mM of reduced glutathione (GSH) after harvest. The fruit was stored at 25 ± 1 °C for 12 days to observe the changes in the antioxidant capacity and postharvest quality.

Results

Compared with the control, the 5 mM GSH treatment significantly decreased the weight loss by 44.0% and 24.4%, total soluble solids content by 25.1% and 4.5%, and soluble sugar content by 19.0% and 27.0%. Conversely, the 5 mM GSH treatment increased the firmness by 25.9% and 30.7% on days 4 and 8, respectively, and the titratable acidity content by 115.1% on day 8. Additionally, the 5 mM GSH treatment decreased the malondialdehyde and hydrogen peroxide contents and improved the antioxidant capacity of mango fruit by increasing the superoxide dismutase and peroxidase activities and upregulating the expression of the encoding genes. Meanwhile, the higher levels of monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase enzyme activities and gene expressions accelerated the AsA-GSH cycle, thereby increasing the accumulation of AsA and GSH and maintaining the redox balance.

Conclusions

Overall, the experimental results suggest that 5 mM GSH maintains high antioxidant capacity and postharvest quality of mangoes and can use as an effective preservation technique for postharvest mangoes.

Effect of oxyresveratrol on the quality and membrane lipid metabolism of shiitake mushroom (Lentinus edodes) during storage

The effect of oxyresveratrol on postharvest quality and membrane lipid metabolism of shiitake mushroom was investigated. The result exhibited that oxyresveratrol retarded browning, maintained firmness and alleviated occurrence of decay of shiitake mushroom. The oxidation and hydrolysis of membrane phospholipids were suppressed by oxyresveratrol treatment, which was associated with reduced LOX and PLD activities and increased SOD and CAT activities. The membrane lipidomics of shiitake mushroom was determined by LC-MS. 385 lipid species and 13 fatty acids in membrane lipids were identified by multiple reaction monitoring method. Compared with control group, the phospholipic acid and lysophospholipid reduced by 29.24% and 21.29% in oxyresveratrol-treated group, respectively, which alleviated hydrolysis of phospholipid. Meanwhile, oxyresveratrol maintained the unsaturation of fatty acids and alleviated oxidation of phospholipid. These results demonstrated that oxyresveratrol could play a dual role of inhibiting the oxidation and hydrolysis of phospholipids to mitigate cellular damage of shiitake mushroom.

Application of chitosan nanoparticles in quality and preservation of postharvest fruits and vegetables: A review

Chitosan is an interesting alternative material for packaging development due to its biodegradability. However, its poor mechanical properties and low permeability limit its actual applications. Chitosan nanoparticles (CHNPs) have emerged as a suitable solution to overcome these intrinsic limitations. In this review, all studies regarding the use of CHNPs to extend the shelf life and improve the quality of postharvest products are covered. The characteristics of CHNPs and their combinations with essential oils and metals, along with their effects on postharvest products, are compared and discussed throughout the manuscript. CHNPs enhanced postharvest antioxidant capacity, extended shelf life, increased nutritional quality, and promoted tolerance to chilling stress. Additionally, the CHNPs reduced the incidence of postharvest phytopathogens. In most instances, smaller CHNPs (<150 nm) conferred higher benefits than larger ones (>150 nm). This was likely a result of the greater plant tissue penetrability and surface area of the smaller CHNPs. The CHNPs were either applied after preparing an emulsion or incorporated into a film, with the latter often exhibiting greater antioxidant and antimicrobial activities. CHNPs were used to encapsulate essential oils, which could be released over time and may enhance the antioxidant and antimicrobial properties of the CHNPs. Even though most applications were performed after harvest, preharvest application had longer lasting effects.