Extension of Quality and Shelf Life of Tomatoes Using Chitosan Coating Incorporated with Cinnamon Oil

This study examined the effects of 2% chitosan (CS) coatings incorporated with varying concentrations of cinnamon oil (CO) (0%, 0.5%, 1.0%, and 1.5%) on the extension of the quality and shelf-life of tomatoes stored under ambient conditions. Control samples were untreated and coated with distilled water. All samples were stored for 14 days at 25 ± 1 °C, with quality assessments conducted every two days. The application of CS-CO treatments was notably effective in controlling weight loss (3.91-5.26%) and firmness loss (10.81-16.51 N), sustaining the color index score (11.98-16.78), and stabilizing the total soluble solids (4.64-4.71 brix), titratable acidity (0.374-0.383%), total phenolic content (75.89-81.54 mg/100 g), ascorbic acid concentration (21.64-33.69 mg/100 g), total antioxidant capacity (85.89-91.54%) and pigment levels, particularly chlorophyll (52.80-63.18 mg/100 g), compared to control samples (p < 0.05). Higher CO concentrations (1.0% and 1.5%) in the CS coating maintained a significant level of phytochemicals in the samples compared to the control group, while CS-CO at 0.5% performed similarly in preserving the other physicochemical qualities. Both CS and CS-CO treatments extended the shelf life of the tomatoes up to 14 days (<6.78 log10 CFU/mL), whereas control samples were only viable for storage for 6 days due to higher microbial growth (>7.8 log10 CFU/mL) (p < 0.05). Overall, CS-CO-treated tomatoes demonstrated superior quality preservation and shelf-life enhancement, with a notable improvement in overall qualities as compared to the CS and control samples.

Enhancement of the Physical and Functional Properties of Chitosan Films by Incorporating Galla chinensis Extract

Composite films based on chitosan (CS) incorporating Galla chinensis extract (GCNE) at different CS/GCNE weight ratios, which are both biodegradable and multifunctional, were fabricated using the solution-casting method. The FTIR analyses indicated that a good interaction was presented among the GCNE and CS through an intermolecular hydrogen bond. The incorporation of the GCNE improved the films' elongation at break, UV-light blocking, and decreased the moisture regain (from 16.68% to 10.69%) and water absorption (from 80.65% to 54.74%). Moreover, the CS/GCNE films exhibited a strong antioxidant activity (from 57.11% to 70.37% of DPPH and from 35.53% to 46.73% of ABTS scavenging activities) mainly due to the high content of phenolic compounds in the incorporated GCNE. The CS/GCNE film-forming solution coatings demonstrated their effectiveness in preserving the quality of postharvest mangoes, specifically by minimizing the change in the firmness, weight loss, titratable acidity, and total phenolic and ascorbic acids. These findings suggest that the multifunctional composite films possess a high application potential to preserve postharvest fruits.

Nanocoating and its application as antimicrobials in the food industry: A review

Nanocoatings are ultra-thin layers on the nanoscale (<100 nm) that are deposited on the substrate to improve their properties and functionality. These nanocoatings provide significant advantages compared to traditional coating, including stain resistance, antimicrobial and antioxidant activities, odor control and delivery of active agents, and liquid repellence properties. In the food industry, nanocoating is widely used in the food packaging sector. In this regard, nanocoating offers antimicrobials and antioxidant properties to active food packaging by incorporating active bioactive compounds into materials used in already existing packaging. The application of nanocoating is applied to these kinds of food packaging with nano coating to improve shelf life, safety, and quality of food packaging. In smart/intelligent packaging, the active packaging coating is promising food packaging, which is designed by releasing preservatives and nanocoating as an antimicrobial, antifungal, antioxidant, barrier coating, and self-cleaning food contact surfaces. In addition, nanocoating can be used for food contact surfaces, kitchen utensils, and food processing equipment to create antimicrobial, antireflective, and dirt-repellent properties. These are critical properties for food processing, especially for meat and dairy processing facilities, which can reduce biofilm formation and prevent cross-contamination. Recently, appreciable growth in the development of the application of nanocoating as edible films for coating food products has emerged to improve food safety issues. In this regard, much scientific research in the area of nanocoating fruits and vegetables, and other food products was performed to address food safety issues. Hence, this promising technology can be a great addition to the agricultural and food industries. Thus, this review addresses the most relevant information about this technology and the applications of nanocoating in the food industry.

Edible coating enriched with cinnamon oil reduces the oxidative stress and improves the quality of strawberry fruit stored at room temperature

BACKGROUND

The present study aimed to assess the impact of a starch/gelatine coating containing cinnamon oil on selected quality attributes and redox status in strawberry fruit stored at room temperature (72 h).

RESULTS

Research showed that the application of cinnamon oil to an edible coating allows an improvement of the quality of strawberry fruit stored at room temperature. The cinnamon oil coating inhibits the development of yeast and mould, and reduces loss of soluble solids and ascorbic acid during 72 h storage at room temperature. Moreover, the coating with cinnamon oil clearly reduced the level of oxidative stress, which was manifested by a lower level of reactive oxygen species, as well as a lower activity of antioxidant enzymes. The elimination of oxidative stress in the cinnamon oil-coated fruit also contributed to lower PARP1 mRNA expression, inhibiting the metabolism of NAD⁺ and reducing ATP losses.

CONCLUSION

The coating of strawberry fruit with a starch/gelatine biofilm containing cinnamon oil is an effective method for delaying postharvest senescence of fruit and the storage degradation of tissue. © 2023 Society of Chemical Industry.

Green synthesized TiO2 nanoparticles: Structural characterization and photoinduced antifungal activity against P. steckii

This study synthesized titanium dioxide (TiO₂ ) nanoparticles (NPs) from mango leaf extract and investigated the features and antibacterial capabilities of three different. The microscopic morphological observation, scanning electron microscopy, and transmission electron microscopy results showed that all three NPs showed agglomeration phenomenon, and the TN-1 sample existed as large agglomerates, whereas the agglomeration phenomenon of TN-3 sample was improved by the modified, without large agglomerates. The biosynthetic TN-2 and TN-3 NPs were spherical and uniform in size, whereas those of the TN-3 sample was the smallest, ranging from 10 to 30 nm. X-ray diffraction and Raman spectroscopy results exhibited that these were highly pure anatase NPs. The result of ultraviolet (UV)-visible-near-infrared spectral analysis showed that the TN-2 and TN-3 samples displayed higher UV absorption properties than the TN-1 samples and were highest in the modified NPs, which was more suitable for preparing chitosan-based nanocomposite material in future experiments and studies. The colony diameters of the TN-1, TN-2, and TN-3 treatment groups were 7.99, 7.80, and 6.86 mm, respectively, after 120 min of UV light induction at a wavelength of 365 nm. Significant differences were evident between the TN-3 and the other two groups (p < 0.05), indicating that the TN-3 sample more effectively inhibited Penicillium steckii than the other TiO₂ NPs. PRACTICAL APPLICATION: Nanomaterials coated film preservation is widely used in fruit and vegetable preservation. In this paper, TiO₂ nanomaterials will be green synthesized using mango leaf and structurally characterized, whereas antibacterial tests will be conducted against the mango fruit-specific bacterium Penicillium steckii, which will provide a theoretical basis for the storage and preservation of mango.

Putrescine with Aloe vera gel coating improves bioactive compounds and quality of table grape under cold storage

Abstract

Bioactive compounds and quality were determined in table grape (Vitis vinifera cv. 'Yaghouti') at storage period after treatment with 2.0 and 3.0 mM putrescine (PUT) and 1:25 and 1:33 Aloe vera gel (AVG). The PUT treatments were given by foliar application on the tree and followed by AVG immersion then storage up to 36 days at 4 ± 0.5 °C. Both treatments retained significantly higher firmness, ascorbic acid, anthocyanin, antioxidant, phenolic content, and sensory attributes as compared with control berries under the storage conditions. Combined application of PUT + AVG showed a better response in retaining vitamin C, total antioxidants, phenolic contents, organoleptic evaluation, enzymes, and fruit firmness than only treated berries with PUT or AVG or untreated berries. The impacts of PUT2.0 mM + AVG 25% treatments were found more pronounced after 36 days of storage in bioactive compounds and sensory attributes.

Graphical abstract

A Gas-Permeation Controllable Packaging Membrane with Porous Microspheres as Gas "Switches" for Efficient Preservation of Litchi

Food wastage represented by the deterioration of perishable food like fruits and vegetables is a serious global problem with tremendous ethical, financial, and environmental costs. The atmosphere (CO₂ and O₂) has a crucial role in food storage and can regulate physiological food metabolism and microbial growth. Modified atmosphere packaging (MAP) is a promising method used to extend shelf life and preserve the quality of perishable food; yet, its use depends on the specific gas permeability and selectivity of polymer membranes to generate an atmosphere desirable for storage. In this study, we established and validated a new plant leaf-mimetic shellac-based MAP membrane embedded with chitosan porous microspheres loaded with antimicrobial tannic acid (TA-CPM) as gas "switches" for regulating O₂ and CO₂ permeability and CO₂/O₂ selectivity. The effects of different amounts of TA-CPM added into the hybrid membranes were examined for litchi preservation at room temperature. Our results showed that this hybrid TA-CPM/shellac packaging membrane could regulate the internal CO₂ and O₂ concentrations and the CO₂/O₂ ratio within the packages containing litchis by adjusting the addition amount of TA-CPM. The 0.05% TA-CPM/shellac and 0.10% TA-CPM/shellac packages, especially 0.05% TA-CPM/shellac, generated a more desirable CO₂ and O₂ atmosphere for litchi preservation compared with controls, which was reflected by the delaying of browning and rotting, maintaining of the natural color of the litchi pericarp, preservation of pulp quality, inhibition of polyphenol oxidase and guaiacol peroxidase activities, and reduction of oxidative cell damage in litchis. The results suggested that 0.05% TA-CPM/shellac and 0.10% TA-CPM/shellac packaging membranes, especially 0.05% TA-CPM/shellac, could generate an ideal atmosphere for litchi storage at room temperature, demonstrating that this permeation-controlled hybrid membrane has great potential in food preservation and other applications requiring a modified atmosphere.

Chitosan as a Coating for Biocontrol in Postharvest Products: A Bibliometric Review

The aim of this work was to carry out a systematic literature review focused on the scientific production, trends, and characteristics of a knowledge domain of high worldwide importance, namely, the use of chitosan as a coating for postharvest disease biocontrol in fruits and vegetables, which are generated mainly by fungi and bacteria such as Aspergillus niger, Rhizopus stolonifera, and Botrytis cinerea. For this, the analysis of 875 published documents in the Scopus database was performed for the years 2011 to 2021. The information of the keywords' co-occurrence was visualized and studied using the free access VOSviewer software to show the trend of the topic in general. The study showed a research increase of the chitosan and nanoparticle chitosan coating applications to diminish the postharvest damage by microorganisms (fungi and bacteria), as well as the improvement of the shelf life and quality of the products.

Effect of Chitosan/Nano-TiO2 Composite Coating on the Postharvest Quality of Blueberry Fruit

Blueberries are a rich source of health-promoting compounds such as vitamins and anthocyanins and show a high antioxidant capacity. Thus, considerable commercial and scientific interest exists in prolonging its postharvest life to meet the year-round demand for this fruit. In this investigation, the effect of a chitosan-based edible coating, as well as a chitosan-based edible coating containing nanosized titanium dioxide particles (CTS-TiO2), on the postharvest quality of blueberry fruit quality was evaluated during storage at 0 °C. The blueberries were treated with a chitosan coating (CTS) and a CTS-TiO2 composite, respectively. The most suitable chitosan and nano-TiO2 fraction concentrations to be incorporated in the coating formulation were prepared based on the wettability of the corresponding coating solutions. Changes in firmness, total soluble solids (TSS), titratable acidity (TA), ascorbic acid (VC), malondialdehyde (MDA), polyphenol oxidase (PPO), and peroxidase (POD) activities, anthocyanins, flavonoids, total phenolic content, and microbiological analysis were measured and compared. This combined treatment prevented product corruption. Compared with CTS, the CTS-TiO2 composite coating application effectively slowed down the decrease in firmness, TSS, VC, and TA in the blueberries. Additionally, changes in the total polyphenol, anthocyanin, and flavonoid contents and the antioxidant capacity of CTS-TiO2 composite coating blueberry fruits were delayed. Therefore, these results indicated that the chitosan/nano-TiO2 composite coating could maintain the nutrient composition of blueberries while playing a significant role in preserving the quality of fruit at 0 °C.

Novel edible coating based on shellac and tannic acid for prolonging postharvest shelf life and improving overall quality of mango

This study aimed to investigate the combined effects of a coating based on shellac and the active agent tannic acid (TA) on the storability and physiological variations of mangoes stored at room temperature. Results showed that TA-shellac prolonged shelf life and improved overall quality of mangoes to a higher extent compared with controls, which was reflected in the extension of shelf life for approximately 10 days, maintaining of tissue firmness and weight loss, slowing down of respiration rate, improvement of physical properties and chemical qualities, suppression of browning, reduction of lipid peroxidation, preservation of aromatic volatiles, and regulation of the related enzymes activities. Addition of TA to shellac coating also improved the antifungal effect of the formulation. The results suggest that a synergistic effect took place between TA and shellac, which demonstrates the high potential for shelf life extension and quality improvement of mangoes of this formulation.

Fortification of edible films with bioactive agents: a review of their formation, properties, and application in food preservation

Biodegradable films constructed from food ingredients are being developed for food coating and packaging applications to create more sustainable and environmentally friendly alternatives to plastics and other synthetic film-forming materials. In particular, there is a focus on the creation of active packaging materials from natural ingredients, especially plant-based ones. The film matrix is typically constructed from film-forming food components, such as proteins, polysaccharides and lipids. These matrices can be fortified with active ingredients, such as antioxidants and antimicrobials, so as to enhance their functional properties. Edible active films must be carefully designed to have the required optical, mechanical, barrier, and preservative properties needed for commercial applications. This review focuses on the fabrication, properties, and functional performance of edible films constructed from natural active ingredients. It provides an overview of the type of active ingredients that can be used, how they interact with the film matrix, how they migrate through the films, and how they are released. It also discusses the potential application of these active films for food preservation. Finally, future trends are highlighted and areas where further research are required are discussed.

Pre-harvest application of chitosan and postharvest Aloe vera gel coating enhances quality of table grape (Vitis vinifera L. cv. 'Yaghouti') during postharvest period

The present study evaluated impact of pre-harvest foliar spraying with chitosan (2.0% and 3.0%) and post-harvest Aloe vera gel (AVG) coating (25% and 33%) to determine the quality of table grape during storage. The results showed that both treatments significantly influenced the storage lifetime of this fruit. In addition, the chitosan and AVG combinations minimized the incidence of decay and reduced the weight loss more than that of chitosan, AVG and control samples. 25 days once the foliar application of chitosan 3.0% with AVG 33% coating extending the storage life of fruit up to 15 days by significantly reducing decay index, malondialdehyde, weight loss and polyphenol oxidase also, maintaining the overall quality index, firmness, antioxidant capacity, peroxidase, total phenols, anthocyanin, SSC and vitamin C. Based on the findings, these natural compound treatments could be considered as suitable alternatives to extend the marketable period of table grapes and minimize post-harvest losses.

Funcionalización de los recubrimientos a base de quitosano para la conservación postcosecha de frutas y hortalizas

En años recientes, se ha buscado el desarrollo y aplicación de recubrimientos comestibles que sean seguros, biodegradables y con adecuadas propiedades tecnológicas y funcionales que ayuden a extender la vida de anaquel de frutas y hortalizas. El quitosano es uno de los biomateriales con mayor potencial para la elaboración de recubrimientos comestibles. Sin embargo, su principal desventaja es la alta permeabilidad al vapor de agua que exhibe, por lo que, una alternativa para mitigar esta limitante, es su funcionalización mediante la incorporación de compuestos orgánicos (aceites esenciales, extractos naturales, ácido ascórbico, hidrolizados de proteína, polisacáridos) e inorgánicos (SiO2, TiO2, ZnO, Ag y montmorillonita), además, de la adición de microorganismos (levaduras) a la matriz polimérica. El quitosano funcionalizado, aplicado a productos hortofrutícolas, ha mostrado mejores resultados (mayor vida de anaquel y cambios mínimos en parámetros de calidad) que los obtenidos al emplear quitosano sin funcionalizar. El objetivo de esta revisión es describir y discutir los beneficios y limitaciones de la funcionalización del quitosano y su aplicación en productos hortofrutícolas.

Effects of Different TiO2 Nanoparticles Concentrations on the Physical and Antibacterial Activities of Chitosan-Based Coating Film

In this investigation, the effect of different concentrations of titanium dioxide (TiO₂) nanoparticles (NPs) on the structure and antimicrobial activity of chitosan-based coating films was examined. Analysis using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the modified TiO₂ NPs were successfully dispersed into the chitosan matrix, and that the roughness of the chitosan-TiO₂ nanocomposites were significantly reduced. Moreover, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses indicated that the chitosan interacted with TiO₂ NPs and possessed good compatibility, while a thermogravimetric analysis (TGA) of the thermal properties showed that the chitosan-TiO₂ nanocomposites with 0.05% TiO₂ NPs concentration had the best thermal stability. The chitosan-TiO₂ nanocomposite exhibited an inhibitory effect on the growth of Escherichia coli and Staphylococcus aureus. This antimicrobial activity of the chitosan-TiO₂ nanocomposites had an inhibition zone ranging from 9.86 ± 0.90 to 13.55 ± 0.35 (mm). These results, therefore, indicate that chitosan-based coating films incorporated with TiO₂ NPs might become a potential packaging system for prolonging the shelf-life of fruits and vegetables.

Antifungal Application of Rosin Derivatives from Renewable Pine Resin in Crop Protection

In the current work, we synthesized two series of dehydroabietyl amide derivatives from natural product rosin and evaluated their antifungal effects on Valsa mali, Phytophthora capsici, Botrytis cinerea, Sclerotinia sclerotiorum, and Fusarium oxysporum. In vitro and in vivo antifungal activities results indicated that rosin-based amide compounds containing thiophene heterocycles had better inhibitory effects on B. cinerea. In particular, compound 5b (5-fluoro-2-thiophene dehydroabietyl amide) exhibited the excellent antifungal properties against B. cinerea with an EC₅₀ of 0.490 mg/L, which was lower compared to the positive control penthiopyrad (0.562 mg/L). Physiological and biochemical studies showed that the primary action mechanism of compound 5b on B. cinerea changes mycelial morphology, increases cell membrane permeability, and inhibits the TCA pathway in respiratory metabolism. Furthermore, QSAR and SAR studies revealed that charge distribution of rosin-based amides derivatives have a key role in the antifungal activity through the hydrogen bonding, conjugation, and electrostatic interaction between the compounds and the receptors of the target. To sum up, this study contributes to the development of rosin-based antifungal agents with a novel structure and preferable biological activity.

Antimicrobial Nanoparticles Incorporated in Edible Coatings and Films for the Preservation of Fruits and Vegetables

Edible coatings and films (ECF) are employed as matrixes for incorporating antimicrobial nanoparticles (NPs), and then they are applied on the fruits and vegetables to prolong shelf life and enhance storage quality. This paper provides a comprehensive review on the preparation, antimicrobial properties and mechanisms, surface and physical qualities of ECF containing antimicrobial NPs, and its efficient application to vegetables and fruits as well. Following an introduction on the properties of the main edible coating materials, the preparation technologies of ECF with NPs are summarized. The antimicrobial activity of ECF with NPs against the tested microorganism was observed by many researchers. This might be mainly due to the electrostatic interaction between the cationic polymer or free metal ions and the charged cell membrane, the photocatalytic reaction of NPs, the detachment of free metal ion, and partly due to the antimicrobial activity of edible materials. Moreover, their physical, mechanical and releasing properties are discussed in detail, which might be influenced by the concentration of NPs. The preservation potential on the quality of fruits and vegetables indicates that various ECF with NPs might be used as the ideal materials for food application. Following the introduction on these characteristics, an attempt is made to predict future trends in this field.

Chitosan-catechin coating as an antifungal and preservable agent for postharvest satsuma oranges

The antifungal properties of chitosan-catechin coating and the effect of fruit preservation were studied. We used catechin to modify chitosan to prepare a coating. The purpose of the study was to use chitosan-catechin coating to prolong the preservation time of satsuma oranges. In vitro experiments, the results showed that the antifungal activity of chitosan-catechin increased with increasing concentration, and the results are also significantly effect of comparing to chitosan and catechin alone (*p < 0.05). In vivo studies, chitosan-catechin coating treatment significantly reduced rot caused by Penicillium Citrinum and Aspergillus niger. The physiological and biochemical indexes of the chitosan-catechin coating treatment group were significantly higher than those of the control group (*p ≤ 0.05). In the toxicity test, mice injected with chitosan-catechin solution showed no significant difference compared to the control group. These results indicate that this chitosan-catechin coating may be useful as an antifungal and preserving agent for satsuma oranges. PRACTICAL APPLICATIONS: The fruit after harvest every year is a large loss due to improper storage, and the preservation of fruits is an effective way to reduce losses. The traditional fruit wrap is not degradable, and the preservation effect is relatively general. The chitosan film is a new type of edible fruit wrap, which has the advantages of being edible and easily degradable, and can effectively reduce environmental pollution. Adding catechin to the preparation process of chitosan film can better improve the fresh-keeping effect and prolong the preservation time of the fruit.

Shelf life extension of fresh fruit and vegetables by chitosan treatment

Among alternatives that are currently under investigation to replace the use of synthetic fungicides to control postharvest diseases in fresh produce and to extend their shelf life, chitosan application has shown promising disease control, at both preharvest and postharvest stages. Chitosan shows a dual mode of action, on the pathogen and on the plant, as it reduces the growth of decay-causing fungi and foodborne pathogens and induces resistance responses in the host tissues. Chitosan coating forms a semipermeable film on the surface of fruit and vegetables, thereby delaying the rate of respiration, decreasing weight loss, maintaining the overall quality, and prolonging the shelf life. Moreover, the coating can provide a substrate for incorporation of other functional food additives, such as minerals, vitamins, or other drugs or nutraceutical compounds that can be used to enhance the beneficial properties of fresh commodities, or in some cases the antimicrobial activity of chitosan. Chitosan coating has been approved as GRAS substance by USFDA, and its application is safe for the consumer and the environment. This review summarizes the most relevant and recent knowledge in the application of chitosan in postharvest disease control and maintenance of overall fruit and vegetable quality during postharvest storage.

Effects of Six Commercial Saccharomyces cerevisiae Strains on Phenolic Attributes, Antioxidant Activity, and Aroma of Kiwifruit (Actinidia deliciosa cv.) Wine

“Hayward” kiwifruit (Actinidia deliciosa cv.), widely planted all around the world, were fermented with six different commercial Saccharomyces cerevisiae strains (BM4×4, RA17, RC212, WLP77, JH-2, and CR476) to reveal their influence on the phenolic profiles, antioxidant activity, and aromatic components. Significant differences in the levels of caffeic acid, protocatechuate, and soluble solid content were found among wines with the six fermented strains. Wines fermented with RC212 strain exhibited the highest total phenolic acids as well as DPPH radical scavenging ability and also had the strongest ability to produce volatile esters. Wines made with S. cerevisiae BM 4×4 had the highest content of volatile acids, while the highest alcohol content was presented in CR476 wines. Scoring spots of wines with these strains were separated in different quadrants on the components of phenolics and aromas by principal component analyses. Kiwifruit wines made with S. cerevisiae RC212 were characterized by a rich fruity flavor, while CR476 strain and WLP77 strain produced floral flavors and green aromas, respectively. Altogether, the results indicated that the use of S. cerevisiae RC212 was the most suitable for the fermentation of kiwifruit wine with desirable characteristics.

Chitosan films and coatings containing essential oils: The antioxidant and antimicrobial activity, and application in food systems

Chitosan edible films and coatings have shown great promise for their application in food preservation and also are promising systems to be used as essential oil (EO) carriers. This review reports the most recent and relevant studies concerning chitosan films and coatings containing EOs. The effect of EO incorporation on the antioxidant, antibacterial and antifungal activities of chitosan films and coatings in vitro and in vivo, as well as their applications in food systems have been discussed. In general, incorporation of EOs significantly increased the antioxidant, antibacterial and antifungal efficacy of chitosan films and coatings in vitro. EO-incorporated films and coatings also showed greater effectiveness against postharvest fungi and foodborne bacteria in food systems than pure films and coatings. The application of chitosan films and coatings containing EOs usually led to an extension of the shelf-life and reduction of lipid peroxidation of fish and meat products over pure chitosan films and coatings. In addition, chitosan coatings incorporated with EOs were more effective in maintaining fruit and vegetable quality, and controlling their postharvest decay during storage and shelf life than pure chitosan coatings.

Preservation Mechanism of Chitosan-Based Coating with Cinnamon Oil for Fruits Storage Based on Sensor Data

The chitosan-based coating with antimicrobial agent has been developed recently to control the decay of fruits. However, its fresh keeping and antimicrobial mechanism is still not very clear. The preservation mechanism of chitosan coating with cinnamon oil for fruits storage is investigated in this paper. Results in the atomic force microscopy sensor images show that many micropores exist in the chitosan coating film. The roughness of coating film is affected by the concentration of chitosan. The antifungal activity of cinnamon oil should be mainly due to its main consistent trans-cinnamaldehyde, which is proportional to the trans-cinnamaldehyde concentration and improves with increasing the attachment time of oil. The exosmosis ratios of Penicillium citrinum and Aspergillus flavus could be enhanced by increasing the concentration of cinnamon oil. Morphological observation indicates that, compared to the normal cell, the wizened mycelium of A. flavus is observed around the inhibition zone, and the growth of spores is also inhibited. Moreover, the analysis of gas sensors indicate that the chitosan-oil coating could decrease the level of O₂ and increase the level of CO₂ in the package of cherry fruits, which also control the fruit decay. These results indicate that its preservation mechanism might be partly due to the micropores structure of coating film as a barrier for gas and a carrier for oil, and partly due to the activity of cinnamon oil on the cell disruption.

Chitosan-Based Coating with Antimicrobial Agents: Preparation, Property, Mechanism, and Application Effectiveness on Fruits and Vegetables

Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables, which is always used as the carrier film for the antimicrobial agents. This review focuses on the preparation, property, mechanism, and application effectiveness on the fruits and vegetables of chitosan-based coating with antimicrobial agents. Chitosan, derived by deacetylation of chitin, is a modified and natural biopolymer as the coating material. In this article, the safety and biocompatible and antimicrobial properties of chitosan were introduced because these attributes are very important for its application. The methods to prepare the chitosan-based coating with antimicrobial agents, such as essential oils, acid, and nanoparticles, were developed by other researchers. Meanwhile, the application of chitosan-based coating is mainly due to its antimicrobial activity and other functional properties, which were investigated, introduced, and analyzed in this review. Furthermore, the surface and mechanical properties were also investigated by researchers and concluded in this article. Finally, the effects of chitosan-based coating on the storage quality, microbial safety, and shelf life of fruits and vegetables were introduced. Their results indicated that chitosan-based coating with different antimicrobial agents would probably have wide prospect in the preservation of fruits and vegetables in the future.

Effect of chitosan coating with cinnamon oil on the quality and physiological attributes of China jujube fruits

Effects of chitosan coating with cinnamon oil on the physiological attributes and preservation quality of China jujube fruits during storage at 4°C for 60 days were investigated. Results indicated that weight loss and decay of jujube fruits were significantly reduced by chitosan-oil coating during the period of 60-day storage, which also exhibited a quite beneficial effect on maintaining the sensory quality for jujube fruits. Meanwhile, the contents of vitamin C and titratable acid decreased to 3.08 mg·g(-1) and 0.342% for the fruits treated by chitosan-oil coating (1.0% + 0.10%), respectively. Polyphenol oxidase, superoxide dismutase, and peroxidase activities were 13.40 U·g(-1), 14.53 U·g(-1), and 63.6 U·g(-1) at the end of storage, respectively. The contents of total soluble phenolics and MDA were 34.51 mg·g(-1) and 19.43 μmol·g(-1) for the combined coating treated samples and control fruits, respectively. These results suggested that the chitosan-oil coating might be recognized as one efficiency technology on the preservation quality of jujube fruits during the storage time.

Application of soy protein coatings and their effect on the quality and shelf-life stability of beef patties

There was no significant change in lipid oxidation up to day 10 of storage for soy-protein-coated samples.