Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming ability. Different chitosan-based films have been fabricated and applied in the field of food packaging. Most of the review papers related to chitosan-based films are focusing on antibacterial food packaging films. Along with the advances in the nanotechnology and polymer science, numerous strategies, for instance direct casting, coating, dipping, layer-by-layer assembly, and extrusion, have been employed to prepare chitosan-based films with multiple functionalities. The emerging food packaging applications of chitosan-based films as antibacterial films, barrie...

Emerging Chitosan-Based Films for Food Packaging Applications

Improvement of quality and shelf-life of strawberries with edible coatings enriched with chitosan

Chitin is the structural material of crustaceans, insects, and fungi, and is the second most abundant biopolymer after cellulose on earth. Chitosan, a deacetylated derivative of chitin, can be obtained by deacetylation of chitin. It is a functionally versatile biopolymer due to the presence of amino groups responsible for the various properties of the polymer. Although it has been used for various industrial applications, the recent one is its use as a biodegradable antimicrobial food packaging material. Much research has been focused on chitosan-based flexible food packaging and edible food coatings to compete with conventional non-biodegradable plastic-based food packaging materials. Various strategies have been used to improve the properties of chitosan - using plasticizers and cross-linkers, embedding the polymer with fillers such as nanoparticles, fibers, and whiskers, and blending the polymer with natural extracts and essential oils and also with other natural and synthetic polymers. However, much research is still needed to bring this biopolymer to industrial levels for the food packaging applications. Industrial relevance As a major by-product of the seafood industry, a massive amount of crustacean shell waste is generated each year, which can be used to produce value-added chitin, which can be converted to chitosan using a relatively simple deacetylation process. Being extracted from a bio-waste product using many energy-efficient methods, chitosan is much cheaper as compared to other biopolymers. Nevertheless, the exceptional properties of chitosan make it a relatively stronger candidate for food packaging applications. Chitosan has already been used in various industries, such as biomedical, agriculture, water treatment, cosmetics, textile, photography, chromatography, electronics, paper industry, and food industry. This review article compiles all the essential literature up to the latest developments of chitosan as a potential food packaging material and the outcomes of its practical utilization for this purpose.

Chitosan-based biodegradable functional films for food packaging applications

Postharvest technologies have allowed horticultural industries to meet the global demands of local and large-scale production and intercontinental distribution of fresh produce that have high nutritional and sensory quality. Harvested products are metabolically active, undergoing ripening and senescence processes that must be controlled to prolong postharvest quality. Inadequate management of these processes can result in major losses in nutritional and quality attributes, outbreaks of foodborne pathogens and financial loss for all players along the supply chain, from growers to consumers. Optimal postharvest treatments for fresh produce seek to slow down physiological processes of senescence and maturation, reduce/inhibit development of physiological disorders and minimize the risk of microbial growth and contamination. In addition to basic postharvest technologies of temperature management, an array of others have been developed including various physical (heat, irradiation and edible coatings), chemical (antimicrobials, antioxidants and anti-browning) and gaseous treatments. This article examines the current status on postharvest treatments of fresh produce and emerging technologies, such as plasma and ozone, that can be used to maintain quality, reduce losses and waste of fresh produce. It also highlights further research needed to increase our understanding of the dynamic response of fresh produce to various postharvest treatments.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2013.0309

Postharvest treatments of fresh produce.

Edible films and coatings based on starch/gelatin: Film properties and effect of coatings on quality of refrigerated Red Crimson grapes

Effect of postharvest treatments and storage temperatures on the quality and shelf life of sweet pepper (Capsicum annum L.)

Carambola fruit have limited marketability due to high degree of perishability and higher moisture content which lead to the extensive postharvest losses. The aim of this study was to determine the efficacy of chitosan (CH), gum arabic (GA) and alginate (AL) coatings on the shelf life and overall quality of carambola fruit. Carambola fruit were dipped for 2 min into the solution of CH (0.3 and 0.5 %), GA (1 and 3 %) and AL (1.5 and 2 %) were stored at 26 ± 1 °C, 65–70 % RH, while the uncoated fruit served as control. Carambola fruit coated with edible coatings showed significant delay in the change of weight loss, decay percentage, titratable acidity (TA), pH, total soluble solids (TSS), sugar accumulation, pigment degradation and ascorbic acid content as compared to uncoated control fruit. In addition, the edible coatings showed a positive effect on maintaining higher concentration of total phenolics, which decreased in control fruit due to their over-ripening and senescence processes. Compared to control, all the coatings had positive effects on the inhibition of cell wall degrading enzyme activities and among them CH 0.3 % and GA 1 % had shown superiority in inhibiting the enzyme activity. After 12 days of storage, the sensory evaluation indicated that carambola fruit coated with CH 0.3 % and GA 1 % had maintained better visual quality than the other coated as well as control samples. These findings suggested that the use of CH 0.3 % and GA 1 % coatings will maintain the carambola fruit quality and lead to better acceptance by consumers.

Effect of edible coatings on quality and shelf life of carambola (Averrhoa carambola L.) fruit during storage

The effects of chitosan 1% and 1.5%, calcium chloride (CaCl2) 1% and 1.5%, chitosan 1% + gibberellic acid 100 ppm, chitosan 1.5% + gibberellic acid 100 ppm, jojoba wax, and glycerol (98%) coatings were evaluated on the shelf life and postharvest quality characteristics of banana fruits stored at 34 ± 1°C and 70–75% relative humidity, while uncoated fruits served as a control. The coatings of chitosan, chitosan + gibberellic acid, and jojoba wax delayed the changes in the weight loss percentage, decay percentage, total soluble solids, pH, titrable acidity, sugar accumulation, pigment degradation, and ascorbic acid compared to uncoated ones. Further, the least disease incidence was found to occur in the banana fruits treated with chitosan and chitosan + gibberellic acid. Hence, it can be concluded that coating with chitosan and chitosan + gibberellic acid has the potential to control decay percentage, prolong the shelf life, and preserve valuable attributes of banana. Calcium chloride and glycerol coatings ...

https://www.tandfonline.com/doi/pdf/10.1080/15538362.2011.578512

Banana Fruit Ripening as Influenced by Edible Coatings

Introduction . Mango is the most economically important and nutritionally rich tropical fruit; it has high commercial value but a highly perishable nature; its sensitivity to postharvest diseases and physical injury limits its successful marketing. Postharvest losses in fruits are a serious problem because of rapid deterioration during handling, transport and storage. Edible films and coatings can be potentially used as an elective preservation technique to extend the shelf life of fruits. Materials and methods . The influence of zein and gelatin coatings on the physicochemical characteristics, softening and antioxidative enzyme activities of mango fruits stored at (32 ± 1) °C were evaluated at regular intervals of their storage period and compared with mango without coatings (control). Results and discussion . Zein and gelatin coatings seemed to have a beneficial impact on delaying the changes in weight loss, soluble solids, titratable acidity, pH, sugar content and total carotenoids. Zein and gelatin coatings resulted in the highest retention of ascorbic acid and phenolic content as compared with that of control. Zein and gelatin coatings delayed the ripening of mango fruit by suppressing the activity of softening enzymes such as polygalacturonase, pectin methyl esterase, cellulase and β-galactosidase. Zein 5% and gelatin 10% coatings maintained the highest induction of defense-related peroxidase enzymes, followed by gelatin 5% and zein 10% coatings. Conclusion . The application of zein 5% and gelatin 10% coatings could be used in delaying the ripening, maintaining the quality attributes and extending the shelf life of mango fruit during storage.

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Neeta B. Gol

Papers

Improvement of quality and shelf-life of strawberries with edible coatings enriched with chitosan

Effect of postharvest treatments and storage temperatures on the quality and shelf life of sweet pepper (Capsicum annum L.)

Effect of edible coatings on quality and shelf life of carambola (Averrhoa carambola L.) fruit during storage

Banana Fruit Ripening as Influenced by Edible Coatings

Influence of zein and gelatin coatings on the postharvest quality and shelf life extension of mango (Mangifera indica L.)