Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

Chitosan-based coatings are used as a postharvest treatment to extend the shelf-life of several fruits. In this study, the effectiveness of chitosan-based coating to preserve the physico-chemical (weight loss, soluble solid content, and titratable acidity) and nutraceutical traits (total polyphenol, anthocyanin, flavonoid, ascorbic acid content, antioxidant capacity) in fresh fig “Troiano” has been evaluated. Furthermore, antioxidant enzyme activities, such as catalase (CAT) and ascorbate peroxidase (APX), were evaluated as well as the enzymes activities involved in fruit browning (polyphenol oxidase (PPO), guaiacol peroxidase (GPX)). Fruits were treated with 1% chitosan and 1% ascorbic acid coating, stored at 4 °C for nine days, and sampled every three days. Chitosan-based coating significantly reduced the weight loss and the qualitative changes, improving the total polyphenol, anthocyanin, and flavonoid contents and the antioxidant activity in stored figs. The higher activity of antioxidant enzymes allowed to reduce oxidative stress and prevent the browning reactions in chitosan-coated figs. The principal component analysis allowed to distinguish different behaviors among uncoated and chitosan-coated figs, indicating that the combined effects of chitosan-based treatment and storage time influenced the physico-chemical, nutraceutical and antioxidant system of figs during storage.

Loquat is a non-climacteric fruit consumed fresh for its essential nutrients and phytochemical compounds. In this study, the effects of chitosan coating (1% w/v) on changes in the enzymatic antioxidant and membrane damage in three loquat selections (CREAFRC-S18; CREAFRC-S35 and CREAFRC-S36) and three loquat cultivars (Golden Nugget, Algerie and Nespolone rosso di Trabia) stored at 7 °C over 21 days were evaluated. Chitosan treatment enhanced the activities of superoxide dismutase, catalase and ascorbate peroxidase. Moreover, this treatment inhibited polyphenol oxidase and guaiacol peroxidase activities, extending the storage life of loquat. Chitosan also preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation. Principal component analysis provided a global view of the responses of both loquat selections and cultivars to the postharvest chitosan coating and storage temperature. These findings suggest that chitosan treatment could be a valid tool for improving the activity of antioxidant enzymes, preserving the enzymatic browning of loquat fruits.