Can Chitosan Applications in Pre- and Post-Harvest Affect the Quality and Antioxidant Contents of Red Raspberries?

Red raspberry fruit production is increasing worldwide due to the growing consumer interest in foods with high antioxidant properties. However, raspberries are very perishable fruit with a short shelf life. Chitosan applications have shown promising results in promoting the storage of different berry fruit. This work aimed at analysing the effects of chitosan applied in pre- and/or post-harvest on the quality and antioxidant properties of raspberry fruit during cold storage and room temperature conditions (i.e., 6 d at 4 °C and 3 d at 20 °C, respectively). Pre-harvest chitosan applications reduced fruit weight loss during cold storage and room temperature conditions but also reduced fruit decay at room temperature conditions. At the end of the whole storage conditions, chitosan-coated raspberries at pre-harvest were brighter than those of the uncoated control fruit. Furthermore, pre-harvest treatments with chitosan increased the total phenol and anthocyanin contents and promoted the highest total antioxidant activity compared with other treatments. After cold storage, post-harvest chitosan application drastically reduced the development of fungi that cause fruit decay, thus minimizing the potential risk of mycotoxin production. Overall, this study demonstrates that applications of chitosan in pre-harvest are sufficient to ensure the goal of maintaining and/or increasing fruit quality and antioxidant properties during cold storage and room temperature conditions.