EFFECTS OF CHITOSAN COATING ON POSTHARVEST QUALITY OF MANGO (MANGIFERA INDICA L. CV. TAINONG) FRUITS

摘要

The effects of chitosan coating on delaying ripening and reducing decay of mango fruits (Mangifera indica L. cv. Tainong) were investigated in this article. The fruits were treated with 0.5, 1.0 or 2.0% chitosan solution, respectively, and were stored at 15C, 85-90% relative humidity. Results showed that the ripening of mango fruits was significantly delayed by the treatment of chitosan coating in a concentration-dependent manner. Among them, the 2.0% chitosan coating was the most effective. Respiration rate, loss of firmness and color change in mango fruits was efficiently inhibited by chitosan coating during storage. The color index in the mango fruits treated with 2.0% chitosan was 58.4% lower (P < 0.05), and firmness was 43.6% higher (P < 0.05) than those of the control after 16 days of storage. Changes of parameters associated with fruit ripening processes were also determined in this study. The declines in titratable acidity, ascorbic acid and fruit weight were all effectively inhibited by chitosan coating, but the increase in total soluble solids was retarded during storage. Disease progress in the mango fruits inoculated with Colletotrichum gloeosporioides was significantly inhibited by the treatment with chitosan coating. The disease incidence and lesion diameter in the fruits treated with 2.0% chitosan were 71.3 and 49.8% lower (P < 0.05) than that in the control fruits after 4 and 16 days of inoculation, respectively. These results suggested that the application of chitosan coating may exhibit a potential for delaying ripening and reducing decay of mango fruits during storage in practice.