Effects of postharvest treatments with chitosan and putrescine to maintain quality and extend shelf-life of two banana cultivars

Chitosan (1.0% and 2.0%) and putrescine (1.0 and 2.0 mmol/L) treatments were used to investigate the effects of these compounds on the postharvest quality and shelf-life of two banana cultivars, "Native" and "Cavendish." Fruits were stored at 15 +/- 2 degrees C and a relative humidity of 85%-90% during a 20-day period. In the controls, increases in weight loss, microbial population, total soluble solids, and ethylene production and decreases in firmness, ascorbic acid contents, and fruit lightness occurred gradually during storage. All these changes were delayed significantly after treatments with chitosan and putrescine. Application of putrescine and chitosan also caused small increases in phenolic compound contents and antioxidant activity at the end of the storage period. Results obtained suggest that a treatment with 1% chitosan is effective in improving the postharvest quality and shelf-life of banana, and open the possibility that lower concentrations of chitosan may be also effective.