The role of hot water treatment and chitosan coating in controlling a latent infection of Colletotrichum musae on banana var. Mas kirana

摘要

Anthracnose disease due to a latent infection of Colletotrichum musae has seriously impacted on bananas decay. This case caused a serious number of economic losses facing in both local and international trades. To overcome this problem, hot water treatment and also chitosan coating have been developed in minimizing this fungal infection during postharvest period. In this research, a number of green mature local premium banana called bananas var. Mas kirana were inserted into hot water at 44, 46 and 48SUPo/SUPC subsequently for 5, 10, 15 and 20 minutes. Another treatment also carried on through a wide range of chitosan solutions from 2.5, 5 and 10 g/L soaked for 2 and 4 minutes. As a single treatment, hot water soaking at 48SUPo/SUPC for 20 minutes gave the best effect on handling the fruit maturity until 18 days of storage. This level treatment could also suppress the lesion only 2.4 cm and also minimized the severe fruit-damaging level until 22 days of observation. Whereas, chitosan coating through dipping in 5 g/L chitosan solution for 2 minutes gave the best result on controlling latent fungal infection in-vitro. However, this treatment only minimized fruit-damage in medium level until 16 days of storage. Furthermore, the combination treatment of hot water treatment at 48SUPo/SUPC for 20 minutes followed by chitosan coating at 5 g/L through dipping in 2 minutes gave the most proper result in terms of handling of fruit ripening until 23 days of storage. Another result proved this combination treatment significantly eliminated the length of lesion up to 0.16 cm and suppressed the fruit-damage in mild level. However, there were no significant differences among the yellow mature of untreated and combination-treated bananas observed from tests results of color characteristics, pulp strength and total dissolved solid content.