POSTHARVEST HANDLING MANAGEMENT OF PITAYA (Hylocereus spp.)
Pitaya, dragon fruit (Hylocereus undatus Britt. & Rose) belongs the Cactaceae family and is native of mid and south America. Its major harvest months in Taiwan is from June to December. Red flesh pitayas are even harvested for nine months per year by lighting treatment, but production season are from July to November and requires short time for storage and exportation. Another disadvantage are that peels on harvested fruits will will appear dry and old, and lower temperature with high moisture storage will induce fungal disease after being reheated to room temperature. In order to overcome these problems, dragon fruit growers should be concerned about postharvest handling technologies.
Precooling is the first step after harvest. This strategy is essential and vital for storage and export. Room cooling is common and is a simple way to remove “field heat”. More efficient methods are Forced-air cooling and Hydrocooling. Within forced-air cooling fruits decreased 5-15 times compared to room-cooling. Hydrocooling is another novel method for precooling, but still needs to overcome water, energy, mico-organism and handling method.
Investigating the cold resistance of white-pulp pitayas’ field in the middle and south fields of Taiwan, whether it be summer (Jul-Aug) or winter (Oct-Dec), the fruits were found to be less divergent to cold resistance. On the other hand, disease which occur on the fruit peel within long time storage severely increased with lobgerstorage time, especially more if it was more than 3 weeks. The object of selecting packing materiasl to avoid chilling injury, non-woven fabric with PE bag( 24 holes with 0.8cm diameter) were used without chilling injury and had better performance for 20 days storage. The preliminary results show that fruits treated with active MAP (bags sealed after flushed with 3% O2 and 5% CO2), followed by hypobaric packaging and sealed package maintained better visual appearance after 19 days of storage at 5℃. In addition, MAP (1~5% O2 and 5% CO2) did not cause significant negative effect on fruit quality.
Quarantine treatment of VHT (vapor heat treatment) usually used for pitaya export to Japan there are no fruit flies. The process of treatment need 2.5-3 hours and the center temperature of fruit is more than 46.5℃ for 30 mins. After quarantine treatment, Differential maturity fruits were treated and quarantine treatment shows no remarkable difference. is the peel and pulp showed no significant change. VHT could also decrease the occurrence of disease during export transportation and shelf storage.