Postharvest physiology and quality of bitter melon (Momordica charantia L.)

Abstract

Developing fruits of Momordica charantia, known as bitter melon, bitter gourd or balsam pear, were harvested at horticultural maturity and stored up to 14 days in humidified air at different temperatures. Respiration rates of fruits at 20 and 10 °C were approximately 40 and 15 μl CO2 g−1 h−1, respectively. Ethylene production rates at these temperatures were 0.1–0.3 nl g−1 h−1. Fruits stored for >8 days at 7.5 °C showed severe chilling symptoms (decay, pitting and discoloration) and typical chill-induced respiratory and ethylene production increases after transfer to 15 °C. Fruit quality was best maintained if bitter melon were stored at 10 and 12.5 °C. Fruits at 15 °C continued to develop, showing undesirable changes including seed development, loss of green color, and fruit splitting. Immature fruit maintained postharvest quality better than fruit harvested at the fully developed green stage. Bitter melon stored at 15 °C in controlled atmospheres (21, 5 or 2.5% O2 in combination with 0, 2.5, 5 or 10% CO2) were not different in quality from air-stored fruits at 2 weeks. Fruits stored 3 weeks in 2.5 or 5% CO2 in combination with 2.5% O2 showed greater retention of green color and had less decay and splitting than air-stored fruit.