Effect of potassium permanganate on postharvest quality attributes of bitter gourd fruit

Bitter gourd is a widely consumed cucurbitaceous vegetable rich in several nutrients and phytochemicals. The fruit is also used in traditional medicine systems to cure a variety of ailments. However, bitter gourd fruit has a very short postharvest life of 3-4 days at ambient conditions, due to which it suffers significant loss after harvest. In the present study, with the aim to extend storage life, bitter gourd fruits were packed in corrugated fiberboard boxes along with sachets of potassium permanganate (KMnO4) granules @ 1.0, 2.0 and 3.0 g per kilogram of fruit; while control fruits were packed without KMnO4 sachets. The results revealed that during 8 days of storage at room temperature, fruits packed with 3.0 g/kg KMnO4 sachets had minimum deterioration in fruit quality compared to control, and also weight loss and decay loss was observed lowest. KMnO4 treated fruit @ 3.0 g/kg retained the highest chlorophyll content and lowest accumulation of carotenoid pigments in the fruit skin. These fruits also had maximum soluble solids, ascorbic acid, total phenolics content, antioxidant capacity and minimum accumulation of malondialdehyde up to 8 days of storage than other treatments.