Physiological, biochemical and microbial changes associated with ripening and shelf life extension of Surya papaya as influenced by postharvest treatments

Abstract: Papaya fruits’ popularity and widespread consumption are due to their peculiar flavour and nutritional characteristics. However, rapid deterioration and high incidence of rots during handling and storage limits its shelf life. Traditionally, people resort to applying synthetic chemical fungicides to control the anthracnose caused by the fungus Colletotrichum gloeosporioides on fruits. However, their repeated use has caused resistance in microorganisms and toxicity in humans. Hence, there is increasing interest in using natural alternatives instead of chemical treatment. Papaya variety Surya fruits collected at the fully mature green stage were subjected to different postharvest management practices and were packaged in corrugated fibre board boxes and stored till the end of shelf life under ambient conditions. Papaya fruits harvested at a fully mature green stage and subjected to precooling followed by external coating with 1% chitosan and packaging with ethylene scrubber KMnO₄ (T₇) recorded the longest shelf life of 9.67 days. The same treatment also registered the lowest physiological loss in weight (5.64 %), least ion leakage (93.41 %), maximum total carotenoids, total soluble solids, total sugar, reducing sugar and minimum acidity after nine days of storage. No fungal spoilage and fruit rot were recorded in T₇ after three days of storage, with zero percent disease index. After six and nine days of storage, the lowest disease index (16.67 and 27.78 % each) was noticed in T₇.