Utilisation of hot water treatment on papaya (Carica papaya L. cv. Eksotika II) to elucidate disease resistance and maintain postharvest quality

Papaya fruit (Carica papaya L.) is one of the most widely farmed fruits in Malaysia, and produced for domestic consumption and exported worldwide. Papaya fruit is susceptible to anthracnose, a fungal infection caused by Colletotrichum gloeosporioides that negatively affects fruit quality and shelf-life. The common disease control approach utilises fungicides such as prochloraz as a postharvest application. However, public concerns regarding the health risks of fungicide residue on food have created interest in safer and greener alternatives. As a result, hot water treatment at 54°C for 5 min was investigated in order to reduce or replace the reliance on fungicides. Results showed that papaya fruits treated with hot water presented a higher reduction in disease incidence and severity. Additionally, hot water treatment preserved the physicochemical properties, prolonged shelf-life, and increased the papaya fruits’ total phenolic and flavonoid contents while up-regulating metabolites that are involved in stress tolerance.