Effect of Hot Water Treatment on Physico-Chemical Properties of Papaya (Carica papaya 'Sekaki') during Ripening

This study was conducted to evaluate the effect of hot water treatment on physico-chemical properties of papaya (Carica papaya 'Sekaki') during ripening. The experiment was done by dipping the papaya twice in hot water that reached a temperature of 42 degrees C for 30 min and 49 degrees C for 20 min, whilst the untreated papaya was considered as the control. Physico-chemical characteristics namely pH, total titratable acidity, ascorbic acid content, total soluble solid, colour, texture, weight loss, general appearances, disease, respiration rate, ethylene production and ACC oxidase activity were observed during storage at ambient (25 degrees C). During ripening process at ambient, the physico-chemical parameters of papaya were changed significantly (p<0.05). However, there were no significant differences (p>0.05) between treatments in all parameters except for general appearances. The hot water treatment gave better appearance which maintained smooth skin better than the control which developed rough skin-and symptom-like senescence spot after storage for several days. 'Sekaki' papaya treated with hot water treatment was free from anthracnose disease while control papaya developed anthracnose disease after 6 days of ripening. The results seemed to suggest that hot water treatment did not affect the physico-chemical changes of 'Sekaki' papaya but maintained the good appearance and prevented from diseases during ripening.