REVISITING THE HOT WATER TREATMENT PROTOCOL FOR 'SOLO' PAPAYA

Abstract

‘Solo’ papaya fruit grown in southern Philippines is increasingly gaining demands in the domestic and export markets. Sea-shipping of papaya takes two weeks to foreign markets thus the possibility of disease development while in transit. Hot water treatment (HWT) at 49-51°C for 10 min followed by 5-min hydrocooling effectively reduced decay but the concern in its adoption is the long treatment time. To shorten HWT, heated azoxystrobin solution at 50°C for 10 min and 53°C for 5 min were tested on color 2 (tinge of yellow) fruit. With heated azoxystrobin, hydrocooling was not done. The conventional HWT of 50°C for 10 min and 53°C for 5 min, both with 5-min hydrocooling in azoxystrobin were also conducted. Fruits were stored for two weeks at 13°C then ripened at 25°C. Diseases (anthracnose and stem end rot) were observed even on treated fruits but was higher for control (no HWT and no hydrocooling). On the other hand, notable results were observed for those treated in heated (50°C, 10-min dip) azoxystrobin showing better disease control especially stem end rot and chocolate spot. This treatment also resulted in the highest sensory scores (peel and pulp color, sweetness and papaya flavor). Based on the results, heated azoxystrobin treatment showed potential in reducing time spent during HWT and in effectively controlling disease on papaya fruits.