Fruitfly Disinfestation Of Mango Cv Gedong Gincu Using Vapor Heat Treatment (Vht) Method

Abstract

Mango fruit (Mangifera indica L.) is one of the most popular fruit in lndonesia and its production is the second largest after banana. However, mango fruit are host for Tephritidae fruit flies, especially for the species of orientat frui{ fly (Bactrocera dorsalis Hendel). To be accepted by many importing markets, mango fiuit must be treated to ensure that it is free of fruit flies. Formerly, chemicat fumigation was used for disinfestation treatment, but now had been replaced b, chemical-free disinfestations treatment such us heat treatments. There are three methods in the use of heat treatments to control fungaldiseases and insect infestation: vapor heat treatment (VHT), hot water treatment (HVW) and forced hot air treatment (FHAT) VHT involves heating air which is nearly saturated with moisture and passrng the air stream across the produce. This study was carried out to find out (1) the effect of temperature and exposure time on mortality of oriental fruitly (Bactrocera dorsalis), and (2) the effect of vHT on fruit respiration and quality of 'Gedong gincu,mangos. The materia.l use! in this study were oriental fruitfly (Bactrocera dorsitisl in the egg sfage obtained from rearing in laboratorium, and "Gedong gincu', mangos were bought from farmer at lndramayu, West Java. The apparatis used in lhis research were VHT chamber, hybrid recorder, cold storage, cage for fruitfty rearing, water bath, rheomefe4 scaies, oven, chromameter, etc. The study was divided inlo two parts: fruitfly moftality and vHT of "Gedong Gincu" mango. Mortatity test of oriental fruitfly in the egg stage_was done by submerging each of 20 eggs into hot water: (1) at temperature of 46oc for 5, !0,10,20 and 30 minutes, (z) foiSo minutes at temperature of 40, 43, 46, and 4g oc. After submerging, the eggs were let to hatch by putting it in artificial media as a hosf for growing the egg tobecome larva. VHT of the mangos were done at temperature of about 46.5 0a untit a fruit core temperature reached 46.0oC and held for 10, 20 and 30 min. The control fruit were not treated in any way. After treatment, the fruits were immediately cooled in ambient temperature water (25 "C) for 30 min and then atlowed to air dry before storage at 13oC and 90 %RH. The fruit respiration were evaluated every days, wh1e the fruit quality were examined every 4 days of storage consisfs of weightt loss, moisture content, color change, hardness, so/uble solid contenf (SSC,) and vitamin C. The results showed that moftality of the fruitfly attained 100 % in hot water dipping at temperature of 43 oC for at teast 30 minutes or at temperature of 46 oC for at least 10 minutes. The same result was reported by Heather et al. (1gg6) that hot water dipping for 10 minutes at temperature of 46,5 oC produce mortaiity of 100% for fruitfly of ceratitis capitata. The VHT significantty reduced the fruit respiration, however, it was not significantly affect the fruit physiology as shown in the climacteric respiration pattern during storage. There were -no sigiificant change in the fruit weighf /oss, water content, hardness, color, soluOte sorc content and vitamin C. Some drseases attackted the mango during storage were identified as collectotrichum gloeospoldes, pestalotiopsis iangiferie, Iasi6aiptodia theobromae and cladosporium cladosporoides. Heat treatment significantly reduced disease attag\ 91used by antracnosa and stem end rot in "Gedong gincu" mango. vHT at 46.5oC for 10-30 minutes were effective to controtfruit diseases and fruitny infested inside the mangos as wel/ as able to maintain mango quality during storage.