Lychee ( Litchi chinensis Sonn.) fruit quality following vapour heat treatment and cool storage

Vapour heat treatment (VHT) was used as a possible disinfestation treatment against fruit flies for lychee fruit. On the basis of an optimum core temperature of 45°C for variety ‘Tai So’, this and two other varieties ‘Kwai May Pink’ and ‘Wai Chee’, were exposed to this temperature for various lengths of time. ‘Tai So’ and ‘Wai Chee’, but not ‘Kwai May Pink’, tolerated this temperature for 42 min. without significant reduction in fruit appearance, eating quality and disease control following 2 weeks storage at 5°C, during which transport to distant markets could be undertaken. Preliminary results suggest that 45°C for only 30 min. is sufficient to kill all stages of the Queensland fruit fly, Bactrocera tryoni, so at least two of the three varieties tested could safely survive these conditions without quality reduction.