Low temperature conditioning before cold disinfestation improves ‘Hass’ avocado fruit quality
Peter J. Hofman , Barbara A. Stubbings, Matthew F. Adkins, Robert J. Corcoran, Anne White and Allan B. Woolf
Postharvest Biology and Technology Volume 28, Issue 1 , April 2003, Pages 123-133
2003
บทคัดย่อ
The potential for low temperature conditioning (LTC) treatments, either alone or in combination with hot water treatment (HWT), to improve the quality of ‘Hass’ avocado (Persea americana Mill.)fruitfollowing cold disinfestation of Queenslandfruitflies, was investigated. Avocadofruitwere held at 4–8 °C for 3–4 days then disinfested for 16 days at 1 °C before ripening at 16 °C. In a second experiment,fruitwere placed in water at 41–42 °C for 15–25 min, either with or without LTC, then disinfested and ripened. In both experiments, LTC at 4 °C for 4 days or at 6–8 °C for 3–4 days increased the percentage offruitwith acceptable external appearance (less than 5% of thefruitwith discrete dark patches on the skin, and skin spotting combined) after disinfestation from 0 to 100% due to the effective elimination of discrete patches on the skin. Disinfestation alone increased body rots and diffuse flesh discolouration severity in ripefruit,while LTC before disinfestation reduced severity of these disorders to similar levels as those in non-disinfested, non-storedfruit.LTC before disinfestation reduced discrete patches severity and improved flesh quality more than HWT. Combined treatments of HWT and LTC before disinfestation were no more beneficial compared with LTC alone. Conditioning offruitat 6 °C for 3 days followed by disinfestation resulted in no survivors from 50748 third instars of Queenslandfruitfly (Bactrocera tryoni Froggatt). LTC efficacy was verified commercially by conditioningfruitat 6 °C for 3 days followed by disinfestation and airfreight to New Zealand. Externalfruitappearance and internal ripefruitquality after disinfestation were found to be high. These results show that LTC before cold disinfestation effectively eliminates skin damage and improves flesh quality of ripe ‘Hass’ avocadofruit,with no negative effect on Queenslandfruitfly disinfestation efficacy.