POSTHARVEST HOT AIR TREATMENTS EFFECT ON AVOCADO FRUIT QUALITY, CHILLING INJURY AND TRIGLYCERIDES AND TOCOPHEROLS CONTENT

   Avocado fruit is sensitive to chilling injury (CI), which limits its postharvest life. ‘Hass’ avocados were exposed to hot air at 38ºC and 50% or 95% RH for 6 h and stored at 5ºC for up to 56 days.
The best external quality was displayed by the non-heated fruits and fruit heated at 50% RH. Fruit heated at 50% RH exhibited the best internal quality and the lowest incidence of CI. Fruits that were not heated and those heated at 95% RH displayed greater deterioration of their internal color, compared to fruits heated at 50% RH. Respiration rate was initially higher in fruits heated at 95% RH compared with the non-heated fruits and fruits heated at 50% RH. In addition, the maximum respiration intensity was always higher in fruit heated at high RH. Fruit firmness decreased to less than 20N at the end of the storage period in the 3 lots of fruits.
The most abundant triglyceride was the 1,2-Dilinoleil-3-Oleil-Glicerol (LLO) followed by trilinolein (LLL) and triolein (OOO). There were more -tocopherol than the other 2 forms.
The content of the tocopherols decreased during storage, and -tocopherol was significantly lower in heated fruits than in non-heated fruits.
In general, fruit heated at 50% RH presented better internal quality, less incidence of CI, less deterioration of external and internal color, less reduction in the 3 triglycerides, but a slight heat injury, as well as higher weight loss and lower tocopherol content compared to the non-heated fruit or fruit heated at 95% RH.