Location: Subtropical Horticulture Research2013 Annual Report
1a. Objectives (from AD-416):
To determine whether an ambient air cooling period of 30 minutes, in place of immediate cooling in water, can allow the hot water treatment to be reduced by 10 minutes or the temperature of the water to be reduced.
1b. Approach (from AD-416):
Follow standard hot water treatment protocols with two treatments, a control which is the standard treatment time period for each size mango for immediate hydrocooling and a treatment reduced by 10 minutes but allowing the fruit to cool in air for 30 minutes before cool water immersion.
3. Progress Report:
This research is directly related to inhouse objective 2. Test novel quarantine treatments for phytosanitary applications on imported and exported fruit or other commodities. Research was conducted in collaboration with Programa Moscafrut SAGARPA-IICA, Chiapas C. P, Mexico. Hot water dip experiments determined the thermal death rate constants and mortality curves for the eggs and different larval instars of the medfly when submerged in isolation in water and submerged within mango fruit in water at 43.1, 44.1, 45.1, and 46.1C. The results of the study indicate that Ataulfo mangoes weighing < 329 ± 2.11 g and at risk infestation by immature medflies should be immersed for 95 min at 46.1-47C to ensure that the fruit pulp remains at this temperature for 10 min. The data collected on mango quality indicate that hot water immersion for 95 min at 46.1-47C can produce a more uniform fruit-color and positively modify the pH (producing more palatable fruit), but can also produce a loss of firmness and weight (5%).