2017 ASHS Annual Conference

Producers and exporters of fresh tropical fruit gain an advantage in the marketplace by supplying unique, high quality products. However, the shelf-life of most tropical fruit is insufficient to reach distant markets by marine transport. Hypobaric (low oxygen partial pressure) conditions may extend the storage life of refrigerated fresh tropical fruit without loss of edible quality, thereby creating a means to ship fresh fruit in sea containers. The quality and storage life of ‘Rainbow’ papaya (Carica papaya), ‘Haden’ mango (Mangifera indica), and cherimoya (Annona cherimola) under low pressure were determined. Four custom fabricated, modular hypobaric chambers (Vivafresh R&D System, Atlas Technologies) were used for the study. The system included automated vacuum pressure regulation, humidification, pressure and temperature sensors, data acquisition, and a computer control system. Low pressures were achieved with a 2-stage rotary vacuum pump. The chambers were stationed inside a walk-in cold room (Polar King). Low pressure treatments ranged from 2-8 kPa and storage temperatures were 10 °C for papaya and 13 °C for mango and cherimoya. Control fruit were held in chambers at atmospheric pressure (100 kPa) and cold temperatures for comparison. The fruit were treated at the quarter-ripe stage for papayas, and mature green stage for mangos and cherimoya. Fruit were evaluated for quality before hypobaric treatment, and then weekly until the end of storage using standard methods for each fruit type, including water loss, surface color, firmness, soluble solids, titratable acidity, disease incidence, and visual quality ratings. Cherimoya fruit stored at 2.7 kPa pressure, 100% RH, and 13 °C had 10 to 12 days extended storage life when compared to control fruit stored at 100 kPa. In contrast, papayas stored at 2.7 kPa pressure, 100% RH, and 10 °C had minimal storage life extension (3-4 days) when compared to control fruit. The storage life for mango fruit was extended by 7-10 days under hypobaric conditions (2.7 kPa, 13 °C) when compared to control fruit. For cherimoyas, papayas and mangos, fruit ripened normally after removal from hypobaric storage, however postharvest diseases limited the shelf-life of control and treated mangos and papayas equally. Although hypobaric conditions delayed ripening of these tropical fruit, disease incidence after ripening was not inhibited in most trials.