Use of very low ethylene levels to extend the postharvest life of Hass avocado fruit

Abstract

Unripe Hass avocados were stored at 0, 10 and 20°C in air containing ethylene at concentrations ranging from 1.0 μl 1-1 down to 0.005 μl 1-1. The time to ripen of fruit held continuously at 10 and 20°C increased linearly with a logarithmic decrease in ethylene concentration. Fruit held at 0°C were transferred to 20°C after 2, 4 and 6 weeks and allowed to ripen. While there was no effect of ethylene concentration on ripening time, the severity of chilling injury on fruit held at 0°C for 4 and 6 weeks was reduced with decreasing log ethylene concentration. Analysis of avocados in the wholesale markets at ambient temperature showed an average presence of ethylene at 0.16 μl 1-1. An increase in storage life would be achieved if levels of ethylene currently present during marketing were reduced.