Endogenous ethylene regulates accumulation of α- and β-carotene in the pulp of harvested durian fruit

- Major carotenoids α- and β-carotene in durian pulp increased >30% in storage.
- Concentrations of the minor carotenoid zeaxanthin also increased during storage.
- Concentrations of the minor carotenoid lutein were not different from controls.
- 1-MCP largely prevented the increase in total and major carotenoids.
- 1-MCP only slightly affected the minor carotenoids.

Durian (Durio zibethinus Murr.) cv. Chanee fruits were harvested at commercial maturity and stored at 25 °C for 9 days. Respiration rates and ethylene production increased during storage, while pulp firmness decreased. The concentrations of the two main pulp carotenoids (α- carotene and β-carotene) increased by more than 30% during storage. The minor carotenoids zeaxanthin also increased, while an increase in lutein was not statistically different from controls. Treatment at 25 °C with 500 μL L−1 1-methylcyclopropene (1-MCP) for 12 h delayed the increase in respiration rate and in ethylene production. It also resulted in a later decrease in pulp firmness. 1-MCP largely prevented the increase in pulp carotenoid concentrations. Ethephon treatment (brushing the stem cut surface) increased the measured ethylene and slightly hastened the decrease in pulp firmness, but did not measurably affect the respiration and carotenoid concentrations. It is concluded that the postharvest increase in pulp α-carotene and β-carotene concentrations is an integral part of pulp ripening in this cultivar.