S23 - Session P5 - Ripening / MCP - Influence of postharvest ethylene treatment on apricots

Authors: Séverine Gabioud Rebeaud *, Coralie Dayer, Pierre-Yves Cotter, Danilo Christen

Apricots are climacteric fruit characterized by a rapid postharvest softening that results in a high sensitivity to mechanical damages and a risk of decay development. To remedy this, apricots are commonly harvested at an early maturity stage and stored at low temperature. The higher firmness, lower sweetness, and greener color of such fruit, compared with tree-ripened ones, does, however, not meet the consumers' preferences. This study evaluated the influence of an ethylene treatment applied on apricots after one week of storage at 1 °C compared with storage at 8 °C. Ten cultivars, all harvested at both 'early' and 'commercial' harvest stages, were included in the study. Firmness was the highest evolving parameter compared with skin colour, total soluble solids and acidity. Ethylene treatment increased firmness loss of all tested cultivars but 'Swired', and tended to be more impactful on early harvested fruit. Total soluble solids content was higher in fruit at 'commercial harvest' than 'early' harvest, but not strongly influenced by ethylene treatment or storage temperature. A cultivar-dependent loss of acidity was observed during storage, but neither storage conditions nor maturity at harvest influenced this parameter. For some cultivars, apricots harvested at a ripe maturity stage were less green compared with early harvested fruit. A slight decrease was observed after storage in some instances, but ethylene and temperature did not influence this parameter. Finally, storing apricots at 8 °C led tendentially to a higher percentage of rotted fruit than storage at 1 °C followed by an ethylene treatment. These results showed that ethylene treatment can be applied to increase softening of apricots. However, the treatment did not influence acidity and total soluble solids, which are essential for sensory quality and acceptance of the fruit.