Influence of fruit maturity, 1-methylcyclopropene (1‑MCP) treatment and storage temperature on ethylene production and firmness of ‘Goldrich’ and ‘Orangered’ apricots

Apricots are climacteric fruits characterized by a fast ripening process after harvest. To avoid fruit quality losses during storage, transport and distribution, fruits are often harvested at an unripe maturity stage, resulting in lower sensory quality and higher heterogeneity of the batches in the supply chain. The aim of this study was to evaluate the influence of two ripening stages at harvest, two storage temperatures (1 and 8°C), and 1-methylcyclopropene (1-MCP) treatment on apricot quality and ethylene production of the cultivars ‘Goldrich’ and ‘Orangered’. Fruit were stored under regular atmosphere (92% relative humidity). During storage and shelf life, firmness was the highest evolving parameter compared to acidity, sugar content and skin colour. The ripening stage of the fruits highly influenced the decrease in firmness during storage. Firmness decrease was 10 to 20% lower for unripe fruits, and no firmness decrease was observed for unripe ‘Orangered’. The same tendencies were observed with ethylene production. Climacteric rise was influenced by the fruit ripening stage and was delayed (5 days) for unripe fruits. Unripe ‘Orangered’ did not produce ethylene; probably due to the non-activation of ethylene biosynthesis genes in unripe fruits. The influence of 1-MCP treatment on firmness change and ethylene production differed depending on the measurement moment: no influence was observed directly after storage, whereas, after 3 days of shelf-life, fruit softening and ethylene production were reduced by using 1-MCP. In contrast, storage temperature highly influenced firmness and ethylene production, exhibiting a 20% higher softening and an earlier (>20 days) climacteric rise at 8°C compared to 1°C for ‘Goldrich’. For ‘Orangered’, ethylene production began after 7 days of storage, independently of the temperature. The interactions between the different influencing factors, as well as potential recommendations for the apricot supply chain actors, are discussed.