Effect of Short-Term High-CO Treatments on the Quality of Highbush and Rabbiteye Blueberries During Cold Storage.

The global demand for blueberries has increased due to their health benefits, but postharvest losses, particularly firmness loss and decay, present significant challenges. This study evaluated the effects of high CO concentrations (15% and 20%) applied for 3 d at 1.0 °C on highbush (cv. 'Duke') and rabbiteye (cv. 'Ochlockonee') blueberries, with a focus on quality maintenance during cold storage. The quality parameters evaluated included titratable acidity, pH, total soluble solids, weight loss, and decay. The effect of gaseous treatments on firmness was analyzed using mechanical parameters and the expression of genes related to cell wall integrity (, , , , , and ). Treatment efficacy varied between species. High CO levels reduced decay in both cultivars, but only the highbush cultivar ('Duke') showed improvements in firmness. In 'Duke', CO treatments affected the expression of , , and , while the role of and in maintaining firmness was minimal, with no significant differences between treatments. In 'Ochlockonee', CO effectively reduced weight loss but did not improve firmness. In conclusion, these results highlight the need for tailored postharvest strategies for different blueberry cultivars and suggest that short-term high CO treatments may effectively prolong the postharvest life of highbush blueberries.