Fermentative metabolism and organic acid concentrations in fruit of selected strawberry cultivars with different tolerances to carbon dioxide

Effects of 20 kPa CO2 treatments on concentrations of fermentation products, organic acids, and activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH), were measured in fruit of selected strawberry cultivars (Fragaria xananassa Duch. 'Annapolis', 'Cavendish', 'Honeoye', 'Kent', 'Jewell', 'Lateglow',and 'NorthEast'). Acetaldehyde, ethanol, and ethyl acetate concentrations accumulated in CO2-treated fruit of 'Honeoye' and 'Kent', but not in 'Cavendish' or 'Annapolis'. The former two cultivars were classified as intolerant to high CO2 and the latter two as tolerant to high CO,. Activities of PDC and ADH were higher in CO2-treated than in air-treated fruit of the tolerant cultivars but not in the intolerant cultivars. Succinate accumulated in fruit of all cultivars, but concentrations were higher in the tolerant than in the intolerant cultivars. Results are discussed in relation to tolerance of fruit to CO2.