Effect of Preharvest Carbon Dioxide Enrichment on the Postharvest Quality of Tomatoes

The effect of preharvest application of elevated CO2 throughout the fruit growing period on organic acid, sugar content, acid invertase activity (β-fructofuranoside fructohydrolase, EC 3.2.1.26), and color quality in tomato (Lycopersicon esculentum Mill. cv. Momotaro) fruit during storage at 20 °C was determined.The CO2-enriched tomato fruits contained significantly lower concentrations of citric, malic and oxalic acids, but had significantly higher reducing sugars and acid invertase activity at harvest and during storage. The concentration of these acids decreased with storage, whereas the activity of acid invertase and reducing sugar contents increased in the treated fruits; they were relatively constant in the control fruits. Furthermore, the elevated CO2 resulted in a deeper red color during storage.