Submitted to: Journal of Agriculture and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/18/2004
Publication Date: 11/19/2004
Citation: Argenta, L.C., Mattheis, J.P., Fan, X., Finger, F.L. 2004. Production of volatile compounds by 'Fuji" apples following exposure to high CO2 or low O2. Journal of Agriculture and Food Chemistry. 52:5957-5963. Interpretive Summary: Improper storage conditions can lead to development of internal browning in 'Fuji' apple fruit. High concentrations of CO2 during cold storage can induce injury that renders fruit unmarketable. Measures to avoid injury development include CO2 control and the use of antioxidant materials including diphenylamine (DPA). Exposure to high CO2 can also result in apples producing abnormal amounts of volatile compounds that can impact fruit aroma and flavor. A similar change in volatile production can occur in apples exposed to very low O2 concentrations during storage where no internal browning occurs. Results of this study indicate volatiles produced after storage in high CO2 or low O2 are similar and respond differently to high CO2 or low O2 in that changes in post-storage volatile production are less pronounced.
Technical Abstract: Emission of volatile compounds by 'Fuji' apples during short- or long-term exposure to high CO2 was examined. Volatile production by fruit treated with antioxidant diphenylamine (DPA) and/or stored in low O2 to induce anaerobic metabolism were also examined. Exposing 'Fuji' apples to 20 kPa CO2 at 20 deg C for 3 to 12 days enhanced production of some volatile compounds including ethanol and methyl and ethyl esters, while production of other compounds including C3-C6 alcohols and propyl, butyl, pentyl and hexyl esters decreased. Additionally, emanation of octanal, nonanal and decanal increased but butanal decreased following 9 or 12 days exposure to 20 kPa CO2. The impact of high CO2 exposure on volatile proudction was dependent on fruit maturity at harvest. Apples stored for 8 months in a low O2 controlled atmosphere (CA) (0.5 kPa O2 + 0.05 kPa CO2) or high CO2-CA (1.5 kPa O2 + 3 kPa CO2) at 0.5 deg C had reduced production of most volatiles, especially butyl and hexyl esters, compared to fruit stored in air. Two exceptions were ethanol and ethyl acetate for which production was enhanced by both CA regimes. For individual volatiles, the impact of storage in high CO2-CA on production of major alcohols and esters was simlar to or less than that of the low O2-CA treatment. There was no impact of DPA on volatile production by apples held at 20 deg C in air following harvest. However, DPA treatment prevented most of the high CO2- and low O2-induced changes in volatile production when treated fruit were held at 20 deg C or 0.5 deg C. Results of this study do not indicate that changes in production of alcohols, esters and aldehydes following exposure of 'Fuji' apples to high CO2 are causally related to development of CO2 injury.