บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Short-term exposures to reduced O2 and elevated CO2 concentrations differently affect the respiratory characteristics of postharvest Citrus fruits

Shi Jian Xin, Aharon Zion, Goren Raphael, Goldschmidt Eliezer. E and Porat Ron

9th Controlled Atmosphere Research Conference (CA2005). Program and Abstract.Michigan State University, East Lansing, Michigan, USA. July 5-10, 2005. page43

2005

บทคัดย่อ

Short-term exposures to reduced O2 and elevated CO2 concentrations differently affect the respiratory characteristics of postharvest Citrus fruits Respiratory responses of citrus fruits to controlled atmospheres (CA) are of fundamental importance, since CA treatments can be beneficially used in postharvest handling procedures o­nly when they do not have any detrimental effects o­n fruit quality parameters.Previous studies evaluated the responses of citrus fruits to low O2 (2% to 3%) and high CO2 (<5%) levels over long-term storage.In this study, we evaluated the physiological responses of ‘Star Ruby’ grapefruits (Citrus paradisi Macf., cv.‘Star Ruby’) and ‘Murcott’ mandarins (Citrus reticulata Blanco, cv. ‘Murcott’) to different concentrations of O2 (5, 10, 15 and 21%) or CO2 (0, 5, 10, and 20%) at 20ºC for a short-term period (l week).Exposures to reduced O2 concentrations significantly reduced respiration rates and internal CO2 levels, but 5% O2 dramatically increased juice ethanol, and, to a lesser extent, acetaldehyde (AA) accumulation.Mandarins exhibited higher and more rapid responses to reduced O2 concentrations than grapefruits, as revealed by the accumulation of juice ethanol and AA, two important indicators of anaerobic respiration.Exposures to low O2 (5-10%) slightly reduced ethylene evolution rates in grapefruits but rather increased their levels in mandarins.Exposure to elevated CO2 (10-20%) markedly increased respiration rates and internal CO2 levels, but without significant effects o­n ethylene evolution.Similarly, mandarins showed earlier increases in respiration rates and internal CO2 levels than grapefruit, following exposure to elevated CO2 concentrations.Exposure to elevated CO2 up to 20% didn’t substantially increase juice ethanol and.AA.Results indicate that reduced O2 and elevated CO2 concentrations affect citrus fruits’ respiratory characteristics differently.Possible mechanisms involved will be briefly discussed.