1996 Volume 65 Issue 2 Pages 397-402
The effects of O2 level on respiration rates in twelve kinds of fruits and vegetables were investigated. Critical O2 concentration (COC), the O2 level at which CO2 output is minimum, and extinction point (EP), the lowest O2 level at which the respiratory quotient (RQ) remains at 1.0, were estimated for each fruit and vegetable. Fruits such as apples, peaches, Japanese persimmons, and satsuma mandarins exhibited a clear classical CO2. response with progressively lower O2 level. However, CO2 output in cucumber, eggplant, cauliflower, lettuce, and cabbage increased slightly even under 1 or 0% O2 level, whereas broccoli and carrot showed no Pasteur effect, the minimum CO2 output being at 0% O2. The EP of peaches, cucumber, eggplant, cauliflower, and sweet potato coincided with the COC, but the EP of Japanese persimmon, satsuma mandarins, lettuce, and carrot was relatively higher than the COC. Our results suggest that EP is more reliable than COC in evaluating the O2 level at which the aerobic-anaerobic transition phase occurs in fruits and vegetables.