EFFECTS OF LOW OXYGEN CONCENTRATIONS ON GLYCOLYSIS IN LIGHTLY PROCESSED CARROTS

Abstract

Carrot (Daucus carota L.) shreds were stored under a continuous flow of 0.5% O2 (balance N2), 2% O2 (balance N2), or air for 9 days at 5C and 15C. The resulting changes in respiration and levels of the glycolytic intermediates were monitored. Low-oxygen atmosphere reduced respiration rate, but the RQ increased. The RQ was higher at 0.5% O2 than at 2% O2 atmosphere at both 5C and 15C. The most significant change in the levels of glycolytic intermediates was the accumulation of fructose 1,6-biphosphate. The level of fructose 1,6-biphosphate at 0.5% O2 was about 2-fold greater than at 2% O2 atmosphere at both 5C and 15C. The level of the other glycolytic intermediates at low-oxygen atmosphere was similar to that held in air atmosphere. These results suggest that phosphofructokinase activity in the tissue of carrots may increase under low-oxygen condition and it may be one of the controlling points in the glycolytic pathway affected by low oxygen concentrations.