REGULATION OF GLYCOLYTIC METABOLISM IN FRESH-CUT CARROTS UNDER LOW-OXYGEN ATMOSPHERE

Carrot (Daucus carota L.) shreds were stored under a continuous now of air or 0.5% and 2% O-2 (balance N-2) for 9 days at 5 and 15C. The res ulting changes in respiration, levels of glycolytic intermediates, and activities of ATP : phosphofructo kinase (ATP-PFK), and PPI : phospho fructokinase (PPi-PFK) were monitored. Carrots under low O-2 atmospher e exhibited an increase in RQ due to a greater reduction in O, consump tion than in CO, production, and the increase in RQ was greater at 0.5 % than at 2% O-2 at both temperatures. Fructose 1,6-bisphosphate (F1,6 P) accumulated with decreased O-2 atmosphere and was 2-fold greater at 0.5% than at 2% O-2 atmosphere at both temperatures. The levels of ot her glycolytic intermediates were not significantly influenced by low O-2. The increase in PPi-PFK activity occurred at the same time as F1, 6P accumulation. A similar relationship was not found with ATP-PFK. Th ese results suggest that PPi-PFK may be involved in regulation of glyc olysis under low O-2 atmosphere.