Ascorbic Acid and β-Carotene Affect the Chlorophyll Degradation in Stored Spinach (Spinacia oleracea L.) Leaves

Abstract

Effects of antioxidants, L-ascorbic acid (AsA) and β-carotene, on chlorophyll (Chl) degradation by a peroxidase-hydrogen peroxide system were determined, and the relationship of the Chl degradation to the antioxidant contents in stored spinach (Spinacia oleracea L.) leaves treated with ethylene was studied. The antioxidants reduced Chl degradation by inhibiting the peroxidase-hydrogen peroxide reaction system. AsA and β-carotene contents in spinach leaves decreased during storage at 25°C, the decrease being greater with AsA than with β-carotene. Degradation of Chl and AsA was hastened when the spinach leaves were treated with 10 ppm ethylene, and the degradation of AsA preceded that of Chl. Thus, AsA was more effective thanβ-carotene in protecting the Chl, but the effect was lost when AsA content dropped below a threshold level