Ascorbic Acid, Dehydroascorbic Acid and Diketogulonic Acid in Frozen Green Peppers

ABSTRACT “Total” ascorbic acid (TAA), L‐ascorbic acid (L‐AA), dehydro‐ascorbic acid (DHAA), and diketogulonic acid (DKGA) were determined in fresh green peppers, frozen blanched peppers, and frozen unblanched peppers. L‐AA accounted for 97% of the TAA in fresh peppers. Freezing resulted in a 9.2% decrease of TAA, a 15% decrease in L‐AA, a 5% increase in DHAA and 1% increase in DKGA. Blanching did not affect the ascorbic acid levels of frozen peppers. DHAA remained relatively constant at 10% of the TAA during frozen storage. DKGA increased during frozen storage to 15% of the TAA. L‐AA decreased after 8 months frozen storage (‐18°C) to 75% of the TAA. Unblanched frozen peppers were superior in flavor, texture, and appearance to the blanched frozen peppers.