Ascorbic Acid and Ascorbic Acid Oxidase in Vegetables

Ascorbic acid dehydroascorbic acid and total ascorbic acid content in fruits and vegetables and the amounts of remaining after 24 hours were measured and compared by high‑performance liquid chro‑ matography. Activity of ascorbic acid oxidase was determined in nine kinds of vegetables. The relationship between the activity of ascorbic acid oxidase and the amount of ascorbic acid dehydroascor‑ bic acid and total ascorbic acid remaining is discussed. The residual ratio of dehydroascorbic acid increased and the amount of total ascorbic acid decreased in the vegetables with high enzymic activ‑ ity. The distribution of ascorbic acid oxidase activity in stem and leaf of tingentsai and taatsai was examined. Ascorbic acid oxidase activity in the leaf was twice as high as that in the stem for both vegetables.