Stability of ascorbic acid in extracts of iris leaves.

The highest average value for the ascorbic acid content of freshly harvested vegetables in Olliver's (1954) list is 1 9 mg./g. fresh wt. for parsley (Carum petroselinum); in the Handbook of Biological Data (1956) the highest value is 1-36 for turnip greens (Brassica rapa). Morgan (1942) found 2-8 mg./g. in fresh parsley leaves. We have found the average value for several batches of lucerne (Medicago sativa) to be 2-4 mg./g. Other high values in published tables are those of Bicknell & Prescott (1953) for nasturtium (Tropaeolum majus) leaves, 2-04-65 mg./g., and of Porotnikoff (1954) for kale, 1-84 mg./g. The present paper shows that leaves of the iris have a higher content of ascorbic acid than any of those mentioned above and also that they have an exceptionally low oxidase activity.