Biochemical Studies on Cooking of Vegetables (Part 1)

The contents of oxalic acid in the blade and the leaf-stalk of spinach, non-boiled and boiled, were determined. Each sample of spinach was prepared from three kinds of spinach, Hoyo, New Asia and Shin Nippon; which were grown under the same condition. Results were as follows.1. Oxalic acid contents of spinach are very different according to the kind.2. The amount of oxalic acid in the blade was far greater than that in the leaf-stalk.3. But, when boiled, the rate of the quantity of oxalic acid freed from the leaf-stalk was greater than that from the blade.