Abstract
The oxalic acid content in about fifty kinds of common vegetables used in Japanese diets were determined by the Indol colorimetry due to Bergerman and Elliot.
It was found that vegetables with the oxalic acid concentration of more than 1% were goosefoot, New-zealand spinach and green tea, and vegetables containing 0.5 to 1% of oxalic acid were spinach, ginger root, leaf-beet, bamboo shoot, phellopterus littoralis, zingiber mioga and giant knotweed.
But other vegetable foods contained small or negligible amounts of oxalic acid.
Small amount of oxalic acid was contained in Japanese honewort on the market in February, but honewort which was picked up the garden in August, contained about 0.135% of the total oxalic acid.
The tuberous root of devil's tongue and bamboo shoot contained high concentration of oxalic acid. Devjl's tongue jelly has negligible and boiling bomboo shoot has 0.165% of oxalic acid.
The amount of oxalic acid in fungus were small and that of root crops were about 0.1%.
