Oxalate content of some leafy vegetables and dry legumes consumed widely in Egypt

Abstract

Oxalic acid and total oxalate contents were determined in four leafy vegetables and six dry legumes consumed widely in Egypt. The four vegetables, normally eaten raw, can be arranged according to their oxalate content, in descending order, as follows: green onion (leaves), green onion (bulbs), leek, radish (leaves), radish (roots) and roquette. Oxalic acid represented 76–86% of the total oxalates. Dry faba beans had the highest oxalic acid content, followed, in descending order, by fenugreek, lentils, peas, chickpeas and lupin. The ratio of oxalic acid to total oxalates differs according to the total oxalate content of the legume variety. Decortication, steeping, sprouting, stewing, boiling and baking reduced the oxalate content of seeds in different ways. Sprouting and steeping, followed by decortication, resulted in the most pronounced decrease in oxalates, especially in faba beans and lupin.