Seeds of five different locally available food legumes were analyzed for phytic acid content using a spectrophotometric method based on precipitation of phytate as ferric phytate. The phytic acid content of legumes investigated was found to be in the range of 0.21% (in lima beans) to 0.45% (in winged beans).
The major portion (88-94%) of phytate phosphorus was found in the cotyledon of navy bean and winged bean seeds while very little was seen in the seed coat. Cooking (boiling) reduced phytate phosphorus content markedly in mungbean (83%) while cooked winged bean seeds had only 53% less phytic acid. This study also shows that the addition of phytate decreases soluble protein in winged beans. The formation of an insoluble phytate-protein complex was more evident at low pH resulting in 30-40% reduction of soluble protein.