Effect of Soaking and Boiling on Nicotianamine Content in Legumes

Abstract

The nicotianamine content in legumes and the effect of boiling on nicotianamine content in each crop were investigated. Nicotianamine content per 100 g wet weight was particularly high in soya beans, followed by adzuki beans, and American potato beans. The rate of nicotianamine loss was 11.8%-18.3% in soya beans after 20 h of soaking and 15 min of boiling. Further loss was observed after 30 min of boiling. Adzuki beans exhibited a similar trend. No difference was observed in the rate of nicotianamine loss relative to boiling time in soybeans (succulent seeds only) and common beans (pods and succulent seeds), with a loss rate of approximately 40%. American potato beans also showed a 40% loss in nicotianamine content after boiling. Even after boiling, 1 mg of nicotianamine was still obtained from approximately four tubers of American potato beans. American potato beans are thus a promising legume source of nicotianamine for practical use.