Contents of D-chiro-Inositol, Vitexin, and Isovitexin in Various Varieties of Mung Bean and Its Products

Mung bean (Vigna radiata L.) is rich in bioactive compounds including D-chiro-inositol (DCI), vitexin, and isovitexin, which have beneficial effects on patients with diabetes. To find a better source for these valuable chemicals, we have collected 110 varieties of mung bean seed samples and 8 mung bean products to determine the levels of these bioactive compounds. We also measured the DCI content in mung bean sprouts at different germination stages. Content of DCI, vitexin, and isovitexin in all mung bean varieties ranged from 0.43 to 5.79, 0.12 to 3.00, and 0.03 to 1.16 mg g−1, respectively. The varieties of C0001321, C0003522, and C0004485 have the highest DCI, vitexin, and isovitexin contents, respectively. The mung bean products in the market contained relatively lower level of these bioactive components. Contents of DCI, vitexin, and isovitexin in all mung bean products ranged from 0.119 to 0.717, 0 to 0.547, and 0 to 0.923 mg g−1, respectively. During the 112 h of germination test, DCI level steadily increased at first stage and reached the highest level at 80 h of germination (4.79 mg g−1). These results provide useful information for the selection of suitable varieties and proper germination stages to obtain functional ingredients from mung beans.