Changes in nutritional components and antioxidant activities from soybean leaves containing high isoflavone contents according to different storage temperatures and periods

Abstract

This study investigated that change of the nutrients (including fatty acids, amino acids, and minerals) and total phenolic (TP), total flavonoid (TF), and isoflavone contents and antioxidant activities during the storage of soybean leaves containing high isoflavone contents at 5, 25, and 55 o C for 180 days. The contents of free amino acids were increased from 1313.81 mg/100 g at 0 day to 1776.15, 1693.93 and 1551.18 mg/ 100 g at 5, 25, and 55 o C storage for 180 days, respectively, but the values of fatty acids were little unchanged. The contents of minerals were detected from 51.65 mg/100 g (0 day) to 49.93 (5 o C), 50.20 (25 o C), and 61.21 (55 o C) mg/100 g at 180 days, respectively. The levels of total isoflavones did not change during the storage periods. In case of storage at 55 o C, the contents of glycosides (1347.78→2195.13 μg/g) and aglycones (342.79→ 480.61 μg/g) increased during storage, while the levels of malonylglycosides (2209.22→1289.48 μg/g) decreased. Also, the TP and TF contents were slightly increased from 9.31 and 8.61 mg/g at 0 day to 9.97 and 9.3 mg/g at 180 days, corresponding to the radical scavenging activities of 2,2-diphenyl-1-picrydrazyl, 2,4,6-azino-bis (3-ethylbenzthiazoline-6-sulphnoic acid), and hydroxyl increased from 30.91, 55.98 and 23.27% from 37.10, 62.54, and 30.95%, respectively.

Comparison of Growth Patterns and Metabolite Composition of Different Ginseng Cultivars (Yunpoong and K-1) Grown in a Vertical Farm

“…For FRAP (ferric reducing antioxidant power assay) determination, the method of Lee et al [31] was used. The FRAP solution was prepared by mixing 300 mM of acetate buffer (pH 3.6), 10 mM of TPTZ in 40 mM of HCl, and 20 mM of FeCl 3 in a ratio of 10:1:1.…”