The effect of germination process on β–glucosidase activities, isoflavone contents as well as antioxidant capacities soybean seeds was investigated. Soaked soybean seeds were germinated at 25◦C in dark condition for 72 hours. Samples were collected every 12 hours during germination for analysis the β–glucosidase activities, which was monitored with a synthetic substrate p–nitrophenyl–β–D–glucopiranoside (p–NPG). The freeze-dried samples were prepared for determination of isoflavone contents by high performance liquid chromatography (HPLC) and antioxidant capacities were assayed by 1,1–diphenyl–2–picrylhydrazyl (DPPH) radical–scavenging activity in term of IC50 value. β–glucosidase activity increased 1.8 fold in soaked soybean seeds and reached to the maximum value (3.2 fold) in soybeans germinated for 48 hours. The increase in β–glucosidase activity led to the transformation in isoflavone forms, namely the hydrolysis of glycosides into aglycones catalysed by β–glucosidase during germination process. Total glycosides (daidzin, glycitin and genistin) content in soybean seeds was unchanged after soaking. During germination, total glycosides in seeds increased and reached the maximum value after 36 hours (1.2 fold), further germination (60 hours) this content significantly reduced (p < 0.05). Total aglycones (daidzein, glycitein and genistein) content increased 1.2 fold in soaked soybeans and about 1.7 fold in soybeans germinated from 48 to 72 hours. The total isoflavones content in soybean seeds was highest in seeds germinated from 48 to 60 hours and decreased when germinated for 72 hours. Antioxidant activity of soybeans was highest when germination time was 60 hours. In addition, there was a high correlation between antioxidant activities (IC50 values) and total aglycones contents (R2 = 0.91) in soybean seed during germination.
Tạp chí khoa học Trường Đại học Cần Thơ
Lầu 4, Nhà Điều Hành, Khu II, đường 3/2, P. Xuân Khánh, Q. Ninh Kiều, TP. Cần Thơ
Điện thoại: (0292) 3 872 157; Email: tapchidhct@ctu.edu.vn
Chương trình chạy tốt nhất trên trình duyệt IE 9+ & FF 16+, độ phân giải màn hình 1024x768 trở lên