Abstract
The dynamic changes of glyceollin contents and concentration depend on various conditions. This study aimed to investigate the role of a pure culture of Saccharomyces cerevisiae versus ragi tape as a commercial starter combined with light/no light for boosting glyceollin accumulation in soybeans followed by the evaluation of its antioxidant activity. Soybeans were subjected to five different treatments: untreated,
S. cerevisiae (gS), ragi tape (gR), S. cerevisiae with light (gSL), and ragi tape with light (gRL). The isoflavonoids daidzin, glycitin, genistin, daidzein, glycitein, genistein, glyceollin I, glyceollin II, and glyceollin III were identified and measured by High-Performance Liquid Chromatography (HPLC) assay, and the antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH). Glyceollin I was increased about 2-fold in gR,
3-fold in gS, 4-fold in gSL and 7-fold in gRL compared to untreated soybeans. The gRL also exhibit a potent antioxidant activity compared to gSL. Taken together, ragi tape with light is the most effective elicitor for boosting isoflavonoids contents. Therefore, ragi tape with light deserves as a potential elicitor with valuable insights to increase the isoflavonoids contents to optimize the impact of soybeans for health.