Lee Da Eun, Lee Sunmin, Singh Digar, Jang Eun Seok, Shin Hye Won, Moon Byoung Seok, Lee Choong Hwan
Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea.
Foods Research Institute, CJ CheilJedang Corp., Suwon 16495, Republic of Korea.
Food Chem. 2017 Sep 15;231:258-266. doi: 10.1016/j.foodchem.2017.03.119. Epub 2017 Mar 23.
A time-resolved non-targeted metabolomic study towards evaluating the effects of three rice substrate types viz., white rice (WR), giant embryo rice (GER), and brown rice (BR), on Koji fermentation was performed. Notwithstanding the relatively higher proportions of metabolites in unfermented BR (BR 0>WR 0, GER 0), the relative levels of metabolic repertoire in BR Koji were marginally enhanced during 36h fermentation except those for phenolic acids, fatty acids, and vitamins. The WR Koji showed higher levels of lysophospholipids (LysoPC's) and protease-released amino acids (WR 36>GER 36>BR 36). The higher β-glucosidase activity in GER Koji effected the increased levels of sugars and flavonoid aglycons complementing its higher antioxidant activity (GER Koji>BR Koji∼WR Koji). The present study holistically underpins the dynamic metabolomes and enzymatic states during rice Koji fermentation with varying substrate types. The present study finds applications in optimization of commercial Koji production.
开展了一项时间分辨非靶向代谢组学研究，以评估三种水稻底物类型，即白米（WR）、巨胚米（GER）和糙米（BR）对酒曲发酵的影响。尽管未发酵的糙米（BR 0>WR 0，GER 0）中代谢物比例相对较高，但在36小时发酵过程中，除酚酸、脂肪酸和维生素外，糙米曲中代谢物库的相对水平略有提高。白米曲显示出较高水平的溶血磷脂（LysoPC's）和蛋白酶释放的氨基酸（WR 36>GER 36>BR 36）。巨胚米曲中较高的β-葡萄糖苷酶活性导致糖和黄酮苷元水平增加，这与其较高的抗氧化活性相匹配（GER曲>BR曲~WR曲）。本研究全面地揭示了不同底物类型的米曲发酵过程中的动态代谢组和酶状态。本研究在优化商业酒曲生产中具有应用价值。
