Changes in Free Sugar, Coixol Contents and Antioxidant Activities of Adlay Sprout (Coix lacryma-jobi L. var. ma-yuen Stapf.) according to Different Growth Stage

Background: Adlay (Coix lacryma-jobi L. var. ma-yuen Stapf.) is an important medicinal and cereal crop that contains high levels of protein, fatty acids and crude fiber, as well as calcium, phosphorus, zinc, minerals, and essential amino acids. Despite its economic significance, little is known about biological activity in adlay sprouts. This study investigated the total free sugar, polyphenol and flavonoid content, and antioxidative activity in adlay sprouts at different growth stages. Methods and Results: The total free sugar and coixol content of germinated adlay sprouts were analyzed by high performance liquid chromatography. The total phenolic content was measured by the Folin and Denis, and flavonoid content by the Davis method. Antioxidative activity was tested by the 2,2-diphenyl-1-picryl hydrazyl method. All measured component, including total phenolic and coixol content ($2.71{\pm}0.02mg/g$ and $59.70{\pm}0.01mg/g$), and antioxidant capacity ($IC_{50}$; $453.93{\mu}g/m{\ell}$) were highest in 3 day old adlay sprouts. In contrast, total free sugar and flavonoid content (3.02% and $0.60{\pm}0.02mg/g$) were highest in sprouts at 5 days after sowing. In addition, there was a strong positive correlation between antioxidative activity and total polyphenol content (r = 0.902, p < 0.001). Conclusions: Adlay sprouts between 3 days and 5 days following germination contain high levels of functional components and free sugar. This study therefore suggests that adlay sprouts can be developed as a valuable health-promoting food and a good source of natural antioxidants.

생육시기 별 새싹율무의 유리당, 기능성 성분 및 항산화활성 변화