Changes in antioxidant activity and vitamin B2 content of Aster glehni based on blanching time

This study analyzed the changes in total polyphenol and flavonoid contents of Aster glehni based on blanching time and examined the relationships between their contents and antioxidant activities. In addition, vitamin B2 content in green vegetables was determined to use as basic data for the availability of A. glehni. Compared with non-treatment, the total polyphenol and flavonoid contents considerably decreased to 13.05-52.96% and 36.63-81.75%, respectively, with the passage of blanching time (1-5 min). Furthermore, 2,2-diphenyl-1-picrylhydrazyl and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging abilities considerably decreased with the antioxidant activity. Before blanching, vitamin B2 content in A. glehni was 1.17 mg/100 g of dried sample, and at the blanching time of 3 min, it decreased to 0.60 mg/100 g (less than 50%) of dried sample. Therefore, further research should be conducted on either additives or cooking methods to prevent the leakage of physiologically active substances in the cooking water at the time of blanching A. glehni.