Characterization, extraction efficiency, stability and antioxidant activity of phytochemicals in Angelica keiskei

Angelica keiskei (Ak) is a dark green leafy vegetable associated in traditional Asian diets with longevity. Phytochemicals in Ak and their extraction efficiency were characterized in ethanol/water (70/30, 40/60, 0/100, V/V) and stability at different temperatures were determined. Ak grown in three geographical areas were lyophilized, milled to a powder, and stored at 22ºC, 4ºC or ‐80ºC for 12 months (mo). Carotenoids and ascorbic acid were analyzed by HPLC systems, total phenols by spectrophotometry, polyphenols by LC‐ESI‐MS/MS, and antioxidant activity by fluorometry. Lutein was a principal carotenoid and chlorogenic acid, chalcones, and glucosides of luteolin and quercetin were prevalent phenolic compounds in Ak . Only 46% of lutein was extracted with 70% ethanol and no carotenoids were detected in 40% ethanol or 100% water extracts. The major Ak phytochemicals were stable at ‐80ºC for 12 mo while β‐carotene degraded at 22ºC and 4ºC in ≤2 mo and lutein at 22ºC by 12 mo. Thus, phytochemicals in lyophilized Ak are stable up to 12 mo, except for some carotenoids. Whole dried Ak power is a richer source of most of these phytochemicals than Ak extracts due to their low extraction efficiency in ethanol/water. [Supported by USDA ARS #58‐1950‐7‐707; USA & BioGreen 21 Program Code #20070301034009 RDA, Korea]