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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #249122
Title: Polyphenol content and antioxidant activity of California almonds depend on cultivar and harvest year

Author
item BOLLING, BRADLEY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item DOLNIKOWSKI, GREGORY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item BLUMBERG, JEFFREY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item CHEN, CHUNG-YEN (OLIV - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2010
Publication Date: 1/20/2010
Citation: Bolling, B.W., Dolnikowski, G., Blumberg, J.B., Chen, C.E. 2010. Polyphenol content and antioxidant activity of California almonds depend on cultivar and harvest year. Food Chemistry. 122:819-825.

Interpretive Summary: Flavonoids are natural chemicals produced by almonds. Consumption of almond flavonoids are thought to promote health, in part by their antioxidant activity. Most flavonoids are found in skins. The variability of flavonoids in almonds is not well known. Flavonoid content may be very different between almond varieties and harvest year. Therefore, the purpose of this study was to determine how much flavonoid levels change in different almond varieties and different growing years. We found differences in flavonoid content and antioxidant activity from different years. The relative levels of types of flavonoids were stable between years among individual varieties. Sonora almonds had the highest flavonoid content, while Fritz almonds had the lowest, a 2.7-fold difference. Almond varieties also had different flavonoid content, profiles, and antioxidant activity. Therefore, antioxidant activity and flavonoid content almonds are related to the variety and the year they were grown.

Technical Abstract: The polyphenol content and antioxidant activity of Nonpareil, Carmel, Butte, Sonora, Fritz, Mission, and Monterey almond cultivars harvested over 3 seasons in California were examined. LC-MS was employed to quantify 16 flavonoids and 2 phenolic acids in acidified methanol extracts of almond skins. The 3-year mean polyphenol content of cultivars ranged from 4.0 to 10.7 mg/100 g almonds. Isorhamnetin-3-O-rutinoside was the most abundant flavonoid, present at 28 to 49% of total polyphenols among cultivars. Almonds from 2006 and 2007 had 13% fewer polyphenols than 2005, but FRAP and total phenols were comparable. Cultivar, but not season, had a differential impact on individual polyphenol synthesis. Using the results of polyphenol, total phenol, and FRAP, multivariate analysis distinguished harvest years and most cultivars with 80% confidence. Flavonoid content and antioxidant activity of almonds may be more dependent on cultivar than on seasonal differences.