Identification of resveratrol‐3‐β‐glucoside in California almond varieties

Abstract

Stilbenes have been identified in grapes, blueberries, peanuts and pistachios, but little is known about its abundance in other polyphenol‐rich foods, such as almonds. Therefore, the objective of this study was to screen Nonpareil, Butte and Carmel almond varieties from California for the presence of stilbenes (n = 3 samples/variety). Stilbenes were determined in ethanolic almond extracts by UPLC‐MS. Instrument conditions were optimized for quantitation of polydatin, piceatannol, resveratrol, pterostilbene, and oxyresveratrol. Polydatin, resveratrol‐3‐β‐glucoside, was identified in almond extracts, with mean contents of 7.19, 8.52 and 7.44 μg/100 g almond in Nonpareil, Butte and Carmel, varieties respectively. Among all varieties, polydatin was concentrated in almond skins, which accounted for 95.6–97.5% of total almond polydatin content. Other stilbenes were not detected in almond extracts. Therefore, almonds contain stilbenes in addition to the previously identified polyphenol classes of proanthocyanidins, hydrolyzable tannins, flavonols, and phenolic acids. This work was supported by the Almond Board of California.Grant Funding Source: Almond Board of California