A pilot study to investigate bioavailability of strawberry anthocyanins and characterize postprandial plasma polyphenols absorption patterns by Q-TOF LC/MS in humans

BACKGROUND: Information on absorption and metabolism of strawberry polyphenols is limited. OBJECTIVE: The aim of this study was to characterize and quantify plasma polyphenols/anthocyanins across 4 doses of strawberry using Q-TOF LC/MS and LC-MS/MS analysis. METHOD: Plasma was collected from 5 subjects (n = 5) every 30-60 min for 6 h after consuming beverages containing 0, 10, 20 or 40 g freeze-dried strawberry powder with a meal. RESULTS: Q-TOF LC/MS and LC-MS/MS analysis of plasma revealed 33 compounds; 7 not reported previously. Pelargonidin-O-glucuronide (PG) was the most abundant metabolite. Maximum concentrations (C-max) of PG were achieved at 148 +/- 31 min and were significantly different among beverages containing 0, 10, 20, 40 g strawberry powder: 0, 93.4 +/- 21.9, 166.5 +/- 16.2 and 226.7 +/- 36.7 nmol/L, respectively (P < 0.05). Area under the concentration curve (AUC) also increased with dose ( P < 0.05); however, Cmax and AUC of PGwas reduced as a percent of pelargonidin-3-O-glucoside (P3G) delivered in the strawberry beverages (P < 0.05). CONCLUSION: Use of both Q-TOF LC/MS and LC-MS/MS allowed for detection of compounds in plasma not previously reported, which may be a useful approach for characterizing postprandial plasma metabolites of lesser known plant foods. Additionally, higher concentrations of key strawberry compounds/metabolites are achieved with eating more strawberry; however, saturation of absorptive capacity of pelargonidin-based anthocyanins was suggested.