Anthocyanins in mesocarp/epicarp and endocarp of fresh açai (Euterpe oleracea Mart.) and their antioxidant activities and bioavailability

Abstract

We measured anthocyanin levels in fresh açai (Euterpe oleracea Mart.), a native Amazonian palm fruit; cyanidin-3-O-glucoside (C3G) and cyanidin-3-O-rutinoside (C3R) in mesocarp/epicarp portion were 5.49 and 13.0 mg/g extracts, respectively, and these amounts were remarkably higher than that in endocarp. Hydrophilic ORAC assay suggested that açai mesocarp/epicarp extracts had potent antioxidant activity compared to blueberry extract. Following, absorption and excretion of açai anthocyanins were evaluated. After oral administration of açai extracts (400 mg/kg body weight) to rats, C3G and C3R appeared as intact forms in the plasma as maximum amounts of 101.0 ± 55.6 nmol/L at 60 min and 537.0 ± 99.1 nmol/L at 120 min after administration, respectively. Most of these anthocyanins were excreted in urine by 2 h post-administration time. In conclusion, fresh açai contained hydrophilic antioxidants including C3G and C3R, and therefore has strong antioxidant potency especially in the mesocarp/epicarp portion. Upon consumption, açai anthocyanins appeared as intact forms in plasma.