Characterization of the antioxidant composition of strawberry tree (Arbutus unedo L.) fruits

The fruits of the strawberry tree (Arbutus unedo L.) are consumed mainly as processed product, but may be a good source of antioxidants if consumed as fresh fruit. The aim of the present study was to identify and quantify the antioxidant components present in strawberry tree fruits, including flavonoids, vitamins C and E and carotenoids. The fruits are a very good source of antioxidants precisely because they have a high flavonoid content (32.37 mg/100 g edible portion) and, within this group of antioxidant compounds, proanthocyanidins are the most abundant, representing more than 80% of the total flavonoid contents. Anthocyanins are also present as glycosides of cyanidin and delphinidin, with cyanidin-3-galactoside the most abundant. Other antioxidants present in this fruit were ellagic acid and its diglucoside derivative. Vitamin C, vitamin E and carotenoids were also identified and quantified.