Chemical composition, antioxidant activities and total phenolic content of Arbutus andrachne L. (Fam. Ericaceae) (the Greek strawberry tree) fruits from Turkey

Arbutus andrachne L. and A. unedo L. are two members of the Ericaceae family. The species are distributed in coastal parts of Anatolia and have edible fruits. We determined several characteristics of eight A. andrachne accessions collected from different parts of the Mediterranean regions of Anatolia. A. unedo is also represented with a sample. Notable differences were found among A. andrachne accessions. On average, the fruit width and length were 12.3 and 10.8 mm, respectively. All of the element concentrations that were tested varied considerably. The average of the total organic acids was 0.47 g/100 g fruit. Among the organic acids measured, malic acid had the highest content (0.34 g/100 g fruit) followed by ascorbic (0.10 g/100 g fruit) and citric acids (0.03 g/100 g fruit). The average for total sugars of the A. andrachne accessions was 16.38 g/100 g fruit. Fructose was the main sugar (average of 9.75 g/100 g fruit) followed by glucose (5.33 g/100 g fruit) and sucrose (1.19 g/100 g fruit). Among the A. andrachne accessions tested, the total phenolics ranged from 2422 to 4102 μg gallic acid/g fresh weight (fw) with an average of 3343 μg gallic acid equiv. g/fw. Antioxidant activities, determined by TEAC (Trolox equivalent antioxidant capacity) and FRAP (Ferric reducing ability of plasma), reached up to 36.1 and 29.5 μmol Trolox equiv. (TE) g/fresh weight, respectively. It can thus be concluded that A. andrachne is a good source of phenols and antioxidants.