Determination and comparison of chemical characteristics of Arbutus unedo L. and Arbutus andrachnae L. (family Ericaceae) fruits.

The fruits and leaves of Arbutus species are well known in folk medicine as antiseptics, diuretics, and laxatives in many parts of Turkey. Some chemical properties including pH, soluble solid content, titratable acidity, protein, moisture, ash, ascorbic acid, fructose, glucose, sucrose, total phenols, total antioxidant activity, and minerals were determined in fully matured Arbutus unedo L. and Arbutus andrachnae L. fruits collected from different sites of Canakkale, Turkey in 2006 and 2007. Total soluble solids, titratable acidity, protein, moisture, and ash content of A. unedo and A. andrachnae berries were on average 16.0% and 14.0%, 0.4% and 0.6%, 2.38% and 3.77%, 47.21% and 38.21%, and 2.82% and 4.35%, respectively. The mean values of ascorbic acid were 270.50 mg/100 g for A. unedo and 140.30 mg/100 g for A. andrachnae, which suggested that Arbutus berries contain high amounts of vitamin C. In the strawberry tree fruits, fructose and glucose were determined to be the major sugars. The analysis showed that fructose and glucose occurred in concentrations of 24.09% and 19.09%, respectively. However, ripe A. andrachnae fruits contained small amounts of fructose (4.12%), glucose (2.73%), and sucrose (0.16%) detectable by high-performance liquid chromatography analysis. The general order of abundance of the minerals was K > Ca > P > Mg > Na in whole fruit of the strawberry tree. The chemical composition of Arbutus fruits indicates that the fruits are good sources of minerals and ascorbic acid and that they are high in phenolics and antioxidant capacity and low in soluble sugars, especially A. andrachnae. The data should be useful for research purposes and for compiling local food composition tables. In view of its chemical composition, the use of Arbutus fruits in some food products may be suggested.