Valorization of wild strawberry-tree fruits (Arbutus unedo L.) through nutritional assessment and natural production data

Abstract

Arbutus wild berries have been traditionally collected and appreciated in the Mediterranean region, although it is actually considered an underutilized fruit-tree species. Increasing the scarce knowledge about its nutritional composition and natural production may interest a broad range of scholars, such as ethnobotanists, chemists, nutritionists and anthropologists. The present study aims to provide original data on the nutritional value and the biomass production of wild strawberry-tree fruits, studying the variation of these characteristics in fruits harvested in different years, from two different Spanish areas. Macro and micronutrient composition of mature Arbutus unedo fruits have been analyzed, with particular attention to the content of some bioactive compounds (fiber, vitamin C as ascorbic and dehydroascorbic acids, total phenolics, carotenoids, including lycopene) and the organic acids profile. The contribution to recommended dietary allowances (RDAs) of this exotic fruit has also been calculated. Fruit crop volume per tree has been estimated as well in the wild strawberry-tree populations surveyed to provide a general framework for discussing the agronomic potential of the species. A wide variability in nutrient composition of strawberry-tree fruits was found which shows that the analysis of many different samples from different origins and seasons, are required to provide average reliable data about the chemical composition of wild fruits. From the results obtained, strawberry-tree fruits can be considered a very good source of health promoting compounds as vitamin C and dietary fiber (202.6 mg/100g and 42.6% minimum contribution to RDAs, respectively). They are also rich in total available carbohydrates, sugars, potassium and secondary metabolites, such as phenolic compounds, being poor in lipids and Na. These results, together with its high production may help to reinforce its consumption, as an alternative to the fruits available in the market or a source of bioactive compounds for dietary supplements or functional foods.