Chemical composition, antioxidant activity and mineral content of arbutus unedo (leaves and fruits)

Abstract

Arbutus unedo is widely used in traditional medicine and is an easily accessible source of natural antioxidants to replace synthetic antioxidants. The bioactive compounds and antioxidant activity of the leaves and fruits extracts (after maceration and sonication) were studied. The mineral analyses exhibited large quantities of many essential minerals in fruits and leaves, especially interesting were the levels of macronutrients (K and Ca) in fruits and micronutrients (Fe) in leaves. The GC–MS analysis of essential oils of leaves and fruits led to the identification of 32 and 35 compounds, respectively. The major components in leaves were camphor, cymenene, and bornyl acetate, and in fruits, camphor, ethyl palmitate and bornyl acetate. The extraction method significantly affected the contents of total phenolics and total flavonoids, with the maceration method rendering the best results in leaves and the sonication in fruits. All maceration extracts had the highest antioxidant activity (assayed by 3 methods DPPH•, ABTS+ and FRAP; besides, A. unedo leaves showed higher activity than fruits. As a conclusion, it can be stated that Arbutus unedo is a plant rich in polyphenols, volatile compounds, and minerals, and that it can be used as a potential source of bioactive compounds, especially from the leaves