Conclusions
This study demonstrated that the WS2 fractions, derived from the acetone:water extracts of leaves and fruits from A. carambola, possessed the strongest antioxidant activities as compared to other extracts and fractions. The active compounds in WS2 fractions responsible for their antioxidant activities identified were essentially of procyanidin-type proanthocyanidins. In addition, fatty acid compositions analysis revealed that the most abundant fatty acids were polyunsaturated α-linolenic acid for leaves and monounsaturated oleic acid for fruits, and the levels of total unsaturated fatty acids in them both reached more than 77% of total fatty acids. Leaves and fruits from A. carambola can not only be considered as a potential source of natural antioxidants but also unsaturated fatty acids.