Ascorbic acid content, phenolic compounds and antioxidant capacity of Brazilian exotic fruits açai (Euterpe oleraceae Mart.) and cupuaçu (Theobroma grandiflorum Schum.)

It is well-known that diets high in fruits and vegetables may decrease the risk of chronic diseases, due to their low fat content and high levels of fiber and antioxidant substances, such as ascorbic acid and polyphenols. Current work describes the characterization of two Brazilian exotic fruits namely açai (Euterpe oleraceae Mart.) and cupuaçu (Theobroma grandiflorum Schum.), for their: antioxidant capacity; ascorbic acid content; and total polyphenolic compounds. Antioxidant capacity was determined in pulps by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Ascorbic acid was quantified by ultra-fast liquid chromatography using a Shimadzu™, UFLC-20A chromatograph with a reversed-phase octadecylsilane column XR-ODS™, and 0.025M of a dihydrogen potassium phosphate solution as the mobile phase. Polyphenolic compounds were determined by the Folin-Ciocalteau method. Antioxidant capacity, expressed in terms of grams of pulp per 100g of DPPH, was 1666.76 for the açai fruit, and 4366.71 for the cupuaçu fruit. Ascorbic acid was not detected in açai pulp, and its content was 7.04mg per 100g of pulp in cupuaçu pulp. Total phenolic compounds content, was 108.5 expressed in terms of galic acid equivalent per 100 grams of pulp for the açai and 91.85 for the cupuaçu pulp. Results pointed out the nutritional and therapeutic potentialities of these exotic fruits, for their antioxidants properties.

Keywords: food phenolics, data base, liquid chromatography, nutritional properties

Acknowledgement: We thank the INCT/CNPq (National Council for the Development of Science & Technology, Brazil) for the financial support received while the fourth and fifth co-authors also thank CAPES for fellowships