Nutritional, bioactive and enzymatic properties of Ouratea fieldingiana (Gardner) Engl. (Ochnaceae) fruits. A little-known plant from Northeastern Brazil

Abstract

The species Ouratea fieldingiana is a bush belonging to the family Ochnaceae, occurring frequently in the "Caatinga" Dominium. This species and other members of the genus Ouratea are rarely studied and no data are available on the chemical composition or medical and industrial potential of this plant. Thus, this work aimed to study the nutritional, medical and industrial potential of O. fieldingiana fruits by determining the proximate composition, caloric value and the content of toxic and antinutritional factors. The search for biological and enzymatic activities with pharmacological and industrial interest was also conducted. The results showed that the dry fruits are rich in proteins (21.58 ± 2.02 g/100g) and dietary fiber (46.72 ± 0.52 g/100g), do not show trypsin inhibitors, toxins or tannins, and have low levels of urease (2.41 ± 0.22 units kg^-1 ) and lectins (780 and 3,098 HU/g protein in native erythrocytes and in protease-treated erythrocytes, respectively). The fruit aqueous extracts showed antibacterial activity (growth inhibition halo with diameter > 10 mm) against Cromobacterium violaceum, possibly due to a protein compound, and also amylolytic (starch degradation area > 60 mm²), hemolytic (100% hemolysis in rat and mouse erythrocytes') and strong anti-coagulant (persisted for more than 24 h) activities. The O. fieldingiana fruits are potentially nutritious, showing high protein and dietary fiber levels, as well as a low content of toxic and/or antinutritional compounds. The fruits aqueous extracts possess bioactive compounds presenting pharmacological and/or industrial interest.