Evaluation of bioactive extracts of mangaba (Hancornia speciosa) using low and high pressure processes

Abstract

Mangaba has high content of vitamin C, carotenoids, phenolic compounds, substances able to scavenge free radicals and a mixture of pentacyclic triterpenes (amyrin, lupeol). The aim of this study was to obtain extracts of mangaba fruit from different methods at low and high pressure methods with distinct solvents. The low pressure methods were Soxhlet, maceration and ultrasound with water, ethanol and n-hexane and extraction with vegetable oils (olive and soybean). The supercritical fluid extraction (SFE) was evaluated at 300 bar and 40–60 °C with carbon dioxide and ethanol as cosolvent (5 and 10%). The processes were evaluated by its global yield and their extracts were analyzed as total phenolic compounds, antioxidant potential (DPPH, ABTS, β-carotene), thermal oxidation in oven and the volatile chemical profile. After SFE, the residue was submitted to another extraction at low pressure. Maceration with ethanol showed higher yield and antioxidant potential. Hexane was the only one solvent capable to solubilize α-amyrin. At high pressure was possible solubilize compounds (oleic, trans-oleic and palmitic acids) with excellent antioxidant potential by β-carotene method. The increase of ethanol concentration 5–10% as cosolvent improved the yield and antioxidant potential. The extraction with oil permitted to enrich the soybean oil with antioxidant compounds provided from mangaba fruit. Two mangaba extracts presented peroxide value 26% less than the control when submitted to accelerate thermal oxidation assay. The SFE residue extracted by maceration with ethanol showed to be an excellent source of polar compounds with high antioxidant potential.