OBTAINING ANTIOXIDANT EXTRACTS FROM ANNATTO BARK USING DIFFERENT EXTRACTION METHODS

While the scientific and technological importance of annatto (Bixa orellana L.) has been extensively studied on the pigments and bioactive compounds extracted from the seeds, there are few studies in the literature directed towards the residues generated during the fruit beneficiation stage, such as the barks (cachopas). Considering that compounds obtained from residues can add value to production chains, the objective of this study was to characterize annatto cachopas in terms of their centesimal composition and to evaluate the effect of different extraction processes (decoction, hot infusion and cold infusion) on the recovery of bioactive compounds and the antioxidant potential of extracts (ABTS, DPPH and FRAP). Initially, the cachopas were ground and their particle size distribution was determined. The cachopa flour had a particle size ranging from 0.05 to 2.83 mm (with 86% of the particles having a size between 0.15 and 1.00 mm). The centesimal composition in terms of moisture, ash, proteins, lipids and carbohydrates was 8.49%, 6.92%, 4.57%, 1.37% and 78.65%, respectively. In comparison, the extract produced by the decoction process (boiling in water for 20 minutes) showed values that were 177% and 441% and 245% and 442% higher for the content of total phenolics and flavonoids, respectively, in relation to the extracts obtained by infusion hot (boiling water and allowing it at rest for 20 min) and cold (cold water and allowing it at rest for 20 min). The same trend was observed for antioxidant potential, in which the extract obtained by decoction showed values 74%, 146% and 253% higher in its activities of scavenging ABTS and DPPH radicals, and in the Ferric Reduction Antioxidant Power (FRAP), respectively, compared to hot infusion, which, in turn, had slightly better results than cold infusion. This study demonstrates that annatto cachopa is a by-product source of antioxidant compounds.