Amazon assai waste: A potential source of bioactive substances

Abstract

Assai (Euterpe oleracea Mart.) is a palm tree from Arecaceae family which has distribution in the central and eastern Amazonia. Chemically, polyphenols are found in assai, mainly anthocyanins and flavonoids. Amongst some substances of these groups antioxidant activity is noted, concerning the capacity of the substance to neutralize excessive harmful free radicals. One consequence of these chemical and biological activities present in acai is the increase in demands for different agroindustrial products and, proportionally, the waste generated – of which little is known. These residues are presented today as a public health issue, since they are improperly discarded. In this study, it was performed the extraction of polar substances of seeds and pulp, antioxidant activity against DPPH and ABTS radicals and quantification of total phenols from these extracts. Comparatively, it is intended to clearly understand their differences, since the pulp of this species are widely used in amazonian bioproducts both nationally and internationally. The plant material was collected in Coari-Amazonas, with cold maceration being performed with ethanol and these extracts being degreased. Qualitative antioxidant activity opposite to DPPH radicals [1] and ABTS [2] had results greater than 100 µg/mL for samples of pulps. The most promising results were for ethanol extracts of seeds and their methanol fraction (DPPH 25.27 ± 0.09 µg/ml ABTS 26.29 ± 0.85 µg/ml; DPPH 17.68 ± 0.61 µg/mL ABTS 17.56 ± 1.20 µg/ml, respectively). As to total phenols, a greater quantity was also observed for the ethanol extracts of seeds and their methanol fraction (34.30%± 1.22 and 38.57 ± 0.74%, respectively). Therefore, it was concluded that the ethanol extract and methanol fraction of the pulp showed inferior results when compared to the results of the seeds of E. oleracea. This indicates that the seeds have promising antioxidant activity to be used in amazonian bioproducts.