Energized Dispersive Guided Extraction (EDGE), a New Extractive Approach of Phenolics from Açaí (E. oleracea) Seeds: Chemical Characterization, Antioxidant Properties, and Bioaccessibility of the Extracts

Açai (E. oleracea) is a fruit known for its health benefits. Its industrial processing generates a large volume of seeds, a waste rich in phenolic compounds. In this work, three techniques of extraction were applied to this residue: dynamic maceration (DM), microwave-assisted extraction (MAE), and energized dispersive guided extraction (EDGE); this last one is a novel sample preparation technique. It evaluated the recovery of phenolic compounds in the extractions. The extraction processes were investigated using a central composite design to obtain an extract rich in phenolic compounds, being the EDGE’s extract exhibited the highest phenolic content. With this result, the antioxidant capacity, phenolic profile (HPLC–DAD), and in vitro digestion model were investigated in this extract. The antioxidant capacities found were 6150 µmol Trolox/g (ORAC), 1.39 mmol Trolox/g (DPPH), and 4.45 mmol Eq Fe2 + /g (FRAP). Procyanidin B1 (4.60 mg/g) and B2 (1.05 mg/g) and catechin (1.62 mg/g) were the prominent phenolics. Bioaccessibility ranged from 6.20 to 179.86%; being caftaric acid, quercetin 3-glucoside, and procyanidin B1 bioaccessible in dialyzed fraction. These remarkable results show the EDGE efficiency for recovering bioactive compounds that remain available for intestinal absorption.