Microwave-Assisted Green Extraction of Bioactive Compounds from Berries

An environmentally friendly microwave-assisted extraction (MAE) method using ethanol/water under mild conditions was developed to extract phenolic acids and flavonoids from acerola, blackberries, and blueberry. The effects of temperature (30–60 °C), ethanol concentration (0–99% v/v), and extraction time (10–50 min) on total phenolic content were optimized by Doehlert design. The optimized procedure enabled extraction of up to 158 mg GAE g–1 dw and high extraction rates: 15.8 g min–1 (phenolics) and 24.8 mg min–1 (flavonoids), surpassing convective heating (0.6–2.1; 1.3–9.0 mg min–1), sequential extraction (1.1–1.7; 1.0–9.1 mg min–1), and ultrasound-assisted extraction (0.5–1.5; 0.6–5.4 mg min–1) using different solvents. Moreover, it extracted about 9- and 4-fold more quercetin (blackberry) and chlorogenic acids (blueberry) than convective heating and reduced the acerola extraction time from 200 to 10 min. The method provides a rapid, efficient, and sustainable alternative for food sample preparation (AGREEprep = 0.78), aligning with Green Chemistry principles.