Hydroalcoholic extraction of bioactive compounds from expeller soybean meal under subcritical conditions

The extraction of bioactive compounds from expeller soybean meal (ESM) was performed using different ethanol + water mixtures under subcritical conditions in a dynamic mode. The influence of temperature, solvent mass flow rate, solvent mixture composition, ionic strength, and particle size of the matrix on the extraction yield and the extract characteristics (total phenol and total flavonoid content and antioxidant activity) was evaluated using a screening design. Extracts that showed better results were analyzed by ORAC and TEAC tests. Finally, to predict the extraction kinetics of the bioactive compounds, the one-site desorption model and the thermodynamic partition model were compared. The results show that it was possible to obtain extracts with a high phenols and flavonoids content (23.04 mg GAE/g ESM and 7.34 mg QCE/g ESM, respectively) with good antioxidant capacity compared to extracts obtained from other vegetable matrices.