Flavonoid Profile of BRS Violeta Grape Pomace Extract Obtained via Pressurized Liquid Extraction

Grape pomace, generated during wine and juice production, retains nutrients and bioactive compounds, particularly phenolics. Flavonoids, the largest class of phenolics, exhibit antioxidant, antimicrobial, antitumor, and cardioprotective activities. Various extraction techniques have been studied to improve the recovery of these compounds. Pressurized Liquid Extraction (PLE) subjects a solvent to high pressure and temperature, below its critical point, enhancing the solubility and diffusion of bioactive compounds from solid or semi-solid matrices. This study aimed to determine the flavonoid profile of BRS Violeta grape pomace obtained by PLE. Pomace from juice production was dehydrated, milled (20-28 mesh), and extracted using 70% acetone at 10 MPa, a flow rate of 5 mL/min, for 30 minutes. The extracts were analyzed by HPLC-DAD for flavonoid identification and quantification. A total of 16 flavonoids were identified, with hesperidin (0.724 ± 0.006 mg/g), myricetin (0.655 ± 0.005 mg/g), naringenin (0.640 ± 0.001 mg/g), petunidin-3-glucoside (0.615 ± 0.009 mg/g), and procyanidin B2 (0.552 ± 0.001 mg/g) being the most abundant. Of nine anthocyanins analyzed, only two were detected, probably due to their extraction into the juice during processing. Results demonstrate the potential of PLE to recover flavonoids of pharmaceutical interest, particularly myricetin, which also exhibits anti-hyperglycemic activity. These findings indicate that BRS Violeta grape pomace is a promising source of bioactive compounds for health applications and metabolic disorder prevention. Despite the variety’s widespread use in juice production, its pomace phenolic composition remains poorly studied, and this work contributes to filling this knowledge gap.