Bioactivity Potential of Industrial Sunflower Meal Ethanol-Wash Solute Obtained as Waste from Protein Isolation Process

Industrial sunflower meal is rich in secondary metabolites, which negatively influence the quality and functional properties of respective protein isolates. To reduce their quantity, sunflower meal was subjected to a four-step treatment with 75% aqueous ethanol solution. The ethanol-wash liquids were collected, concentrated, and freeze-dried to prepare powdery sunflower meal ethanol-wash solute (SEWS). Otherwise considered waste from the main process of protein isolation, the SWES was turned into a novel product containing macrocomponents, microelements, and bioactive compounds. It was found to be rich in carbohydrates (62.14%), lipids (7.73%), and bioactive compounds such as phenols (16.38%) and flavonoids (4.41%). Gas Chromatography-Mass Spectrometry (GC–MS) analyzes revealed prevalence of sucrose (14.01%), linoleic acid (12.10%), and chlorogenic acid (85.41%) based on total ion current (TIC) of polar, nonpolar, and phenolic compounds, respectively. The SEWS was found to be rich in microelements with iron (259.02 mg/kg) and copper (109.36 mg/kg) being the highest amounts. The product contained 0.10 mg/kg selenium. Scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals increased with the increase in SEWS concentrations and reached 52.3% and 69% for 0.05% SEWS when dissolved in water and 70% ethanol, respectively. The highest hydroxyl radical scavenging activity (52.4%) was achieved at 0.1% SEWS. For all studied concentrations (0.005% to 0.1%), the SEWS exhibited a higher inhibition capacity than mannitol, which was used as a positive control. The SEWS demonstrated inhibiting properties against Gram (+) Curtobacterium flaccumfaciens PM-YT and Fusarium moniliforme ATCC 38932 fungus. The obtained results outline the SEWS as a natural product with bioactive properties that might be useful in the agriculture, food, and nutraceutical industries.