When sourcing refined edible oil, buyers must distinguish between Grade 1 (First Grade) and lower grades based on the degree of processing. High-quality refined oil should be transparent, odorless, and bland in flavor, indicating the successful removal of impurities, free fatty acids, and pigments. Key technical indicators include the Peroxide Value (typically <10 meq/kg) to ensure freshness and the Acid Value (typically <0.6 mg KOH/g) to measure the degree of refinement. Always request a Certificate of Analysis (COA) for every batch to verify these parameters.