Substances present in fats and oils that are not glycerides and are resistant to saponification with strong alkalis. Unsaponifiable matter includes sterols, tocopherols, hydrocarbons (such as squalene), pigments, and fat-soluble vitamins — typically 1–2% of edible oils. Because its content and composition vary among different types of oils and fats, it serves as a valuable fingerprint for characterization and authentication, helping detect adulteration (e.g., olive oil diluted with seed oils). Determination involves saponifying the oil and extracting the unsaponifiable fraction with solvent; chromatographic profiling of sterols within it is a standard authenticity test.