A high-quality lipid composition is disclosed having low oxidative deterioration such as measured by low anisidine values. Also disclosed are methods of preparing the same from a lipid-containing material that include enzymatic degradation of protein and/or carbohydrate components of the material. Lipid-containing materials include biomass, such as microorganisms. The invention further includes products containing the lipid compositions, such as dietary supplements, food products, pharmaceutical formulations, humanized animal milk, and infant formula.