deoiled

Deoiled is a descriptor used for material from which oil has been removed. In food processing and agriculture, the term most often applies to seeds, kernels, or their meals left after oil extraction. The resulting deoiled product is typically higher in protein and fiber than the original seed, while containing little to no oil.

Oil removal is accomplished by mechanical pressing, such as expeller or screw pressing, or by solvent extraction, typically using organic solvents such as hexane. In a typical sequence, seeds are cleaned, conditioned, cracked, and flaked to increase surface area; oil is extracted and the solvent is recovered; the deoiled residue (cake or meal) is dried and prepared for storage. In some processes, the oil is recovered for sale as liquid oil and the remaining solid is deoiled.

Deoiled meals and cakes are widely used as protein-rich animal feed for livestock and poultry, and as ingredients in pet foods and aquaculture. They can also be used as fertilizer or soil amendments. Some deoiled materials are further processed into protein concentrates or flours for human consumption in niche products.

Quality and safety considerations include potential residual solvent, which must be limited to meet safety standards. Contaminants such as aflatoxins can be a concern in some seeds if improperly stored, so quality controls and testing are important. The exact composition depends on the seed type and extraction method, and nutritional profiles vary accordingly.

See also: defatted, defatting, oil extraction, meal, cake (by-product).