Oil is extracted from a number of fruits, nuts and seeds for use in cooking and soap making or as an ingredient in other foods such as baked or fried goods. Oil is a valuable product with universal demand, and the possible income from oil extraction is therefore often enough to justify the relatively high cost of setting up and running a small scale oil milling business. Oil can be obtained from an oil seed through mechanical methods or solvent extraction. Mechanical expression of oil involves the application of pressure (using hydraulic or screw presses) to force oil out of the oil bearing material.