The mesocarp of palm fruits contains about 56-70% edible oil when fully ripened. This oil can be extracted using different methods. These methods are grouped into four categories based on their throughput and degree of complexity. They are the traditional methods, small-scale mechanical units, medium-scale mills and large industrial mills, The basic unit operations associated with palm oil processing include fruit sterilization, fruit loosenin g stripping, digestion oil extraction and clarification. Fruit sterilization denotes heat rendering and moisture absorption. The aim is to inactivate the lipolytic enzymes in the fruit mesocarp. The two major extraction procedures are mechanical pressing and solvent extraction. oil extraction efficiency range of 75 90% has been reported for mechanical screw presses obtained by either mechanical pressing or solvent extraction contains desirable and undesirable compounds. Desirable compounds include triacylglycerols(TAGs) (neutral lipids) and health beneficial compounds such as the vitamins E(tocopherols and tocotrienols), carotenoids and phytosterols. The desired compounds serve as nutrients, antioxidants and health beneficial compounds. Free fatty acids(FFAs), phos pholipids(PLs) or gums, and lipid oxidation products are the major undesirable compounds. The impurities are objection able from a sensory point of view. The impurities are removed during oil refining
The most common methods of palm oil extraction are either the'wet' or the dry processes. In the'wet' process a