Recovering nut oil

The oil in nuts is in the form of an emulsion in the protoplasm of individual cells. The emulsion is broken by boiling, freezing or mechanically rupturing the cell walls. When the emulsion is broken, the microscopic droplets coalesce to form droplets of free oil , which can be recovered by pressure or by extracting with solvents. Other constituents of the protoplasm are water, proteins, carbohydrates, soluble minerals, vitamins and intermediate products. 

While harvesting oil-containing nuts is becoming more mechanized each year, many of them such as pine nuts, hazel nuts, black walnuts, hickory nuts, pecans, coconuts and others, are harvested by members of the farm family at low cost. This is especially true in the Himalaya Mountains of India, and the Appalachian Mountains of the eastern United States, as well as the wild coconuts of the Philippines. 

Nuts have been pounded in a mortar with a pestle for centuries and this is still done in Africa, Haiti and tropical Asia. The mortar may be ceramic or hardwood lined with metal and may hold from 1-10 lb of nuts or seed. The pestle may be of similar material, and weigh up to several pounds. 

A few nuts are placed in the mortar and pounded until a paste or butter is produced, or until theoretically every cell of the nuts is ruptured. The product is then poured into taU cylinders for the oil to rise to the surface and be skimmed off. When placed in a warm place oil will continue to rise to the surface for many weeks. 

There are several methods of recovering oU from nuts. Sunflower seed may be cold pressed to produce a virgin oil similar to virgin olive oil. 

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