Edible Oils

The Edible Oils listed below account for almost all the worldwide production by volume. All are used as both cooking oils or to make biodiesel;

• Palm – The most widely produced tropical oil, also used to make biofuel
• Soybean – Accounts for about half of worldwide edible oil production
• Rapeseed – One of the most widely used cooking oils
• Sunflower – A common cooking oil, also used to make biodiesel
• Peanut – Mild flavoured cooking oil
• Cottonseed – A major food oil, often used in industrial food processing
• Coconut – Used in soaps, cosmetics and cooking
• Olive – Used in cooking, cosmetics, soaps and as a fuel for traditional oil lamps

As can be seen in the list above there are several types of plant oils. They are generally distinguished by the method(s) used to extract the oil from the plant. The relevant part of the plant (seed, nut or bean) may be placed under pressure to extract the oil, giving expressed (or pressed) oil. Oils may also be extracted from plants by dissolving parts of the plant in water or another solvent. The solution may be separated from the plant material and concentrated, giving extracted or leached oil.

The mixture may also be separated by distilling the oil away from the plant material. Oils extracted by this latter method are called essential oils. Essential oils often have different properties and uses than pressed or leached vegetable oils.

Finally, macerated oils are made by infusing parts of plants in a base oil, a process called liquid-liquid extraction.

All of the techniques above have a separation requirement for at least one of the following somewhere in the process;

• a liquid-solid
• a liquid-liquid-solid
• or a liquid-liquid separation requirement

Vertical Disc Bowl Centrifuges and Horizontal Continuous Solid Bowl Decanter Centrifuges are to be found in virtually oil edible oil processing facilities. Their optimisation along with operator training is a vital part in ensuring an efficient operation is maintained at all times.