by Yeong Sek Yee
Highly refined cooking oils (sometimes referred to as “plastic fats”) go through 3 main refining procedures. These are neutralization, bleaching, and deodorization and then the final light golden colour oil is usually called NBD Palm Oil (or Soya, Corn, etc) Nowadays it is just referred to as refined palm (or soya, corn) oil or refined vegetable oil.
Below is a brief description of the 3 procedures in getting the oils out of seeds, nuts, pericarps, etc and onto the supermarket shelves.
NEUTRALIZATION (sometimes referred to as refining):
Once extracted, the oil ‘needs’ to be refined, which involves the treatment of the crude oil with a lye solution to reduce the free fatty acid (FFA) content to 0.05 percent. This is done primarily to prevent spoilage—to help the oil last an eternity on the grocer’s shelf. In addition, other impurities in the oil, such as gums, phosphatides, pigments, and other oxidation products, which would ‘impair’ the taste, odor, shelf life, and other ‘desired’ properties of the oil are likewise removed. This degumming and neutralization process is accomplished by means of phosphoric acid and more lye.
The now ‘neutral’ oil is mixed with bleaching earth (a type of clay) and activated carbon to give the oil a lighter color. Final purification is accomplished using filters, presses, and polishing filters. After this, the oil is pumped into storage tanks.
All edible oils and fats contain certain compounds that give the particular oil its identifiable taste and smell. In all commercial oils, these compounds are removed to make the oil as neutral tasting as possible. This process is called deodorization, and because of the high temperatures involved, it is extremely damaging to the oil.
Refined, bleached oil from refining is first transferred to a de-aerator operating under a vacuum for removal of any air in the oil. The oil then passes through a series of heaters, where the temperature is raised high enough for efficient steam distillation and deodorization—upwards of 200°C (450°F). At these temperatures, the fundamental structure of many oils is changed into a different form of fatty acid through a process called isomerization. These new forms are not beneficial to the human body. The high heat also causes a small amount of trans fatty acids to be formed. Finally, steam is blown through the oil to vaporize those components of the oil that actually give it any lingering odor or taste. The fully deodorized, tasteless, and refined oil then passes through a cooler and polishing filter basket for removal of any fine suspension before being finally pumped to the storage tank.
THE FINAL PRODUCT
What’s left is oil that is virtually colorless, odorless, and tasteless, which can last for years in a bottle with no danger of spoilage. On the other hand, it has no connection with the beneficial oil that was originally contained in the seed or nut. It is now a ‘plastic fat,’ fundamentally changed in structure, that offers no benefits to the human body—a plastic fat that is actually quite harmful. In addition, all of the beneficial phyto-chemicals (such as the lignans, which are an integral part of the oil complex and play a key anti-cancer role) have been removed.
With the chemicals used in the refining process, can you visualize what would happen to your body when you consume refined oils on a regular basis such as fried foods like goreng pisang, fried kueh teow, fried chicken, etc? In some cases, the already toxic oils is re-used again and again and sometimes plastic straws, plastic bags are added to the frying oil to make the final product “ crispy” for a longer period.
For cancer patients, we strongly recommend that you use cold-pressed oils (such as coconut, olive, flaxseed, etc) where the oil is extracted without the use of heat or chemicals.
If you would like to read more about the benefits (or dangers) of fats and oils we recommend the following texts:
FATS THAT HEAL, FATS THAT KILL by Udo Eramus who has a PhD in Nutrition. The book exposes the manufacturing processes that turn healing fats into killing fats and explains the effects of these damaged fats on human health.
TOXIC OIL…WHY VEGETABLE OIL WILL KILL YOU by David Gillespie, a lawyer who decided to research thoroughly on “vegetable oils” after his family was faced with some health issues. His opening statement in the book will stun you:
“Vegetable” oil makes you exceedingly vulnerable to cancer. Every mouthful of vegetable oil you consume takes you one step closer to a deadly (and irreversible) outcome. You are eating “vegetable oil” because it is cheaper to make food with oils that are chemically extracted/ refined from plant seeds.