The Dangers of Vegetable Oil Extraction and Processing – Mother Earth News

11 Nov.,2022


Refined Oil Machine

We qualified ourselves to make public observations about oils by conducting a threefold research program. First, we read from the following sources: The Encyclopedia Britannica;  “Rancidity in Oils” and “The Lowdown on Edible Oils” published by the Lee Foundation for Nutritional Research, Milwaukee, Wisconsin; and “The Story of Oils” published by Walnut Acres, Penns Creek, Pennsylvania. Second, we talked for several hours with Frank Lachle, a retired oil chemist with eminent technical qualifications who now owns Healthway Natural Foods, Watsonville, California. Third, we toured one of the largest vegetable oil extraction and refining plants in California, specializing in the production of safflower oil.

There are three methods of extracting vegetable oils from nuts, grains, beans, seeds or olives. The first is by use of a hydraulic press. This is an ancient method and yields the best quality oil. The only two materials that will yield enough oil without heating them first are sesame seeds and olives. Therefore, sesame oil and olive oil from a hydraulic press are the only oils which could truly be called “cold pressed”. The terms “cold pressed” as applies to all oils and “virgin” as applies to olive oil are meaningless to the consumer. They have no legal definition, mean whatever the manufacturer wants them to mean, and do not give a true description of the product behind the label. Organic Merchants will not condone misleading labeling. The term “virgin” for olive oil will refer only to the first pressing by a hydraulic press without heat. The term “cold pressed” will refer only to hydraulic pressing without heat. These oils are the closest possible to the natural state, therefore have the most color, odor and flavor–in a word, the most NUTRITION–but they will often be unavailable because so little is produced this way.

If an Organic Merchant has an oil which has been extracted by hydraulic press but has been heated prior to pressing, he will refer to it as “pressed”, not “cold pressed”.

The second method is by expeller, described in “The Low down on Edible Oils” as follows: “This uses a screw or continuous press with a constantly rotating worm shaft. Cooked material goes into one end and is put under continuous pressure until discharged at the other end with oil squeezed out.” Temperatures between 200 and 250 degrees are normal. Obviously, this type of extraction does not qualify as “cold pressed” either. Organic Merchants will refer to it as “expeller pressed.”

Now with a hydraulically pressed oil labeled “cold pressed” or “pressed”, you can assume you have a crude or unrefined of. But this is not true of “expeller pressed” oil because the common fate of expeller pressed oil is to be refined after extraction. So you need additional information with the words “expeller pressed”. Organic Merchants will use either the word “crude” or “unrefined” to identify this additional classification of acceptable oils. 

So Organic Merchants draws the line of acceptability at this point and, to review, you may expect us to carry only four classifications of oil: 

  • Virgin 
  • Cold pressed 
  • Pressed 
  • Expeller pressed-crude

And this paper is your tool to remind yourself of what we mean by those words.

The last method is solvent extraction, described in “The Lowdown on Edible Oils” as “definitely dangerous to health.” “Oil bearing materials are ground, steam cooked, then mixed with the solvent (of a petroleum base) which dissolves out of the oils, leaving a dry residue. The solvent is separated from the oils. This method is universally used by the big commercial oil processors because it gets more oils out quicker and cheaper. About 98% of the soy oil in the U.S. is solvent extracted.

“What about these solvents? Most commonly used solvents are light petroleum fractions–four types of Naptha used are Pentane, Heptane, Hexane, and Octane types; another solvent used is synthetic Trichlorethylene. Some of these are commonly found in gasoline. Most used solvent is Hexane. Oils dissolved by this method are solvent extracted DISSOLVED oils are not pressed oils.

“The big commercial edible oil processors and distributors tell us that if any of the solvent remains in the oils it is VERY LITTLE. But you know just how harmful these solvents may be. Pertinent here is an observation coming out of a symposium of cancer specialists organized by the International Union Against Cancer meeting in Rome in August 1956. Among many things they observed. Since various petroleum constituents, including certain mineral oils and paraffin, have produced cancer in man and experimental animals, the presence of such chemicals in food appears to be objectionable, particularly when such materials are heated to high temperatures.”‘

The VERY LITTLE argument for solvent residues is just as weak for solvents as it is for pesticide residues. The amount of petroleum solvent that should enter the human system is ZERO! 

So you have two classifications of oils which are unacceptable in an Organic Merchant store: 

  • Expeller pressed-refined 
  • Solvent extracted oil

Even if there were NO solvent residue EVER, there would still be the matter of refining and here the facts are clear.

Refining is usually accomplished with the addition of sodium hydroxide and temperatures around 450 degrees. The refined oil is not considered edible without further processing, such as filtration, deodorization, bleaching.

Encyclopedia Britannica says of refined oils, they are “low in color, [thinner] and more susceptible to rancidity.” Where bleaching is concerned they say, “Physical adsorption methods involve treating hot oils with activated carbons, fuller’s earths’ or activated clays. Many impurities including chlorophyll and Vitamin A are absorbed onto the agents and removed by filtration. Bleaching by any of these means reduces the resistance of oils to rancidity.”

There’s a pretty picture for you–an industry which regards precious nutrients as “impurities.” Not just the chlorophyll and Vitamin A either, but the Vitamin E and phosphorous compounds such as lecithin, too. Then they further compound an already thoroughly compounded felony by virtually guaranteeing the oil will turn rancid. Unless of course they load the product with preservative–which of course they always do. Except in the case of so-called “health food” oils which are at least free of preservatives and should therefore (if you can tolerate a mislabeled, low quality product) be kept refrigerated to avoid rancidity.

Where rancidity is concerned, “Rancidity in Oils” says, “it has been found that the digestion of oils is clearly retarded by rancidity. The products of rancidity were found to be lethal to rats. The degenerative diseases caused by rancid oils are undoubtedly brought about by the destruction of vitamins E, F, and A, both in the oil itself and in the body.”

Oil processing is so effective at making the end result free of odor and flavor that it is possible for rancid oil to be “reclaimed” and sold for human consumption. We have no proof that this is actually done but such is the rumor and it seems a likely enough prospect that it should be repeated. Unfortunately for the health of this nation this is the era of industrialized foods; in this era, good nutrition for the people be damned–it’s the privilege of the manufacturer to handle huge quantities of food at a profit that must be protected.

Health and natural food store operators have in almost all cases not been able to advise the consumer because they have been misled too. This illustrates the great need for Organic Merchants, an organization designed to work for the people by seeking the truth and telling it as Clearly as they can. We discovered that oils which have been solvent extracted, refined, bleached and deodorized have been sold as “cold pressed”. Knowing the facts, no one genuinely interested in good nutrition can continue to be a party to the hoax.

The process of refining oils is exactly analogous to the refining of whole wheat and whole sugar into white ones. In all cases, one takes a product full of natural vitamins, minerals, enzymes and other food factors and reduces the original natural food into a relative “non-food”–devitalized, stripped.

One thing may not be clear and probably will be asked: What keeps crude oil from going rancid, especially in store, that handle it in bulk as well as bottled? The answer is that crude oils, being unrefined, retain their natural anti-oxidants. Haw could you test it just to be sure? One drop on the tongue is sufficient to tell the story–rancidity is so bitingly, bitterly sharp as to be unmistakable.

Of course, when one is accustomed to bland, virtually tasteless refined oils, the introduction of crude oil into the diet requires one to experience the “real thing”. This experience of reality is due to the fact that for the first time you are tasting an oil which contains ALL its natural vitamin A, ALL its natural vitamin E, ALL its natural lecithin, and ALL of the other natural food factors. We are confident that, appreciating the facts, the consumer will easily accept superior food. It is not at all a matter of getting accustomed to something which tastes bad, but rather different–fuller and richer due to being so much more wholesome.

Although Organic Merchants will not sell anything but crude, pressed oil, we recognize this is a sudden and radical departure as far as the processors of packaged natural foods are concerned. So we will have an interim situation where there will still be some products made with refined oils as an ingredient while we are phasing them out and replacing them. As Organic Merchants grows, support for our efforts to establish real food integrity for the consumer will grow. And as that support grows, more and more positive changes will be made because no processor can prosper unless he pleases the consumer. We know we are assured success because ultimately, in this rapidly awakening world, the consumer voice and the Organic Merchants voice will become one, saying “We will have only the best.”