Demystifying oils and fats, part three
Processing of Oils
The highest-quality oils are called first
cold-pressed or extra virgin, and they are unheated, unfiltered and
unrefined. The name refers to a traditional method that is no longer widely
used. Today, many commercially processed oils are “pressed” in a centrifuge. No
heat is applied during extraction, so the initial process can still rightfully
be called “cold pressed.” But in a
second step, steam (heat) and solvents are used to extract more oil from the
leftover pulp, producing an oil of inferior quality. In the case of olive oil
this oil may be called olive pomace oil or pure olive oil.
high pressure, heat and chemical solvents are used to squeeze the oil out of
corn, grape seeds, safflower seeds and soybeans. These oils have high
polyunsaturated fatty acid content, so they already become rancid in the
manufacturing process. The rancid oils are then deodorized—with the help of
more harmful chemicals—in order to be made palatable. For these reasons, please
stay completely away from refined corn, grape seed, safflower, and soybean
oils. Remember, if it is not
specifically stated, that an oil is unrefined you may assume it is refined
and therefore compromised.
oils also come from sunflower seeds, walnuts, sesame seeds and wheat germ. If you can find unrefined versions of these oils, feel free to use them cold in
dressings or simply sprinkled over your cooked food once it is served. Buy flaxseed oil only if it is contained in
an opaque dark bottle and was kept refrigerated until your purchase. Keep all these last mentioned oils in the
would like to address the issue of hydrogenated oils, partially hydrogenated
oils and trans fats. In essence these are all the same thing. While
hydrogenation is the manufacturing process, trans fats are the outcome. All
hydrogenated and partially hydrogenated oils contain trans-fats. Food companies
wanted to create a cholesterol-free, easy-to-spread product with a long shelf
life—and margarine came into being. But you can find partially hydrogenated
oils even in processed liquid vegetable oils.
is a manufacturing process that uses high temperature and high pressure to
force hydrogen gas into polyunsaturated fatty acids in order to solidify them.
In essence, the hydrogen atom breaks into the double bond, takes out the bend,
and straightens out the fatty acid chain.
The polyunsaturated fatty acid has thus been transformed into a so-called
trans fat. Now it behaves more like a saturated fatty acid and packs together
well to form a semi-solid mass.
fats are biochemically incompatible with the human body. In fact, their
chemical makeup resembles that of plastic. After hydrogenation, the original
vegetable oil has turned into a grey, ill-smelling mass. This mass then gets
bleached and deodorized, again with the help of harmful chemicals. As a last
step, a yellow dye is added to make the product appear more butter-like.
The human body is unable to metabolize trans fats. They
remain in the bloodstream and are likely to collect on the artery walls as
plaque, which can lead to coronary heart disease. Other conditions
associated with trans fats are Alzheimer's disease, cancer, diabetes, obesity, liver dysfunction and infertility in women.
decades, margarine has been touted a health food, when it clearly is not. Even
today, although trans fats are in the news and have been recognized as a
serious health hazard (in New York City, restaurants are prohibited from
cooking with trans-fats), some medical professionals still recommend eating
margarine over butter for heart health.
To sum it up:
always choose extra virgin or cold
pressed oils – that guarantees the highest quality of oils.
away from all refined oils, even those in the health food store. What the
health food store has going for it is the fact that they at least point out to
you on the label – which oil is refined and which oil is unrefined. Always prefer the unrefined versions.
Please stay away completely from partially
hydrogenated and hydrogenated oils, including so called “vegetable oils”
found in supermarkets, margarine and shortening. And because most commercially
produced baked goods are made with margarine or shortening it is advisable to
stay away from those too. Rather bake your own cookies and cakes and use good
old fashioned butter in the process.