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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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Polyunsaturate
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1992-09-02
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A type of triglyceride (fat or oil) in which
the long carbon chains of the fatty acids
contain several double bonds. By contrast,
the carbon chains of saturated fats (such as
lard) contain only single bonds. The more
double bonds the chains contain, the lower
the melting point of the triglyceride.
Unsaturated chains with several double bonds
produce oils, such as vegetable and fish
oils, which are liquids at room temperature.
Saturated fats, with no double bonds, are
solids at room temperature. The
polyunsaturated fats used for margarines are
produced by taking a vegetable or fish oil
and turning some of the double bonds to
single bonds, so that the product is
semi-solid at room temperature. This is done
by bubbling hydrogen through the oil in the
presence of a catalyst, such as platinum. The
catalyst is later removed. Medical evidence
suggests that polyunsaturated fats are less
likely to contribute to cardiovascular
disease than saturated fats, but there is
also some evidence that they may have adverse
effects on health. Monounsaturated oils, such
as olive oil, with a single double bond, are
probably healthier than either saturated or
polyunsaturated fats. Butter contains both
saturated and unsaturated fats, tog ther with
cholesterol, which also plays a role in heart
disease.