Dave said:
Quoted message said:Note that trans fatty acids are unsaturated fatty acids
that have gone through the hydrogenation process
without getting hydrogenated. Strictly speaking only
"partially hydrogenated oils" should have trans fats.
Fully hydrogenated fats/oils should have no trans fats
as they have no unsaturated fat at all. Whether the
food labelling legal directives allow some loopholes I
don't know.
MattLB
Hmmm.
If I understand you, saturated fats cannot be made in
trans fats. Soybean oil is 14% saturated fat, so I figure
the other 86% is unsaturated fat. When you say that a
fully hydrogenated fat or oil would have no trans fats
because they have no unsaturated fat, you imply that our
example, hydrogenated soybean oil has no transfats.
However, if the soybean oil is 86% unsaturated fat, the
result of hydrogenation should produce trans fats. No?
Your first sentence seems to say that unsaturated fatty
acids can go through the hydrogenation process without
getting hydrogenated.
That's true.
Quoted message said:This seems self contradictory. Can a house go through the
painting process without getting painted?
If you don't have enough paint, yes.
Quoted message said:Either I am seriously failing to understand you, or
you are yanking my chain. The later would not be
unusual on USENET.
No chain yanking, I promise. A bit of background: Saturated
fats have straight fatty acids, whereas unsaturated fats
have kinked fatty acids. This leads to saturated fat being
solid a room temperature, whereas unsaturated fat is liquid
(oil). To make margarine, which is solid, requires
converting some of the unsaturated (with hydrogen) oil to
saturated fat. This is done by pumping hydrogen gas through
the oil in the presence of a catalyst.
The catalyst binds and distorts the unsaturated fatty acid
making it vunerable to attack by the hydrogen. If the
hydrogen attacks and binds the fatty acid it will no longer
be unsaturated, it will have become saturated (with
hydrogen). If there is enough hydrogen and the process is
done for long enough you should end up with all the fatty
acids fully hydrogenated (saturated). If the hydrogenation
is only partial - just enough to make the oil more solid -
not all of the unsaturated will be turned into saturated.
If the unsaturated fatty acid is released from the catalyst
without
picking up any hydrogen it will spring back to its original
shape, OR,
it will spring back in a trans shape. The key thing is that
this trans
shape, while still unsaturated is straight instead of
kinked. This means
it appears to be a saturated fat and behaves like one
physically, but as
soon as the body tries to burn it like saturated fat it
finds it can't.
The result is that trans fats hang around in the body and
are difficult to get rid of without free radicals. Any
unsaturated fats + free radicals = damage to the body, so
all in all trans fats are bad news.
MattLB
