Rancitidity of cooking oil and its spread
 

You really shouldn't be messing with this very dangerous stuff in the
first place. Use stable oils like coconut or palm kernel. Now, to
answer your question: let's say you've got high quality olive oil,
rich in antioxidants. Then you pour it into this container that has a
trace of the old rancid oil in it. The amount of the rancid oil will
be taken care of by the antioxidant rich olive oil. The problem is
that low quality olive oil, for example, doesn't need help from this
trace amount - it's ready to go rancid very quickly once exposed to
air. If you keep the jar closed, and use one of those stoppers that
can be vacuum sealed, it will not go rancid. However, this stuff will
go rancid inside your body, unless you eat a very antioxidant rich
meal. So again, why mess with this stuff to begin with?

Sammy wrote:

> If cooking oil goes rancid in a container then would any oil poured
> into that same (unwashed) container go rancid more quickly?

Yes. Any remaining oil will act as an initiator for the
free radical chain reaction.

See:
http://www.britanniafood.com/common/invite_17.htm

"montygram" > wrote in message
ups.com...
> You really shouldn't be messing with this very dangerous stuff in the
> first place. Use stable oils like coconut or palm kernel. Now, to
> answer your question: let's say you've got high quality olive oil,
> rich in antioxidants. Then you pour it into this container that has a
> trace of the old rancid oil in it. The amount of the rancid oil will
> be taken care of by the antioxidant rich olive oil. The problem is
> that low quality olive oil, for example, doesn't need help from this
> trace amount - it's ready to go rancid very quickly once exposed to
> air. If you keep the jar closed, and use one of those stoppers that
> can be vacuum sealed, it will not go rancid. However, this stuff will
> go rancid inside your body, unless you eat a very antioxidant rich
> meal. So again, why mess with this stuff to begin with?
>

This post is perhaps the silliest nonsense I have ever read. It is so bad
that I do not even know where to start criticizing it.


--
Peter Aitken

Remove the crap from my email address before using.

"Sammy" > wrote in message
...
> If cooking oil goes rancid in a container then would any oil poured
> into that same (unwashed) container go rancid more quickly?
>
> (1) I have the impression that a trace of rancid oil acts like a
> sort of catalyst for rancidity in non-rancid oil.

No, this is not true. Rancidity is the result of the oil reacting (slowly)
with oxygen in the air. A trace of old rancid oil will not hasten the
deterioration of new oil - but it will affect the flavor.

> (2) If the container were washed but the merest hint of oil rancid
> oil were left behind then is this sufficient to accelerate rancidity
> in any new oil?

As per above, no. A good washing will in any case remove all the old oil.


--
Peter Aitken

Remove the crap from my email address before using.

"Mark Thorson" > wrote in message
...
> Sammy wrote:
>
>> If cooking oil goes rancid in a container then would any oil poured
>> into that same (unwashed) container go rancid more quickly?
>
> Yes. Any remaining oil will act as an initiator for the
> free radical chain reaction.
>
> See:
> http://www.britanniafood.com/common/invite_17.htm
>
>
>

Did you bother to read your reference? Do you understand it? I did, and I
see no reference to trace quantities of rancid oil hastening the
deterioration of new oil.


--
Peter Aitken

Remove the crap from my email address before using.

From: "montygram" "You really shouldn't be messing with this very
dangerous stuff in the
first place. Use stable oils like coconut or palm kernel. "
-------------------
Palm oil and coconut oil are BAD stuff, if you're trying to keep your
arteries clear.

Come on. Do better than this. Present some primary
source study that supports your case. It looks like
you are just stating a preprogramed response.

"nancree" > wrote in message
oups.com...
>
>
> From: "montygram" "You really shouldn't be messing with this very
> dangerous stuff in the
> first place. Use stable oils like coconut or palm kernel. "
> -------------------
> Palm oil and coconut oil are BAD stuff, if you're trying to keep your
> arteries clear.
>

"Peter Aitken" > wrote in message
. com...
> "montygram" > wrote in message
> ups.com...
> > You really shouldn't be messing with this very dangerous stuff in the
> > first place. Use stable oils like coconut or palm kernel. Now, to
> > answer your question: let's say you've got high quality olive oil,
> > rich in antioxidants. Then you pour it into this container that has a
> > trace of the old rancid oil in it. The amount of the rancid oil will
> > be taken care of by the antioxidant rich olive oil. The problem is
> > that low quality olive oil, for example, doesn't need help from this
> > trace amount - it's ready to go rancid very quickly once exposed to
> > air. If you keep the jar closed, and use one of those stoppers that
> > can be vacuum sealed, it will not go rancid. However, this stuff will
> > go rancid inside your body, unless you eat a very antioxidant rich
> > meal. So again, why mess with this stuff to begin with?
> >
>
> This post is perhaps the silliest nonsense I have ever read. It is so bad
> that I do not even know where to start criticizing it.


I suggest you try. Use primary sources as references.

John Que wrote:

> Come on. Do better than this. Present some primary
> source study that supports your case. It looks like
> you are just stating a preprogramed response.
>
You're right. Trans fats are a bigger problem, not saturated fats per se.

gtoomey

> Did you bother to read your reference? Do you understand it? I did, and I
> see no reference to trace quantities of rancid oil hastening the
> deterioration of new oil.

Although its not written in this article, it is basic organic chemistry-
radical reactions (like the one when oils go rancid) start faster when a
radical starter (like rancid oil) is present.

http://www.meta-synthesis.com/webboo...l/radical.html

> No, this is not true. Rancidity is the result of the oil reacting (slowly)
> with oxygen in the air. A trace of old rancid oil will not hasten the
> deterioration of new oil - but it will affect the flavor.

This is not true, in fact.

The products of fat oxidation are (among others) Epoxides and Peroxides.
(besides chain fragments, aldehyds etc).
Peroxides work as starters of radical chain reactions.
Epoxides can react (with oxygen) to Peroxides.

Thus: having old oxidized oil in your new unoxidized oil will speed up the
oxidation process
(mostly by reducing the antioxidant capacity in the new oil).

"MMu" > wrote in message
...
>> No, this is not true. Rancidity is the result of the oil reacting
>> (slowly) with oxygen in the air. A trace of old rancid oil will not
>> hasten the deterioration of new oil - but it will affect the flavor.
>
> This is not true, in fact.
>
> The products of fat oxidation are (among others) Epoxides and Peroxides.
> (besides chain fragments, aldehyds etc).
> Peroxides work as starters of radical chain reactions.
> Epoxides can react (with oxygen) to Peroxides.
>
> Thus: having old oxidized oil in your new unoxidized oil will speed up the
> oxidation process
> (mostly by reducing the antioxidant capacity in the new oil).
>

You are way beyond my knowledge of organic chemistry so I'll accept what you
say. But the question remains. Regardless of what goes on theoretically,
does a trace of old oil actually make a practical difference in how long you
can keep oil in the kitchen? For example will your oil go rancid in 2 weeks
instead of 2 months? Or will it go rancid in 59 days instead of 60 days?


--
Peter Aitken

Remove the crap from my email address before using.

On Sun, 20 Feb 2005 23:31:16 GMT, Sammy >
wrote:

> If cooking oil goes rancid in a container then would any oil poured
> into that same (unwashed) container go rancid more quickly?
>
> (1) I have the impression that a trace of rancid oil acts like a
> sort of catalyst for rancidity in non-rancid oil.
>
> (2) If the container were washed but the merest hint of oil rancid
> oil were left behind then is this sufficient to accelerate rancidity
> in any new oil?

Wash the container, problem solved.

sf

You are worrying about the wrong thing. I don't know what that guy's
problem is, but in a scientific debate, you make your case, you don't
say that you "don't know what to do to begin to address it" or
whatever. That is the silliest thing I've ever heard an "expert" say,
and that's saying something. And I'm not the first to say what I've
said. I've cited scientific papers on this NG over and over again.
Just go do a search for montygram and you'll see.

Do you realize, nancree, that peoples have used these oils for
thousands of years, are very "primitive" in terms of Western medicine,
and yet have incredibly low rates of heart disease and other "chronic
diseases?" Get a grip. Go to the WHO website and do some research.
I'm not asking anyone to "believe" me. The scientific evidence is
what it is. And if you want a more precise reason why highly saturated
fats are among the healthiest things you can eat, search here for
montygram. Even in Willett's "Nutritional Epidemiology," he makes the
point that "red meat" is dangerous for all kinds of reasons - saturated
fatty acids are not one of those reasons.

"montygram" > wrote in message
ups.com...
> You really shouldn't be messing with this very dangerous stuff in the
> first place. Use stable oils like coconut or palm kernel. Now, to
> answer your question: let's say you've got high quality olive oil,
> rich in antioxidants. Then you pour it into this container that has a
> trace of the old rancid oil in it. The amount of the rancid oil will
> be taken care of by the antioxidant rich olive oil. The problem is
> that low quality olive oil, for example, doesn't need help from this
> trace amount - it's ready to go rancid very quickly once exposed to
> air. If you keep the jar closed, and use one of those stoppers that
> can be vacuum sealed, it will not go rancid. However, this stuff will
> go rancid inside your body, unless you eat a very antioxidant rich
> meal. So again, why mess with this stuff to begin with?

I belive it is you that has mentioned that in the US we do not have quality
olive oil. Any suggestions on where to order good quality extra virgin
olive oil? I get my coconut oil from
Garden of Life
http://www.nutritionwarehouseoutlet....products_id=32

or Wilderness Family Naturals
http://www.wildernessfamilynaturals....oconut_oil.asp

René

In rec.food.cooking montygram > wrote:

> That is the silliest thing I've ever heard an "expert" say,
> and that's saying something.

Given the identity of the guy who said it, you still have not heard an
expert say it.

--
In the councils of government, we must guard against the
acquisition of unwarranted influence, whether sought or unsought,
by the military-industrial complex. The potential for the
disastrous rise of misplaced power exists and will persist.
-- Dwight David Eisenhower

Found this study that just made its way to pubmed.com It's consistent
with the points I've made on this NG time and time again.

"Nutrition. 2005 Feb;21(2):240-8. Related Articles,Links

Changes in lipid metabolism and antioxidant defense status in
spontaneously hypertensive rats and Wistar rats fed a diet enriched
with fructose and saturated fatty acids.

Girard A, Madani S, El Boustani ES, Belleville J, Prost J.

Universite de Bourgogne, UPRES Lipides Nutrition EA 2422, Faculte des
Sciences Gabriel, Dijon, France.

OBJECTIVE: Larger doses of fructose and saturated fat have been
associated with oxidative stress and development of hypertension. The
effects of modest amounts of fructose and saturated fatty acids on
oxidative stress are unknown. METHODS: To increase knowledge on this
question, 10-wk-old spontaneously hypertensive rats and Wistar rats
were fed for 8 wk with a control diet or an experimental diet enriched
with fructose (18%) and saturated fatty acids (11%; FS diet). The total
antioxidant status of organs and red blood cells was assayed by
monitoring the rate of free radical-induced red blood cell hemolysis.
Sensitivity of very low-density lipoprotein and low-density lipoprotein
(VLDL-LDL) to copper-induced lipid peroxidation was determined as the
production of thiobarbituric acid-reactive substances. Antioxidant
enzymes and vitamins were also measured to establish the oxidative
stress effect. RESULTS: The FS diet did not affect blood pressure in
either strain, but it increased plasma insulin concentrations only in
Wistar rats without affecting those of glucose of either strain. The FS
diet significantly enhanced plasma and VLDL-LDL triacylglycerol
concentrations without affecting concentrations of VLDL-LDL
thiobarbituric acid-reactive substances. The decreased content of
arachidonic acid and total polyunsaturated fatty acids in VLDL-LDL by
the FS diet may have prevented lipid peroxidation in this fraction.
Moreover, FS consumption by both strains was accompanied by a
significant increase in total antioxidant capacity of adipose tissue,
muscle, heart, and liver. This may have resulted from increased tissue
ascorbic acid levels and glutathione peroxidase and glutathione
reductase activities in tissues. CONCLUSIONS: These findings clearly
indicate that the FS diet did not alter blood pressure of spontaneously
hypertensive rats and Wistar rats. The FS diet resulted in
hypertriglyceridemia but increased the total antioxidant status, which
may prevent lipid peroxidation in these rats."