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So many recipes list olive oil in the ingredients, as the oil to fry things in. What are the benefits or reasons that I should use olive oil over regular generic "cooking oil" and should I always use olive oil over other oils?

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This question includes an answer for you: cooking.stackexchange.com/questions/701/… –  michael Jun 5 '11 at 16:56
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4 Answers

up vote 12 down vote accepted

According to Harold McGee, using olive oil to fry is basically a waste of money. "After I’d heated them, none of the olive oils had much olive flavor left. In fact, they didn’t taste much different from the seed oils."

According to a Spanish study I have access to, you could use high oleic sunflower oil for frying as it degrades better.

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I agree with him, there really is not much point in frying with olive oil. The flavour gets whittled down to nothing by the end, and the low smoke point makes the supposed health benefits a pretty tough sell. –  Aaronut Jun 5 '11 at 22:52
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I agree as well UNLESS we're talking about refined olive oil labelled as "pure olive oil" and not extra virgin. That has a much higher smoke point, and presumably the health benefits of monounsaturated fats would carry through to products fried in it. But generally using olive oil as a frying oil is just another piece of nonsense people latch onto for "health reasons." –  BobMcGee Jun 6 '11 at 7:09
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Compared to refined olive oil, Canola (rapeseed) oil is far cheaper and a fat profile at least as good. –  derobert Jun 6 '11 at 20:10
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Olive oil is preferred for the flavor it imparts, and by many because it is healthier than other oils. As far as frying goes, it is actually not that great since it has a relatively low smoke point, meaning it will start smoking on you at a lower temperature.

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Additional information: the smoke point of extra virgin olive oil is around 320F/160C, Virgin Olive oil is 420F/216C (hot enough for almost all uses), and extra light olive oil is 468F/242C. "Pure" (refined, not extra virgin) olive oil should smoke from 420-450F. –  BobMcGee Jun 5 '11 at 17:42
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First at all I apologize for my English.

Basically remarks made before are not really true. Smoke point took alone does not mean anything. There are other consideration that must be done to analize oil transformation.

  • What is friying?

Let's go in order considering two aspects: oxidation parameters and healthy parameters:

Frying is an accelerated process of oxidizing (air oxigene attacks lipidic substratum).
The transformation is more accelerated as higher is the oil unsaturation (presence of double connection that is a point of weakness).

So the stability of fatty acids is related to double connections in its structure and decreases in the order of those categories:

-saturated: 0 unsaturation
-monounsaturated: 1 unsaturation
-poliunsaturated: 2-3 unsaturations

So it means 0 unsaturation are definitely more stable oils during frying.
But there's an healthy parameters to be considered: saturated fatty acid are hamful for cardiovascular illnesses.

satured: lard, palm;
monounsaturated: olive, sunflower (high oleic acid);
poliunsaturated: maize, soy, sunflower (high linoleic acid);

So until now the better choice are monosaturated oils!

  • The thorny subject of smoke point:

Often associated to formation of acrolein, is closely related to the physic state of oil and not to its fatty acid composition.

The presence of humidity and acidity (free fatty acid), decreases the smoke point.
So for the same acidic composition smoke point descrease for oil with more acidity.

  • So which is the better oil to fry?

Although smoke point is lowest you have to consider the oxidation stability as well.
Even if you can see an oil smoking it does not always mean that the oil decomposes.

That's because they wrongly talk about smoke point as the central point instead of a more complex process called pyrolysis that is:

Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures in the absence of oxidizing agent (normally oxigen).

So here we came!
Even if extra virgen oil has a less smoke point is the more oxidation stable oil thanks to its liposoluble antioxidant (Vitamin E) and idro-soluble (biofenoli).

I hope to have explained in better way why the smoke point is not the right (or better the only one) property of oil that has to be considered.

  • About the taste:

Of course the extra virgen oil has a strong taste and it's used for food without own taste as said potatoes, fries.
To not alter some taste food (fish) can be used for example peanut oil that does not have a strong taste (for its good combination of oxidation parameters and smoke point).

Other staffs should be considered.

  • Not use the same oil to fry? it's true, but there is something called polar compound formed during frying that is the health indication of frying oil.
    That means that should not exceed a limit value (defined by healty department; some place the value is 25g/100g, but that means pretty more than 8 home frying; it is to control restaurant industry).
  • heat the oil before but not cross 180ºC / 356ºF
  • do not bathe cold food even if the box says yes
  • try to keep the temperature constant
  • do not salt/sweeten during frying but after it
  • fry little portion of food to shorten the fry time

I hope I've been helpful!

Kind regards!

-----------------------------------------------------------------------------------------

  • Editing to answer to comments:

@Aaronut I completaly agree with you. I always advice to not believe surfer doctor improvisation. This is just a place for opinions!
I agree that you need reliable source! I'm gonna give you some!
But first of all I want to say. Don't trust on everything because market business let say many deceitful things! Market business is misleading! It's able to corrupt everything.

I'm just pretty surprise of your doubt: "saturated fatty acid are hamful for cardiovascular illnesses"
Satured fatty acid are responsible for cholesterol. Cholesterol is responsible of coronary disease.
Do you agree with me about it?
Anyway if you think this is my opinion...
here you some reliable sources! (All are Government Institutes! No privates or indipendents!)


I'm sorry but I don't have time to find more!
By the way I want to show all theory :) There is an opposite one.
But in my opinion a single researcher can be corrupted very easy. He's Ronald Krauss and I don't really have time to find his study.

@rumtscho I definitely prefear Extra Virgen Olive oil. For some frying (very few) I use Peanut oil to not alter some food taste.
I will answer to other comments as soon as I can.


Kind regards to everyone!

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I find your information on the difference between smoke point and pyrolysis very interesting. Still, I have two issues with this answer. 1) I don't clearly understand if you are for or against frying with olive oil (I think you support it, but it isn't entirely clear) 2) The other answers mentioned not only smoke point, but the obvious loss of taste when non-refined olive oil is heated at frying temperatures. Even if the fatty acids don't pyrolise, the aromatic compounds probably do. So why use the expensive EVOO for frying when the cheap sunflower oil (monounsaturated, has Vit E) will do? –  rumtscho Jun 6 '11 at 16:14
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I very much appreciate a lot of the technical details here, but I have a problem with this statement: "saturated fatty acid are hamful for cardiovascular illnesses" - can you back this up with some reliable source? I know that this is true for trans fats but I do not believe this statement to be the scientific consensus for saturated fats. –  Aaronut Jun 6 '11 at 16:23
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Also, my understanding is that oil smoking does in fact indicate oxidation, and that the antioxidants in olive oil (or any oil) are a component of the smoke point. Now that could very well be wrong, but as above, I'd really like to hear that from a reliable source. –  Aaronut Jun 6 '11 at 16:28
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@TFD: First of all, yes I can; food safety and general health are two very different subjects as we've made plainly clear in the past. More importantly, vague allusions are not citations; I'd like to know specifically where this was stated and in what context. I've seen certain limited evidence to suggest that increasing the intake of monounsaturated fatty acids (relative to other kinds) can reduce the risk of heart disease, but that's a very far cry from cutting out saturated fat entirely and/or claiming that it causes heart disease. –  Aaronut Jun 7 '11 at 2:06
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1. @soneangel I for one appreciate the effort you are putting in your contribution. English is my third language, and I know how hard it is to produce good arguments in a foreign language. The problem is, you can't convince anybody if they don't understand the arguments you make. If you don't find the time to translate, I will vouch for you: the sources you linked indeed state that the eating of saturated fat causes elevated cholesterol levels, which are linked to heart disease. But I don't think that @Aaronut doubted that a similar statement is contained there; more likely he wanted to judge –  rumtscho Jun 7 '11 at 16:28
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I think the best thing to do is use olive oil for cases when you are drizzling it on or cooking for a short time. Otherwise, use vegetable/canola/etc.

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