Olive oil is a great oil for cooking. Strong flavored olive oils can be used for frying fish or other strong flavored ingredients. A mellow late harvest Mission variety oil could be used in baking a cake. Olive oil has a high smoke point, 410 degrees F, and doesn't degrade as quickly as many other oils do with repeated high heating. Use a variety of healthy vegetable oils when preparing food and incorporate a good extra virgin olive oil when you want its health benefits and wonderful Mediterranean flavor. There are some myths which have recently circulated about olive oil which we are constantly answering via email and our newsletter. Olive oil has been used for thousands of years and is one of the cornerstones of the healthy Mediterranean diet. Click here for a more scholarly discussion of storage and rancidity Olive Oil Myth: Olive oil loses its benefits when heated The Facts: Excessively heating olive oil will evaporate the alcohols and esters which make up its delicate taste and fragrance. Heating olive oil will not change its health aspects, only the flavor. Use a cheaper olive oil which doesn't have much flavor to begin with if you want to fry with it, add a more flavorful olive oil after cooking or at the table. Olive Oil Myth: Heating a cooking oil will make it saturated or a trans-fatty oil. The Facts: As far as making a saturated fat, according to Dr. A. Kiritsakis, a world renowned oil chemist in Athens, (Book - OLIVE OIL FROM THE TREE TO THE TABLE -Second edition 1998), all oils will oxidize and hydrogenate to a tiny degree if repeatedly heated to very high temperatures such as is done in commercial frying operations. Olive pomace oil and virgin olive oil are both highly monounsaturated oils and therefore resistant to oxidation and hydrogenation. Studies have shown oxidation and hydrogenation occurs to a lesser degree in olive oil than in other oils. But in any case, the amount of hydrogenation is miniscule and no home cook would ever experience this problem. The large refinery-like factories which take unsaturated vegetable oil and turn it into margarine or vegetable lard do so by bubbling hydrogen gas through 250 to 400 degree hot vegetable oil in the presence of a metal catalyst, usually nickel or platinum. The process can take several hours. You cannot make a saturated product like margarine at home by heating olive oil or any other vegetable oil in a pan. We don't know where this weird notion has come from. For more see our olive oil chemistry page Changing a cis-fat to a trans-fat does not occur on a home stove. Olive Oil Myth: Cooking in olive oil diminishes the nutritional value of the food. Olive Oil Fact: Heating food will break down its nutritional value. High heat such as frying is worse than moderate heat such as steaming, which is worse than eating vegetables raw. It is not the cooking oil per se, but the high heat of frying. I am not aware of any edible cooking oil which of itself diminishes the nutritional value of the food cooked in it. Most nutritionists recommend lightly steaming vegetables or eating them raw. A touch of a flavorsome olive oil added at the table will add taste and healthful anti-oxidants. Such is the "Mediterranean diet" which has been shown to help prevent coronary disease and have other health benefits.
Frank Asks:
Can I deep fry croquettes in olive oil without an undesirable taste ? Is it
healthy ? If it the answer is yes, why is there so little information
publicized and why don't the fast food restaurants use it ? Olive pomace oil is often recommended for frying due to the fact that it is cheaper than virgin olive oil. Olive pomace oil and virgin olive oil are both high monounsaturated oils and therefore resistant to oxidation (rancidity). See cooking chart at bottom of page Walter asks: What is the boiling point of olive oil? OOS answers: The boiling point of olive oil (570 degrees Fahrenheit) is much higher than the smoking point (375 - 400 degrees F) and would be a very dangerous temperature to try to achieve on a home stove. It would certainly ruin the oil and would be close to the flash or fire point (around 600 degrees F) and the danger of a conflagration would be great. (When you are deep frying and you see the oil "boiling" you are actually seeing the water in the batter or food boiling, not the oil.) A more useful temperature would be the smoke point. see smoke point Shelby asks: Does cooking oil evaporate? Dear Shelby: Volatile oils will evaporate in a few days or weeks, "fixed" oils are more resistant to evaporation. Most vegetable cooking oils are classified as fixed oils. However, if you set out a container of most cooking oils, it would partially evaporate very slowly over months to years leaving a sticky varnish. You can see this varnish on the sides of pots and baking pans where the process has been speeded up by heat. Linda asks: A friend used cold pressed olive oil to roast and fry certain pieces of meat and it has damaged his non-stick frypanDear Linda: Any oil if heated excessively will leave a varnish like coating on a pan. Remember that vegetable oils like linseed oil were formerly the primary ingredient in tough paints and finishes used on furniture, etc. Question: Which is better for your health, Extra Virgin, Virgin, or plain olive oil? Answer: The difference between the olive oils you listed is their acidity level, which affects mostly taste, not nutritional content. Lower acidity oils, such as extra virgin, tend to have more anti-oxidants, but that is not reflected in their classification. Anti-oxidants in olive oil may help prevent heart disease and cancer so sticking with extra virgin seems to make sense. Pomace olive oil is processed with hexane and other solvents just as most seed oils like canola, corn, safflower, soy, etc. This removes many of the minor constituents which may be the healthiest part of this natural product. 10/12/02 Kevin asks: Why is there a conversion chart for butter/margarine to olive oil? Do you do that for all cooking recipes? OOS replies:
The conversion chart is more for cake and pastry recipes where
quantities are critical. Frank asks: Does olive oil have Polycyclic aromatic hydrocarbons (PAHs)?: Dear Frank: Many foods naturally contain small quantities of PAHs. It is not good to eat foods high in PAHs as some studies connect them with cancer. Olive oil, like all other vegetable cooking oils, has been found to contain minute amounts of up to 17 PAHs such as benzanthracene and chrysene. Unripe olives tended to have more than ripe olives. Burning any cooking oil can increase the amounts of PAHs. This is not considered a major risk source in the diet and the oil would have to be heated repeatedly and for extended periods to the smoking point. It is unlikely that in home use olive oil or other cooking oils would be a significant source of PAHs. Claire asks: What's the best way to store olive oil? Dear Claire: See Olive Oil Storage Sue inquires: I
am in Australia, and have been given a 1 lit bottle of olive oil, but
unfortunately it is very rancid and I cannot use it for cooking. I there any
way I can filter this oil so it becomes usable? A reader asks: Is it possible to make olive oil hard for spreading, like margarine? Margaret Chidgey, editor of the journal of the Australian Olive Association recently answered this question: "We use 500g of butter to 1.5 cups of evoo. Make sure it is fairly light-flavoured oil, otherwise the oil will overwhelm the butter taste. Beat the butter in a food processor or Mixmaster until softened, then gradually add the olive oil. When it is all completely blended, it will be quite pourable. I pour it into 500 ml containers and put lids on, then store them in the fridge. When cold it is quite hard. Variations: You can add some milk to make it go a bit further - up to 1/4 cup for this quantity. We make winter and summer blends too. The recipe above is for winter. In summer I use only 1 cup of olive oil, because the spread becomes too soft when it is left out in warm weather." Grimmy asks: I make large batches of pesto and was wondering if I could freeze it and have it return to its original consistency. OOS responds: Freezing pesto is the best way to preserve it. Freezing olive oil will not harm it; it will actually prolong it's nutritional benefits and its flavor. Here is a statement on cooking with olive oil from the International Olive Oil Council (IOOC):
Frying temperatures
An excellent resource
with voluminous bibliography is a monograph entitled "Frying Food in Olive oil"
by Gregorio Varela, Professor of Nutrition, Madrid University. It is available
from the International Olive Council (IOC) |
Last updated: 04/14/08
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