Posted on Leave a comment

Can We Use Extra Virgin Olive Oil for Cooking?

Image: flickr. The holy oils of cooking

One question people often ask: Can we use extra virgin olive oil for home cooking? And at a high temperature? If your answer is a “oh, no,” well, don’t worry, you are not the only one who would have reacted as such.

Like many other misconceptions of the use of extra virgin olive oil (here and here), research studies such as this has dispelled the myths of frying with extra virgin olive oil at high temperatures.

Here, however, we want to explore another more interesting question …

QUESTION: When we fry or sauté with extra virgin olive oil at a high temperature, will its nutrients lost in heating?

Following this questioning, will it be more cost-effective to cook with a “normal” extra virgin olive oil?

“Normal” in this case is referring to “cheaper” extra virgin olive oil or simply using pure olive oil, extra light olive oil, or olive-pomace oil, which are all refined oils, processed at a very high temperature and used of chemical substances during the oil extraction.

These are valid questions. Who wants to waste money on high quality extra virgin olive oil for high-temperature cooking if we can do away with a cheaper oil?

Some Facts About Cooking, Oil & Temperature

Hold on to your horses before you are reaching a conclusion. Here we present some facts for you to ponder about.

Standard Cooking Temperature: In a study conducted by Dr. Nurhan Dunford (Oilseed Chemist) of the Oklahoma State University, the food service (i.e. restaurants and eating houses) fries at a temperature between 160°C and 190°C.

Most foods cook rapidly in this temperature range and develop a golden colour, crisp texture, and good flavour.

Types of Food & Cooking Temperature: The International Olive Council has identified common temperature range for various types of food as shown below.

Cooking TemperatureFood Type
Medium
(130–145ºC)
Food with high water content such as vegetables, potatoes, fruit, etc.
Hot
(155–170ºC)
Food coated in batter, flour or breadcrumbs, forming a crust.
Very hot
(175–190ºC)
Food required small, quickly fried such as small fish, croquettes.

Our home cooking temperature generally falls below 190ºC, and most often between 130-145°C.

Cooking Methods & Temperature: Various cooking methods require certain cooking temperature range:

Cooking MethodCooking Temperature
Pan Frying (Sautéing) on stove top120°C
Deep Frying160-180°C
Oven Baking180-200°C

When people say they (home) cook at a very high temperature in a conversation, they are actually saying that they use deep frying method to cook the food – the temperature surely falls below 180ºC.

Smoke Point is a term we often refer to but also misunderstood. Smoke point is defined as the oil begins to smoke and starts to form unhealthy compounds when heated over its tolerable limit.

As a comparison, the following table shows a rough estimation of the smoke point of some common cooking oils.

OilSmoke Point
Avocado (unrefined)248°C
Avocado (refined)271°C
Butter120-150°C
Butter (Clarified) – Ghee250°C
Canola Oil (refined)220-230°C
Coconut Oil (virgin)177ºC
Coconut Oil (refined)232°C
Extra Virgin Olive Oil (unrefined, cold-extracted)190-210ºC
Grapeseed Oil (refined)216-220ºC
Lard (unrefined)180-205ºC
Olive Oil (refined: Pure, Extra Light, Pomace)200-243°C
Rice Bran Oil213°C
Sunflower Oil (refined)227ºC
Vegetable Oil Blend (refined)220°C

From the smoke point perspective, extra virgin olive oil is good for deep frying, at a cooking temperature as high as 190-210ºC.

Secondly, various studies have shown that the smoke point of an oil is not indicative of the heating-suitability of a cooking oil, and on the contrary, those with highest smoke points tend to produce higher levels of harmful compounds after heating.

For example, Avocado oil, rice bran oil, canola oil, sunflower oil and grapeseed oil have higher smoke points but they also produce higher levels of harmful polar compounds after cooking (or read this study.)

Oxidative Stability, on the other hand, is a much better predictor of an oil performance during cooking and how it withstands the heat.

Oxidative stability is defined as the reaction rates of the unsaturated fatty acids (monounsaturated and polyunsaturated fatty acids) with oxygen.

The longer an oil resists oxidation, the healthier it is to eat the food the oil has been heated with.

With a high percentage (75%) of monounsaturated fatty acids (oleic acid), extra virgin olive oil is one of the safest and most stable cooking oil for cooking at a high temperature as compared to other vegetable oils that have high polyunsaturated fatty acids, such as canola oil.

Expert like Dr. Mary Flynn, Associate Professor of Clinical Medicine at Brown University’s Alpert Medical School, who has highlighted this point in The Science of Cooking with Olive Oil, as well as the Australian Olive Association, here and here.

Heat Stability depends on the amount of antioxidants & Vitamin E in the oil. The larger amount of these phytonutrients helps fight oxidation during heating.

Because extra virgin olive oil is cold-extracted and unrefined, it will retain most of the phytonutrients, such as the antioxidants and Vitamin E, which in turn will help to protect the oil from damage during high heat cooking.

Scientific Studies of Cooking with Olive Oil

Here is a summary of the research findings from the scientific studies conducted over many years:

  • One research study shows that there is a 14% reduction in oleuropein (antioxidant and anti-inflammatory compounds in extra virgin olive oil) after one hour of heating at 80°C.
  • In another study, heating olive oil at 180°C for 36 hours led to a decrease in antioxidants and Vitamin E, but most of the trace compounds were intact (read the article here).
  • Heating olive oil at 240°C for 90 minutes reduced the amount of oleocanthal (an anti-inflammatory compound that can fight cancer cell) by 16% (read the article here and here).
  • Another study simulated frying for 24 hours saw a reduction of some beneficial compounds, but 10 minutes in a microwave or boiling in water had only minor effects (read the article here).
  • Heating extra virgin olive oil removes its aroma and taste, which is in the trace compounds in olive oil.

Extra virgin olive oil has been used as a multi-purpose oil for many centuries in the West, as a condiment to a finished food to enhance its flavour, and as a medium for pan frying, sautéing and deep frying.

Will the Nutrients of the Extra Virgin Olive Oil Lost in Heating?

In short, “no”.

For a more complete answer, according to the research findings, “only minor lost and only after a long period (from 90 minutes to over 20 hours) of heating at a high temperature such as 180°C”.

Even under such extreme heating condition, extra virgin olive oil still retains most of its phytonutrients, and mostly undamaged.

Interestingly, the study also shows that when we use high quality extra virgin olive oil to cook our vegetable (heated between 130–145ºC), the polyphenols (antioxidants and anti-inflammatory properties) are transferred to the vegetable after cooked.

In this case, we are reaping the nutrients from the vegetables as well as the extra virgin olive oil. You may be interested to read this article here.

Here is a summary of the research findings:

  • From these studies reported, we can see that extra virgin olive oil starts to loss the nutrients after one hour, 24 hours, and 36 hours.
  • For home cooking, we do not cook for that long for one dish, nor re-use the oil in another cooking.
  • The temperature used in the research studies is as high as 180°C, and 240°C and for a long period of cooking (one hour, 24 hours and 36 hours). In home cooking, we do not usually cook at this temperature nor for that long duration.
  • Dr. Mary Flynn said that a high quality extra virgin olive oil can be heated to 215°C before it reaches its smoke point. And that cooking with extra virgin olive oil below the smoke point does not destroy most of its health benefits under normal cooking conditions. (For more information, read the section on “Olive Oil and Cooking” in The Science of Cooking with Olive Oil, and read this article on using extra virgin olive oil for cooking.)

Despite the impact that heating has in reducing the antioxidant content in extra virgin olive oil, a significant amount of substances related to health benefits such as biophenols, tocopherols, sterols and squalene still remain in extra virgin olive oil after heating, and they are absorbed by the cooked food.”

—– Lead Author, Florencia De Alzaa. Evaluation of Chemical and Physical Changes in Different Commercial Oils during Heating.

We Are What We Are Eating!

When we make chili oil or fry eggplant, the finished food either contains the oil or tends to absorb part of the oil during frying. Hence, the quality of the frying oil will drastically affect the quality of the food fried.

It is the “olive Juice!” 

Extra virgin olive oil is cold-extracted and unrefined.

Image: Your Everyday Veggie Stir Fry. November 30, 2016. Australian Extra Virgin Olive Oil.

Have No Fear of Frying With Extra Virgin Olive Oil

If you are still not sure whether extra virgin olive oil can be used for frying, you can try this everyday veggie stir fry recipe, and drizzle high quality extra virgin olive oils to finish it for taste.

“This dish is also packed full with veggies – to make sure you have the recommended five serves per day.”

Australian Extra Virgin Olive Oil. Your Everyday Veggie Stir Fry. November 30, 2016.

Baking & Oven Roasting

The temperature of baking and oven roasting can be in the range of 200°C or more. The question is, can extra virgin olive oil be used in baking?

Extra virgin olive oil is an ingredient commonly used in replacement of butter for baking by health advocates.

The smoke point of a regular butter is between 120-150°C (clarified butter is higher, 250°C) whereas a high quality extra virgin olive oil with low free fatty acid (0.3% and below) is about 210°C (see a field test here).

From this point, if a regular butter is used for baking, there is no reason why extra virgin olive oil cannot.

Extra virgin olive oil has been found to be one of the safest and most stable oil for cooking at a high temperature, which is much higher than standard home cooking temperatures such as 120℃ in stir frying (sautéing), 160-180℃ in deep frying and 200℃ in oven baking.”

Image: The Healthiest Roast Around! November 21, 2016. Australian Extra Virgin Olive Oil.

Healthiest Roast Chicken

Either for cooking, baking or oven grilling, extra virgin olive oil has been one of the key pantry staples in the West.

Here is a recipe and instruction on how to roast a chicken in the oven for about one hour using extra virgin olive oil as one of the ingredients at a temperature 200°C.

Image: Olive Bread. Maggie’s Food Club.

Bread Recipes Using Extra Virgin Olive Oil Instead of Butter

Extra virgin olive oil is not only great for bread dipping but also a wonderful ingredient to use when baking the bread itself. The temperature of such oven baking can go up to 230℃ for about 15 minutes of so.

Olive bread, garlic bread, banana bread, rosemary crock pot bread, focaccia, you can find these bread recipes here and learn how to replace butter with the extra virgin olive oil below.

Butter
Extra Virgin Olive Oil
1 teaspoon=¾ teaspoon
1 tablespoon=2¼ teaspoons
¼ cup=3 tablespoons
1/3 cup=¼ cup
½ cup=¼ cup and 2 tablespoons
2/3 cup=½ cup
1 cup=¾ cup

How to Cook With Extra Virgin Olive Oil?

When we use extra virgin olive oil for cooking, pour sufficient amount of extra virgin olive oil on the cold pan before turning on low heat to heat up the oil. When the oil is heated enough, we then throw in our ingredients into the hot pan.

Why Olive Oil Is Good for Us?

Because a high quality extra virgin olive oil contains:

Antioxidants, which can help prevent cell damage and protect our body from damage caused by free radicals and reduce our risk of having heart disease.

Anti-Inflammatory Properties, which may prevent or delay the occurrence of Alzheimer’s disease and related neuro-degenerative dementia, as well as reduce the severity of its symptoms. It is also found that to be able to kill cancer cells.

Monounsaturated Fatty Acids, which may help protect our heart by lowering blood pressure, improving our cholesterol profile, lowering peak blood-glucose response, and reducing our risk of cardiovascular disease.

For more information, please read the health benefits of extra virgin olive oil.

Which Cooking Oil We Should Use?

From the studies, it is obviously the extra virgin olive oil.

Extra virgin olive oil has been shown to be a most resistant to heat and therefore most suitable and healthier cooking oil for sautéing, pan frying, deep frying and oven baking.

Moreover, the polyphenols (antioxidants and anti-inflammatory properties) in the extra virgin olive oil will be transferred to the food after cooked.

From a healthy lifestyle point of view, we should avoid, as much as possible, cooking at a very high temperature, such as 180℃ and beyond.

Very high temperature cooking will destroy some of the nutrients in the food as well as the phytonutrients in the oil used.

In case, we do need to deep fry, use a healthier unrefined oil, which is high in monounsaturated fat and low in polyunsaturated fat, so that we can reap the health benefits of the food and oil.

Just be aware that there is a difference between lower and higher quality of extra virgin olive oil, namely in the amount of antioxidants, anti-inflammatory properties, and monounsaturated fat contained within the oil. 

Leave a Reply

Your email address will not be published.