Olive oil for frying: myth or truth?

Introduction

Olive oil is a popular and versatile ingredient in cooking, but there is always uncertainty about whether it can be heated and used for frying. In this blog post we will explore the facts and myths surrounding heating olive oil.

We should answer the question taking into account three aspects:

It is possible to heat any olive oil, whether it is cold pressed, virgin or extra virgin. However, you should be careful not to heat the oil too much, otherwise it may start to smoke. If the oil starts to smoke, you should not heat it any further, as volatile components such as water or free fatty acids can evaporate from this point on. For health reasons, you should never heat fats and cooking oils to the point where they begin to smoke, as this can promote the release of acrolein, which is suspected to be carcinogenic.

Health

What factors define the suitability of olive oil for heating? The smoke point?

It's a common myth that you shouldn't cook with extra virgin olive oil (EVOO), but there is no scientific basis for this. Many people mistakenly believe that high smoke point oils are the best for cooking. However, an oil's smoke point does not indicate its safety and suitability for cooking. New research has shown that the percentage of polyunsaturated fats and the degree of refining of the oil are the factors that predict an oil's safety and stability at high heat .

The study "Evaluation of Chemical and Physical Changes in Different Commercial Oils during Heating" examines the effects of heating different cooking oils on their chemical and physical composition. Five different oils were used: olive oil, sunflower oil, rapeseed oil, coconut oil and sesame oil.

The results of the study show that olive oil is one of the best oils for heating. Compared to the other oils, it had greater stability during heating and produced fewer harmful compounds such as free fatty acids or peroxides.

What is also particularly interesting is that extra virgin olive oil stood out in the study as the best oil for heating. It had the highest heat resistance and produced the fewest harmful compounds compared to the other oils tested.

One reason for this could be the composition of olive oil, which has a high proportion of monounsaturated fatty acids, which improves its stability when heated. Additionally, olive oil contains many antioxidants that can help reduce the formation of harmful compounds.

However, it is important to note that even with olive oil, heating past its smoke point should be avoided as this can promote the formation of acrolein, which is considered a carcinogen. The smoke point of olive oil is around 190°C, which is sufficient for most cooking processes.

Overall, olive oil is a good choice for cooking and frying due to its composition and stability when heated. In particular, extra virgin olive oil has proven to be the best option. Of course, care should always be taken not to overheat the oil and not to exceed the smoke point in order to avoid harmful compounds.

Are health benefits lost by heating?

No, the main health benefit of olive oil is its fat composition. Olive oil consists mainly of monounsaturated fats. When you cook an oil, its fat composition does not change. The percentage of monounsaturated fatty acids in olive oil remains the same even after heating, even at high temperatures.

And the phenols?

The University of Barcelona study, published in the journal Antioxidants in 2020, confirms that extra virgin olive oil (EVOO) retains healthy compounds such as antioxidants and phenols during cooking. The influence of various factors such as temperature, time and water content on the chemical composition of olive oil during cooking was examined and it was found that heating EVOO at temperatures up to 180°C or 356°F does not have a significant effect on it has antioxidant properties.

The study's conclusion says that cooking with EVOO is a great way to reap the health benefits of olive oil because it is rich in antioxidants and phenols, and these healthy compounds remain intact even when heated. However, it is emphasized that the quality of olive oil is crucial and that heating low-quality olive oil can lead to compounds harmful to health.

The taste

The aromatic substances in olive oil are delicate and evaporate when heated. Heating does not damage the olive oil, but it does lose some of its flavor. Some people view this as a positive because they don't want their food to taste like olive oil. However, if you have an expensive olive oil with complex flavors, you may want to save it for finishing and cold applications.

Money

According to a study titled "Evaluation of Chemical and Physical Changes in Different Commercial Oils during Heating," extra virgin olive oil is the best choice for heating oils. Many people think that cheaper olive oil is also suitable for frying due to its weaker taste. However, this is wrong because inferior olive oils are less stable and therefore less suitable for frying. It is also important to note that not all olive oil is suitable for this purpose, but at least extra virgin olive oil should be used. It doesn't necessarily have to be the most expensive, but it should be of good quality (EVOO) to ensure the benefits and stability when frying.

Summary

• The smoke point says nothing about an oil's performance when heated.
• Oxidation stability and UV coefficients are better predictors when combined with total polyunsaturated fatty acid content
• Of all the oils tested, EVOO was the oil that produced the lowest amount of polar compounds.
• The production of polar compounds was more pronounced in refined oils.
• EVOO was found to be the most stable oil when heated, closely followed by other virgin oils.

Definitions of terms

fatty acids

What are monounsaturated, saturated and polyunsaturated fatty acids and in which foods are they found?

Fatty acids are organic molecules that occur as components of fats and oils in many foods. There are three main types of fatty acids: monounsaturated fatty acids, polyunsaturated fatty acids and saturated fatty acids.

It is important to have a balanced amount of different types of fatty acids in the diet as each type has its own advantages and disadvantages. A diet high in saturated fat can increase the risk of cardiovascular disease, while a diet high in monounsaturated and polyunsaturated fat can reduce the risk of these diseases.

What is a smoke point?

First of all, it's important to know that olive oil has a relatively low smoke point, meaning that it can quickly start to smoke and burn at high temperatures.

The smoke point refers to the lowest temperature at which significant smoke can be observed over heated cooking fat or oil. However, oils and fats can break down at temperatures below the smoke point.

It is a common misconception to assume that the smoke point is the temperature at which oil or fat breaks down and releases potentially harmful substances. In fact, the smoke point is the temperature at which certain volatile components such as water, free fatty acids or short-chain oxidation degradation products evaporate under certain conditions and become visible as smoke.