Cooking with olive oil helps preserve food nutrients

In addition to being rich in monounsaturated fats, bioactive compounds, vitamins, among others, extra virgin olive oil is able to reduce the loss of nutrients from food during cooking.

This is what a review of more than 90 scientific papers by researcher José Fernando Rinaldi de Alvarenga, a Fapesp grantee and post-doctoral fellow at Forc (Center for Research in Food), a Fapesp Research, Innovation and Dissemination Center based in Faculty of Pharmaceutical Sciences at USP (University of São Paulo).

The research was carried out in partnership with colleagues from the University of Barcelona, ​​Spain, and published in an article in the scientific journal Trends in Food Science & Technology.

“Before any explanation, it is important to reject once and for all that cooking with this oil is not healthy”, says Alvarenga, in an interview with Forc’s Communications Office. In the past, according to him, it was believed that fatty acids in extra virgin olive oil would oxidize at higher temperatures.

“This is because of the smoke point of olive oil, which is when the oils start to burn, smoke and oxidize. Although its smoke point occurs at lower temperatures than other oils, today we know that the smoke does not come from of these fatty acids, but of minor components of the oil. Extra virgin olive oil ‘withstands’ higher temperatures just like other oils.”

He explains that in extra virgin olive oil there is a predominance of monounsaturated fats, which, among other benefits, have antioxidant potential. “Because of this action, the degradation of olive oil is slower compared to other oils. And this protects both the nutrients in the oil itself and in the food.”

An example is the bioactive compounds in food, which have several health-beneficial properties. “Extra virgin olive oil helps to prevent phytochemicals from being oxidized. This makes cooked foods healthier, as it preserves important components that could otherwise disappear. can be reduced without the presence of olive oil in the cooking process. However, by using extra virgin olive oil, we managed to preserve this compound that is associated with the prevention of prostate cancer”, comments the postdoctoral student.​

Influence of cooking

The study shows, however, that the degradation of bioactive compounds varies according to the cooking method used. Several studies were analyzed on the loss of nutrients with foods prepared in the oven, in the pan, sautéed, fried or braised, using a Spanish technique called stew, which is similar to the preparation of a moqueca or pot meat.

“We saw that the technique that promotes the greatest degradation is oven preparation, as it involves very high temperatures and a very long cooking time”, explains Alvarenga.

Degradation levels also vary depending on the bioactive compound. In the case of water-insoluble compounds, such as carotenoids and fat-soluble vitamins, boiling and steaming are the techniques that best preserve these compounds. On the other hand, there is considerable loss of them when microwaved and fried.

According to the researcher, it is important to highlight that there is no contraindicated method. “But, in general, if the aim is to make the most of the nutrients from plant foods and olive oil, it is preferable to use techniques with shorter cooking times and milder temperatures.”

manufacturing

For Alvarenga, extra virgin olive oil brings benefits because it does not go through the same industrialization processes as the most popular oils in Brazil, such as sunflower, soy and corn.

“The Mediterranean diet is considered one of the healthiest in the world, largely because of the olive oil. One of the reasons behind this is that most oils are taken directly from olives. That is, they do not go through a refining process. “, he explains. “The processing of extra virgin olive oil does not involve heating, only physical processes such as cold pressing, centrifugation and filtration, which preserve these compounds.”

There are oils produced from different olives, being arbequina, picual and hojiblanca some of the most common. However, in the study it was observed that this has little impact after cooking, as well as the amount of bioactive compounds in the final product.

“What must be taken into account is not the type of olive, but its cultivation conditions. In other words, climate, temperature and amount of rainfall. In addition to the conditions of extraction, processing and storage”, the researcher points out.

*With information from the Forc Communications Office