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Should I fry vegetables or boil them?
29 October 2015 @ 18:28


It has been revealed by a Spanish scientific study that vegetables fried in extra virgin olive oil  are more nutritionally beneficial than boiling them, contrary to common belief. It has been shown that frying vegetables in extra virgin olive oil  EVOO (not any olive oil)  actually increases  the antioxidant qualities of the produce being cooked.

The study which was carried out by the University of Granada revealed that frying vegetables in extra virgin olive oil is a far better method of cooking as it imprives the nutrient value.

There has been much debate on the advantages and disadvantages of different cooking methods for vegetables and how certain techniques affect phenolic compounds.

This latest study aimed to put domestic cooking techniques to the test and determine how they affect or enhance the antioxidant qualities as well as the quantities of phenolic compounds found in a Spanish Mediterranean diet which typically contains high volumes of potato, pumpkin, eggplant and tomato.

The Mediterranean diet in Spain is also characterized by high consumption of extra virgin olive oil which, alongside vegetables, are sources of certain compounds that have been linked to the prevention of chronic degenerative diseases like cancer, diabetes and macular degeneration, a condition that causes blindness.

During the study three cooking methods were employed; 120 gram cubes of the vegetables were fried in EVOO, or boiled in water, or boiled in a mix of water and extra virgin olive oil.

All tests were carried out under controls with close analysis of the cooking methods and storage of the vegetables in optimum conditions so as to accurately measure factors like moisture, fat, dry matter, phenol content and antioxidant capacity, said the university.

In what they described as a “breakthrough in food science,” the researchers found frying in EVOO produced higher levels of natural phenols.

Professor Cristina Samaniego Sanchez said  “while comparing the total phenol content of the fresh vegetables, we found both increases and decreases in their levels, depending on the cooking method employed,”.

“As a heat transfer medium, the EVOO increases the amount of phenols in the vegetables, in contrast with other methods such as boiling, which use a water-based heat transfer medium.”

According to the results of the study, the overall quality of the vegetables was significantly improved when fried in EVOO because the produce becomes enriched with EVOO phenols transferred from the oil.

“We conclude that frying in EVOO was the technique with the highest associated increases of phenols and can therefore be considered an improvement in the cooking process, although it also increases the calorie density of the food because of the amount of oil absorbed,” Sanchez added.

“If the concentration of phenols found in the raw ingredients is high to start with, the overall concentration level is further increased if EVOO is employed during the cooking process, while boiling does not significantly affect the concentration levels.” Boiling is recommended if the vegetables are to be consumed together with the cooking medium (i.e. the water/sauce/stock) .


If this interested you,  you might like to read my article : Can I fry with olive oil?




[source olive oil times]

Like 1


GB45 said:
30 October 2015 @ 10:05

I am surprised at that Ian, as I thought that EVOO should never used for frying and only for dressings etc.

eos_ian said:
30 October 2015 @ 10:56

Yes that is a very common misunderstanding.

Alden12 said:
31 October 2015 @ 07:53

Stir-frying is very similar to sautéing, with two important differences. Stir-frying is done over very high heat, and the food is constantly stirred to prevent it from burning on the hot pan. Stir-frying is often done in a wok, the classic utensil of Chinese cooking. But you can also stir in a sauté pan, as long as the bottom is thick enough to distribute the high heat evenly.

mestala said:
31 October 2015 @ 08:12

Used EVOO for at least last 20 years for frying all sorts of foods,still do

SandrainAlgorfa said:
31 October 2015 @ 08:45

I've always used EVOO for frying too. I read about not being supposed to use it, but I reckoned anything that tasted as good as an egg fried in EVOO couldn't possibly be bad for you. If I make a ratatouille-type mix, I always fry the vegetables because they keep their shape better and taste so much nicer. Sharing this to explode the myth.

icaru said:
31 October 2015 @ 09:29

Fact is, the best is to eat the veggies raw, including broccoli.

Olive oil ... here is an interesting article summarizing all research on olive oil, including a longevity study of 23,349 people.

While not bad, it does not offer all the benefits that myths suggest.

eos_ian said:
31 October 2015 @ 10:08

Well that is not entirely true, some vegetables are best eaten raw but carrots, spinach, mushrooms, asparagus, cabbage, peppers and many other vegetables also supply more antioxidants, such as carotenoids and ferulic acid to the body when cooked than they do when raw. Remember some vegetables are extremely dificult for the body to digest (high in cellulose fibre for example) and although they are high in nutrients the body doesn't really get to absorb them unless they have been softened through cooking,a process which helps digestion.It's pointless to eat a high nutrient food if the body can't absorb the nutrients. Have in mind the human body is not designed to eat and digest anything and everything.

The key with cooking vegetables is how long they are cooked for, the quickest nutirent to be reduced, but not destroyed, is Vitaman C which is very unstable. However this is present in many different food products so it is not a nutrient that should worry anyone when it comes to cooking vegetables.

To give you an idea if you cook tomatoes on average heat for 2 minutes the Vitamin C content will reduce by 10% approximately. So it's not a huge loss. Whichever way you look at it the key to a healthy diet is balance and moderation. Olive Oil in it's 'Extra Virgin' format is undeniably healthier than any other fat out there.

Now, all fats have an effect on the body long term which is what that report set out to prove, not that olive oil wasn't a healthier option when chosing an oil for cooking or eating. Of course high calorie foods have their negative effects if abused and not used in moderation. But they also have beneficial effects if used in moderation and that has been scientifically proven too.

anthomo16 said:
31 October 2015 @ 10:42

I must admit that I always cook my cabbage in EVOO absolutely gorgeous wouldn't cook it any other way

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