Cooking

Vegetables Fried in Extra Virgin Olive Oil More Nutritionally Beneficial than Boiled

Sep. 22, 2015
By Gaynor Selby

Recent News

A new study car­ried out by the University of Granada revealed that frying veg­eta­bles typ­i­cal to the Mediterranean diet in EVOO, as opposed to boil­ing, is a much better method of cook­ing in terms of nutri­ent value.

There has been much debate on the pros and cons of dif­fer­ent cook­ing meth­ods for veg­eta­bles and how cer­tain cook­ing 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 EVOO 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.
See more: The Health Benefits of Olive Oil
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 EVOO.

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.

Advertisement

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

“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,” said one of the authors of the work, Professor Cristina Samaniego Sanchez.

“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.”

Advertisement

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.

Advertisement

“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).