Cooking vegetables in olive oil is a hallmark of the much-praised Mediterranean diet. To see how diﬀerent cooking methods aﬀect the antioxidant capacity of vegetables, Mexican researchers compared the antioxidant capacity in potatoes, tomatoes, eggplant, and pumpkin that were raw, deep fried in olive oil, sautéed in olive oil, or boiled. They found that the veggies deep fried in olive oil had the greatest total phenols, followed by the sautéed veggies, then the boiled veggies. The researchers suggest that “deep frying and sautéing conserve and enrich the phenolic composition.” That said, there is no “bad” way to eat vegetables. Rather, this research shows that if it takes a bit of olive oil to make vegetables most delicious to you, all the better.
Food Chemistry. 2015 Dec 1;188-430-8. (Ramirez-Anaya Jdel P et al).