Frying vegetables in Extra Virgin Olive Oil (EVOO) enhances their antioxidant properties and releases a greater amount of phenolic compounds that protect against a range of diseases, says an article published in Food Chemistry magazine.
Researchers from the University of Granada (UGR) unveil how vegetables like potato, pumpkin, tomato, and eggplant can be cooked in such a way as to increase their phenolic fraction. They describe frying in EVOO as a cooking process that improves foods.
Their original aim was to evaluate the effects of different cooking methods on the antioxidant capacity and phenolic compound concentration in vegetables included in the Mediterranean diet which is known for its high consumption of greens, olive oil, and similar food items.
Using EVOO to fry the vegetables increases the amount of phenolic compounds that, in turn, prevent diseases like cancer, diabetes, and macular degeneration. It is to be noted that both vegetables and EVOO are important sources of dietary phenols. The kind of oxidants present in them can be changed (increased or decreased) as per the processing the foods are subjected to.
The experiment entailed cooking 120 grams cubes of potato, pumpkin, tomato, and eggplant without seeds and skin. These were fried and sautéed in EVOO, and were later boiled in water and EVOO. From the resulting food, the phenol content was measured using high-performance liquid chromatography (HPLC).
How is the phenol content increased? The researchers explain that phenols are transferred from EVOO to the veggies. The latter are enhanced with compounds that are otherwise exclusive to oil and thus not naturally present in them.
To conclude, the authors highlight their findings that frying and sautéing preserve and increase the phenolic composition, which compensates for the deficiencies in raw food. They recommend hydrothermal cooking methods when the cooking water is also consumed together with the food.