Phenols and the antioxidant capacity of Mediterranean vegetables prepared with extra virgin olive oil using different domestic cooking techniques

Food Chem. 2015 Dec 1:188:430-8. doi: 10.1016/j.foodchem.2015.04.124. Epub 2015 Apr 28.


Potato, tomato, eggplant and pumpkin were deep fried, sautéed and boiled in Mediterranean extra virgin olive oil (EVOO), water, and a water/oil mixture (W/O). We determined the contents of fat, moisture, total phenols (TPC) and eighteen phenolic compounds, as well as antioxidant capacity in the raw vegetables and compared these with contents measured after cooking. Deep frying and sautéing led to increased fat contents and TPC, whereas both types of boiling (in water and W/O) reduced the same. The presence of EVOO in cooking increased the phenolics identified in the raw foods as oleuropein, pinoresinol, hydroxytyrosol and tyrosol, and the contents of vegetable phenolics such as chlorogenic acid and rutin. All the cooking methods conserved or increased the antioxidant capacity measured by DPPH, FRAP and ABTS. Multivariate analyses showed that each cooked vegetable developed specific phenolic and antioxidant activity profiles resulting from the characteristics of the raw vegetables and the cooking techniques.

Keywords: Antioxidant capacity; Chlorogenic acid; Domestic cooking; Extra virgin olive oil; Phenolics; Vegetable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / analysis*
  • Benzothiazoles / analysis
  • Chlorogenic Acid / analysis
  • Chromatography, High Pressure Liquid
  • Cluster Analysis
  • Cooking / methods*
  • Cucurbita / chemistry
  • Dietary Fats / analysis
  • Furans / analysis
  • Iridoid Glucosides
  • Iridoids / analysis
  • Lignans / analysis
  • Multivariate Analysis
  • Olive Oil*
  • Phenols / analysis*
  • Phenylethyl Alcohol / analogs & derivatives
  • Phenylethyl Alcohol / analysis
  • Rutin / analysis
  • Solanum lycopersicum / chemistry
  • Solanum melongena / chemistry
  • Solanum tuberosum / chemistry
  • Sulfonic Acids / analysis
  • Vegetables / chemistry*


  • Antioxidants
  • Benzothiazoles
  • Dietary Fats
  • Furans
  • Iridoid Glucosides
  • Iridoids
  • Lignans
  • Olive Oil
  • Phenols
  • Sulfonic Acids
  • 3,4-dihydroxyphenylethanol
  • 4-hydroxyphenylethanol
  • 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid
  • oleuropein
  • Chlorogenic Acid
  • Rutin
  • Phenylethyl Alcohol
  • pinoresinol