Effect of different cooking methods on the polyphenol concentration and antioxidant capacity of selected vegetables

The objective of this study was to evaluate the effect of different methods of cooking on the concentration of polyphenols and antioxidant capacity found in vegetables. Squash, broccoli, carrots, kale, cabbage, green beans, and tomato were submitted to different cooking methods and then compared with their fresh form. Heat treatment was shown to have a significant effect on the antioxidant capacity and soluble and hydrolysable polyphenolic content of most vegetables analyzed, either increasing or decreasing the concentration of these compounds. The results suggest that the best cooking method for increasing the concentration of polyphenols and antioxidants was steaming, while microwave cooking was the least recommended method.