Researchers at the University of Murcia and the University of Complutense in Spain examined how various cooking methods affected antioxidant activity by analyzing six cooking methods with 20 vegetables. The six cooking methods were boiling, pressure-cooking, baking, microwaving, griddling and frying. Their findings showed the following:
• The highest antioxidant loss was observed in cauliflower after boiling and microwaving, peas after boiling, and zucchini after boiling and frying.
• Green beans, beets, and garlic were found to keep their antioxidant levels after most cooking treatments.
• The vegetables that increased their antioxidant levels after all cooking methods were green beans (except green beans after boiling), celery and carrots.
• Artichoke was the only vegetable that kept its high antioxidant level during all the cooking methods.
Griddle- and microwave-cooking helped maintain the highest levels of antioxidants, produced the lowest losses while “pressure-cooking and boiling [led] to the greatest losses,” says lead researcher A. M. Jiménez-Monreal. “In short, water is not the cook’s best friend when it comes to preparing vegetables.”" (FP)