Carrots have more antioxidants when cooked

NEW YORK, Aug 30 (Reuters Health) - While carrots are always a healthy food choice, recent findings suggest that cooking and mashing them up may increase their nutritional value.

According to a study presented at a recent meeting of the American Chemical Society, the level of antioxidants in carrots that were cooked and pureed was more than three-times higher than levels of the compound measured in raw carrots.

Antioxidants are compounds in food that prevent damage to cells caused by free radicals, natural byproducts of metabolism that can destroy the DNA of cells. Studies have shown that antioxidants may help prevent chronic diseases such as cancer and Alzheimer's disease.

"Many consumers think that fresh vegetables are always superior in nutritional quality than processed vegetables but this does not appear to be true for carrots," Luke Howard, the study's lead author, told Reuters Health.

He stressed that additional studies are needed to determine if antioxidants in processed carrots are well absorbed in the human body and can prevent free radical damage to human tissues.

The team of researchers with the University of Arkansas in Fayetteville heated carrots with and without the skin. They stored samples at 40 degrees Centigrade (104 degrees Fahrenheit) for 4 weeks, measured antioxidant levels and compared measurements with antioxidant levels in raw carrots.

Investigators used an antioxidant method that measures the ability of plant extracts containing phenolics, a type of antioxidant found in red wine and chocolate, to prevent oxidation of beta-carotene. When ingested, beta-carotene becomes the antioxidant vitamin A.

The findings, published in the Journal of Agricultural and Food Chemistry, show that antioxidant levels increased by more than 34% immediately after carrots were cooked. Howard explained that heating softened the carrot tissue and allowed phenolics attached to the cell wall to be released.

Levels of antioxidants continued to rise during the first week of storage and then began to fall after 2 weeks in storage. However, antioxidant levels of stored carrots remained higher than that of fresh raw carrots.

Howard explained that reactions that occurred during storage resulted in the formation of new phenolic compounds "with excellent antioxidant activity."

Keeping the outer skin on carrots also boosted antioxidant activity slightly, researchers found.

"Numerous phenolic compounds are located in the (skin) of fruits and vegetables, many of which are removed by peeling steps prior to processing," the study notes.