Writing in the latest issue of the Journal of Agriculture and Food Chemistry (April 17), Rui Hai Liu, M.D., Cornell assistant professor of food science, notes, "This research demonstrates that heat processing actually enhanced the nutritional value of tomatoes by increasing the lycopene content -- a phytochemical that makes tomatoes red -- that can be absorbed by the body, as well as the total antioxidant activity. The research dispels the popular notion that processed fruits and vegetables have lower nutritional value than fresh produce."
Tomato samples were heated to 88 degrees Celsius (190.4 degrees Fahrenheit) for two minutes, a quarter-hour and a half-hour. Consistent with previous studies, vitamin C content decreased by 10, 15 and 29 percent, respectively, when compared to raw, uncooked tomatoes. However, the research revealed that the beneficial trans-lycopene content of the cooked tomatoes increased by 54, 171 and 164 percent, respectively. Levels of cis -lycopene (which the body easily absorbs) rose by 6, 17 and 35 percent, respectively; and antioxidant levels in the heated tomatoes increased by 28, 34 and 62 percent, respectively. Antioxidants protect the human body from cell and tissue damage, which occurs when harmful molecules called free radicals, released as oxygen, are metabolized by the body.
Lycopene, a carotenoid responsible for the red color in tomatoes and other fruits, has long been known as a powerful antioxidant that decreases cancer and heart-disease risk. Carotenoids, along with phenolic acids and flavonoids, are all phytochemicals, the nutritionally beneficial ac
Contact: Blaine P. Friedlander Jr.
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