Antioxidant content higher in organic tomatoes
July 19, 2007
by Keith Nunes
DAVIS, CALIF. — A decade-long study evaluating organic versus conventionally grown tomatoes revealed antioxidant differences between the two farming systems. The study, published in the Journal of Agricultural and Food Chemistry and conducted by the University of California-Davis’ (U.C.D.) Long-Term Research on Agricultural Systems (L.T.R.A.S.) project, analyzed tomato samples collected from 1994 to 2004 and found that the organic tomatoes had higher amounts of some flavonoids.
"The results of our study are intriguing, and warrant a closer look at the agricultural systems used across the United States," said Dr. Alyson Mitchell, professor and food chemist in the Department of Food Science and Technology at U.C.D. "Additional well-controlled studies like L.T.R.A.S. will provide a much deeper understanding of the differences between organic and conventional crops."
In the study, the conventional tomatoes were grown using fertilizers and other standard irrigation and farming practices while the organic plots used crop rotation, manure and sustainable farming practices. Over time, the organic tomatoes had increasingly higher amounts of three flavonoids: quercetin, naringenin and kaempferol. The flavonoid levels did not vary significantly in the conventionally grown tomatoes.