Fresh Ideas from ARS Nutrition Research

Today, salads are more nutritious than ever before, thanks in part to research conducted by the Agricultural Research Service (ARS), the U.S. Department of Agriculture's chief scientific research agency.

Iceberg lettuce is the foundation for many garden salads, and ARS plant breeders in Salinas, Calif., have developed an experimental technique to boost its nutritional value. Scientists in the agency's Crop Improvement and Protection Research Unit in Salinas pried open the leaves of iceberg lettuces as they grew, preventing the formation of tightly closed heads.

With more surface exposed to sunlight, the lettuces accumulated twice as much iron and calcium and five times as much vitamin C as typical icebergs. Now the researchers are determining how to help developing plants store these nutrients without changing the features that have made iceberg America's favorite lettuce.

Everyone knows that carrot sticks are more nutritious than carrot cakes, but fewer people know that they're also more nutritious than the carrots that were eaten 30 years ago. That's because ARS scientists discovered a way to breed carrots with high amounts of beta-carotene, an orange pigment that helps humans make vitamin A. In fact, modern carrots have nearly 50 percent more beta-carotene than their predecessors.

Scientists in the ARS Vegetable Crops Research Unit in Madison, Wis., helped raise beta-carotene levels in carrots, and are now working to produce the same results in cucumbers and melons. The same researchers are also using classical breeding methods to raise levels of heart-healthy compounds in onions and garlic.

ARS scientists with the Genetic Improvement of Fruits and Vegetables Laboratory, part of the Henry A. Wallace Beltsville Agricultural Research Center in Beltsville, Md., developed tomato breeding lines to produce cherry tomatoes with enhanced beta-carotene content. And colleagues at the ARS Western Regional Research Center in Albany, Calif., have been seeking genes that cue tomatoes to produce another nutritious pigment: lycopene.

Read more about this research in the March 2008 issue of Agricultural Research magazine.