During the last decade, their curiosity has introduced us to a whole new language of phytonutrients, the beneficial compounds in plant foods. At the forefront of this inquiry are chemists in ARS's Food Composition Laboratory at Beltsville, Maryland. Their collaboration with a sister laboratory has resulted in two phytonutrient databases. Until now, he says, chemists have had to tailor their flavonoid analyses to different types of foods. He expects the new system will be adopted by university scientists and commercial laboratories.
Western diets provide from several milligrams to a gram of flavonoids each day.
The list of their health-giving properties is lengthy and growing. He says several methods exist for identifying and measuring one or two, maybe even three, of the subclasses. But mixed diets contain flavonoids from all five subclasses. Most of the food flavonoids have glucose or some other sugar attached. The system Merken developed with Beecher finds and separates the 18 most common food flavonoids, representing all 5 subclasses.