Epidemiological and clinical data are accumulating on the health-promoting properties of diets rich in fruits, vegetables and grains associated with the reduced risk for degenerative diseases. Health-promoting components present in fruits, vegetables and grains are important for wellness benefits. Amongst many food components, polyphenols have attracted a considerable interest in recent years due to their various functionality and physiological effects. This book covers the important areas of polyphenols from fundamental chemical composition and classification to potential disease prevention and food application. It also covers the typical case of quality and quantity analysis of polyphenols as well as their individual components present in fruits and vegetables with a broad spectrum from tropical fruits, apples, grapes, blueberries, teas, wines, traditional herbal medicines, to food processing by-products and other functional foods.