ABSTRACT
Historically, the terms phenolics, vegetable tannins, and plant polyphenols have been used in unclear and confusing ways. An overview of phenolics definitions, types, properties, and research status is presented in this chapter. Polyphenols have the ability to scavenge free radical species; such antioxidant activity has been underlined as one of the essential molecular stabilizing actions to prevent or retard degenerative and age-related diseases. However, many polyphenol properties can be explained by mechanisms of interaction with proteins and their consequent changes in structural, functional, and nutritional properties of the components. These actions include the inhibition of biologically important enzymes. Accordingly, phenolics are the most investigated group of secondary metabolites so far.
