Identification and analysis of plant phenolic antioxidants

Food plants contain a range of nutrient and non-nutrient compounds with antioxidant properties. Principal among these compounds are flavonols and the cinnamic acid derivatives. These two groups exist in plant foods largely as conjugates with sugars or with organic acids; and typically, plant foods contain complex mixtures of these glycosides and conjugates. The analysis of such mixtures in foods is an important outstanding problem. The present paper outlines methods for the extraction and purification of phenolic antioxidants as the conjugated forms that exist in plant foods.