Antioxidant Dietary Fiber Product:  A New Concept and a Potential Food Ingredient

Abstract

The main characteristics of a natural product, antioxidant dietary fiber (ADF), rich in both dietary fiber (DF) and polyphenolic compounds (PP), obtained from red grape pomace is described. Both nonextractable proanthocyanidins (28.6%) and extractable polyphenols (2.0%) are associated with the dietary fiber matrix. The antioxidant capacity of this product was in vitro determined by lipid oxidation inhibition (LOI) and free radical scavenging (FRE) procedures. One gram of the product showed similar LOI and FRE effect than 400 mg and 100 mg of dl-(α-tocopherol, respectively. Extractable PP of grape ADF showed higher antioxidant capacity than red wine PP. The physiological and nutritional significance of ADF is discussed and the requirements of vegetable materials to be considered as ADF is proposed. Keywords: Antioxidants; dietary fiber; polyphenols; grape pomace; proanthocyanidins