Abstract:

Water soluble dietary fiber (SDF) is one of the main functional components in peanut hull. In order to obtain this component, one-stage, two-stage and three-stage extraction using citric acid alone, microwave-assisted extraction and ultrasonic extraction were adopted and their effectiveness was comprehensively assessed in terms of two indicators, including SDF extraction yield and non-starch polysaccharide (NSP) content in SDF. Results showed that among these extractions, three-stage extraction presented the highest SDF extraction yield and the largest weighed score of the above indicators, and obtained using microwave-assisted extraction exhibited the highest NSP content in SDF. In addition, SDF was found to have significant radical scavenging capacity against hydroxyl, superoxide anion and DPPH free radicals and excellent ferric-reducing power and molybdenum- reducing power.

Key words: peanut hull, water soluble dietary fiber, extraction, antioxidant activity