Ultrasonic-Assisted Extraction and in vitro Antioxidant Activity Evaluation of Polysaccharides from Tartary Buckwheat

Objective: To explore the optimal ultrasonic-assisted extraction process of polysaccharides from tartary buckwheat using response surface methodology,and to determine in vitro antioxidant activity of polysaccharides from tartary buckwheat.Methods: The content of polysaccharides was determined by phenol-sulfuric assay,and optimal ultrasonic-assisted extraction process of polysaccharides from tartary buckwheat was investigated by Box-Behnken design based on single factor tests.Meanwhile,the in vitro antioxidant activity of tartary buckwheat polysaccharides was also studied.Results: Optimal ultrasonic-assisted extraction conditions were material-liquid ratio of 1:15.69(g/mL),extraction temperature of 61.05 ℃ and extraction duration of 65.5 min.Under the optimal extraction conditions,the extraction rate of polysaccharides was up to 4.41%.Tartary buckwheat polysaccharides showed potent scavenging activity against DPPH and hydroxyl radicals.Conclusion: The ultrasonic-assisted extraction method can shorten greatly the time required for extracting polysaccharides from tartary buckwheat and tartary buckwheat polysaccharides are a good source of natural antioxidants.