Abstract:

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.

Key words: tartary buckwheat polysaccharides, process optimization, ultrasonic treatment, response surface, antioxidant activity