Optimization of extracting water insoluble dietary fiber from buckwheat shell

[Objective]Using chemical extraction, optimal technological parameters for water insoluble dietary fiber were determined to provide references for rationally utilization of buckwheat shell resources. [Method]Water insoluble dietary fiber was extracted from buckwheat shell by chemical extraction method. Effects of liquid-solid ratio, reaction time and temperature, and NaOH concentration on extraction rate of water insoluble dietary fiber were studied and the extraction technology was optimized using an orthogonal experiment. [Result]The sequence of affecting extraction rate was like this: NaOH concentrationreaction time and temperatureliquid-solid ratio. The optimal technological parameters for chemical extraction of water insoluble dietary fiber were as follows: liquid-solid ratio 1.0 ∶15.5, reaction time of 60 min, reaction temperature 45℃, NaOH concentration 4%. [Conclusion]Under above-mentioned optimal extraction conditions, the water insoluble dietary fiber extracted from buckwheat shell was toast tan with water-holding capacity of 300.25 g/g and expansibility of 5.57 mL/g , which could be used as food additives.