Optimization of Extracting Process of Soluble β-glucan from Purple Wheat Bran by Response Surface Methodology

The purple wheat bran as raw material and dilute alkalis as solvent,the soluble β-glucan was extracted by ultrasonic wave assisted extraction.The preparation of soluble β-glucan were optimized by Response Surface Methodology(RSM) based on Box-Behnken design.The results showed that the main affecting factors ranked in sequence of NaOH concentration,solid-to-liquid ratio,ultrasonic wave power,extraction temperature,and extraction time.The optimum conditions were that NaOH concentration was 4.5%,ultrasonic wave power was 400 W,extraction temperature was 50℃,extraction time was 1.5h,and solid-to-liquid ratio was 23∶ 1.Under the optimum conditions,the actual measured yield of polysaccharides was 1.95%.