Study on Ultrasonic Wave-assisted Alkali Extraction of Polysaccharides from Peanut Meal

Ultrasonic wave was applied for extraction of polysaccharides from peanut meal with alkali solution. Effects of ultrasonic temperature,ultrasonic power,ultrasonic time,alkali concentration and material-liquid ratio on extraction yield of polysaccharides were investigated,and the extraction process conditions were optimized by respond surface design. Yield of peanut polysaccharides by ultrasonic wave-assisted alkali extraction was compared with that by hot alkali extraction. And by scanning electron microscopy(SEM) observation,difference of dissolution way of polysaccharides from cells by hot water extraction,ultrasonic wave-assisted alkali extraction and ultrasonic wave-assisted water extraction were analyzed. Results showed that the optimum technological conditions are ultrasonic temperature 73 ℃,power 70 W,time 18.65 min,alkali concentration 2.12 mol/L and material-liquid ratio 1:20. Under these conditions,the yield of polysaccharides is 13.78%,increased by 4% compared with hot alkali extraction.