Comparison of ultrasonic-assisted and microwave-assisted extraction of oligosaccharides from high denatured soybean meal

High denatured soybean meal was used as material to extract oligosaccharides by ultrasonic and microwave extraction.Based on the single experimental results,the orthogonal experiment was designed to obtain optimized technology for extracting oligosaccharides from high denatured soybean meal and HPLC was used to determine the composition of functional oligosaccharides.The results showed that the optimum conditions to extract soy oligosaccharides by ultrasonic extraction were: pH 9.5,solid-liquid ratio of 1∶15,70 ℃,the power of 302 W,25 kHz,30 min.Under these conditions,the yield of soy oligosaccharides was 12.03%,the content of functional soy oligosaccharides was 49.04%.The optimum conditions to extract soy oligosaccharides by microwave extraction were: pH 9.0,the liquid-solid ratio of 1∶15,600 W,30 min.Under these conditions,the yield of soy oligosaccharides was 12.56%,the content of functional soy oligosaccharides was 38.49%.Microwave extraction is still the preferred method for extracting oligosaccharides.