Abstract: Objective To determine the extraction process of oligosaccharides from Yacon by microwave-assisted extraction. Methods Microwave-assisted extraction was used to extract oligosaccharides from Yacon. The yield of oligosaccharides was used as the evaluation index,and extraction temperature, extraction time、liquid/solid ratio, microwave power, microwave time, analytical agent ratio as affecting factors, the optimal extraction process was determined by orthogonal experiments. Results The optimal extraction process was set as follows: extraction temperature 80℃, extraction time 60min, liquid/solid ratio 5:1, microwave power 700W, microwave time 180s, analytical agent ratio 7:1. Conclusion Under the optimum conditions, the average yield of oligosaccharides was 52.85%.

Key words: Yacon, oligosaccharides, microwave-assisted, extraction, orthogonal experiments