Abstract: In the experiment, inulin was prepared from burdock root by microwave-assisted hot water extraction. The extraction rate of inulin by microwave-assisted extraction and traditional water extraction were 58.18% and 50.19% respectively. Single factor analysis of a number of major factors to choose ratio of solid to liquid,microwave extraction,water extraction temperature,water extraction time four factors as the rate of extraction to determine their conditions. The results showed that the orthogonal factors affecting ranking : water extraction time>microwave extraction time>water extraction temperature>ratio of solid to liquid. In hot water extraction, microwave extraction and water extraction, temperature is a major factor. The best combination of factors of the inulin extracting were ratio of solid to liquid 1:30. Microwave extracting 240 s, water extracting temperature 70 ℃ and extracting time 1.5 h, under which the extraction ratio of inulin was 91.40%. Inulinis white or yellow floc solid, easy to moisture, easy caking, blended, odorless, easily soluble in water, good thermal stability.

Key words: burdock root, inulin, microwave-assisted hot water extraction, optimization