Abstract: This paper used the garlic as the experimental material and adopted the technology of ultrasonicassisted extraction of garlic polysaccharide.On the basis of the result of single factor experiment and using the extraction of garlic polysaccharide as evaluation indicators,the orthogonal experiment was carried out to determine the optimal conditions of extraction of garlic polysaccharide.The results made clear that the optimal conditions by orthogonal test as following:The liquidsolid ratio of degreasing was 3:1;the ratio of material to water was 1:6,ultrasonic extraction temperature was 85 ℃;time of ultrasonic extraction was 45 min.According to the optimal congditions,the parallel experiment was carried out and the result showed that the average extraction of garlic polysaccharide was 24.9%,the average content of polysaccharide was 68.1%.

Key words: polysaccharide of garlic, ultrasonicassisted, orthogonal experimental design