Extraction, degree of polymerization determination and prebiotic effect evaluation of inulin from Jerusalem artichoke

•We extracted inulin from different growth of Jerusalem artichoke within 90 days.•GFC method was employed to determine DP of the extracted inulin.•Inulin with lower DP is more effective on probiotics in the yogurt.•These data are instructive to get inulin with different properties. The tubers of Jerusalem artichoke are rich of inulin, which makes the plant one of primary inulin resources in China. The aim of this study was to extract inulin from tubers and test the degree of polymerization (DP) 10 days before flowering to 80 days after flowering. The DP of inulin reaches a maximum of 19 at 50 days after flowering. The variation tendencies of inulin content and DP were almost the same, which increase rapidly at the beginning and then decrease gradually at a lower speed. Meanwhile, the effects of inulin on probiotics in yogurt have been evaluated. It indicated that inulin with low DP has higher activities. Experimental data improve the understanding of status change of inulin in whole growth of Jerusalem artichoke tubers in Northeastern China and are instructive to get inulin with different properties.