中文摘要：

采用Aspergillus ficuum内切型菊粉酶Endo-Ⅰ酶解商品菊粉制备低聚果糖,经正交试验确定其最适酶解条件为：pH5.0、温度45℃、底物浓度50g/L、加酶量10U/g,在此酶解条件下,低聚果糖得率可达70.37%,酶解产物以DP3和DP4为主,同时含有一定量的DP2、DP5、DP6、DP7、DP8;在此条件下酶解自制菊芋干粉时,低聚果糖得率为41.72%,酶解产物以DP3～DP6的低聚果糖为主,DP2含量很少,同时酶解液中还含有大量的果糖;在此条件下酶解自制菊芋提取液时,低聚果糖得率高达79.80%,酶解产物中除DP6含量较低外,其他各聚合度的低聚糖分布比较平均。在此相同酶解条件下酶解72h时,3种底物中,以菊芋提取液酶解后的低聚果糖得率最高。因此,应用Aspergillus ficuum内切型菊粉酶Endo-Ⅰ酶解菊芋制备低聚果糖宜选择菊芋提取液作底物。

英文摘要：

Purified endoinulinase from AspergiUusficuum was used for inulo-oligosaccharides production at the optimal condition obtained with orthogonal experiments, including pH 5.0, 45℃, 50 g/L inulin, and enzyme concentration of 10 U/g substrate. With pure inulin as substrate, the inulin-hydrolyzing degree was up to 75% and the total inulo-oligosaccharides yield was 70.37% after 72 h. The hydrolysis products consisted of DP2 to DP8 determined by HPLC, DP3 and DP4 exhibited a relatively high content. With Jerusalem artichoke powder as substrate, the inulin-degrading extent was 62.38% and the inulo- oligosaccharides yield was 41.72% after 72 h. DP3 to DP6 were liberated as the main products with a great amount of fructose in the reaction mixtures. With Jerusalem artichoke juice as substrate, the inulin-hydrolyzing extent reached 89% and the maximum inulo-oligosaccharides production was up to 79.80% after 72 h. Various inulo-oligosaccharides with different DPs （mainly DP2, DP3, DP4, DP5, DP7, DP8） were evenly distributed in final reaction products. Therefore, the juice was the most suitable for inulo-oligosaccharides production by A. ficuum endo-inulinase.