盐碱滩涂菊芋菊糖的提取纯化及其聚合度分布

Extraction,Purification and Polymerization Degree Distribution of Inulin from Jerusalem artichoke Grown in Saline-alkaline Soil

对来自江苏盐城盐碱滩涂上生长的菊芋中菊糖的提取纯化与聚合度分布进行研究。经过菊芋成分分析可知,来自盐碱滩涂的菊芋灰分含量较高;通过考察不同提取条件,确定最优提取条件为90℃水浴、料液比(g/mL)1:15、提取时间40min、提取两次后提取率可达89.56%。与传统的磷酸-石灰乳法纯化相比,采用截留分子质量为10kD的有机膜可去除大分子蛋白质及果胶,蛋白质去除率及菊糖得率分别提高了27.12%和13.41%。采用不同截留分子质量的超滤膜对提取液中菊糖的聚合度分布进行分析,其聚合度主要分布在16～60之间,占总菊糖成分的76.1%。确定了活性炭脱色的最佳条件为活性炭用量5g/L、60℃脱色20min,脱色率达92.87%,菊糖得率91.63%。超滤纯化方法简便、快速,大大减少了纯化工序,便于工业化应用。

The extraction and purification of inulin from Jerusalem artichoke grown in the saline-alkaline soil of Yancheng,Jiangsu province.The ash content of the botanic material was higher than those previously reported in the literature for Jerusalem artichoke samples from Fujiang province and Gan county,Jiangxi province.Twice repeated extraction for 40 min each time at 90 ℃ with a 15-fold volume of water proved optimal,and the resulting extraction efficiency was 89.56%.Ultrafiltration membrane separation with10 kD MWCO membrane could more effectively remove macromolecular substances such as protein and pectin from the obtained inulin extract when compared with the conventional phosphate-lime milk method,and the removal rate of protein and the retention ratio of inulin were improved by 27.12% and 13.41%,respectively.Polymerization degree analysis of different MWCO（10000,5000,2500 D and 340 D） fractions of the inulin extract showed that the polymerization degrees of inulin were varied from 16 to 60,which accounted for 76.1% of the total inulins.The optimal decoloration conditions for the inulin extract were activated carbon dosage of 5 g/L,decoloration temperature of 60 ℃ and decoloration time of 20 min.Under these conditions,the decoloration efficiency and the recovery of inulin were 92.87% and 91.63%,respectively.Therefore,ultrafiltration can greatly reduce the separation procedure due to convenience and rapidity and fewer procedures,thus showing a very promising prospect for industrial applications.