菊芋粕菊粉的酶法提取、组成及抗氧化活性研究

本研究拟应用酶法提取技术解决菊芋菊粉工业化生产中的废弃物——菊芋粕再利用程度低的问题,并评价菊芋粕菊粉的抗氧化活性功效。对菊芋粕菊粉的果胶酶酶法提取的最佳条件通过响应面法进行了优化,并对菊芋初次水提菊粉(primary water-extracted inulin,PWI)和二次酶提菊粉(secondary enzymatic-extracted inulin,SEI)的组成成分和抗氧化活性进行了比较分析。响应面法优化确定的菊芋粕菊粉最佳酶法提取条件为:pH4.5、提取温度50 ℃、酶底比7.5 U/g、提取时间2 h,该提取方法所得菊芋粕菊粉的得率为35.30%±0.85%,与传统热水浸提法相比菊粉得率提高38.16%。组成分析结果显示,SEI的总糖和菊粉含量均显著高于PWI( P <0.05)。在菊粉聚合度方面,PWI中蔗果三糖和蔗果四糖含量较高,而SEI中蔗果五糖、蔗果六糖及其以上聚合度菊粉的含量较高。此外,SEI的抗氧化活性优于PWI。因此,果胶酶辅助提取方法有望为菊芋粕菊粉的再利用难题提供新的解决思路。

Enzymatic extraction of inulin from Jerusalem artichoke pulp and its composition and antioxidant activity analysis

In this study,we applied enzymatic extraction technology to solve the problem of low recycling of Jerusalem artichoke pulp,which comes from waste in the industrial production of Jerusalem artichoke inulin,and then evaluated the antioxidant activity of inulin from Jerusalem artichoke pulp.The enzymatic extraction process was optimized by using response surface methodology,and the optimum parameters were as follows:pH4.5,extraction temperature 50 ℃,pectinase-substrate ratio 7.5 U/g,extracting time2 h.The yield inulin from Jerusalem artichoke pulp was35.30%±0.85% by using optimized enzymatic extraction process,which is38.16% higher than that by traditional hot water extraction.Subsequently,we comparatively analyzed the chemical composition and antioxidant activity of primary water-extracted inulin (PWI) and secondary enzymatic-extracted inulin (SEI).The results showed that the total sugar and inulin contents of SEI were significantly higher than those of PWI ( P < 0.05).Compared with PWI,SEI contained more inulin with six and higher polymerization,but less sugarcane trisaccharide and sugarcane tetrasaccharide.Furthermore,the antioxidant activity of SEI was superior to PWI,according to the total antioxidant capacity,DPPH,hydroxyl and superoxide anionradicals scavenging activity,Fe2+-chelating ability and reducing power assays.Therefore,pectinase-enzymatic extraction method has the potential to be a new solution for the problem on reutilization of inulin of Jerusalem artichoke pulp in the inulin industry.