茴香及其秸秆膳食纤维的组成成分、结构与物化功能特性

Chemical Composition, Structure, Physicochemical and Functional Properties of Dietary Fiber Obtained from Fenneland Its Straw

目的：明确茴香及其秸秆膳食纤维的组成成分、结构、物化及功能特性。方法：采用剪切乳化辅助酶解法提取茴香及其秸秆膳食纤维,通过AOAC法、离子色谱、X-射线衍射、扫描电子显微镜、傅里叶红外光谱分析其组成成分及结构,并对其保水能力、吸水膨胀性、持油能力以及葡萄糖吸收能力、α-淀粉酶活性抑制能力和胆汁酸阻滞指数等进行测定。结果：茴香及其秸秆膳食纤维的纯度分别为84.76%和78.73%,均由纤维素、半纤维素、果胶和木质素构成,并含有鼠李糖、阿拉伯糖、半乳糖、葡萄糖和木糖;茴香膳食纤维具有多孔网状结构,而秸秆膳食纤维呈块状,均有纤维素晶区和特征基团;茴香秸秆膳食纤维的保水能力、吸水膨胀性和持油能力（6.91 g/g,6.77 m L/g和6.99 g/g）优于茴香膳食纤维（5.91 g/g,5.70 m L/g和6.47 g/g）,而茴香膳食纤维的葡萄糖吸收能力、α-淀粉酶活性抑制能力和胆汁酸阻滞指数（18.23%,3.05-34.58 mmol/g和32.94%~34.65%）显著高于茴香秸秆膳食纤维（13.49%,1.39~15.63 mmol/g和13.12%~23.44%）。结论：茴香及其秸秆膳食纤维均具有稳定的结构,良好的物化特性及功能特性,可作为一种新型的膳食纤维产品进行开发利用。

Objective： To investigate the chemical composition, structure, physicochemical and functional properties of dietary fiber obtained from fennel and its straw. Method： The AOAC methods, ion chromatography, X-ray diffraction（XRD）, scanning electron microscope（SEM） and Fourier Transform Infrared Spectroscopy（FTIR） were used to determine the chemical composition and structure of fennel dietary fiber and fennel straw dietary fiber which were obtained by shear emulsifying assisted enzymatic hydrolysis, the water retention capacity, water swelling capacity, oil holding capacity, glucose adsorbtion capacity, α-amylase inhibitory activity and bile acid retardation index were also tested to evaluate the physicochemical and functional properties of the two dietary fibers. Results： The purity of dietary fiber of fennel and its straw were 84.76% and 78.73%, respectively. Cellulose, hemicelluloses, pectin, lignin and five neutral sugars, viz.rhamnose, arabinose, galactose, glucose and xylose were also existed in the above two dietary fibers. Fennel dietary fiber exhibited porous network structure while fennel straw dietary fiber had a plate structure.In addition, cellulose crystal area and characteristic group were observed in both two dietary fibers. Furthermore, the fennel straw dietary fiber exhibited higher water retention capacity, water swelling capacity and oil holding capacity（6.91 g/g, 6.77 m L/g, and 6.99 g/g） than fennel dietary fiber（5.91 g/g, 5.70 m L/g, and 6.47 g/g）, while fennel dietary fiber had a higherglucose adsorbtion capacity, α-amylase inhibitory activity and bile acid retardation index（18.23%, 3.05-34.58 mmol/g, and 32.94-34.65%） than fennel straw dietary fiber（13.49%, 1.39-15.63 mmol/g, and 13.12-23.44%）. Conclusion： Dietary fiber of fennel and its strawhave stable structure, better physicochemical and functional properties, indicating that they have great potentialfor utilization in food industry as new types ofdietary fibers.