该文研究了以红薯叶为原料提取红薯叶不溶性膳食纤维（Insoluble Dietary Fiber，IDF），并采用物理粉碎法、酸法、碱-过氧化氢法、纤维素酶法对其进行改性，通过对改性处理后的样品进行表征分析及理化性质的变化的研究，探究不同改性处理对其微观形貌、化学结构、晶相结构及功能特性的影响。扫描电子显微镜（SEM）结果显示改性处理改变了红薯叶IDF的微观结构；傅里叶变换红外光谱（FT-IR）结果显示化学结构无明显变化；比表面积（BET）结果显示改性前后红薯叶IDF 比表面积有一定影响。X射线衍射（XRD）结果显示改性前后的特征衍射峰位置基本未发生改变。改性操作提高了不溶性膳食纤维的阳离子吸附能力（CEC）和负电荷吸附能力（TNC）分别提升0.31~2.86、0.75~2.88倍，以酸改性的SIDF3表现出最强的持水力（WHC）、膨胀力（SC）、葡萄糖吸附能力（GAC），相较于未改性的SIDF1分别提升了0.34、4.33、0.16~0.39倍；以酶改性的SIDF5的持油力（OHC）最强，相较于未改性的SIDF1提升了0.24倍。研究结果表明对红薯叶进行不同改性处理可以改变其性质和功能特性，为进一步应用红薯叶不溶性膳食纤维提供了基础。

Insoluble dietary fibers (IDFs) were extracted from sweet potato leaves and modified by physical crushing or using an acid, alkali-hydrogen peroxide, and cellulases. The modified samples were characterized, and changes in their physical and chemical properties were evaluated. The effects of different modification treatments on the micromorphology, chemical structure, crystal phase structure, and functional properties were investigated. Scanning electron microscopy showed that the microstructure of IDF in sweet potato leaves was altered by the different treatments. Fourier transform infrared spectroscopy suggested no obvious changes in the chemical structure. Additionally, the specific surface areas of IDFs in sweet potato leaves before and after modification varied. X-ray diffraction analysis indicated that the positions of characteristic diffraction peaks were mostly unchanged before and after modification. The cation exchange capacity and total negative charge of IDFs increased by 0.31~2.86- and 0.75~2.88-fold, respectively. Acid-modified SIDF3 showed the highest water-holding, swelling, and glucose adsorption capacities, which were 0.34, 4.33, and 0.16~0.39-fold higher than those of unmodified SIDF1, respectively. The oil-holding capacity of enzyme-modified SIDF5 was the highest, 0.24-fold higher than that of unmodified SIDF1. The results demonstrated that the properties and functional properties of sweet potato leaves can be altered by different modification treatments, providing a basis for further application of insoluble dietary fibers in sweet potato leaves.

国家重点研发计划项目（2016YFC0500307-07）