发芽对绿豆皮膳食纤维结构及性质的影响

为研究发芽对绿豆皮膳食纤维结构及功能性质的影响，采用X射线衍射分析、红外光谱分析和电子显微镜扫描等方法测定其结构，并对其持水力、持油力、膨胀力、阳离子交换能力、吸附葡萄糖能力、吸附胆固醇能力和吸附NO2 － 能力等功能性质进行对比研究。结果表明：发芽处理后绿豆皮中总膳食纤维含量增加3.40%，可溶性膳食纤维增加13.62%。发芽绿豆皮膳食纤维的持水力、持油力、膨胀力明显提高，分别达到（6.97±0.32）、（4.93±0.10） g/g、（4.79±0.11） mL/g，阳离子交换能力略有降低，为（0.47±0.02） mmol/g，吸附葡萄糖能力增加，为（8.37±0.18） mmol/g，吸附胆固醇能力增加，为（2.23±0.11） mg/（mL·g），吸附NO2 － 能力有所降低，为（3.92±0.09） mg/g。扫描电子显微镜结果表明，发芽可使绿豆皮膳食纤维表面出现更多孔隙和褶皱，有利于膳食纤维吸附能力的提高；X射线衍射结果表明，发芽没有改变绿豆皮膳食纤维的结晶度，较好地保留了膳食纤维的结晶区和非结晶区；傅里叶红外光谱分析表明，发芽没有破坏绿豆皮膳食纤维的官能团结构。绿豆经发芽处理后改善了绿豆皮膳食纤维的大部分功能性质，较好地保留了其结构，有利于绿豆副产物的开发利用。

Effect of Germination on the Structure and Properties of Dietary Fiber in Mung Bean Skin

This research was done to study the effect of germination on the structure and functional properties of skin dietaryfiber in mung bean. The structure of dietary fiber was determined by X-ray diffraction, scanning infrared spectroscopy andscanning electron microscopy. Functional properties such as water-holding capacity, oil-holding capacity, swelling capacity,cation exchange capacity, glucose adsorption capacity, cholesterol adsorption capacity and NO2 － adsorption capacity werecompared. The results showed that the content of total dietary fiber in mung bean skin increased by 3.40%, and soluble dietaryfiber increased by 13.62% after germination. Additionally, water-holding capacity, oil-holding capacity and swelling capacitysignificantly increased to (6.97 ± 0.32) g/g, (4.93 ± 0.10) g/g and (4.79 ± 0.11) mL/g, respectively. Cation exchange capacityslightly decreased to (0.47 ± 0.02) mmol/g. Glucose and cholesterol adsorption capacities rose to (8.37 ± 0.18) mmol/g,and (2.23 ± 0.11) mg/(mL·g), respectively. NO2 － adsorption capacity declined to (3.92 ± 0.09) mg/g. The results of scanningelectron microscope showed that the surface of dietary fiber in mung bean skin after germination showed more cavities andwrinkles, thereby improving its adsorption capacity. X-ray diffraction showed that the degree of crystallinity of dietary fiber inmung bean skin did not change after germination and the crystalline region and amorphous region were well reserved. Fouriertransform infrared spectroscopy analysis indicated that the functional groups of dietary fiber in mung bean skin were not destroyedafter germination. After germination, most functional properties of dietary fiber in mung bean skin were improved, and its structurewas well retained, which is conducive to the development and utilization of mung bean by-products.