Abstract: This research was done to study the effect of germination on the structure and functional properties of skin dietary
fiber in mung bean. The structure of dietary fiber was determined by X-ray diffraction, scanning infrared spectroscopy and
scanning 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 were
compared. The results showed that the content of total dietary fiber in mung bean skin increased by 3.40%, and soluble dietary
fiber increased by 13.62% after germination. Additionally, water-holding capacity, oil-holding capacity and swelling capacity
significantly increased to (6.97 ± 0.32) g/g, (4.93 ± 0.10) g/g and (4.79 ± 0.11) mL/g, respectively. Cation exchange capacity
slightly 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 scanning
electron microscope showed that the surface of dietary fiber in mung bean skin after germination showed more cavities and
wrinkles, thereby improving its adsorption capacity. X-ray diffraction showed that the degree of crystallinity of dietary fiber in
mung bean skin did not change after germination and the crystalline region and amorphous region were well reserved. Fourier
transform infrared spectroscopy analysis indicated that the functional groups of dietary fiber in mung bean skin were not destroyed
after germination. After germination, most functional properties of dietary fiber in mung bean skin were improved, and its structure
was well retained, which is conducive to the development and utilization of mung bean by-products.

Key words: germination, mung bean, dietary fiber, structure, properties