• 营养卫生 •

### 小米硒化水溶性膳食纤维的抗氧化活性及对小鼠肠道菌群产色氨酸能力的影响

1. （1.黑龙江八一农垦大学食品学院，黑龙江 大庆 163319；2.国家杂粮工程技术研究中心，黑龙江 大庆 163319）
• 出版日期:2021-06-15 发布日期:2021-06-29
• 基金资助:
“十三五”国家重点研发计划重点专项（2018YFE0206300）；黑龙江省优势特色学科资助项目（[2018]No.4号）； 黑龙江省杂粮现代农业产业技术协同创新推广体系“品质改良与深加工”岗位； 教育部粮食副产物加工与利用工程技术研究中心建设项目

### Antioxidant Activity of Selenium-Modified Soluble Dietary Fiber from Millet and Its Effect on the Tryptophan-Producing Capability of Mouse Intestinal Flora

WANG Juan, CAO Longkui, WEI Chunhong , WANG Weihao, ZHAO Shuting, LIU Dezhi, QUAN Zhigang, WANG Yifei, WU Yunjiao, SU Youtao, ZHANG Dongjie

1. (1. College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China;2. National Coarse Cereals Engineering Research Center, Daqing 163319, China)
• Online:2021-06-15 Published:2021-06-29

Abstract: The present study was undertaken with two aims: 1) to determine the optimal preparation process for selenium-modified soluble dietary fiber from millet and 2) to explore the influence of selenium modification on the structure and antioxidant activity of millet water-soluble dietary fiber (SDF) and on its effect on the ability of intestinal flora to produce tryptophan. SDF was modified by a nitric acid-sodium selenite method, and the selenization conditions were optimized by the Taguchi method. The molecular mass, particle morphology, functional groups and crystallinity of the native and modified SDF were determined by gel permeation chromatography (GPC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy and X-ray diffraction. In addition, their antioxidant activity was compared with each other, and the change of the tryptophan content in the culture broth of mouse intestinal microbes utilizing Se-SDF as a carbon source was analyzed. The results showed that the optimal conditions of modification were as follows: reaction temperature of 40 ℃, reaction time of 6 h, 3 mL of 5 mg/mL Na2SeO3, and 0.65 g of BaCl2. Under these conditions, the yield of Se-SDF was 10.56% with a selenium content of 2.69 mg/g. The relative molecular mass of the Se-SDF was increased compared with the native SDF, and the surface showed a porous honeycomb-like structure with large pore size. The degree of polymerization was reduced relative to that of the native SDF, and functional groups such as Se=O, Se–OH and Se–O–C were appeared in the Se-SDF. Despite no obvious change in the crystal structure, the crystallinity of SDF was decreased after the modification. The hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and total antioxidant capacity of SDF as well as its promoting effect on the tryptophan-producing capability of the mouse intestinal flora were enhanced after the modification. In summary, the Se-SDF prepared using the optimized process can be used to produce dietary selenium and tryptophan supplements.