• 基础研究 •

### 磁性Fe3O4/壳聚糖复合微球的制备及其对苹果汁有机酸的吸附

1. （1.西北农林科技大学食品科学与工程学院，陕西 杨凌 712100；2.农业农村部农产品质量安全风险评估实验室（杨凌），陕西 杨凌 712100；3.国家杨凌农业综合试验工程技术研究中心，陕西 杨凌 712100）
• 出版日期:2020-05-15 发布日期:2020-05-15
• 基金资助:
国家自然科学基金面上项目（31371814）；“十三五”国家重点研发计划重点专项（2017YFD0400702）

### Preparation and Adsorption Properties of Magnetic Fe3O4/Chitosan Microspheres for Separation of Organic Acids from Apple Juice

JIANG Feihong, LEI Huanqing, REN Tingting, MENG Diaoqin, YUE Tianli,

1. (1. College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China; 2. Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture and Rural Affairs, Yangling 712100, China; 3. National Engineering Research Center of Agriculture Integration Test (Yangling), Yangling 712100, China)
• Online:2020-05-15 Published:2020-05-15

Abstract: The aim of this study was to provide an efficient method for the separation of organic acids from apple juice. Magnetic Fe3O4/chitosan microspheres were prepared by inverse suspension cross-linking method and were characterized by a scanning electron microscope, a laser particle size analyzer, a Fourier transform infrared spectrometer, a thermal gravimetric analyzer, an X-ray diffractometer, and a superconducting quantum magnetic measurement system. Also, the recovery rates of the magnetic Fe3O4/chitosan composite microspheres and pure Fe3O4 microspheres were determined as a function of time (0-5 min) and pH (pH 2-11) under a certain magnetic field intensity. Then, the composite microspheres were used to adsorb and desorb organic acids from apple juice for three times. The composite microspheres owned a narrow size distribution ranging from 22 to 158 μm, had good dispersity and were regularly spherical in shape. The X-ray diffraction (XRD) patterns indicated that chitosan coating procedure did not change the spinal structure of magnetic Fe3O4 nanoparticles. Fourier transform infrared and thermogravimetric analyses demonstrated that chitosan was coated on Fe3O4 nanoparticles successfully and Fe3O4 was accounted for about 38.66% of the composite microspheres. The saturated magnetization of the composite microspheres was 35.98 emu/g. The microspheres showed a high recoverability of 99.99% in 2 minutes, obviously higher than that of pure Fe3O4 nanoparticles. After three cycles of adsorption and desorption, the equilibrium adsorption capacity was still as high as 109.92 mg/g and the recovery rate of organic acids was 86.86%. These results showed that the magnetic Fe3O4/chitosan composite microspheres had good magnetic response and good recoverability and could be repeatedly used to efficiently separate organic acid from apple juice as an environmental friendly adsorbent.