负载硒蛋白果胶微凝胶的制备、 结构表征及体外消化特性研究

为了提高植物硒蛋白的使用稳定性并有效用于富硒食品的开发,本研究以商品化柑橘果胶为壁材,CaCl₂为固化剂,一步凝聚构建负载硒蛋白果胶微凝胶。以硒蛋白包埋率为参考指标,结合单因素和正交试验确定硒蛋白果胶微凝胶的最佳制备工艺。采用扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)和热重分析仪(TGA)对微凝胶的微观形态、分子结构以及热稳定性进行表征,并通过体外模拟试验研究其消化特性。结果表明,硒蛋白果胶微凝胶的最佳制备工艺为果胶浓度5%(w/v),CaCl₂浓度为2%(w/v),包埋操作温度30 ℃,此时其包埋率为66.3%±1.64%;对硒蛋白果胶微凝胶的表征结果证实了果胶微凝胶能有效且紧实完整包裹硒蛋白,并提高其热稳定性能;体外释放试验显示,模拟胃液体系中硒蛋白的释放量仅为6.1%,而模拟肠液体系中9 h后累计释放73.6%,证明了果胶微凝胶结构能较好的保护目标蛋白、提高缓释效果。本研究相关结论可期为植物硒蛋白的高值化利用以及富有机硒食品的开发提供新思路。

Preparation,Structure Characterization and in Vitro Digestibility of Selenoprotein Rich Pectin Microgel

The purpose of work was to improve the usability of plant-derived selenoprotein and develop selenium-rich foods. In this work,the selenoprotein pectin microgel was constructed by one-step polymerization process using commercial citrus pectin and CaCl₂ as wall material and curing agent,respectively. The best preparation conditions of the selenoprotein pectin microgel were found by single factor tests and orthogonal test using selenoprotein embedding rate as reference. The microscopic morphology,molecular structure,and thermal stability of the selenoprotein microgels were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analyzer(TGA). The simulation experiment in vitro were performed to study its digestive properties. Results showed that,the optimized preparing condition for the selenoprotein pectin microgel wtih the selenoprotein embedding rate 66.3%±1.64% was:Pectin concentration 5%(w/v),CaCl₂ concentration 2%(w/v),and operation temperature 30 ℃. The pectin microgel could effectively and tightly encapsulate the selenoprotein and improve its thermal stability. The sustained release of the prepared selenoprotein pectin microgel in mimic gastric and intestinal environments was observed. It showed that the release rate of the selenoprotein in the gastric juice system was only 6.1%,while the cumulative release rate in the intestinal system after 9 hours was 73.6%. The result indicated that the microgel structure could better protect the target protein and control the release rate. The relevant conclusions would provide a new idea for the high-value utilization of plant-derived selenoprotein and the development of selenium-rich foods.