固载β-CD磁性材料脱除蛋黄胆固醇的研究

发布时间：2018-10-19 11:22

【摘要】：功能性磁性纳米材料由于其粒径小,易定位,在磁场条件下能快速分离等特点,而被广泛应用于食品、环境和化工等领域,对目标分子进行分离与提取。固载β-CD磁性材料(Fe_3O_4@cyclodextrin)即在磁性颗粒表面包覆β-环糊精(β-CD),该材料既保留β-CD对疏水性物质良好的包覆功能,又具有磁性颗粒独特的优势。相较于传统的β-CD粉末包埋法,将此功能性材料应用于脱除蛋黄胆固醇的过程中,β-CD不易残留于蛋黄体系,材料易较快与目标分子结合,且在磁场条件下能将磁性材料快速从蛋黄体系中分离,应用安全性高。本论文中利用壳聚糖作为中间体,在交联剂己二酸二异腈脂(HMDI)和催化剂辛酸亚锡的作用下制备得Fe_3O_4@cyclodextrin磁性材料。研究制备Fe_3O_4@cyclodextrin磁性材料过程中影响β-CD固载量的因素,优化Fe_3O_4@cyclodextrin磁性材料的制备条件。实验所得磁性材料的较佳制备条件为:反应体系温度为60℃,搅拌速度为700 r/min,反应体系中β-CD与Fe_3O_4@chitosan-HMDI磁性材料的质量比为3:1。对Fe_3O_4@cyclodextrin磁性材料的基团结构、颗粒粒径、分散性、磁含量等进行表征。本论文所设计的Fe_3O_4@cyclodextrin磁性材料制备工艺简便,制备的材料在乙醇/水体系中具有良好的分散性,平均粒径为232 nm,磁含量为64.2%,具有工业化的可操作性和应用性。Fe_3O_4@cyclodextrin磁性材料应用于胆固醇标准溶液中,研究其对胆固醇分子的吸附性;采用pseudo一级、二级模型来描述Fe_3O_4@cyclodextrin吸附胆固醇的静态动力学过程。结果显示:在胆固醇标准溶液中,pH=3.0,25℃条件下,Fe_3O_4@cyclodextrin磁性材料吸附胆固醇的平衡时间为45 min,胆固醇吸附载量为210 mg/g。胆固醇吸附过程符合pseudo二级动力学方程。研究Fe_3O_4@cyclodextrin磁性材料对蛋黄胆固醇的脱除性能,探究材料添加量、温度、稀释度、蛋黄体系pH值、磷脂酶酶解预处理等条件对蛋黄胆固醇脱除率的影响,并探究这些影响产生的内在原因。优化脱除蛋黄胆固醇的工艺条件,得到较佳的条件为:Fe_3O_4@cyclodextrin磁性材料的添加量为蛋黄液质量的10%,脱除时间80 min,蛋黄原液与水的比例为1:10(w/v),磷脂酶A2酶解预处理蛋黄液40 min,pH值调节至3.0或9.0。在上述条件下,蛋黄胆固醇脱除率为58%,且优化所得工艺条件利于蛋黄液的后续应用。研究Fe_3O_4@cyclodextrin磁性材料作用于蛋黄液后,蛋黄蛋白含量、磷脂含量、蛋黄乳化性的变化。当胆固醇脱除率为42%时,蛋黄蛋白损失率为7.6%,蛋黄卵磷脂损失率为10.1%。胆固醇从蛋黄体系中的分离会引起部分蛋黄蛋白的结构变化,影响蛋黄的乳化特性。Fe_3O_4@cyclodextrin磁性材料具有良好的重复使用性,在重复循环吸附-洗脱过程15次后,对胆固醇的最大吸附载量仍能维持在200 mg/g以上,回收率为95%。
[Abstract]:Functional magnetic nanomaterials are widely used in the fields of food, environment and chemical industry because of their small particle size, easy location and rapid separation in magnetic field. The immobilized 尾-CD magnetic material (Fe_3O_4@cyclodextrin) is coated with 尾-cyclodextrin (尾-CD),) on the surface of magnetic particles. The material not only retains the good encapsulation function of 尾-CD to hydrophobic substances, but also has the unique advantages of magnetic particles. Compared with the traditional 尾-CD powder embedding method, the functional material was used in the removal of yolk cholesterol, 尾-CD was not easy to remain in the yolk system, and the material was easy to bind to the target molecule quickly. The magnetic material can be quickly separated from the yolk system under the condition of magnetic field. In this paper, chitosan was used as intermediate to prepare Fe_3O_4@cyclodextrin magnetic material under the action of crosslinking agent diisonitrile adipate (HMDI) and stannous octanoate catalyst. The factors affecting the 尾-CD loading during the preparation of Fe_3O_4@cyclodextrin magnetic materials were studied, and the preparation conditions of Fe_3O_4@cyclodextrin magnetic materials were optimized. The optimum preparation conditions are as follows: the reaction temperature is 60 鈩，

本文编号：2280971