發(fā)布時(shí)間：2018-10-19 11:22

【摘要】：功能性磁性納米材料由于其粒徑小,易定位,在磁場(chǎng)條件下能快速分離等特點(diǎn),而被廣泛應(yīng)用于食品、環(huán)境和化工等領(lǐng)域,對(duì)目標(biāo)分子進(jìn)行分離與提取。固載β-CD磁性材料(Fe_3O_4@cyclodextrin)即在磁性顆粒表面包覆β-環(huán)糊精(β-CD),該材料既保留β-CD對(duì)疏水性物質(zhì)良好的包覆功能,又具有磁性顆粒獨(dú)特的優(yōu)勢(shì)。相較于傳統(tǒng)的β-CD粉末包埋法,將此功能性材料應(yīng)用于脫除蛋黃膽固醇的過程中,β-CD不易殘留于蛋黃體系,材料易較快與目標(biāo)分子結(jié)合,且在磁場(chǎng)條件下能將磁性材料快速?gòu)牡包S體系中分離,應(yīng)用安全性高。本論文中利用殼聚糖作為中間體,在交聯(lián)劑己二酸二異腈脂(HMDI)和催化劑辛酸亞錫的作用下制備得Fe_3O_4@cyclodextrin磁性材料。研究制備Fe_3O_4@cyclodextrin磁性材料過程中影響β-CD固載量的因素,優(yōu)化Fe_3O_4@cyclodextrin磁性材料的制備條件。實(shí)驗(yàn)所得磁性材料的較佳制備條件為:反應(yīng)體系溫度為60℃,攪拌速度為700 r/min,反應(yīng)體系中β-CD與Fe_3O_4@chitosan-HMDI磁性材料的質(zhì)量比為3:1。對(duì)Fe_3O_4@cyclodextrin磁性材料的基團(tuán)結(jié)構(gòu)、顆粒粒徑、分散性、磁含量等進(jìn)行表征。本論文所設(shè)計(jì)的Fe_3O_4@cyclodextrin磁性材料制備工藝簡(jiǎn)便,制備的材料在乙醇/水體系中具有良好的分散性,平均粒徑為232 nm,磁含量為64.2%,具有工業(yè)化的可操作性和應(yīng)用性。Fe_3O_4@cyclodextrin磁性材料應(yīng)用于膽固醇標(biāo)準(zhǔn)溶液中,研究其對(duì)膽固醇分子的吸附性;采用pseudo一級(jí)、二級(jí)模型來(lái)描述Fe_3O_4@cyclodextrin吸附膽固醇的靜態(tài)動(dòng)力學(xué)過程。結(jié)果顯示:在膽固醇標(biāo)準(zhǔn)溶液中,pH=3.0,25℃條件下,Fe_3O_4@cyclodextrin磁性材料吸附膽固醇的平衡時(shí)間為45 min,膽固醇吸附載量為210 mg/g。膽固醇吸附過程符合pseudo二級(jí)動(dòng)力學(xué)方程。研究Fe_3O_4@cyclodextrin磁性材料對(duì)蛋黃膽固醇的脫除性能,探究材料添加量、溫度、稀釋度、蛋黃體系pH值、磷脂酶酶解預(yù)處理等條件對(duì)蛋黃膽固醇脫除率的影響,并探究這些影響產(chǎn)生的內(nèi)在原因。優(yōu)化脫除蛋黃膽固醇的工藝條件,得到較佳的條件為:Fe_3O_4@cyclodextrin磁性材料的添加量為蛋黃液質(zhì)量的10%,脫除時(shí)間80 min,蛋黃原液與水的比例為1:10(w/v),磷脂酶A2酶解預(yù)處理蛋黃液40 min,pH值調(diào)節(jié)至3.0或9.0。在上述條件下,蛋黃膽固醇脫除率為58%,且優(yōu)化所得工藝條件利于蛋黃液的后續(xù)應(yīng)用。研究Fe_3O_4@cyclodextrin磁性材料作用于蛋黃液后,蛋黃蛋白含量、磷脂含量、蛋黃乳化性的變化。當(dāng)膽固醇脫除率為42%時(shí),蛋黃蛋白損失率為7.6%,蛋黃卵磷脂損失率為10.1%。膽固醇從蛋黃體系中的分離會(huì)引起部分蛋黃蛋白的結(jié)構(gòu)變化,影響蛋黃的乳化特性。Fe_3O_4@cyclodextrin磁性材料具有良好的重復(fù)使用性,在重復(fù)循環(huán)吸附-洗脫過程15次后,對(duì)膽固醇的最大吸附載量仍能維持在200 mg/g以上,回收率為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，

本文編號(hào)：2280971