负载槲皮素的酶法糖基化酪蛋白复合纳米粒子的构建与表征

利用转谷氨酰胺酶法糖基化修饰酪蛋白并制备糖基化复合纳米粒子，用纳米粒子包埋槲皮素，探究其对槲皮素的稳定效果。利用酶法糖基化交联使壳寡糖接入酪蛋白中，并使用超声自组装法构建酪蛋白-壳寡糖复合纳米粒子，利用酪蛋白、酪蛋白-壳寡糖对槲皮素进行包埋，形成槲皮素纳米粒子，采用透射电镜（TEM）、傅利叶红外光谱（FITR）、X射线衍射仪（XRD）对槲皮素纳米粒子的外观形态、微观形态、结合机理进行分析，并在37、60（巴氏杀菌）和99 ℃（煮沸）条件下探究槲皮素纳米粒子的热稳定性。结果表明:在pH为5.8、超声功率为200 W、糖基化产物的浓度为4 g/L时，酪蛋白-壳寡糖复合纳米粒子的粒径最小，为125.6 nm。槲皮素被酪蛋白、酪蛋白-壳寡糖包埋后，所形成的槲皮素纳米粒子包埋率分别为74.14%、85.21%。在透射电镜下，槲皮素纳米粒子呈圆球状，包埋槲皮素前后纳米粒子无明显差别。在37、60、99 ℃下，负载槲皮素的酪蛋白-壳寡糖复合纳米粒子表现出更好的热稳定性，槲皮素保留率分别为87.6%、63.5%、5.13%。

Construction and Characterization of Quercetin-loaded Enzymatic Glycosylated Casein Composite Nanoparticles

In this study,glycosylated composite nanoparticles were prepared by transglutaminase glycosylation to modify casein(Cas),and quercetin(Que)was embedded with nanoparticles to investigate its stabilization effect on Que.Enzymatic glycosylation was used to conjugate Chito-oligosaccharides(Cos)into Cas,and casein-chito-oligosaccharides composite nanoparticles(n-Cas-Cos)were constructed by ultrasonic self-assembly method.Que was embedded with Cas and caseinchito-oligosaccharides to form quercetin nanoparticles(n-Cas-Que and n-Cas-Cos-Que).The appearance,micro morphology and binding mechanism of the quercetin nanoparticles were analyzed by Transmission electron microscopy(TEM),Fourier transform infrared spectrum(FITR)and X-ray diffractometer(XRD).The thermal stability of quercetin nanoparticles was investigated at 37,60(pasteurized)and 99℃(boiling)conditions.The results showed that when the pH was 5.8,the ultrasonic power was 200 W,and the concentration of glycosylated products was 4 g/L,the average particle size(Dz)of n-Cas-Cos was the smallest,which was 125.6 nm.After loading with Que,the encapsulation efficiency(EE)of n-Cas-Que and n-Cas-Cos-Que were 74.14%and 85.21%respectively.Besides,the quercetin nanoparticles were spherical under transmission electron microscopy,and there was no significant difference between the nanoparticles before and after embedding Que.At 37,60 and 99℃,the casein-chito-oligosaccharide composite nanoparticles loaded with Que showed better thermal stability,the retention rates of Que were 87.6%,63.5%and 5.13%respectively.