负载虾青素的油凝胶纳米乳液的构建及体外消化研究

The development and its digestion study of astaxanthin-loaded oleogel-based nanoemulsions in vitro

为提升虾青素的生物利用率,构建了油凝胶基纳米乳液,并以此为输送体系来递送虾青素。以小烛树蜡作为凝胶剂制备油凝胶,小烛树蜡的最低添加量为1.2%(质量分数,下同)。2.0%的小烛树蜡油凝胶比1.2%的具有更高的凝胶相变温度、硬度以及弹性。流变学研究表明,两者均表现出凝胶网络结构,而2.0%的小烛树蜡油凝胶网络更强。以2.0%小烛树蜡油凝胶为油相制备2种纳米乳液,同鸡蛋清白蛋白相比,以乳清分离蛋白作为乳化剂的纳米乳液具有更小的粒径和更大的ζ-电位,乳液稳定性更强。包埋虾青素的油凝胶和2种纳米乳液的体外模拟消化实验表明,纳米乳液的脂解程度和虾青素的生物利用率均显著高于油凝胶,且以乳清分离蛋白为乳化剂的纳米乳液的消化情况优于鸡蛋清白蛋白稳定的乳液。该研究将虾青素的生物利用率提高到了43.6%,为虾青素的高效利用提供了新的思路。

In this paper,in order to improve bioaccessibility of astaxanthin,an oleogel-based nanoemulsion was developed to deliver astaxanthin.Using candelilla wax as gelator,oleogel can be formed only when the mass fraction of candelilla wax is more than 1.2%(w/w).The gel-sol transition temperature,hardness and rheological properties of the oleogel with 1.2%and 2.0%candelilla wax content were characterized.The results showed that oleogels with 2.0%candelilla wax had a higher gel-sol transition temperature of 48℃,and its hardness is also far greater than oleogels with 1.2%candelilla wax.Their rheological studies show that both of them exhibit gel network structure,while oleogels with 2.0%candelilla wax have stronger gel network.Because of the excellent physicochemical property of oleogels with 2.0%candelilla wax,the oleogel was used as oil phase to prepare oleogel-based nanoemulsion with egg white albumin and whey protein isolate,respectively.The oleogel-based nanoemulsion emulsified by whey protein isolate had smaller particle size and largerζ-potential than egg white albumin-coated nanoemulsion,which endowed it a stronger stability.In vitro digestion study revealed that oleogel-based nanoemulsion could improve both the extent of lipolysis and astaxanthin bioaccessibility compared with oleogel.Whey protein isolate-stabilized nanoemulsion had stronger extent of lipolysis and higher astaxanthin bioaccessibility than egg white albumin-stabilized nanoemulsion.This study demonstrates that astaxanthin bioaccessibility can be improved to 43.6%,which provides a novel approach to efficient utilization of astaxanthin.