Nanostructured lipid carriers (NLCs) stabilized by natural or synthetic emulsifiers for lutein delivery: Improved physicochemical stability, antioxidant activity, and bioaccessibility

This study investigated the impacts of individual emulsifiers on the physicochemical stability, antioxidant ability, and in vitro digestion behavior of lutein-loaded nanostructured lipid carriers (NLCs). NLCs particles stabilized by ethyl lauroyl arginate, rhamnolipid, or tea saponin were fabricated by high-pressure microfluidization method. Differential scanning calorimetry and X-ray diffraction results confirmed the regulatory effect of emulsifiers on the crystallization behavior of NLCs. NLCs stabilized by rhamnolipid presented higher encapsulation efficiency (94.73%) for lutein than those stabilized by tea saponin (90.39%) or ethyl lauroyl arginate (88.86%). Meanwhile, the stability of embedded lutein during storage or photothermal treatments was greatly enhanced. Individual emulsifiers, together with lutein, endowed NLCs with excellent antioxidant capacity. During in vitro digestion, rhamnolipid-stabilized NLCs showed the slowest release of free fatty acids (50.87%) and provided an optimal sustained release for lutein with relatively high bioaccessibility (23.01%).

Automated summary

This study investigated the impacts of individual emulsifiers on the properties, stability, and digestion behavior of lutein-loaded nanostructured lipid carriers. The results showed that different emulsifiers have regulatory effects on the crystallization behavior of the carriers, and can improve the encapsulation efficiency and stability of lutein. Additionally, the individual emulsifiers and lutein endowed the carriers with excellent antioxidant capacity and optimal sustained release properties.