Abstract

Phlorotannins are potential and abundant resources in Laminaria japonica , which possess multiple biological activities. However, their poor water solubility and stability have been limiting their applications in various fields. In this study, to expand the application scope of phlorotannin, we developed phlorotannin loaded whey protein isolate (WPI)-chitosan oligosaccharide (COS) nanocomplexes (CPW nanocomplexes) which were further characterized by Transmission Electron Microscopy (TEM), Fourier transformed infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Fluorescence spectrum and circular dichroism (CD). The stability and bioactivity were also investigated. The results showed that the CPW nanocomplexes were spherical. And formation of CPW nanocomplexes altered the micro-environment and secondary structure of the WPI. Compared with free phlorotannin, the CPW nanocomplexes improved its water solubility and the stability against UV. And they presented antioxidant and anti-inflammatory properties with no cytotoxicity. The results may promote the successful application of CPW nanocomplexes in developing phlorotannin based foods and nutraceuticals.