Abstract: Purpose: To determine the loading, antioxidant activity protection and sustained-release effect of wheat starch on Ligustrum robustum (Rxob.) Blume extract (LRE) for the purpose of providing a theoretical basis for the high value added development and utilization of LRE in the food and biomedical industries. Methods: The major compounds in LRE were identified by mass spectroscopy (MS) and nuclear magnetic resonance (NMR) spectroscopy, and the in vitro antioxidant capacity of LRE was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and reducing power assays. The loading capacity and stability of starch for LRE were measured by cumulative release of total phenols. Besides, the protective effect of starch on the antioxidant activity of LRE was analyzed, and the sustained-release effect of starch on LRE during in vitro simulated digestion was investigated. Results: The major bioactive compounds in LRE were identified as ligurobustoside B (C31H44O13), ligurobustoside N (C35H46O18) and ligupurpuroside J (C35H46O19), and LRE had strong free radical scavenging capacity and reducing power. Furthermore, different concentrations of wheat starch could stably load LRE, delaying the attenuation of the free radical scavenging capacity and reducing power of LRE and inhibiting the release of LRE during in vitro simulated digestion to a certain extent.

Key words: Ligustrum robustum (Rxob.) Blumes; wheat starch; loading; antioxidant activity; sustained release