Stabilization and Solubilization of Astaxanthin by Inclusion Complex Formation with Cyclodextrin

Soyoung Kim1, Eunah Cho1, Jimin Yoo1, Man-Jin In2, and Hee Jeong Chae1. (1) Food and Biotechnology, and Center for Food Function and Safety, Hoseo University, Asan, 336-795, South Korea, (2) Human Nutrition and Food Science, Chungwoon University, Hongseong, 350-701, South Korea

The inclusion complexes of astaxanthin with various cyclodextrins were prepared and characterized with respect to water-solubility and stability. The inclusion characteristics were determined using SEM (scanning electron microscope) and FT-IR spectrometer. The best host material for the inclusion of astaxanthin was selected as b-cyclodextrin. The optimum ratio of astaxanthin and cyclodextrin for the inclusion complex formation was found to be 1 : 200. The stability of the astaxanthin in inclusion complex was examined under storage at various pHs, and temperatures, under UV irradiation and in the presence of oxygen for 4 weeks. Also, the effects of heating on the stability of the inclusion complex were investigated at various conditions. The stability of the inclusion complexes against heating, light and oxidation was greatly enhanced compared to free astaxanthin. The water-solubility of the inclusion complexes was also investigated at various temperatures (4C, 25C and 45C) and pHs (2, 6.5 and 8). As a result, the solubilities of the inclusion complex (As-b-CDIC) were about 110 times higher than those of free astaxanthin at pH 6.5 and 25C, respectively. In conclusion, the inclusion complex of astaxanthin and b-CD showed a highly improved water-solubility and stability against heating, light, oxidation and acidic pH.