Abstract: using DSC analyzed the most suitable storage temperature and oxidation stability of astaxanthin,infrared detected changes in the structure of astaxanthin before and after the heat treatment,and then detected human body’s maximum tolerated dose and antioxidant of astaxanthin through the cell.Using different methods to get astaxanthin oil and compared their ability to clean DPPH.Conclusion:astaxanthin optimum storage temperature is about 25 ℃,storage conditions should be cold,dark and protected from air.From DSC detection of oxidation’s oxidation induction period in oils,this paper found that when oils placed in the air at 25 ℃,oxidative induction period is 8.5 d,when the temperature is 4 ℃,oxidative induction period is 29.89 d,when the temperature is 4 ℃,oxidative induction period is 48.3 d.Infrared Spectral analysis found that astaxanthin conjugated double bonds and aromatic ring’s C=C,aromatic rings’s C=O and O-H,six-membered cyclic secondary alcohols’s C-O changes after thermal oxidation,The maximum tolerated dose of astaxanthin in human body is 5×10⁶ mol/L,comparison of astaxanthin oil gotten by supercritical fluid(Scf)and the microwaveassisted extraction(Mae),cable-extraction(Sox),their ability to clean DPPH is MAE > SCF > SOX.

Key words: astaxanthin, differential scanning calorimeter, oxidation induction time, antioxidant