Abstract:The study focused on astaxanthin extracted from Haematococcus pluvialis and optimized its saponification process.Through single-factor experiments and response surface optimization，the saponification process using NaOH-methanol solution was optimized，followed by purification using preparative high performance liquid chromatography（HPLC）.The optimal conditions obtained were saponification time of 12 h，saponification temperature of 32 ℃，and NaOH-methanol solution concentration of 2.5%.Under these conditions，the astaxanthin content was measured to be（19.423±0.186）μg/mL.Further purification of the saponified astaxanthin was achieved through preparative HPLC，resulting in a purity of over 94% as determined by liquid chromatography.Qualitative analysis of the purified product was conducted using infrared spectroscopy and nuclear magnetic resonance，and spectral analysis revealed a close similarity between the prepared astaxanthin and the standard astaxanthin.