Statistical optimization of microwave-assisted astaxanthin extraction from Phaffia rhodozym

The statistical experimental design was used in this study to optimize the extraction of astaxanthin with the assistance of microwave. Three factors, including the volume of anhydrous alcohol, the extracting time, and cell wall breaking time, were screened out by Fractional Factorial Design (FFD). Then the stable area was obtained by the steepest ascent method. And finally the extraction process was optimized by the response surface method. The optimal extraction process of astaxanthin was dimethyl sulfoxide (3.0 ml), anhydrous alcohol (12.6 ml), cell wall breaking time (2.6 min), extracting time (15 min), extracting temperature (50°C) and microwave frequency (416.5 MHz).Under this condition, astaxanthin could be extracted in amounts of 2.9269±0.01 mg/l and the yield of astaxanthin was 21.56% higher than the initial yield.