Abstract:

The extraction of capsaicin by vacuum inner ebullition was optimized to obtain improved yield and quality.
Firstly, factorial design analysis was used to identify main optimization parameters. Secondly, their optimal region was
approached by the steepest ascent method. Finally, response surface methodology was employed to optimize the parameters
and the optimized process was compared with traditional ethanol extraction. Ethanol concentration and dosage for capsaicin
adsorption and ehanol concentration for capsaicin desorption were identified as main variables. The extraction efficiency of
capsaicin was 0.211% under the conditions of extraction at 50 ℃ for 5 min with 82% ethanol at a solvent-to-solid ratio of
3.5 mL/g and desorption with 44% ethanol. Compared with traditional ethanol extraction, the quality of the extract obtained
using the optimized process was considerably improved despite only an 0.011% increase in extraction efficiency. After being
purified by column chromatography, the extract obtained by the proposed method was increased in the recovery and purity of
capsaicin by 15.8% and 5.0% respectively, compared with the one obtained by traditional ethanol extraction. Vacuum inner
ebullition can shorten the time required to extract capsaicin and shows a very promising prospect for industrial applications
in the extraction of high-quality capsaicin.

Key words: capsaicin, response surface optimization, vacuum inner ebullition, extraction