Abstract: As one of the largest biomass of multi-cellular animal species on earth,Antarctic krill (Euphausia superb) is paid more attention for its large biomass and potential value in recent years.To improve the extraction yield of Antarctic krill protein,Box-Behnken design was employed based on the single factor experiments.The independent variables,namely centrifugation temperature,solid-liquid ratio and homogenization time on the extraction yield of Antarctic krill protein were evaluated by response surface methodology (RSM).The results showed that the optimum conditions for extracting protein from Antarctic krill were as follows:pH value of alkali-dissolving stage 11.5,pH value of acid-precipitation stage 5.5,centrifugation temperature 4 ℃,centrifugation rate 10000 rpm,centrifugation time 10 min,solid-liquid ratio 1:3 (w/v),homogenization time 3 min.Under the optimum conditions,the extraction yield of Antarctic krill protein reached 10.81%.

Key words: Antarctic krill, protein, alkali solubilization and acid precipitation, extraction yield