Abstract: The protein in frozen Antarctic krill Euphausua superba was recovered by pH-shifting at a 0.5 interval via acid and base and protein composition was analyzed by SDS-PAGE to explore the utilization of Antarctic krill. Feasibility of isolating krill protein with pH-shifting was evaluated using recovery of edible protein and yield of protein isolated as indexes.Results showed that there was no significant difference between acid-aided treatment and alkali-aided treatment in recovery of krill protein.The maximum recovery rate was obtained at pH 1.5(49.8%) and pH 12.0(45.7%).The analysis of SDS-PAGE showed that composition of frozen krill protein included mainly low molecular weight protein,approximately 80 000 and 35 000-45 000.The profile of protein molecular weight of dissolved and pro-dissolved substances was compared,indicating that the acid-aided treatment recovered most of protein,while the residues still present some protein unrecovered in the alkali-aided treatment.Finally,distribution of krill nitrogenous compounds in the isolation process was traced,and negative effect of pH-shifting on protein recovery was found with yield of 37.76%in the acid-aided treatment and 37.13%in the alkali-aided treatment.
2013, Vol. 28 
