Application of partial autoproteolysis to extraction of protein from Antarctic krill (Euphasia superba) Part 1. Effect of pH on protein extraction intensity

The method of protein extraction from krill using partial autoproteolysis was investigated in this work. Three distinct pH maximal ranges (4.50 to 6.25; 7.75 to 8.50; 9.25 to 9.75) were found to occur at nitrogen substances extractions, depending on pH applied. The highest yield of protein was obtained by the extraction carried out at pH 5.8. Using the above mentioned pH ranges and the extraction parameters described in this paper, it is possible to obtain yields of 11.8 g and 13.38 g of crude protein without washing and with one washing of centrifuged solids, respectively, from 100 g of whole krill which is equivalent to 80.9 % and 91 % yields, respectively, of the total krill protein.