Frozen samples of Antarctic krill (Euphausia superba Dana) were found to contain 71·4% moisture, and on a dry matter basis 24·6% lipid, 49% protein (N × 6·25), 2·5% chitin, and 9·8% ash. Fatty acids from the crude lipid fraction were made up of 43·8% saturated, 32·8% mono-unsaturated, and 23·4% polyunsaturated types.
Krill protein concentrate prepared as a light, free-flowing powder by isopropanol extraction of krill contained 74·3% crude protein, 15·4% ash, 6% chitin and 0·3% lipid, and was rich in lysine, arginine, tryptophan, and threonine. The protein efficiency ratio of this concentrate was found to be the same as that of casein.
The significance of these results in relation to those obtained for other fish protein concentrates is discussed.