Subcritical Water Treatment for Producing Seasoning From Semidried Isada Krill

Semidried Isada krill (Euphausia pacifica) was treated with boiling water and subcritical water at 100–240C for 10 min with a semidried krill to a water ratio of 8/52 w/v to produce seasoning. The protein concentration, lipid content and odor concentration of the extract increased after increasing the treatment temperature. The highest protein content of the extract (0.047–0.049 kg/kg‐extract) was obtained by subcritical water treatment at 180 or 200C. Compounds with lower molecular mass were detected in the extracts derived from subcritical water treatment at temperatures higher than 160C. The extract prepared by subcritical water treatment at 160 and 180C received the high score in the flavor preference test by a group of panelists. Treatment at temperatures lower and higher than 160–180C, respectively, conferred undesirable fishy and smoky or burnt odors to the extracts and residues. Practical Application Although Isada krill is abundant in the Sanriku coast, Japan, its usage is limited to low–value‐added products such as animal and aquaculture feeds. However, we found that subcritical water treatment of the krill produces an extract solution and a solid residue, both of which possess good flavor and proffer a great prospective for use as seasoning. Establishment of a method for using the krill as a raw material for seasoning with shrimp‐like flavor would increase the value of the krill as a food resource for human consumption.