Improvement of "kurozukuri ika-shiokara" (fermented squid meat with ink) odor with Staphylococcus nepalensis isolated from the fish sauce mush of frigate mackerel Auxis rochei

Abstract

The Staphylococcus nepalensis strain, which was isolated from frigate mackerel fish-sauce mush added with soy sauce koji, was inoculated into "kurozukuri ika-shiokara" ("kurozukuri"), fermented squid meat with salt, liver and ink traditionally produced in Toyama Prefecture, to improve its odor. Extractive components and volatile components of "kurozukuri" after incubation at 4°C for 30 days with the cultured bacterium were examined by HPLC and GC/MS analyses. There was no difference in the contents of extractive components between bacteria-treated "kurozukuri" and non-treated one. However, the contents of volatile components, acids, aldehydes, sulfur-containing compounds, alcohols and esters, in the former were different from those in the latter, and dimethyl disulfide, which existed in the latter, did not detected in the former. Sensory evaluation revealed that fishy odor and disagreeable squid odor notes of the former treated with the bacterium were weaker than those of the latter.