Studies on the Offensive-Odor Fish of the Nagara River. IX. Confirmation of the Offensive-Odor Substances

Abstract

In order confirm the role of volatile fatty acids, aromatic hydrocarbons, and phenol found as the main substances responsible for offensive odor of fish meat, odor-imparting experiments were carried out on these three components, their concentrations being based on their analytical values obtained from river water in which the fish with unpleasant odor lived. The odor of fish bred in such a solution was close to that of the fish in natural waters but there was still a very fine difference, and the odor of the odorous fish itself was not the same, indicating that it is difficult to reproduce the original odor due to a slight difference in the componental principles. It was found that there was a limit to the transfer of odor to fish from the water area, which is of importance in the counter-measure for odorous fish, and the limit exist between the concentration of 1st and 2 nd experiments in Table I. Tetra methyl pyrazine and tetralin were found by GC-MS analysis in the offensive odor fish meat, but fish was not scented with tetra methyl pyrazine. Taste of fish scented with tetralin was different from that of the offensive odor fish. Therefore, the compounds did not responsible for offensive odor substances.