Tajima Fisheries Technology Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Mikata, Hyogo 669-6541, Japan
A method for the quality assessment of hard-shelled and soft-shelled male snow crab Chionoecetes opilio (terminal molted) was investigated. In order to distinguish the quality of hard-shelled and soft-shelled crab while alive, it is possible to measure the coefficient of fatness (body weight/(carapace width)3) and the color (b* value) of the first pereiopod from the ventral surface of the crab. Similarly, in the case of dissecting, it was possible to distinguish by measuring the moisture of pereiopod, the ignition loss of the carapace, the color (L* value and b* value) and the proximate compositions (particularly crude lipids) of the hepatopancreas. These results suggested that the difference of the ignition loss was related to the thickness of the carapace (the thickness of the cuticle layer), while the difference in the color of the hepatopancreas (L* value and b* value) was related to the lipid content.