Studies on the composition of mullet Mugil cephalus roe and Karasumi produced in Nagasaki

A salted and dried roe of the mullet Mugil cephalus, is known as Karasumi and consumed worldwide. In order to present the characteristics of Karasumi produced in Nagasaki, proximate compositions and lipid classes were analyzed together with unprocessed roe available on the market for raw materials of the Karasumi. The Karasumi commercially produced in Nagasaki showed a ratio of 0.86±0.11 of crude protein to crude lipid, whereas Karasumi of foreign products showed 0.65±0.07. The Karasumi is characterized by its high lipid content and wax ester content. The content of free fatty acids was higher than that of the unprocessed roe because of the decomposition of triacylglycerols which showed high content compared with other reports. The decomposition of wax ester was not observed during processing.