Seasonal variation of phosphatidylcholine hydroperoxides in blood of sweetsmelt Plecoglossus altivelis

Sweet smelt was reared at two fishery experimental stations for 5 months fr om June to October. Every 2 weeks blood was collected from the caudal vesse ls and, subsequently, the phosphatidylcholine hydroperoxide contents and th e fatty acid compositions in the blood were determined by high-performance liquid chromatography and gas chromatography, respectively. The seasonal va riation of the contents of accumulated hydroperoxides and fatty acids in th e sweet smelt blood were observed in both experimental stations. Sweet smel t started performance of cucumber-like or watermelon-like aroma in the midd le of July and the aroma was enhanced in August. The content of phosphatidy lcholine hydroperoxides and the amount of total fatty acid in the fish bloo d, in terms of possible precursors of volatile compounds, were also extreme ly high in the same period. According to lipid peroxidation mechanisms. the strong characteristic aroma of sweet smelt during July to August might be due to the high contents of accumulated lipid hydroperoxides and polyunsatu rated fatty acids in their tissues. (C) 2001 Elsevier Science Inc. All righ ts reserved.