Development of analytical methods for the determination of free and ester bound 2-, 3-MCPD, and esterified glycidol in fishery products

摘要

In the present study, existing official methods for oils were modified in order to analyze free and bound MCPD and bound glycidol in fish. Free 3-MCPD was determined in aqueous extracts of fishery products. DGF standard methods C-VI-17(10) and C-VI-18(10) and the 3 in 1 method were modified and tested to quantify ester-bound 2- and 3-MCPD and glycidyl esters. The different methods were validated using spiked fish mince and a naturally contaminated reference material consisting of homogenized smoked sprat and fish sticks. The methods showed good agreement. Assay B of the modified DGF method C-VI-18(10) and the adapted 3 in 1 method allow a quantitative determination of bound 2- and 3-MCPD in fishery products. In addition, glycidyl esters can be quantified applying the 3 in 1 method. The screening of various fishery products showed that smoked fish may contain considerable amounts of free 3-MCPD. Concentrations ranged between 8 and 388 mu g/kg wet weight (ww). Only traces of free 3-MCPD were found in all other fishery products. Fish sticks and fried fish products are potential sources of 3- and 2-MCPD esters, but large variation were observed. Bound 3-MCPD ranged between 45 and 377 mu g/kg ww, bound 2-MCPD between 9 and 116 mu g/kg ww.