suggested that the acetic acid presence
may have important influence on the increased ratio of 3-MCPD to
2-MCPD. The ability of acetic acid to enhance 3-MCPD generation
versus 2-MCPD was connected to the neighbouring group participation
and formation of cyclic acyloxonium ion. On the other hand,
the sn-2 position of the triglyceride may be less accessible for
chlorination. Fish oils are rich in long chain polyunsaturated fatty
acids (EPA, DHA), which are mainly located at sn-2 position. Most
lipases show regioselectivity towards the primary position of triacylglycerols,
and for several lipases stereopreference for the sn-1
or sn-3 position had been demonstrated. There is no correlation
between the forms of the dietary supplement and the level of
bound monochloropropanediols determined in described
screening research. The level of bound 3-MCPD did not depend on
the fact that the oilwas encapsulated or stored in a liquid form. This
leads to the conclusion that the process of fish oil refining has
greater impact on the 3-MCPD and 2-MCPD esters content than the
storage of final product. Also, it is difficult to point out any
connection between bound 3-MCPD and bound 2-MCPD content
and the origin of the oil (liver or other fish tissues).