Testing of the Effect of Food Additives on the DNA Isolation from Mackerel and Fish Products

Abstract

Authentication of fish products by DNA analysis requires the extraction of high quality DNA without the presence of inhibitors. Many nucleic acid isolation methods are currently available; silicate centrifugal columns have become very popular due to their speed and ease of extraction. However, their disadvantage may be the principle based on DNA charge, which may be affected by food composition, or clogging due to a poor sample pretreatment. The aim of this work was to compare three DNA isolation methods using different principles (silicate centrifugal columns, modified magnetic beads, Cetrimonium bromide and chloroform extraction) and to evaluate their suitability for DNA isolation from fish muscle. The criteria assessed were the recovery, purity and amplifiability of the isolated DNA. Mackerel tissue was analysed without and with the addition of additives commonly used in the manufacture of fish products, namely diphosphates (E 450) and colorants (E 110 and E 124), and the selected method was subsequently applied to commercial fish products. The modified method using the detergent CTAB proved to be the most suitable.