Species identification by oligonucleotide hybridisation: The influence of processing of meat products

We have evaluated the influence of meat processing on the results obtained with a species identification test by DNA oligonucleotide hybridisation. Freezing and thawing of meat did not cause a substantial reduction in the hybridisation signal. Heating of meat at 100°C or 120°C, however, led to signal reduction caused by DNA degradation, but identification was still possible. The signal is highly influenced by the kind of tissues processed. Four extensively processed products with 50 g kg^-1 species admixtures were tested. Admixtures could be detected in three products but no hybridisation signal was observed with corned beef. We conclude that the quantification of admixtures by hybridisation is not better than with most alternative methods of species identification, as the strength of the signal depends on factors such as tissue origin and sample processing.