TDK conference 2019

In this study we used the ISAG required microsatellites to prove the donkey origin of collected raw organic and non-organic meat cuts (n=4) and collected cured and smoked meat products (n=6). To fortify and broaden the spectrum of our study we included raw meat samples of four horses, which were analysed using the ISAG required microsatellite panel for horses in raw stage, later in a mixed matrix of donkey and horse in raw and cooked stage. In this experimental setup, there was a stability test of the DNA with that the effectiveness of the microsatellite markers was analysed.

After DNA extraction with QIAGEN QIAamp DNA Blood Mini Kit, the primers were added and amplification was performed using GeneAmp PCR System 9700 equipment, in the next step, the fragments have been analysed using an ABI 3130 Genetic Analyser and a GeneMapper software in the Genetic Laboratory of NÉBIH.

All of our samples with the exception of two have been correctly associated to the species of origin indicated on the label, by the vendor or compiled by us. These two samples were tested negative for donkey and after further investigation, using the bovine specific primers for the ISAG required microsatellites, both products marketed as “organic donkey cheek” have been classified as a bovine, more precisely to the same bovine individual through the matching alleles on the electropherogram. In three out of four samples (sausage samples containing pork fat) derived from the donkey sausages more than two alleles appeared, proving us that the nuclear material in the sausage originates from more than one animal. Surprisingly, the smoked donkey neck which macroscopically seemed to be one large muscle, showed four alleles on HMS6 locus which suspected contamination with nuclear material from another Equidae individual during processing. None of the following six horse specific STR’s (AHT5, ASB2, ASB17, HTG4, HTG6 HMS1) were amplified by the genetic material extracted from the smoked donkey neck, thus we could successfully exclude food fraud by mixing horse meat with the more valuable donkey meat.

It is concluded genetic markers available for DNA identification of donkey individuals remains efficient for fresh meat and product evaluation. Food chain can be controlled after the meat has been prepared by both the producer and consumer.