Application of ELISA and RT-PCR for the detection of pork adulterated in beef meat products marked in Kosovo

The problem of adulterated ingredients in processed food products is widely observed in the food industry and remains a continuous concern for consumers. This problem may interfere not only with consumers’ religious ethics, but also with their health and diet. Therefore commercial foods should be monitored for the accuracy of the declared ingredients. This study aims at identification of pork matter adulterated in processed beef meat products marked in Kosovo. Commercial beef food samples were routinely collected at different markets around Kosovo. The analyzed samples consisted of sausages, salami, pate and ragu sauce and were declared as 100% beef. All samples were initially prepared into a test portion and further processed for serum albumin or genomic DNA extraction (CTAB, ISO-21571:2005). After the initial processing, samples were first tested for the presence of pork matter by the ELISA method and all positive samples were tested for confirmation by RT-PCR. From a total of 25 analyzed food products, ELISA was able to detect pork in 32% of them with an accuracy of 100% among duplicate samples. All ELISA positive samples were further confirmed by RT-PCR, either by a commercial kit or designed primers specific for pork mitochondrial DNA. The specificity of the amplified PCR products was confirmed at the end on the micro-fluidal electrophoresis. These data show that the adulteration of beef meat products is frequent in Kosovo marked and that the combination of ELISA and RT-PCR provides a very effective and reliable option that can be applied for routine monitoring of food adulteration in commercial products of animal origin in the Kosovo