Myoglobin as marker in meat adulteration: A UPLC method for determining the presence of pork meat in raw beef burger

The identification of meat animal species used in raw burgers is very important with respect to economic and religious considerations. Therefore, international supervisory bodies have implemented procedures to control the employed meat species. In this paper we propose myoglobin as a powerful molecular marker to evaluate the presence of non-declared meat addition in raw beef burgers by using ultra-performance liquid chromatography (UPLC) for the separation and identification of edible animal species (beef, chicken, horse, ostrich, pig and water buffalo). Meat samples were pre-treated with sodium nitrite to transform oxymyoglobin and deoxymyoglobin to the more stable metmyoglobin. The developed method was validated, preparing mixtures with different percentages of pork and beef minced meat. The obtained results show that using myoglobin as marker, 5% (25 mg/500 mg) of pork or beef meat can be detected in premixed minced meat samples.