Influence of cooking processes on Cu, Fe, Mn, Ni, and Zn levels in beef cuts

Abstract

Beef is an important source of micronutrients, but little is known about how cooking processes affect the nutritional value. In this study, microwave-induced plasma optical emission spectrometry (MIP OES) was used to determine the contents of Cu, Fe, Mn, Ni, and Zn in three cuts of Uruguayan beef when cooked to two degrees of doneness (medium and well done). The content of minerals varied in the range: Cu (84.9–117.4), Fe (2288–2689), Mn (11.6–20.7), Ni (12.4–19.8), and Zn (4100–7471) μg per 100 g portion for medium and Cu (76.3–97.0), Fe (1886–2689), Mn (9.7–15.4), Ni (12.7–26.8), and Zn (3187–6204) for well-done. No significant losses through leaching were observed up to a weight loss of 16 % (medium). However, when the weight loss was 28–35 % (well done), the micronutrients content decreased. Despite these losses, Uruguayan beef was confirmed to be a particularly good source of Zn and a good source of Cu and Fe. The daily contribution of Mn was not significant (1%) and the Ni content was far below the tolerable upper intake level. In addition, this work revealed MIP OES to be an economical and green method for the determination of trace elements in beef.