Authentication of meat species and net muscle proteins: updating of an old concept

Abstract

The aim of the study was to develop an efficient method for assessment of meat origin and determination of net muscle protein (NMP; based on amino acids and β-alanylhistidine dipeptides) in meat products using the ultra-high performance liquid chromatography coupled with mass spectrometry. As an important result, a database of ratios of particular amino acids to 3-metylhistidine, applicable for muscle protein origin confirmation, was established. Based on the specific ratios of 1-methylhisitidine/3-methylhistidine, revealing of undeclared addition of 2% of chicken meat to the pork was enabled. Similar outcome was achieved by considering the ratios of β-alanylhistidine dipeptides. In the case of chicken-pork and pork-beef admixtures, as low additions as 0.5 and 2% of chicken or pork adulterant could be recognized. The ratio of 4-hydroxyproline/3-methylhisitidine was shown to be diagnostic for detection undeclared addition of 0.5 and 1.5% of connective tissues into the pork and chicken meat, respectively. On the basis of 3-methylhisitidine concentration, the conversion factor F = 292 ± 4 was calculated for quantification of NMP (%) content.