Free amino acids and dipeptides in porcine muscles: differences between 'red' and 'white' muscles

Three porcine muscles (m. longissimus dorsi, masseter and trapezius), chose n to represent the three main metabolic types, from 18 carcasses had their free amino acids and dipeptides quantified by reverse-phase high performanc e liquid chromatography (HPLC) in aqueous extracts derivatized with phenyl isothiocyanate. Of the 25 measured compounds, four amino acids and the dipe ptide carnosine were closely related to the metabolic type of the three mus cles. Masseter, a red oxidative muscle, had the highest contents of asparti c acid, glutamine and taurine. Longissimus dorsi, a white glycolytic muscle was characterised by the highest contents of beta-alanine and carnosine. T rapezius, an intermediate muscle, had intermediate contents. These results show that free amino acid and dipeptide contents could partly explain diffe rences in taste of muscles from the same species. (C) 1998 Elsevier Science Ltd. All rights reserved.