Nitrogen compounds as potential biochemical markers of pork meat quality

Muscle proteins, peptides and free amino acids were analysed at 2 h post-mo rtem as potential markers of different pork meat qualities. The meat qualit y classification was based on the measurements: pH(2h), pH(24h), the colour parameter L, and drip loss. The measurement of proteolytic fragments by SD S-PAGE revealed that the nebulin band was different among classes being mor e defined in the dark, firm and dry meat class. The detection and character isation of small peptide fragments resulting from protein breakdown was don e by isolation through cationic and reverse-phase chromatography. The analy sis of peptide fractions isolated by reverse-phase chromatography revealed that could be used as potential markers of meat quality. So, peptide fracti on 1 could be used to distinguish exudative from non-exudative meats and pe ptide fraction 4 distinguished dark, firm and dry meat from the rest. The c oncentration of free amino acids present in muscle was not different among qualities, probably due to the early post-mortem time (2 h) used in the stu dy. (C) 2000 Elsevier Science Ltd. All rights reserved.