Differential abundance of proteome associated with intramuscular variation of meat quality in porcine longissimus thoracis et lumborum muscle

Intramuscular variation of meat quality in the porcine longissimus thoracis et lumborum (LTL) muscle was evaluated by assessing the differential abundance of proteome components. Twenty LTL muscles were individually divided into three regions (anterior, medial, and posterior) according to meat color. CIE L* and b* were higher (P < 0.05), but Warner-Bratzler shear force (WBSF) was lower (P < 0.05) in the anterior region, where myosin-1 and -2, TPM2, MLC1f, MLC2, Hsp27, and TPI1 were highly (P < 0.05) abundant. However, CIE a*, drip loss, and WBSF were higher (P < 0.05) in the medial region. Glycolysis enzymes including enolase 3, ALDOA, LDHA, PGM1, and TPI1 were highly abundant in the medial and posterior region, whereas GAPDH and myoglobin were overexpressed in the medial region (P < 0.05). Therefore, intramuscular variations in color, water-holding capacity, and tenderness were associated with differential abundance of the proteome, especially contractile, glycolysis enzymes, and Hsp27.