β-alanine or L-carnosine prevents the development of pale, soft and exudative pork by inhibiting the glycolysis of porcine longissimus dorsi muscle

Carnosine plays an important role in regulating muscle buffering capacity and glycolysis. In order to investigate the effects of dietary β-alanine,L-histidine and L-carnosine supplementation on the pH value, glycolytic potential, the activities of AMP-activated protein kinase (AMPK) and pyruvate kinase (PK) activities in the porcine longissimus dorsi muscle, a total of 60 barrows with an average body weight (BW) were assigned into five groups which received diets containing basal diet (control, CON), 0.04%β-alanine (β-ALA), 0.06% L-histidine (L-HIS), 0.04%β-alanine+0.06% L-histidine (β-ALA+L-HIS), or 0.1% L-carnosine (L-CAR). The results showed that dietary supplementation of the combination of β-ALA and L-HIS or L-CAR significantly increased (P 0.05) in back fat thickness and loin eye area among treatments. At 0, 1 and 24 h postmortem (PM) the pH values in the longissimus dorsi muscle (LM) of pigs receiving L-CAR were higher (P 0.05) among treatments. At 1, 24 h PM the AMPK activities in LM of pigs receiving β-ALA, β-ALA+L-HIS and L-CAR were much lower (P