Phospholipase A2 Activity in Poultry Pse, Pale, Soft, Exudative, Meat

Abstract

The interrelationship between phospholipase A2 activity (PLA (2)) and the development of pale, soft, exudative meat (PSE) in chicken was evaluated. Pectoralis major m. from female birds of 45 days of age after hatch was studied and determination of the enzyme activity was estimated by the formation of long‐chain fatty acids. The occurrence of PSE was evaluated by measuring pH, L* values, water holding capacity and sarcoplasmic Ca2+ concentration from both heat‐stressed and nonstressed birds. In addition, the occurrence of the syndrome was monitored with birds advancing in age. Our studies revealed that PLA(2) plays an important role towards the occurrence of PSE symptoms and its activity increased as the birds became older. The enzyme activity was detected from the beginning of our experiment at 36 days and increased up to 70 days after hatch. The overall average activity was 1.25 times more pronounced in PSE samples from heat‐treated birds when compared to control animals (P ≤ 0.05).

Lipid oxidation and fatty acid profile related to broiler breast meat color abnormalities

“…As expected, PSE meat samples had the lowest pH values; DFD-like samples had higher pH than normal meat samples (p≤0.05). The Minolta L* values, which expressed the meat brightness, were highest in the PSE group, indicating paler meat in comparison sequentially to that of normal meat and DFD-like samples, thus confirming previous results (Olivo, et al, 2001, Soares et al, 2003b, Guarnieri et al, 2004, Fletcher, 1999, Alvarado and Sams, 2004. The a* and b*, a* values were significantly lower for PSE meat samples in relation to normal and DFD-like meat while b* values did not show any significant difference (p≤0.05), similar to those reported by Fletcher (1999).…”

“…Endogenous thermal stress promotes a higher intracellular phospholipase A2 (PLA2) activity in the presence of micromolar elevation in intracellular Ca 2+ as originally proposed by Cheah et al (1986) in pigs and by Soares et al (2003b) in broiler. As these authors originally hypothesized, this enzymatic reaction might be the triggering factor to initiate the formation of PSE meat by increasing substantially the peroxidation reactions, confirmed by the results shown in Table 2.…”

“…Soares et al (2003b) postulated that thermal stress promoted higher mitochondrial phospholipase A2 (PLA2) activity in the presence of higher concentrations of Ca 2+ and that this could be the triggering factor in initiating the characteristic symptoms, leading to broiler PSE meat formation. PLA2 is a lypolytic enzyme which acts upon phospholipid membrane, liberating arachidonic acid (Murakami and Kudo, 2002).…”

Commercial preslaughter blue light ambience for controlling broiler stress and meat qualities

“…The b* values of the fillets from the control group were significantly higher than those from the blue light group. The pH and L* values of the fillet control group were typical of PSE broiler meat as previously reported (Olivo et al 2001;Soares et al 2003;Barbut et al 2008;Wilhelm et al 2010). Fillets from the control group exhibited characteristics that were more yellowish than the characteristics of PSE broiler meat (Qiao et al 2001).…”

“…The color values were measured at three different sites on the same sample. These sites were the proximal extremity of the muscle, distal extremity of the muscle and medial side at the halfway point between the proximal and distal extremities (Soares et al 2003;Soares et al 2009) …”