Effect of electrical stunning frequency on meat quality, plasma parameters, and protein solubility of broilers

Abstract

This study was designed to compare the effects of different stunning frequencies of pulsed direct current on meat quality of broilers. This was achieved by investigating plasma parameters, blood loss, carcass damage, meat water-holding capacity, meat color, meat shear value, muscle pH, and protein solubility. A total of 400 broilers was divided into 5 treatment groups and stunned with 500, 600, 700, 800, and 900Hz at 15V for 10 seconds. Blood samples were collected immediately after cutting the neck. Pectoralis major muscles were removed from the carcass after chilling and placed in ice. Breast muscle pH and meat color were determined at both 2 and 24h postmortem. Drip loss, cooking loss, pressing loss, and cooked breast meat-shear values were determined at 24h postmortem. Treatment at 500 and 900Hz significantly increased (P <0.05) blood plasma corticosterone and lactate concentrations compared with the 700Hz group. The wing damage of carcasses was significantly serious in the 500, 800, and 900Hz groups. The Pectoralis minor damage of carcesses in the 700Hz group was significantly lower (P <0.05) compared to the other stunning groups. The pH at 2h postmortem in the 500 and 900Hz groups was significantly lower (P <0.05) than in other groups. However, the final pH and meat color were not affected by stunning frequency. In the 500 and 900Hz groups, the protein solubility and shear force values were significantly lower (P <0.05) and drip loss was significantly higher (P <0.05) than in the 700Hz group. This study indicates that the waveform of the pulsed direct current is acceptable for stunning broilers at a stunning frequency of 700Hz.