Effects of Electrical Stunning Methods on Broiler Meat Quality04 September 2014
No stunning or medium-voltage stunning conditions reduced meat water-holding capacity and decrease meat shear force when compared with either low- or high-voltage stunning, according to new research from Nanjing, China.
A study has been designed at Nanjing Agricultural University to compare the effects of different stunning systems on the meat quality of broilers.
In a paper in Poultry Science, corresponding author X.L. Xui, and colleagues explain that they investigated meat water-holding capacity, meat colour, muscle glycogen and lactate concentrations, as well as blood parameters, low-field nuclear magnetic resonance (NMR) transverse relaxation, and myofibrillar ultrastructures.
A total of 160 broilers were divided into four treatment groups:
- a low-voltage stunning (LS) with a constant voltage of 15V at 750Hz for 10 seconds
- a mid-voltage stunning (MS) with a constant voltage of 50V at 50Hz for 10 seconds;
- a high-voltage stunning (HS) with a constant voltage of 100V at 50Hz for five seconds, and
- a control group with no stunning (NS).
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, meat color, glycogen, and lactate contents were determined at both two hours and 24 hours post-mortem.
Drip loss, cooking loss, pressing loss, cooked breast meat shear values, low-field NMR and ultrastructures of myofibrils were determined 24 hours post-mortem.
The NS and MS treatments significantly increased (P<0.05) blood plasma corticosterone, initial rate of glycolysis and drip loss, and significantly reduced (P<0.05) initial muscle pH and shear force values when compared with LS and HS.
The results of low-field NMR reflect that NS and MS significantly decreased (P<0.05) NMR transverse relaxation population 1 (T21) and increased (P<0.05) NMR transverse relaxation population 2 (T22).
The myofibrils of NS and MS samples showed significantly (P<0.05) longer sarcomere length when compared with the LS and HS samples.
Meat colour, cooking loss, pressing loss and final pH were not affected by the stunning methods.
Xu and colleagues concluded their results indicates that NS and MS treatments reduce meat water-holding capacity and decrease meat shear force when compared with LS and HS.
Huang J.C., M. Huang, J. Yang, P. Wang, X.L. Xu and G. . Zhou. 2014. The effects of electrical stunning methods on broiler meat quality: Effect on stress, glycolysis, water distribution, and myofibrillar ultrastructures. Poultry Science. 93 (8): 2087-2095. doi: 10.3382/ps.2013-03248
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