Effect of Different Electrical Voltages Stunning on Meat Quality of Broilers Postmortem
|School||Nanjing Agricultural College|
|Course||Of Food Science|
|Keywords||electrical stunning voltage broiler edible quality energy metabolism ultrastructure|
Stunning is an effective method to avoid pain of animals during slaughter from the point of animal welfare. Electrical stunning has been used widely in broiler slaughter in China, but the effect of stunning on meat quality of broilers has not been studied yet. The effect of stunning voltage on meat quality was studied in this paper, and the theory of stunning was learned by energy metabolism and ultrastructure changes after different stunning voltages.1 Effect of voltages of electrical stunning on edible quality of broilerExperiment was conducted to determine the effect of different stunning voltages on edible quality of broiler breast meat. Broilers were stunned with 60V,80V,90V,100V or 120V(duration 5s, frequency 50Hz), the stunning affect was written down, and then breast fillets were removed from carcasses after colding, and analyzed for color, pH, drip loss and share value. Results showed:the broilers stunned with 100V and 120V were all inconscious, the quality of carcass with less blood sparks or broken bones of broilers stunned with 100V was better than others. L* of 120V stunning process group was significantly lower than any of other groups, but a* and b* were not significantly affected by stunning voltage. The pH at 3h was significantly higher than the other groups under 100V stunning condition with the lowest pH at 24h. The breasts dealed with 120V stunning had the highest drip loss, while 100V disposal group lower. The shear value of the samples stunned with 100V with the worst tenderness, the total protein solubility and myofibril protein solubility of 100V disposal group was lower than any of the other groups.2 Effect of voltages of electrical stunning on energy metabolism of broiler postmortemExperiments were conducted to determine the effect of different stunning voltages on the energy metabolism of broilers postslaughter. Broilers were stunned with 60V,80 V,90V, 100V or 120V(duration 5s, frequency 50Hz), breast fillets were removed from carcasses at 1h,2h,4h,8h and 24h postmortem and analyzed for glycogen, lactic acid, pH, ATP, ADP, AMP and IMP content. Results showed that the glycogen content of 100V and 120V stunning groups with lower lactic acid level was higher than the others at 1h postmortem. The breast stunned with 60V and 80V had less glycogen than the other groups at 24h, but the lactic acid accumulation was not significantly affected by stunning treatments at this time. At 1h,2h and 4h postmortem, the pH value of 100V stunning group was higher than the other groups, while no difference at 24h postmortem between treatments. As the voltage raised, the ATP level increased first and then decreased at 1h, however the ATP content under 100V stunning treatment was higher than others which tended to be 0 at 8h. The content of IMP of 60V,80V and 90V disposal groups was significantly higher than the other two groups, but they were not significantly different at 4h,8h and 24h.3 Effect of voltages of electrical stunning on ultrastructure of broilerThe changes of ultrastructure of chicken dealed with different stunning voltages were studied in this chapter. Broilers were stunned with 60V,80V,90V,100V or 120V (duration 5s, frequency 50Hz), breast fillets were removed from carcasses. Experiments were carried out including observation of frame structure changes under transmission electron microscope and light microscope, analyzation of protein using DSC, SDS-PAGE leectrophoresis, and finding out the water distribution using low-filed NMR after different voltages stunned. Results were as follows:the frame structure of sarcomers was destroyed, and abnormal shapes appeared after 120V stunning. The fiber diameters we got at 3h postmortem were shorter than that at 24h postmortem except 120V stunning disposal. The protein weighting 49kDa isolated from 60V disposal unbounded in the SDS-PAGE leectrophoresis graphs, while the protein weighting 24kDa and 28kDa increased; the proportion of T22 area dealed with 100V stunning voltage was higher notably than the others, indicating better water holding capacity.