Effects of Pre-Slaughter Gas Mixture Stunning with Different Carbon Dioxide Concentrations on Liver Color,Lipid Oxidation and Antioxidant Capacity of Meat Geese

ZHANG Xin;LUO Zhaoyun;XU Lei;WAN Xiaoli;CHEN Xiaoshuai;WANG Zhiyue;College of Animal Science and Technology,Yangzhou University;Institutes of Agriculture Science and Technology Development,Yangzhou University;

controlled atmosphere stunning;;carbon dioxide concentration;;geese;;liver color;;lipid oxidation

This experiment was conducted to investigate the effects of pre-slaughter gas mixture stunning( controlled atmosphere stunning) with different carbon dioxide( CO_2) concentrations on liver color,lipid oxidation and antioxidant capacity of meat geese. Fifty-six 85-day-old Yangzhou male geese were selected and randomly divided into 7 groups( one control group and six test groups) with eight replicates per group and one goose per replicate. The geese in the control group were slaughtered without stunning,and those in test groups were stunned by gas mixture with different CO_2 concentrations. The gas mixture composition of six test groups as follows: G40 group,40%CO_2+21% oxygen( O_2) +39% nitrogen( N_2); G50 group,50%CO_2+21%O_2+29% N_2; G60 group,60%CO_2+21%O_2+19% N_2; G70 group,70%CO_2+ 21% O_2+ 9% N_2; G79 group,79%CO_2+ 21% O_2; G40+G79 group,40%CO_2+30%O_2+30%N_2 stunning for 2 min,and then 79%CO_2+21%O_2 stunning for 5 min. The stunning time for the first5 groups was 7 min. The results showed as follows: the bleed out efficiency of G79 group was the lowest,which had significant difference compared with that of control,G40,G50,G70 and G40+G79 groups( P<0.05). Liver lightness value of G40 group was significantly higher than that of G79 and G40+G79 groups at 1 and 4 days after slaughter( P<0.05). Liver yellowness value of G40 group was significantly higher than that of G79 and G40+G79 groups at 1 day after slaughter( P<0.05). At 1 day after slaughter,the malondialdehyde( MDA) content in liver of G40 group was significantly lower than that of G70 and G79 groups( P < 0. 05); at 4 and 7 days after slaughter,the MDA content in liver of G79 group was significantly lower than that of G40 group( P<0.05). At 0 day after slaughter,the liver 1,1-diphenyl-2-picrylhydrazyl( DPPH) free radical scavenging activity of G79 group was the lowest,and it of G40 group was the highest,but there was no significant difference among groups( P>0.05). The activity of glutathione peroxidase( GSH-Px) in liver of G40 group was significantly lower than that of G79 group at 1,4 and 7 days after slaughter( P<0.05). The activity of total superoxide dismutase( T-SOD) in liver of G40 group was significantly higher than that of G79 group at 4 days after slaughter( P < 0.05). In conclusion,pre-slaughter gas mixture stunning with 40% CO_2( 40%CO_2+21%O_2+39%N_2) can improve liver color. The liver DPPH free radical scavenging activity is the highest and lipid oxidation degree is the lowest when geese stunned with 40% CO_2 at the initial stage of storage( 0 to 1 day),whereas,the lipid oxidation at a longer storage time( 4 to 7 days) is lower in geese stunned by gas mixture( 79%CO_2+ 21% O_2) with high concentration( 79%) of CO_2.