Evaluation of the quality characteristics of nitrogen gas-stunned chicken meat and small intestine.

Abstract

This study aimed to confirm the applicability of the new nitrogen (N2) gas stunning method in the broiler slaughtering process by comparing the meat and small intestine quality following different stunning methods (electrical, carbon dioxide (CO2), N2, and halal). Four treatments were compared: (i) electrical stunning (Elec), (ii) 80% CO2 gas stunning (CO2-gas), (iii) 98% N2 gas stunning (N2-gas), and (iv) the non-stunning method (halal). N2 gas stunning (98%) and the halal method were conducted at the pilot plant abattoir of the national institute of animal science, Korea, and electrical and 80% CO2 stunning were performed on the nearest commercial slaughter house. Meat pH24h, color (lightness, redness and yellowness), proximate composition, water holding capacity (WHC), cooking loss, and Warner-Bratzler shear force (WBSF) were measured, and in the small intestine, pH24h, color, thickness, and WBSF were measured. The Elec treatment showed high lightness, yellowness, and low redness in both meat and the small intestine, indicated by a pale color; the CO2-gas treatment showed high redness, low lightness, and low yellowness, and the coloration of meat from the N2-gas treatment was intermediate between Elec and CO2-gas. For other quality traits, the N2-gas showed good results and was between Elec and CO2-gas. Additionally, severe stress (low pH in both meats), low WHC in meat, and cracked small intestine with numerous apertures were observed in the CO2-gas, and pale colored hemorrhagic breast meat was found in the Elec. Therefore, in view of animal welfare and quality traits of meat and the small intestine, 98% N2 gas can be considered in broiler stunning.