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

This study aimed to confirm the applicability of the new nitrogen (N 2 ) gas stunning method in the broiler slaughtering process by comparing the meat and small intestine quality following different stunning methods (electrical, carbon dioxide (CO 2 ), N 2 , and halal). Four treatments were compared: (i) electrical stunning (Elec), (ii) 80% CO 2 gas stunning (CO 2 -gas), (iii) 98% N 2 gas stunning (N 2 -gas), and (iv) the non-stunning method (halal). N 2 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% CO 2 stunning were performed on the nearest commercial slaughter house. Meat pH 24h , 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, pH 24h , 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 CO 2 -gas treatment showed high redness, low lightness, and low yellowness, and the coloration of meat from the N 2 -gas treatment was intermediate between Elec and CO 2 -gas. For other quality traits, the N 2 -gas showed good results and was between Elec and CO 2 -gas. Additionally, severe stress (low pH in both meats), low WHC in meat, and cracked small intestine with numerous apertures were observed in the CO 2 -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% N 2 gas can be considered in broiler stunning.