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 (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 treatment groups were compared: (i) electrical stunning (T1), (ii) CO₂ gas stunning (80%; T2), (iii) N₂ gas stunning (98%; T3), and (iv) the halal method (non-stunning, T4). 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 pH-24h, color, 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 electrical stunning group (T1) showed high lightness (L*), yellowness (b*), and low redness (a*) in both meat and the small intestine, indicated by a pale color; the CO₂ stunning group (T2) showed high redness (a*), low lightness (L*), and low yellowness (b*), indicated by a dark-red color; and the coloration of meat from the N₂ stunning group (T3) was intermediate between T1 and T2, indicated by a bright red color. For other quality traits, the T3 showed good results and was between T1 and T2. Additionally, severe stress (low pH in both meats), low WHC in meat, and cracked small intestine with numerous apertures were observed in the T2, and pale colored hemorrhagic breast meat was found in the T1. Animal welfare was ignored in the non-stunning halal method. Therefore, in view of animal welfare and quality traits of meat and the small intestine, N₂ gas (98%) can be considered in broiler stunning.