Color, lipid, and protein oxidation of chicken meat from differently intensified production systems during...

This study aimed to compare the oxidative stability of chicken breast and thigh meat from four distinct production systems differing in their level of intensification using an accelerated oxidation display model. The systems differed in housing conditions and growth rate of the genotypes: indoor and fast-growing (Ind_Fast), indoor and fast-medium-growing (Ind_Fastmed), outdoor and medium-growing (Out_Med), and outdoor and slow-growing (Out_Slow). Sixty mixed-sex broilers were randomly selected from 20 farms in Belgium (5 farms per production system × 3 chickens per farm). On day 2 post-slaughter, skinless breast and thigh meat from each chicken were ground separately. Forty g of ground sample was stored under light (1,600-2,200 lux, 2-4°C) for 168 h, while the remaining ground meat was used for composition analyses. Color CIE L* a* b* coordinates were measured at 0, 48, 96 and 168 h, with total color change (ΔE) calculated at the end of the display period. Lipid oxidation (thiobarbituric acid reactive substances, TBARS), and protein oxidation (protein carbonyl compounds, PCC) were measured at the end of display. In both breast and thigh, indoor-raised chickens exhibited lighter color, characterized by higher L*, and lower a* and b* (P < 0.001) compared to outdoor-raised chickens. However, outdoor-raised chickens showed greater ΔE compared to indoor counterparts, indicating lower color stability. TBARS were higher in breast meat from Out_Slow than Ind_Fast chickens (P < 0.05), whereas there were no significant differences between production systems in thigh meat. The TBARS values remained below the 1 mg/kg threshold for off-flavors in both meat cuts. PCC was not affected by production system in either meat cut. These differences in oxidative stability may be due to production system-related variation in fatty acid composition, heme iron concentration, and antioxidant status, with effects depending on the meat cut. The findings suggest that the observed variation in oxidative stability reflects the combined influence of multiple production system characteristics rather than the effect of any single factor.