Meat quality and flavor compounds of soft-boiled chickens: effect of Chinese yellow-feathered chicken breed and slaughter age

The objective of this research was to investigate the effects of Mahuang and Tuer chickens, 2 representatives of the native chicken breed, and the slaughter age on meat quality and flavor compounds of soft-boiled chickens (SCs) in comparison to a commercial cross boiler. A total of 432 chicks were randomly allocated into the following groups: 817 groups raised for 55 d, and Mahuang and Tuer chickens raised for 60, 65, 70, and 75 days (d). After the completion of rearing period, the chickens were slaughtered, and 5 carcasses per group were randomly selected for SC manufacturing. Meat quality was determined based on product yield, pH, color, meat tenderness, and textural and sensorial attributes. The volatile compounds of chicken breast were identified by gas chromatography-ion mobility spectrometry (GC-IMS). The results showed that the yellow-feathered chicken breed, especially Mahuang chicken, had a higher product yield, and lower shear force and sensorial scores than the cross broiler. The pH, L* and b* values in SC breast meat were not significantly influenced by breed (P > 0.05), while greater a* was observed in SC of yellow-feathered chickens compared to cross broilers. The slaughter age had a significant effect on the pH, color, shear force, and textural properties of SC (P < 0.05). The meat tenderness of SC was significantly decreased as the age of chicken increased from 65 d to 75 d (P < 0.05). The relatively young age of yellow-feathered chickens (60 d and 65 d) was rated to have a higher overall sensory score of SC (P < 0.05). A total of 65 organic volatile compounds were identified in SC, including 18 aldehydes, 16 alcohols, 10 ketones, 9 esters, 2 acids, 3 furans, 5 pyrazines, and 2 sulfur-containing compounds. Three chicken breeds were separately clustered in the plot of principal component analysis, indicating breed-specific flavor characteristics. Collectively, the present study provides valuable information for SC processing in terms of carcass selection of yellow-feathered chicken breeds and slaughter age.