Abstract: Chemical and physical properties of Thai indigenous chicken, spent hen and broiler pectoralis and biceps femoris muscles were investigated before and after heating in mixed herbs acidified soup (Tom Yum). Raw muscles of Thai indigenous chicken contained higher protein and fat but lower in ash content, compared to spent hen and broiler muscles (p< 0.05). Spent hen biceps femoris muscle had significantly higher total collagen content but less soluble collagen among the breeds (p< 0.05). Heating under Tom Yum soup (pH 2.8, 95°C) decreased the collagen content and increased soluble collagen of chicken muscles leading to decrease shear value of chicken muscles especially in spent hen muscles. L*, a*, b* values of all breeds chicken muscles were increased after cooking. The indigenous chicken and spent hen biceps femoris muscles exhibited the higher shear force value with the higher cooking loss than those of broiler muscles (p< 0.05). After thermal process in Tom Yum soup at 116 and 121°C to an F0 value of 6.0, there were no significant differences between treatments for shear values, total collagen and sensory characteristics of spent hen muscles (p>0.05). However, process at lower temperature increased more soluble collagen (p< 0.05).
Khwunsiri Chuaynukool , Saowakon Wattanachant and Sunisa Siripongvutikorn , 2007. Chemical and Physical Properties of Raw and Cooked Spent Hen, Broiler and Thai Indigenous Chicken Muscles in Mixed Herbs Acidified Soup (Tom Yum) . Journal of Food Technology, 5: 180-186.