Changes of Physicochemical Indexes and Characteristic Flavor Substances in Wuding Chicken Processing

Objective:To study the differences of physicochemical indexes and volatile flavour compounds in Yunnan Wuding chicken processing,and to analyze the changes of moisture and volatile flavour compounds in different processing stages,so as to provide scientific basis for controlling the processing process of Yunnan Wuding chicken. Methods:The changes of moisture content,color,shearing force,pH,fat content and protein content during processing of Wuding chicken were determined. Nuclear magnetic resonance(NMR)was used to analyze the changes of water migration in Wuding chicken raw meat,chicken boiled for 1 h,fried chicken,chicken boiled for 2 h. Meanwhile,gas-phase ion mobility spectrometry(GC-IMS)was used to determine the differences of volatile flavour compounds in different processing stages. Results:During the processing,the color,shear force,pH and protein content of chicken showed an upward trend. During the frying stage,the fat content of meat sample was the highest. The moisture content of Wuding chickens decreased by 11.54%(P<0.05)after cooking,and the content of immobilized water decreased gradually. Compared with the first-hour stage of brine cooking,the content of bound water increased by 0.75%(P<0.05)and 1.17%(P<0.05)in the fried chicken and chicken boiled for 2 h,respectively. GC-IMS results showed that the volatile flavour substances in different processing stages of boiled Wuding chicken were significantly different,the quantity of volatile flavour compounds were increasing,the concentration of benzaldehyde and glutaraldehyde increased gradually,and the concentration of n-hexanol and propanol decreased. There were significant differences in volatile flavour compounds in different processing stages. After processing,the volatile flavour compounds in Wuding chicken were more abundant. Conclusion:The moisture of Wuding chicken is changing constantly during processing,the concentration of volatile flavour substances increase. In short,the cooked Wuding chicken not only has better flavor,but also improves nutritional value.