Studies On The Characteristic Of Quality Chicken Flavor

Nutrition regulation was a potential way to improve poultry meat quality. In this thesis, four experiments were carried out to study the effects of strain, age, and body part on the concentrations of taste compounds and aroma precursors, and research the quantitative changes of those flavor-relating compounds during cooking, then investigate the components of flavor volatiles released from roasted and cooked meat samples. At last, model systems were used to estimate the relative contributions of aroma precursors to total poultry meat aroma. The aim was determining the major flavor precursors of poultry meat and factors resulting in flavor differences between fast-growing and quality chickens, and provided basic information for improving poultry meat quality by nutrition regulation.Experiment 1. The effects of strain, age, and body part on the concentrations of taste compounds and aroma precursorsShiqihuang chicken and Arber Acres broiler fed under same production regime were slaughtered at 56 days and 90days. The breast and thigh meat of those birds were used as experimental materials. The contents of DM, CP, EE, fatty acids, amino acids, free amino acids, thiamine, total reducing sugar, IMP, HxR, and Hx in all meat samples were measured. The results were as follows: 1) Significant differences in the concents of flavor-relating compounds were observed between two strains (P<0.05). The concents of DM, EE, most of fatty acids, total reducing sugars, and IMP in breast and thigh meat of Shiqihuang chicken were markedly higher than those in Arber Acres broiler(P<0.05), and the concentrations of most free amino acids in Shiqihuang chicken were lower than those in Arber Acres broiler(P<0.05), and no differences were found in contents of CP, amino acids, and thiamine between two strains (P>0.05); 2) Age had a markedly effect on the chemical composition of meat samples. Older birds had higher concentrations of DM, CP, and IMP and lower concentrations of most of free amino acids and thiamine in breast meat when compared with younger birds (P<0.05). The concentrations of DM, EE, most fatty acids and total reducing sugar in thigh meat of older birds were significantly higherthan those in younger birds (P<0.05), but younger birds had higher concentrations of most free amino acids (P<0.05); 3) The contents of CP, most amino acids, total reducing sugar, and IMP in breast meat were significantly greater than those in thigh meat (P<0.05), but the concentrations of EE, most fatty acids, most free amino acids, and thiamine in breast meat were lower compared with those in thigh meat (P<0.05); 4) Shiqihuang chicken at 90 days had higher contents of EE, fatty acids, total reducing sugars, and IMP and lower concentrations of most of free amino acids when compared with 56 day Arber Acres broiler(P<0.05). The above results indicated that there were significant differences in concentrations of flavor-related compounds between strains, ages or body parts, and Shiqihuang chicken' better flavor possibly resulted from its' higher contents of EE, fatty acids and IMP. This study has set up a foundation for further investigation in the differences of volatile compounds and sensory flavor among between two strains, and for determining the major factors resulting in those differences. Experiment 2. The effect of cooking on the concentrations of important flavorprecursors in poultry meat samplesConsidering the different market ages of Shiqihuang chicken and Arber Acres broiler, and the quantitative changes of flavor-related compounds in meat samples at different ages might be similar, the breast and thigh meat of 90 days Shiqihuang chicken and 56 days Arber Acres broiler were chosen for this study. The concentrations of fatty acids, free amino acids, thiamine, total reducing sugar, IMP, HxR, and Hx in cooked meat samples were measured. The results showed that: 1) After being cooked, the contents of most fatty acids, total reducing sugar, and IMP in breast meat of Shiqihuang chicken were significantly higher than those in Arber Ac...