2016-06-272016-06-272016-052016-05May 2016http://hdl.handle.net/2346/67136Flavor has become the most important palatability trait when consuming beef, particularly when tenderness is acceptable. Thus, the objective of this study was to assess the raw and cooked precursor compounds associated with beef flavor in relation to consumer sensory evaluation of USDA quality grades, muscle sources, and wet-aging periods. Carcasses of A maturity representing USDA Prime, Low Choice, and Standard (n = 6/Quality Grade) were identified for procurement of the top sirloin (Gluteus medius, GM), bottom round (Biceps femoris, BF), and chuck roll (Serratus ventralis, SV) from the left and right sides of each carcass for 21 or 42-d wet-aging. Immediately following each aging period, ground beef patties were generated for each sample within each treatment for consumer sensory analysis, volatile compound collection, and raw and cooked proximate, lipid oxidation by-products, and neutral and polar lipid fatty acids. Data were analyzed using generalized linear mixed models with USDA quality grades, muscle sources, and wet-aging periods serving as the fixed effects, with least square means separated using an α of 0.05. Principal Component Analysis (PCA) was utilized for the exploration of the influences of muscle source and wet-aging period on the relationships between consumer sensory scores and presence of precursor compounds (volatiles, neutral and polar fatty acids, proximate composition, and TBARS). Consumer sensory evaluation indicated increased wet-aging period led to decreased flavor/overall liking/acceptability scores, regardless of quality grade and muscle source. Muscle source and wet-aging period together influenced consumer sensory evaluation as GM 42d was negatively associated with flavor and overall liking, as evident by PCA. Lipid-derived volatile compound classes (aldehydes, ketones, and alcohols) and cook TBARS relate to these observations as 42d samples, particularly within the BF and GM muscles, contained increased concentrations of these chemical compounds in cooked samples. Additionally, pyrazine and sulfide volatile compounds as well as percentages of polyunsaturated fatty acids within the cooked polar lipid fraction, associated themselves more so with 21d GM and BF samples and 42d GM and BF samples, respectively. Proximate composition (raw and cooked intramuscular fat and pH) were highly associated with SV muscles rather than GM and BF muscles, regardless of wet-aging periods as noted by PCA.application/pdfengMeatLipidAgingVolatilesOxidationMuscleThesis2016-06-27Unrestricted.