Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed May 16, 2007). PDF text: xi, 280 p. : ill. (some col.) ; 2.59Mb. UMI publication number: AAT 3236913. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.Ag.Sc.)--University of Adelaide, Dept. of Animal Sciences, 2004? / Includes bibliographical references (leaves 196-214). Also available online.

This study determined how quality grade and degree of doneness influence the development of beef flavor compounds among whole muscle and ground patties. Proximate composition, pH, cooking duration, neutral and polar lipid fatty acids, free and total amino acids, total reducing sugars, and volatile compounds were evaluated in beef strip steaks and ground patties of Longissimus lumborum from three USDA quality grades (Prime, Low Choice, and Standard; n=8 per quality grade) and six degrees of doneness (4, 25, 55, 60, 71, and 77°C). In the split-plot experiment, quality grade was the whole-plot, product-type was a sub-plot, and degree of doneness was the sub-sub-plot. The 3-way interaction of quality grade, degree of doneness, and product type impacted moisture (P = 0.004) and protein content (P = 0.006); pH (P < 0.001); neutral and polar lipid fatty acids (P ≤ 0.048); free and total amino acids (P ≤ 0.044); total reducing sugars (P < 0.001); and volatile compounds (P ≤ 0.029). The 2-way interaction of quality grade and degree of doneness impacted free amino acids (P ≤ 0.036); PUFA within the neutral lipid fraction (P ≤ 0.033); fatty acids within the polar lipid fraction (P ≤ 0.043); volatile compounds (P ≤ 0.038); and the total fat percentage (P = 0.046). The 2-way interaction of quality grade and product type impacted fatty acids within the neutral lipid fraction (P ≤ 0.042); fatty acids within the polar lipid fraction (P ≤ 0.015); and volatile compounds (P ≤ 0.047). The 2-way interaction of product type and degree of doneness affected fatty acids within the neutral lipid fraction (P ≤ 0.046); fatty acids within the polar lipid fraction (P ≤ 0.035); free amino acids (P ≤ 0.005) and total amino acids (P ≤ 0.004); volatile compounds (P ≤ 0.029); and cooking duration (P < 0.001). Overall the results of this study indicated that quality grade, grinding, and cooking have interacting effects on flavor related compounds. Thus, each factor must be considered during any model development which aims to predict beef flavor.

In an effort to increase beef demand, the beef industry has expanded beyond commodity beef merchandizing into value-added cuts. As these beef cuts are developed it is critical that the industry be able to characterize the flavor attributes of these products. A trained sensory panel is typically utilized to determine flavor characteristics of food products including beef. Prior to product evaluation, a product lexicon or dictionary of terms is developed in order to anchor and orient panelists to the various samples. Once the lexicon is developed, it can be used by a descriptive panel to evaluate samples. Currently, the beef industry does not have a full beef flavor lexicon with defined references; therefore a comprehensive sensory lexicon for describing the aroma and flavor of beef was developed by a 6-member panel at Kansas State University with extensive experience in lexicon development and descriptive analysis. Three descriptive panels utilized the beef flavor lexicon developed in Phase I by Kansas State University to evaluate the effect of USDA Quality Grade and cut on beef flavor and to validate the beef flavor lexicon to determine if it is ready for use by scientists. iv Results indicated that Choice steaks and roasts were higher in fat-like, and overall sweet flavor. Eye of round roasts were lowest in aroma and flavor attributes and bottom round roasts were highest in liver-like flavor. Flat iron steaks were highest in fat-like flavor compared to other cuts and top loin steaks tended to have the lowest intensity in flavor attributes compared to the steak cuts. The three sensory panels rated steaks and roasts similarly for aroma and flavor attributes and were generally less than 2- to 1-point different in rating intensities. The beef flavor lexicon was easily applied across the three institutions and should be ready to be used as a viable research and product development tool.