Browsing by Author "Tatum, J. Daryl, advisor"
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Item Open Access Effect of USDA carcass maturity on eating quality of beef from fed steers and heifers that have been classified into maturity groups using dentition(Colorado State University. Libraries, 2015) Semler, Megan Lynn, author; Woerner, Dale R., advisor; Tatum, J. Daryl, advisor; Belk, Keith E., committee member; Enns, Kellie J., committee memberObjectives were to compare sensory properties of LM steaks from A maturity and B maturity or older carcasses that were produced by grain finished steers and heifers classified as less than and greater than 30 months of age at the time of slaughter by dentition. Carcasses were selected to represent 2 dentition groups, 2 maturity groups, and 3 marbling categories within each dentition x maturity group resulting in 12 dentition x maturity x marbling subclasses; each subclass consisting of 50 carcasses. Dental age groups consisted of carcasses classified as less than or 30 months of age (MOA) or 30 MOA or older by dentition. Maturity groups consisted of carcasses classified by USDA graders as either A⁰⁰ to A⁹⁹ overall (A) maturity or B⁰⁰ to D⁹⁹ overall (B-D) maturity; marbling categories consisted of carcasses with instrument marbling scores of Slight (SL), Small (SM), or Modest ⁰⁰ to Moderate ⁹⁹ (MT-MD). Carcasses were selected in pairs so that each carcass selected to represent the B-D maturity group was paired with an A maturity carcass of the same sex and similar marbling score (± 50 marbling units.) Strip loin (LM) steaks were obtained from both sides of each carcass. After a 14-d aging period, 1 LM steak was evaluated for Warner-Bratzler shear force (WBSF) and slice shear force (SSF). The other LM steak was used for sensory analysis by a trained descriptive attribute panel. No differences (P > 0.05) were detected in WBSF, SSF, or sensory panel ratings for tenderness juiciness, or flavor between LM steaks from carcasses classified as A maturity vs. steaks of carcasses classified from B-D maturity. Sex class influenced (P < 0.05) WBSF and sensory panel tenderness. As degree of marbling increased, sensory tenderness, juiciness, meaty/brothy flavor, and buttery/beef fat flavor increased (P < 0.05) while bloody/serumy flavor, WBSF and SSF decreased (P < 0.05). There was a significant interaction between dental age group and marbling category for SSF and panel tenderness ratings, where cattle classified as 30 MOA or older with a slight degree of marbling produced the toughest (P < 0.05) LM steaks. Within the SM and MT-MD marbling categories dental age had no effect. Results from this study suggest that USDA quality grades could be effective at determining eating quality differences to grain-finished cattle with a dental age less than 30 mo old at the time of slaughter if the A and B-D maturity groups were combined and quality grades were assigned only by marbling. In grain-finished cattle 30 mo or older at the time of slaughter the evidence was not sufficient to make conclusions.Item Open Access Effects of pre-slaughter cattle management on postmortem tenderization of beef(Colorado State University. Libraries, 2009) Gruber, L. Sandra, author; Tatum, J. Daryl, advisorTwo independent studies were used to investigate the effects of pre-slaughter cattle management on postmortem tenderization of beef. In experiment I, relationships between behavioral and physiological symptoms of pre-slaughter stress and beef LM tenderness were examined using calf-fed steers (n = 79) and heifers (n = 77). Pen, chute, and post-transportation behavior scores were assigned to each animal. Physiological indicators of stress included cortisol, epinephrine, creatine kinase, lactate, glucose, heart rate, respiration rate, and rectal temperature. Positive correlations (P < 0.05) between behavior scores and physiological parameters indicated that cattle that exhibited behavioral symptoms of stress also responded physiologically. Mean Warner-Bratzler shear force (WBSF) was positively correlated (P < 0.05) with all 3 measures of stressful behavior (r ≥ 0.23). Plasma lactate concentration at slaughter was associated (P < 0.05) with mean WBSF and response to postmortem aging. In Experiment II, effects of genotype and implant program on LM and gluteus muscle (GM) postmortem tenderization were investigated using crossbred steer (n = 185) and heifer (n = 158) calves. The 3-marker GeneSTAR Tenderness panel was used to determine each animal's genotype. Calves were assigned to 1 of 2 implant programs, conventional or delayed. Steaks from conventionally implanted cattle had WBSF values that were approximately 0.2 kg higher (P < 0.05) than steaks from animals that received a single delayed implant, but only during the early postmortem period (3 to 7 d). For both muscles, a linear effect of genotype on WBSF was detected (P < 0.05). Steaks from cattle with most desirable genotype had WBSF values 0.33 kg lower than steaks from cattle with the least desirable genotype. Pre-slaughter factors (sex, implant program, and genotype) controlled in Experiment II each accounted for less than 10% of the explained variation in tenderness of the experimental population. Results of Experiment I identified behavioral and physiological symptoms of acute pre-slaughter stress that were associated with pH-independent differences in tenderness. Findings from Experiment II suggest that pre-slaughter cattle management can impact beef tenderness, but the factors evaluated only accounted for a small proportion of variation in beef tenderness for the experimental population.Item Open Access Identifying preferences for specific beef flavor characteristics(Colorado State University. Libraries, 2012) O'Quinn, Travis Gene, author; Belk, Keith E., advisor; Tatum, J. Daryl, advisor; Woerner, Dale R., committee member; Engle, Terry E., committee member; Chapman, Phillip L., committee memberDescriptive sensory analysis of beef samples was conducted at culinary institutions in three regions of the United States to determine differences in beef flavor attributes and flavor preferences among 12 different beef product categories (treatments). Treatments were chosen specifically to permit identification and characterization of production-related beef flavor differences, including effects of USDA grade (Prime, Premium Choice, Low Choice, Select), cattle breed-type (Angus, Holstein, American Wagyu), finishing diet (grass-fed, corn-fed, barley-fed), use of growth technologies (non-implanted, implanted, implanted & fed β agonists), and postmortem aging method (wet-aged, dry-aged). Panelists (N = 307) rated ground strip loin samples from each treatment for 13 different flavor notes (beefy/brothy, browned/grilled, buttery/beef fat, nutty/roasted nut, earthy/mushroom, bloody/metallic, grassy, livery, fishy, sour, sweet, and bitter) and overall flavor desirability. Each sensory attribute was rated on a 10-cm, unstructured line scale with 0 cm verbally anchored at very low intensity for all flavors and dislike extremely for flavor desirability and 10 cm verbally anchored at very high intensity for all flavors and like extremely for flavor desirability. In addition, samples were analyzed to determine percentage chemical lipid, moisture, protein, and ash of raw products, fatty acid composition of cooked products, and quantities of volatiles produced during cooking. Of the factors analyzed, USDA Quality grade and finishing diet (grain-fed vs grass-fed) had the largest effects on beef flavor attributes. Differences in cattle-breed type (Angus vs Wagyu), grain source (corn vs barley), aging technique (dry-aged vs wet-aged), and use of growth technology (non-implanted vs implanted vs implanted & fed β agonists) had only minimal effects on flavor. Extending the wet-aging period from 14 to 46 d had a negative effect on flavor, producing samples that scored higher (P < 0.05) for sour flavor than all other treatments. Panelists preferred samples with flavors described as beefy/brothy, browned/grilled, buttery/beef fat, nutty/nutty roasted nut, and sweet, and disliked flavors identified as bloody/metallic, grassy, gamey, livery, fishy, sour, and bitter. Moreover, overall flavor desirability scores were positively correlated (P < 0.05) with the concentration of several monounsatured fatty acids including C12:1, C14:1, C16:1 c9, and C18:1 c9. Stearic acid (C18:0) concentration was negatively correlated (P < 0.05) with overall flavor desirability and positively correlated (P < 0.05) with bloody/metallic, grassy/hay like, gamey, livery, fishy, sour, and bitter flavors. The concentration of several polyunsaturated fatty acids including C18:2t (total), C18:3 n-3, and C22:5 n-3, were found highest (P < 0.05) in Organic grass-fed samples and were negatively correlated (P < 0.05) with overall flavor desirability. Overall flavor desirability was positively correlated (P < 0.05) with diacetyl (2, 3-butanedione), acetoin (3-hydroxy-2-butanone), 3-methyl butanal, and pentanal concentrations. Samples with higher concentrations of dimethyl sulfide were rated lower (P < 0.05) for overall flavor desirability. The concentrations of several volatile compounds were correlated with various beef flavors including beefy/brothy, buttery/beef fat, browned/grilled, earthy/mushroom, nutty/roasted nut, sour, bitter, and sweet.Item Open Access Relationships between USDA camera-based quality grades and beef sensory attributes(Colorado State University. Libraries, 2011) Emerson, Mallory R., author; Woerner, Dale R., advisor; Tatum, J. Daryl, advisor; Belk, Keith E., committee member; Pendell, Dustin L., committee memberThis study quantified relationships of recently adopted camera-based USDA beef quality grades to LM sensory attributes and shear force. Heifer and steer carcasses (n = 718, all A-maturity) were selected at beef processing plants in CO, KS, NE, and TX, using marbling scores determined by on-line camera grading systems, to represent 7 marbling degrees: Traces (TR), Slight (SL), Small (SM), Modest (MT), Moderate (MD), Slightly Abundant (SA), and Moderately Abundant (MA). Strip loin steaks were obtained from both sides of each carcass and aged for 14 d. One steak was used to obtain Warner-Bratzler shear force (WBSF) and slice shear force (SSF) measurements; the other steak was evaluated by a trained sensory panel for juiciness, tenderness, detectable levels of several flavors (meaty/brothy, buttery/beef fat, bloody/serumy, livery/organy, and grassy), and overall sensory experience (negative vs. positive). Camera marbling score explained 45, 40, 32, 71, and 61% of the variation in panel ratings for juiciness, tenderness, meaty/brothy flavor intensity, buttery/beef fat flavor intensity, and overall sensory experience, respectively. Increased degree of marbling resulted in steaks having greater (P < 0.001) juiciness, tenderness, meaty/brothy flavor intensity, and buttery/beef fat flavor intensity. The likelihood of a steak delivering a positive sensory experience also became greater (P < 0.001) as degree of marbling increased (MA = SA > MD = MT > SM > SL > TR). Nearly all (98 to 99%) of the steaks with MA and SA marbling, and most (between 80 and 90%) of the steaks with MD and MT marbling received positive ratings for overall sensory experience compared with 62% of the SM steaks, 29% of the SL steaks and 15% of the TR steaks. Steaks produced by steers had lower (P < 0.05) WBSF and SSF values and were generally rated as more tender by sensory panelists than steaks produced by heifers, but the effect of sex on panel tenderness was significant only within the TR category. Comparison of 2 methods for determining camera-based quality grades (i.e., use of original camera grade lines, based on marbling assessments of USDA grading experts vs. use of adopted camera grade lines, based on marbling assessments of field graders) showed that both methods of grade placement effectively stratified carcasses into grades that differed (P < 0.05) with respect to steak juiciness, tenderness, and flavor, with little discernible difference between methods.Item Open Access Use of video image analyses to identify carcass characteristics and sensory quality of beef products generated from mature cow carcasses(Colorado State University. Libraries, 2009) Woerner, Dale R., author; Belk, Keith E., advisor; Tatum, J. Daryl, advisorA single study (sponsored by the beef check-off) was conducted to investigate the ability of video image analysis technology to identify carcass characteristics and sensory attributes of products generated from mature cow carcasses. Market cows representing three pre-harvest management strategies were used to evaluate the ability of video image analysis (VIA) to identify the impacts of pre-harvest management (MGMT) on carcass muscle and beef sensory characteristics. Cow MGMT groups were as follows: (1) Non-fed cows (n = 104) (NON-FED; beef-type cows entering the slaughter facility as culls from sale barns and/or ranching operations); (2) Fed cows (n = 108) (FED; beef-type cows entering the slaughter facility from a finishing yard having received a corn-based, high energy diet for a 95 d ± 1 d period); (3) Dairy cows (n = 113) (DAIRY; cows entering the slaughter facility directly from dairies as culls). FED market cows were fatter, heavier, and more muscular than either NON-FED or DAIRY cows. DAIRY cows were slightly fatter (in the carcass), heavier, and less muscular (alive, muscle score) than were NON-FED beef cows. FED beef cows had the most desirable lean color scores, the most tender LM steaks, and had whiter colored fat than NON-FED beef cows. DAIRY cows were the most youthful (lowest SKELMAT and dentition scores) at the time of harvest and produced carcasses that had similar marbling and fat color scores to those of FED beef cow carcasses. NON-FED beef cows produced the lowest marbling scores, the toughest LM steaks, and the most yellow colored fat. Correspondingly, fat from NON-FED beef cows had the highest concentrations of vitamin A and 3-carotene in the fat. NON-FED cows had the greatest probability of producing beef with undesirable flavor attributes but no meaningful differences were found among MGMT groups in fatty acid composition. Cow LM representing all MGMT groups responded to postmortem muscle-aging (P < 0.001) whereas the PM did not (P = 0.075). A MGMT x postmortem muscle aging time interaction existed for the INFRA (P < 0.042). A significant interaction of MGMT x evaluation method (USDA grader vs. VIA instrument) existed for marbling score, LMA, and 12th rib fat thickness. Compared to USDA grader determined values, VIA instrument scores were higher for marbling score and lower for LMA. A prediction model developed from VIA instrument outputs demonstrated the ability to characterize the MGMT of cow with less than 13% error. The findings of this research warrant the continued development VIA instruments to identify cow carcass characteristics and sensory quality.