Browsing by Subject "Warner-Bratzler shear force"
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Item Identifying beef muscles and processing treatments suitable for use in fajita application(2009-06-02) Huerta Sanchez, Diana LorenaBeef fajitas have become a popular food item, but the supply of traditional muscles is insufficient to meet the growing demand. There is a need for alternative muscles that have similar eating characteristics to those currently marketed as beef fajitas. Four different treatments - papain (P), blade tenderization (B), papain + blade tenderization (P+B), and control (C) - were applied to sixty USDA Choice M. diaphragma pars costalis, M. transversus abdominis, M. obliquus abdominis internus, M. rhomboideus, M. trapezius, M. latissimus, and M. serratus ventralis. Muscles were cut into sections and frozen at -10?C for evaluation by a trained sensory panel, consumer panel, and Warner-Bratzler shear force (WBSF) measurements. Trained panelists found that regardless of muscle, the addition of papain improved palatability scores. In general, treatment tended not to affect the palatability scores of the M. diaphragma pars costalis and M. serratus ventralis, which tended to receive higher scores in comparison to the other muscles. In general, the control and blade tenderized M. trapezius received the lowest trained and consumer panel palatability scores and had the highest WBSF values (P < 0.05). Regardless of muscle (except for M. diaphragma pars costalis and M. serratus ventralis), P and P+B treatments reduced WBSF values (P < 0.05). Consumers (n=81) gave the M. transversus abdominis, M. serratus ventralis, and M. latissimus similar (P > 0.05) tenderness ratings when the P treatment was applied. Consumers tended to prefer the flavor and tenderness of beef fajita strips that were treated with P and P+B and indicated a preference to purchase muscles with these treatments. Consumers were willing to purchase M. serratus ventralis treated with P+B and M. latissimus treated with P the majority of the time. Papain improved the eating quality of the muscles studied. The M. latissimus and M. serratus ventralis when treated with papain alone or in combination with blade tenderization, performed well enough to be considered as alternatives for traditional beef fajitas.Item Investigation of Genomic Estimated Breeding Values and Association Methodologies using Bayesian Inference in a Nellore-Angus Crossbred Population for Two Traits(2013-05-15) Hulsman, Lauren LoreneThe objectives of this study were to 1) evaluate marker associations for genomic regions of interest and significant ontology terms, 2) evaluate and compare 4 models for their efficacy in predicting genetic merit, 3) evaluate and compare the impact of using breed-of-origin genotypes in a Bayesian prediction model, and 4) evaluate the effects of data partitioning using family structure on predictions. Nellore-Angus F2, F3 and half-sibling calves were used with records for overall temperament at weaning (OTW; a subjective scoring system; n = 769) and Warner-Bratzler shear force (WBSF; a measure of tenderness; n = 389). After filtering, 34,913 markers were available for use. Bayesian methods employed were BayesB (using ?) and BayesC (using ? = 0 and ?) in GenSel software, where, after estimation, ? ? = 0.995 or 0.997 for WBSF or OTW, respectively. No regions associated with either trait were found using ? ?, but when ? = 0 associated regions were identified (37 and 147 regions for OTW and WBSF, respectively). Comparison of genomic estimated breeding values from these 3 Bayesian models to an animal model showed that BayesC procedures (using ?) had the highest accuracy for both traits, but that BayesB had the lowest indication of bias in either case. Using a subset of the population (n = 440), genotypes based on the breed in which the alleles originated from (i.e., breed-of-origin genotypes) were assigned to markers mapped to autosomes (n = 34,449), and incorporated into prediction analyses using BayesB (? ? = 0.997) with or without nucleotide-based genotypes. In either case, there was an increase in accuracy when breed-of-origin genotypes were incorporated into prediction analyses. Data partitions based on family structure resulted in 13 distinct training and validations groups. Relationship of individuals in the training with validation individuals did have an impact in some cases, but not all. There was poor prediction of genomic estimated breeding values for individuals in the validation population using BayesB methods, but performed better in all cases than breeding values generated using an animal model. Future studies incorporating breed-of-origin genotypes are of interest to determine if accuracy is improved in these groups.Item Relationships between Beef Postharvest Biochemical Factors and Warner-Bratzler Shear Force(2013-04-01) Orozco Hernandez, PilarBiochemical changes in muscle postmortem have been associated with initial beef tenderness early postmortem, and with improvements in tenderness during postmortem storage, defined as meat aging. Differences in the initial contractile state of the sarcomere, the ionic environment of the sarcoplasm including pH, the activity of neutral proteolytic enzymes, and collagen content and solubility have been associated with beef tenderness. In Phase I, steaks from four genetic lines of steers and heifers were used to understand the biochemical differences between tough and tender steaks. The most tender (< 30 N Warner Bratzler shear force (WBS)) and toughest Longissimus steaks (< 30 N WBS) from Angus, Braford, Brangus, and Simbrah heifers and steers were used. For Phase II, samples were obtained from a subset of Santa Cruz yearling heifers selected based of genotypes for tenderness (tough and tender) using a commercial genetic marker. Within genotype for tenderness, each animal was randomly assigned to one of four growth enhancement treatments. The most tender (< 30 N WBS) and toughest Longissimus steaks (< 30 N WBS) were selected for use in this study. In Phase I, tough steaks after 3, 10, and 17d postmortem had higher (P < 0.0005) WBS values than tender steaks. Tender steaks came from carcass with slightly higher (P = 0.008) marbling score and (P = 0.01) Quality grade. Sarcomere length, total and soluble collagen, potassium concentration, and m and ?calpain did not differ (P > 0.05) between tough and tender steaks. Sodium concentration at 10 d was higher (P = 0.03) in tough steaks, but only account for 0.05% of the variation in WBS at 3d. Tender steaks had less (P = 0.04) intact desmin at 24h, but intact desmin was not correlated (P > 0.05) with WBS. In Phase II, tough steaks after 3, 10, and 17d postmortem had higher (P < 0.0001) WBS values than tender steaks. Tender steaks came from carcass with slightly higher (P < 0.03) marbling score and (P = 0.02) Quality grade. Tender teaks were slightly lighter (P = 0.02), with more red (P = 0.02) and yellow (P = 0.007) color, and had slightly lower (P = 0.02) pH, compared with tough steaks. Sarcomere length, total and soluble collagen, sodium and potassium concentration, and m and ?calpain did not differ (P > 0.05) between tough and tender steaks. Tender steaks had less (P < 0.0001) intact desmin at 17d postmortem than tough steaks. Intact desmin at 17d was responsible for 4%, 47%, and 30% of WBS variation after 3, 10, and 17d postmortem, respectively. The slight difference in marbling and quality grade did not account for a significant amount of variation in WBS. However, meat color and pH accounted for variation in shear WBS. Calcium flux may have influenced meat tenderness by activation of calpains and may have altered protein to protein interactions. Results suggested that marbling, ? calpain activity, and desmin degradation, and to a lesser extent pH and meat color contributed to meat tenderness.Item The Heritability of Factors that Influence Tenderness in Beef Cattle(2010-12) Johnson, Paige A.; Miller, Markus F.; Moser, Dan; Thompson, Leslie D.; Johnson, Bradley J.; Jackson, Samuel P.The heritability, phenotypic correlations and genetic correlations of 63 factors were determined in this study. The traits studied (with their heritabilities and standard errors in parenthesis) included: days on feed (1.00 ± 0.116), longissimus muscle area (0.85 ± 0.183), marbling (0.83 ± 0.170), adjusted preliminary yield grade (0.61 ± 0.156), quality grade (0.59 ± 0.148), yield grade (0.56 ± 0.150), preliminary yield grade (0.48 ± 0.143), muscle score (0.44 ± 0.140), 21-day Warner-Bratzler Shear force (0.42 ± 0.148), 3-day initial juiciness (0.42 ± 0.148), hump height (0.40 ± 0.141), 7-day Warner-Bratzler Shear force (0.37 ± 0.147), 7-day initial tenderness (0.37 ± 0.140), 48-hour temperature (0.35 ± 0.121), lean color (0.34 ± 0.122), 14-day sustained tenderness (0.33 ± 0.135), 3-day initial tenderness (0.32 ± 0.131), 3-day sustained tenderness (0. 31 ± 0.129), 7-day sustained tenderness (0.31 ± 0.129), a* (0.29 ± 0.115), 3-hour temperature (0.29 ± 0.114), 14-day initial tenderness (0.28 ± 0.126), 14-day Warner-Bratzler Shear force (0.28 ± 0.121), b* (0.28 ± 0.120), final weight (0.26 ± 0.113), m-calpain (0.24 ± 0.195), 3-day overall mouthfeel (0.24 ± 0.119), 3-day Warner-Bratzler Shear force (0.23 ± 0.114), kidney, pelvic and heart fat (0.23 ± 0.107), temperament (0.23 ± 0.094), 3-day flavor intensity (0.22 ± 0.114), average daily gain (0.22 ± 0.105), 21-day initial tenderness (0.19 ± 0.110), frame score (0.19 ± .097), 21-day beef flavor (0.18 ± 0.110), 14-day overall mouthfeel (0.18 ± 0.107),14-day sustained juiciness (0.18 ± 0.105), μ-calpain (0.17 ± 0.197), 14-day initial juiciness (0.17 ± 0.104), lean firmness (0.17 ± 0.094), 21-day sustained tenderness (0.16 ± 0.108), 48-hour pH (0.16 ± 0.097), hot carcass weight (0.15 ± 0.091), 7-day overall mouthfeel (0.14 ± 0.097), 14-day beef flavor (0.12 ± 0.097), calpastatin (0.11 ± 0.095), 14-day flavor intensity (0.11 ± 0.094), 21-day flavor intensity (0.10 ± 0.087), lean texture (0.10 ± 0.086), initial weight (0.10 ± 0.078), L* (0.09 ± 0.087), 7-day flavor intensity (0.06 ± 0.081), 3-hour pH (0.06 ± 0.073), 3-day sustained juiciness (0.05 ± 0.081), heat ring (0.05 ± 0.061), 21-day overall mouthfeel (0.02 ± 0.076), 3-day beef flavor (0.01 ± 0.072), 7-day sustained juiciness (0.01 ± 0.062), 21-day sustained juiciness (0.00 ± 0.089), 7-day beef flavor (0.00 ± 0.080), sarcomere length (0.00 ± 0.075), 21-day initial juiciness (0.00 ± 0.072) and 7-day initial juiciness (0.00 ± 0.062). Phenotypic correlations and their respective p-values were determined and reported for all 3,969 relationships. Genetic correlations (n = 276) were determined for traits that were heritable including correlations for tenderness traits such as m-calpain activity, calpastatin activity, 48-hour pH, 48-hour carcass temperature, and marbling. Other genetic correlations studied included extensive sensory taste panel traits including 3-, 7- ,14- and 21-day initial tenderness, sustained tenderness, initial juiciness, sustained juiciness, flavor intensity, beef flavor and overall mouthfeel. The genetic correlations of color traits were also determined including Hunter colorimeter readings for a* and b*, as well as, subjective lean color scores. Other carcass traits studied using genetic correlations included lean texture, lean firmness, yield grade, hot carcass weight, and longissimus muscle area. Genetic correlations for 21-day Warner-Bratzler shear force, temperament, breed type and hump height were also determined.