Warner-Bratzler Shear Force Values Research Articles

Genomewide association mapping and pathway analysis of meat tenderness in Polled Nellore cattle1

Brazil is one of the world's largest beef exporters, although the product has a low price due to quality issues. The meat exported by Brazil is considered medium and low quality by international buyers, mainly due to lack of tenderness. The predominant Zebu breeds (80% Nellore) are known for producing tougher beef than taurine breeds. Nonetheless, some studies have shown that there is substantial genetic variability for tenderness within the Nellore breed, although it is a difficult trait to improve by conventional selection methods. Therefore, the aim of this study was to perform a genomewide association study (GWAS) and a gene set enrichment analysis to identify genomic regions and biologically relevant pathways associated with meat tenderness in Polled Nellore cattle. Data consisted of Warner-Bratzler shear force values of LM from 427 Polled Nellore animals divided into 3 experimental slaughters (years 2005, 2008, and 2010). The animals were genotyped with either the Illumina BovineHD BeadChip (777k, on 61 samples) or the GGP Indicus HD chip (77k, on 366 samples). Single nucleotide polymorphisms were excluded when the call rate was <90%, the Hardy-Weinberg proportions -value was <1% (Fisher exact test, Bonferroni adjusted), and the minor allele frequency was <1%. Imputation from the GGP Indicus HD chip to the Illumina BovineHD BeadChip was performed using the FImput program. Genomewide association analysis was performed using the Efficient Mixed Model Association eXpedited (EMMAx) and the population parameters previously determined (P3D) methods. The GWAS was complemented with a gene set enrichment analysis performed using the FatiGO procedure. Significant markers ( < 0.0001) explaining a larger proportion of variation than other significant SNPs were located on chromosomes 3, 13, 17, 20, 21, and 25, indicating QTL associated with meat tenderness throughout the genome. Additionally, gene set analysis identified 22 Gene Ontology functional terms and 2 InterPro entries that showed significant enrichment of genes associated with tenderness. The functional categories included protein tyrosine and serine/threonine kinase activity, calcium ion binding, lipid metabolic process, and growth factors, among others. These results help to elucidate the genetic architecture and metabolic pathways underlying this trait, which is of extreme economic and social importance to Brazil, because Nellore is the dominant beef cattle breed in the country.

The effect of ageing on changes in myofibrillar protein in selected muscles in relation to the tenderness of meat obtained from cross‐breed heifers

AbstractThe aim of this study was to evaluate the impact of the ageing on changes in selected myofibrillar proteins and Warner–Bratzler shear force values in muscles from cross‐breed Charolaise × Holstein Friesian heifers. Triceps brachii (TB), infraspinatus (IS), vastus lateralis (VL), semimembranosus (SM), biceps femoris (BF) and semitendinous (ST) muscles after ageing were examined. A significant muscle effect was found in the case of basic chemical composition, Warner–Bratzler shear force values and cooking loss. The vastus lateralis characterised by the lowest intramuscular fat percentage (P ≤ 0.05). The highest connective tissue content was shown for infraspinatus. This muscle had the lowest Warner–Bratzler shear force values in every ageing time, regardless of the cooking method. Throughout the ageing process, selected myofibrillar proteins were altered in all examined muscles, but at varying rates. The SDS‐PAGE electrophoresis and Western blotting analysis showed that desmin and troponin‐T degradation affected both muscles and ageing effects (P ≤ 0.001).

The effect of the packaging system and storage time on myofibrillar protein degradation and oxidation process in relation to beef tenderness

This study investigated the impact of packaging systems on the degradation and oxidation of beef proteins regarding beef tenderness of longissimus lumborum (LL) and biceps femoris (BF) muscles stored in vacuum skin packaging (VSP), a modified atmosphere with high oxygen concentration (MAP), and combined of these two methods (VSP+MAP). A significant decrease in the Warner-Bratzler shear force (WBSF) in VSP at D14 and D28 for LL was observed compared to BF. A significant effect of packaging system on troponin-T (Tn-T) and desmin degradation was shown (p≤0.001). A high concentration of oxygen in MAP and VSP+MAP affected protein oxidation, which was reflected in myosin oxidative cross-linking. An increase of WBSF values detected in steaks packed in VSP and VSP+MAP systems could be caused by the intensification of protein oxidation. Furthermore, BF was more susceptible to oxidation compared to LL. The VSP+MAP packaging system has resulted in the maintenance of a bright, red color, however has not improved the beef tenderness.

Characterizing Products from the Beef Rib Resulting From an Alternative Carcass Break

ObjectivesThis study was aimed at investigating the impacts of separating the beef rib from the chuck between the 4th and 5th rib versus the 5th and 6th ribs on beef tenderness, connective tissue content, steak composition, and product yield.Materials and MethodsThirty USDA Choice carcasses were selected at random for inclusion in the study. Alternating sides of each carcass was fabricated into either an 8-rib rib separated from the chuck between the 4th and 5th rib or a traditional 7-rib rib separated from the chuck between the 5th and 6th rib. All comparisons between 8-rib and 7-rib ribs were made within animal. All ribs were collected and transported under refrigeration to the Colorado State University for fabrication. Comprehensive cutout data was collected from conversion of each individual NAMP 107 oven-prepared rib to a NAMP 112 boneless ribeye roll. Within 7 d of product collection, the boneless ribeye rolls were transported to a steak portioning facility, and all pieces were cut into equally portioned ribeye steaks. At the time of portioning, steak measurements were collected and recorded. All weight and steak yield comparisons were made between 7-rib and 8-rib ribs. Following steak portioning, an image of each steak was obtained on a gridded background. Individual images were analyzed using image software capable of making measurements by quantifying pixel size (Image J). From each steak image, all meaningful dimensional measurements were obtained. Following image capture, steaks were individually identified, packaged, frozen and stored for shear force evaluations.Steaks were thawed and cooked to a peak internal temperature of 71°C using a combination convection oven. Following cooking, the peak internal temperature was recorded for each steak. Warner-Bratzler Shear Force (WBSF) values were obtained for the primary muscles in every steak (longissimus, complexus, and spinalis). A single mean WBSF value was obtained and averaged for each muscle individually.Comparisons of least squares means for product yield and steak cutting yield were made between 8-rib and 7-rib ribs. Means for WBSF and steak measurements were compared by steak location within the portioned 8-rib ribs only.ResultsThe 112 ribeye rolls resulting from 8-rib ribs were 5.26 cm longer, which resulted in 2.8 more steaks per carcass, on average. Additionally, 112 ribeye rolls resulting from 8-rib ribs were 558 g heavier than 7-rib ribeye rolls. Steak location did not affect WBSF values of the complexus, or spinalis, but steak location did affect (P = 0.0077) the WBSF values of the longissimus. Even though the WBSF of the longissimus was affected by steak location, there were no meaningful trends by steak location and the values were not affected by alternating the fabrication style. The data indicated that tenderness and eating quality was not affected by fabrication style. As expected, the size of the longissimus decreased toward the anterior end of the ribeye rolls, and the size of the complexus increased inversely with the size of the longissimus. Most notably, the amount of intermuscular fat (kernel or star fat) was less in the most anterior steaks than in steaks that would normally appear on the ends of traditionally cut, 7-rib ribeye rolls.ConclusionChanging the fabrication style would not detrimentally impact the eating qualities of ribeye steaks but would add significant weight and value to the rib.

Influence of Heat Shock Protein Activity on the Beef Tenderness during Aging

ObjectivesThe aim of this study was to evaluate aging effects on tenderness and Heat Shock Proteins activity of beef muscle.Materials and MethodsWere evaluated 303 F1 immunocastrated steers cross cattle (Nellore × South African Simmental), aged 18.0 ± 2.0 mo and live weights at slaughter of 500 kg. After 24 h post mortem, two 2.5 cm steaks were collected at the 12th and 13th ribs of the Longissimus muscle. The steaks were individually identified, vaccum packaged and aged for 1 and 14 d. Also, in each aging time, 1 piece of meat was cut and immediately frozen in liquid nitrogen for further Heat Shock Protein (HSP) analysis. The meat samples were analyzed for Warner Bratzler Shear Force (WBSF) according American Meat Science Association (1995) and the HSP quantification were determined by Bovine HSP 27 and HSP 70 ELISA kits (Mybiosource). The total of protein content was calculated by Bradford method. Beef samples were classified into 2 groups according WBSF values at 14 aging days: Tender ( 5.2 kg) and after then, were selected 20 samples from each group for HSP quantifications. Data were analyzed using GLM procedures of SAS (SAS Inst. Inc., Cary, NC), LS MEANS statement and the TUKEY adjustment were used for mean separation with an ɑ level of 0.05 (Version 9.2, SAS Inst. Inc., Cary, N.C.).ResultsAs expected, WBSF values (n = 300) at 14 aging days from Tender group were smaller (4.2 kg) than Tough group (5.3 kg; P < 0.05). The HSP 27 values decreased from 1 to 14 aging days inside the Tender and Tough groups, but no differences were detected between groups at the same aging day. Witch respect of the HSP 70 values, were observed differences only inside the Tender group and instead of HSP 27, the values increased from 1 to 14 aging days (Table 1).ConclusionIn conclusion, there are no evidence of relationship between HSP 27 activity and meat tenderness but with respect to HSP 70 activity, more studies should be conduce for elucidate this question.

Effects of Enhancement and Degree of Doneness on Trained Sensory Panel Ratings of Beef Strip Loin Steak Palatability

ObjectivesTo determine the effect of enhancement on trained sensory panel palatability ratings of beef strip loin steaks of three quality grades cooked to three degrees of doneness (DOD).Materials and MethodsUSDA Prime, Low Choice, and Low Select strip loins (n = 72; 24/grade) were used in the study. Within each quality grade, one-half were enhanced to 108% green weight with a water, salt, and alkaline phosphate solution. Strip loins were aged for 21 d, fabricated into 2.5 cm steaks, vacuum packaged, and frozen at -20°C until further analysis. Consecutively cut steaks were paired, with one steak from each pair assigned to trained sensory panel evaluation and the other to Warner-Bratzler shear force (WBSF) determination. Steak pairs from each strip loin were assigned to one of three DOD: Rare (60°C), Medium (71°C), and Very Well Done (82°C). Steaks were cooked using clamshell grills and internal temperature was monitored using a thermocouple. Sensory panelists were trained according to procedures described by the American Meat Science Association Sensory Guidelines (2015) and evaluated samples for initial and sustained juiciness, myofibrillar tenderness, connective tissue amount, overall tenderness, beef identity, beef flavor intensity, salt intensity, and off-flavor intensity on continuous 100 mm line scales with verbal anchors at each end and midpoints.ResultsAmong the 3 quality grades, enhanced steaks were similar (P > 0.05) for initial juiciness, sustained juiciness, myofibrillar tenderness, connective tissue amount, and overall tenderness. Additionally, all enhanced steaks rated higher (P < 0.05) than non-enhanced Low Choice and Low Select steaks for initial juiciness, myofibrillar tenderness, and overall tenderness. Enhanced steaks were also rated higher (P < 0.05) in salt intensity when compared to non-enhanced steaks. As quality grade decreased in enhanced steaks, salt intensity ratings increased (P < 0.05; Low Select > Low Choice > Prime). Enhanced steaks, regardless of quality grade, were similar (P > 0.05) to non-enhanced Prime steaks for initial juiciness, sustained juiciness, myofibrillar tenderness, and overall tenderness. Panelists rated non-enhanced Prime steaks higher (P < 0.05) than either non-enhanced Low Choice or Low Select for sustained juiciness, beef identity, and beef intensity. Non-enhanced Prime steaks were rated similar (P > 0.05) to non-enhanced Low Choice steaks for myofibrillar tenderness, connective tissue amount, and overall tenderness. Additionally, when cooked to Rare, non-enhanced Prime steaks were similar (P > 0.05) to non-enhanced Low Choice steaks for initial juiciness. As DOD increased, panelists’ ratings for initial juiciness, sustained juiciness, myofibrillar tenderness, and overall tenderness decreased (P < 0.05; Rare > Medium > Very Well Done). For instrumental tenderness, all enhanced treatments and non-enhanced Prime steaks had similar (P > 0.05) WBSF values. However, in non-enhanced steaks, Low Select steaks had higher (P < 0.05) WBSF values than either Prime or Low Choice steaks. Moreover, Rare steaks had lower WBSF values (P < 0.05) than Medium and Very Well Done steaks.ConclusionAfter enhancement, palatability traits were unaffected by quality grade, with few differences found among quality grade treatments in enhanced samples. These results indicate enhancement does not provide an additive effect with marbling level for beef palatability traits.

Meat quality traits of male Herik lambs raised under an intensive fattening system

The aim of the study was to determine certain meat quality traits of Herik lambs finished under the intensive husbandry conditions. Twenty single male lambs with an average final weight of 42 kg were used in the study. Concentrate feed and fresh water were given ad libitum, whereas 300 g of alfalfa per lamb per day was provided. At 24 h postmortem, the pH levels were 5.51, 5.63, and 5.24 for musculus longissimus dorsi, musculus semitendinosus, and musculus semimembranosus, respectively. The corresponding Warner-Bratzler shear force values (P < 0.001) of cooked meat were 3.359, 2.318, and 3.601 respectively. At 24 h postmortem, the L*(42.18) and a* (19.95) values of Herik lambs were near the acceptable values of L*(34-35) and a*(19.00). At 72 h postmortem, cooking loss and water holding capacity were 34.78% and 10.55%, respectively. Chemical composition traits, namely dry matter (26.35%), protein (22.21%), ether extraction (2.98%), and ash percentage (1.02%), were similar to those of other indigenous breeds. Consequently, these results indicated that the meat of Herik lambs may be suitable for sale after the lambs are raised under an intensive fattening system.

Sensory Evaluation of Enhanced Beef Strip Loin Steaks Cooked to 3 Degrees of Doneness

The objective of this study was to evaluate the impact of marbling level in combination with enhancement on beef palatability when strip loin steaks were cooked to 3 degrees of doneness. Consumer and trained sensory panelists evaluated strip steak palatability traits of 3 USDA quality grades: Prime, Low Choice, and Low Select. Additional strip loins from each grade were enhanced to 108% with a water, salt, and alkaline phosphate solution. Steaks from each treatment were cooked to 3 degrees of doneness (DOD; Rare: 60°C, Medium: 71°C, or Very Well-Done: 82°C). Consumer panelists rated all enhanced treatments similar (P &gt; 0.05) for each palatability trait. Enhanced steaks had greater (P &lt; 0.05) juiciness, tenderness, flavor liking, and overall liking ratings than all non-enhanced treatments, regardless of grade. Consumer juiciness, tenderness, and overall liking scores increased (P &lt; 0.05) as DOD decreased. Trained sensory panelists rated all enhanced treatments similar (P &gt; 0.05) for initial and sustained juiciness, myofibrillar tenderness, and overall tenderness and greater (P &lt; 0.05) than all non-enhanced treatments, other than non-enhanced Prime, for the same traits. Trained sensory panel ratings increased (P &lt; 0.05) as DOD decreased for sustained juiciness, and both myofibrillar and overall tenderness. Moreover, Warner-Bratzler shear force values were similar (P &gt; 0.05) among all enhanced treatments, and lower (P &lt; 0.05) than non-enhanced Low Choice and Low Select treatments. Results from this study indicate marbling level has no impact on the palatability traits of enhanced strip loin steaks. Therefore, enhancement of higher valued, high marbled cuts does not provide additional palatability benefits over low marbled cuts, as enhancement does not provide an additive effect with marbling on beef eating quality.

Predicting Beef Tenderness and Juiciness

ObjectivesThe objective of this study was to predict overall consumer liking (OLike) or Warner-Bratzler shear force (WBSF) using either consumer tenderness (OTend) and juiciness (OJuice), trained descriptive tenderness (Tend) and juiciness (Juice) attributes, or WBSF.Materials and MethodsData where consumer sensory, trained meat descriptive tenderness and juiciness attributes, and Warner-Bratzler shear force were used. Study 1 used top loin steaks cooked to 58°C or 80°C utilizing a George Forman grill (191°C) or a flat food-service grill (232°C). A second study used Choice beef top loin steaks cooked to 58 or 80°C on a flat electric grill (176°C). Companion steaks were cooked for WBSF (kg). A third study used 60 top loin steaks cooked on an open hearth electric grill (176°C) and served to a trained meat descriptive attribute panel. For study 1, consumers (n = 80 per city) were recruited in Portland, OR; Olathe, KS; State College, PA and study 2 recruited 120 consumers per city from Olathe, KS; State College, PA; Portland, OR; and Griffin, GA.ResultsConsumer ratings (n = 3228), Warner-Bratzler shear force values, and 400 trained descriptive attribute values (n = 400) were used to develop 13 equations (Table 1) . Equation [1] used Tend ratings to account for 24.6% of the variation in WBSF. Inclusion of Juice and their interaction did not appreciably increase the amount of variation accounted for by Eq. [3] (R2 = 0.25) compared to Eq. [1]. Equations to predict OLike using Tend, Juice or WBSF had very low R2. OTend and OJuice were better predictors of OLike (R2 = 0.500, 0.492, 0.554 for Equations 10, 11, and 12, respectively) than when Juice, Tender or WBSF were used.ConclusionWBSF is more highly related to trained descriptive tenderness ratings then to consumer tenderness liking values. Overall consumer liking is difficult to predict using trained descriptive attribute and WBSF values and is most highly related to consumer sensory liking ratings for tenderness and juiciness. Juiciness ratings, either trained or consumer, did not appreciabilty improve predictability of regression equations to predict either WBSF or consumer overall liking.

Effect of Location and Postmortem Aging on Tenderness and Sarcomere Length of Beef Longissimus Lumborum and Semitendinosus Steaks

ObjectivesThe purpose of this study was to determine the effect of steak location and postmortem aging on cooked meat tenderness and sarcomere length of steaks from the Semitendinosus (ST) and Longissimus lumborum (LL). Materials and MethodsForty crossbred steers were processed at a commercial facility, and from 1 side of each carcass, the ST and LL subprimal were collected. Each ST was divided into 5 locations (LOC) with LOC 1 being the most proximal and LOC 5 the most distal. Similarly, each LL was divided into 3 LOC with LOC 1 starting within the middle of the subprimal and LOC 3 being the most posterior. Within each subprimal location a 2.54-cm thick steak was fabricated for Warner-Bratzler shear force (WBSF) and sarcomere length analyses. Steaks from each LOC within the ST were randomly assigned to 7, 14, 28, 56, or 112 d of aging (DOA) and steaks from each LL LOC were randomly assigned to 7, 28, or 112 d of aging. After the appropriate aging period, WBSF and sarcomere steaks were cooked to 71°C and chilled overnight. Six cores were removed parallel to muscle fibers and were sheared perpendicular to the muscle fibers. Sheared cores were frozen and powdered for sarcomere length. The Z- and M-Lines were marked under a laser beam, and the equation established by Cross et al. (1981) was utilized to quantify sarcomere length. Data were analyzed as a randomized complete block design with repeated measures. ResultsThere were no LOC × day of aging interactions for ST or LL steaks for WBSF or sarcomere length (P > 0.25). Steaks from the ST had reduced WBSF values in LOC 4 compared to other LOC (P 0.05). Additionally, sarcomere length of LL steaks was not different across LOC (P > 0.05). As day of aging increased, WBSF values decreased in ST steaks (P 0.05) were detected for sarcomere length in ST steaks as day of aging increased. In LL steaks, WBSF values decreased and sarcomere length increased (P < 0.05) as day of aging increased. ConclusionSemitendinosus steaks from the center portion of the subprimal were instrumentally tenderer than proximal steaks, but LOC had no effect on instrumental tenderness for LL steaks. Increased day of aging resulted in more tender ST and LL steaks. To provide the highest eating satisfaction to consumers on a budget, extended aging and steak location should become most valued when selecting ST steaks. While loin steaks can be more consistent in tenderness, consumers can value quality over steak location.

Effects of Feeding Calcium Hydroxide Treated Corn Stover During Backgrounding on Beef Carcass and Quality Characteristics

ObjectivesSixty-seven purebred Angus steers (initial BW 197 ± 38 kg.) were used to evaluate the effects of calcium hydroxide treated corn stover in backgrounding diets and a common finishing phase.Materials and MethodsSteers were randomly assigned to 1 of 4 treatments: untreated corn stover (CON), corn stover treated with 50% DM water (H2O); 50% DM water and calcium hydroxide treated corn stover (CaOH2); grazing on a turnip cover crop (CC) for 29 d before adapted to ad libitum alfalfa haylage diet fed in feed bunks for remaining 20 d of backgrounding. Steers were fed individually using a Calan system. All diets were formulated on a dry matter (DM) basis to contain 30% corn stover, 15% alfalfa haylage, 25% dried distillers grains with solubles, 25% dry rolled corn, and 5% supplement containing monensin. Steers were harvested at 240 d on feed. Carcass characteristics were recorded 48 h postmortem. Strip loins and shoulder clods (IMPS #180 and #114) from the right side of the carcass were collected. The shoulder clods were frozen immediately on arrival to the meat lab. Strip loins were fabricated into 2.54 cm steaks at 96 h postmortem. Strip loin steaks were used to evaluate vacuum purge, cook loss, and Warner-Bratzler shear force (WBSF). Shoulder clods were processed to ground beef before processing into bologna. Consumer sensory panels comprised of untrained panelists were utilized for both strip steaks (n = 130) and bologna (n = 126) to evaluate overall liking, flavor liking, texture liking, toughness, juiciness, and off-flavor. Data was analyzed using Proc Mixed of SAS 9.4 (SAS Inst. Inc., Cary, NC).ResultsTreatment had no effect on HCW (P = 0.694), REA (P = 0.259), backfat (P = 0.780), USDA Yield Grade (P = 0.890), USDA Quality Grade (P = 0.877), and marbling score (P = 0.845). Although purge loss (P = 0.884) and cook loss (P = 0.149) were not affected by treatment, WBSF values were lower for CC than CON (1.6 vs. 2.23kg respectively; P = 0.001). Objective L* and b* values for bologna were different among treatments (P < 0.001) with CaOH2 being higher than all other treatments. Objective a* values were lower for H2O than CC and CaOH2 (P < 0.001) and higher for CC and CaOH2 than CON on Day 0 (P = 0.002 and P < 0.001 respectively). For steak sensory, no differences were found in flavor liking (P = 0.102), juiciness (P = 0.375), or off-flavor (0.313). Differences were found in overall liking (P = 0.008) with CC being more liked than CON (P = 0.013) and CaOH2 (P = 0.019). Texture liking (P < 0.001) for CC was higher than CON (P < 0.001), H2O (P = 0.021), and CaOH2 (P < 0.001). Toughness scores were lowest for CC (P < 0.001) compared to CON (P < 0.001), H2O (P = 0.015), and CaOH2 (P < 0.001). For bologna sensory, no differences among treatments were found in overall liking (P = 0.610), flavor liking (P = 0.707), texture liking (P = 0.828), juiciness (P = 0.371), and off-flavor (P = 0.716). A difference in toughness was found (P = 0.011) with H2O being more tough than CaOH2 (P = 0.008).ConclusionThe use of calcium hydroxide treatment in backgrounding diets of beef calves does not affect carcass characteristics or moisture loss, but does affect processed meat shelf life, and sensory characteristics for fresh steaks and bologna.

Relationship of Myofibrillar Fragmentation Index to Warner-Bratzler Shear Force and Palatability Tenderness of Longissimus Lumborum and Semitendinosus Steaks

ObjectivesThe objective of this study was to determine the relationship between the myofibrillar fragmentation index (MFI) and the Warner-Bratzler shear force (WBSF) and sensory traits of longissimus lumborum (LL) and the semitendinosus (ST) steaks.Materials and MethodsForty beef strip loins (IMPS #180) and 40 eye of rounds (IMPS #171C) were collected from a Midwest beef processor and transported to the Kansas State University Meats Laboratory. Sub-primals were divided into anatomical location (anterior, medial, and posterior for strip loins; proximal and distal for eye of rounds) and cut into three 2.54 cm thick steaks and aged 14 d. Within location, steaks were randomly assigned to WBSF, trained sensory panel evaluation, or MFI analysis. Steaks utilized for WBSF and trained sensory panel were cooked to an internal temperature of 71°C on electric clamshell grills. Steaks used for WBSF were chilled overnight at 4°C, and six 1.27-cm cores were removed parallel to the orientation of the muscle fiber and sheared once through the center using an Instron testing machine with a Warner-Bratzler shear head. Sensory panel steaks were cut into 1 cm × 1 cm × 2.54 cm samples and immediately served to sensory panelists trained per AMSA guidelines for Sensory Evaluation (2016). Myofibrillar fragmentation index was determined using the procedures described by Culler et al. (1978). Data were analyzed as a completely randomized design with muscle as the fixed effect. Sub-primal location data were analyzed muscle independent and as a completely randomized design with location as the fixed effect.ResultsWhen comparing muscles, there were muscle differences for all variables measured (P < 0.05). Steaks from LL had smaller WBSF, sensory panel connective tissue ratings, and MFI values than ST steaks (P < 0.05). Additionally, LL steaks had greater myofibrillar and overall tenderness sensory panel ratings (P < 0.05). There were location effects for sensory and WBSF of both muscles (P < 0.05). Warner-Bratzler shear force values of all 3 locations within the LL were different from one another (P < 0.05). Panelists rated anterior steaks greater for myofibrillar and overall tenderness than middle and posterior steaks (P < 0.05), which were not different (P > 0.05) from each other. Panelist detected less connective tissue in anterior steaks when compared to middle and posterior steaks (P < 0.05), which were not different (P > 0.05) from each other. In the ST, proximal steaks had greater WBSF values and sensory connective tissue amounts than distal steaks (P < 0.05). Proximal steaks had less myofibrillar and overall tenderness than distal steaks (P < 0.05). Within each sub-primal, anatomical location had no effect on MFI value (P > 0.05). Myofibrillar fragmentation index was correlated (P < 0.05) to myofibrillar tenderness (r = –0.18), connective tissue (r = 0.11), and overall tenderness (r = –0.15); however, MFI was not correlated (P = 0.056) to WBSF.ConclusionAs expected, the LL was rated tenderer than the ST by sensory panelists and had smaller WBSF values. The ST had a higher MFI versus the LL. In both muscles, MFI was not dependent on anatomical location. Moreover, the correlation between MFI, WBSF, and sensory measures of tenderness were weak, indicating MFI was not a reliable indicator of beef tenderness for the muscles evaluated.

Effect of Carcass Management on Horse Meat Quality

ObjectivesCanada is one of the largest exporters of horse meat. To remain competitive, it is necessary to ensure the highest quality of horse meat. Hence, the objective of the current study was to characterize the meat quality of horse meat aged under vacuum for up to 90 d to ensure the highest quality of horse meat.Materials and MethodsTwelve Semimembranosus (SM) muscles were collected over 4 consecutive visits from an Alberta abattoir, with 3 muscles collected at each visit. Visits were performed over a 3 wk interval. At each visit, at 17 h post mortem the SM muscles were separated from the right side of 3 randomly selected carcasses. The collected SM muscles were cut into 5 equal portions, with each portion consisting of 2 steaks. Portions were randomly distributed to either 3, 30, 60, and 90 d ageing (at 0 ± 0.5°C) with the exception of the third and middle portion, which was frozen and stored at –18°C on d 3 for intramuscular connective tissue analysis. The steaks within the remaining portions were packaged individually under vacuum for ageing. After each ageing period, 1 steak within each portion was assessed for purge loss, cooking loss, Warner Bratzler Shear force (WBSF) while the other steak was cubed and freeze dried for proximate (protein, fat, moisture) analysis. Prior to these analyses, the color (L*, a*, b*; Commission Internationale ĹEclairage) and pH were measured in both steaks at 3 different places in each steak. Data were analyzed by R (version 3.3.1) using the package nlme as a mixed model, where ageing was a fixed effect, visit a random effect, and carcass weight a covariate. Differences between least square means (p < 0.05) were determined by Tukey’s multiple comparison and Pearson correlations were used to identify significant linear relationships.ResultsThere was no effect of ageing on horse meat cooking loss and intramuscular fat (IMF) content. However, the meat color as indicated by L* and b* changed (p < 0.05) throughout the ageing period. The L* gradually decreased as ageing time increased, with mean L* value highest and lowest on d 3 and d 60 post mortem, respectively. The highest value of b*, however, was observed on d 30 and the lowest value at d 3 post mortem. Muscle pH increased with length of ageing, with the mean pH value for d 3 being less than that at d 30 and 60. Similarly, mean purge loss gradually increased with length of ageing, with the highest purge losses observed at d 60 and the lowest at d 3. WBSF decreased with length of ageing period, with the highest and lowest mean WBSF values observed at d 3 and 60, respectively. Besides ageing period, WBSF at d 3 appeared influenced by muscle pH and IMF content, as there was a positive correlation between muscle pH and WBSF (r = 0.69, p = 0.013) and a negative correlation between WBSF and IMF content (r = –0.64, p = 0.025).ConclusionThese preliminary results suggested that meat color and WBSF did not differ between d 30 and d 60; therefore, horse meat quality appeared to be optimal at d 30 post mortem as it exhibited minimum purge loss while still having the best technological quality.

Effects of Reduced-Fat Modified Distillers Grains with Solubles in Finishing Diets of Feedlot Steers on Fresh and Processed Beef Quality

ObjectivesThe impact of utilizing varying concentrations of reduced-fat modified distillers grains with solubles (RFMDGS) was evaluated using fifty crossbred (Angus × Gelbvieh × Holstein × Jersey) steers (initial body weight: 379 ± 32 kg) that were randomly assigned to one of four dietary treatments. Materials and MethodsDietary treatments consisted of: 14.93% RFMDGS of diet dry matter (DMD) with 0.74% corn oil DMD (FF15); 15.60% RFMDGS DMD (RF15); 30.84% RFMDGS DMD (RF30); and 46.27% RFMDGS DMD (RF45). All steers received Rumensin. Steers were fed dietary treatments for 181 d utilizing a Calan gate system then fed a common diet for 4 d before harvesting at a commercial abattoir. Hot carcass weight (HCW), 12th rib backfat (BF), ribeye area (REA), percent kidney, pelvic, and heart fat (KPH), and marbling score data were collected 24 h postmortem. Strip loins (IMPS #180) were collected for vacuum purge loss evaluation and fabricated into 2.54 cm steaks for drip loss, cook loss, Warner-Bratzler shear force (WBSF), and sensory evaluation (n = 122). Shoulder clods (IMPS # 114) were used to create ground beef and bologna. Thiobarbituric acid reactive substances (TBARS) analysis occurred utilizing ground beef while bologna samples were evaluated for sensory attributes (n = 108). Twelfth rib backfat was analyzed for fatty acid composition and calculated iodine value. All data was analyzed using PROC MIXED procedure in SAS (SAS Inst. Inc., Cary, NC). ResultsThere was no treatment effect for HCW (P = 0.96), BF (P = 0.63), REA (P = 0.62), KPH (P = 0.27), or marbling score (P = 0.67). All moisture loss attributes did not differ among treatments (P = 0.09). Warner-Bratzler shear force values for FF15 were greater compared to all other treatments (P = < 0.01). There was no treatment effect for overall liking (P = 0.15), flavor liking (P = 0.75), texture liking (P = 0.07), or off-flavor (P = 0.72) in steak sensory analysis. Subjective toughness values of steaks from FF15 were higher than RF15 (10.78 and 8.77, respectively; P = 0.01). Subjective juiciness values of steaks from FF15 were higher than RF45 (8.50 and 6.94, respectively; P = 0.03). There was no treatment effect for flavor liking or off-flavor in bologna sensory analysis. Subjective overall liking was higher in RF45 compared to FF15 bologna samples (78.14 and 71.63, respectively; P = 0.03). Subjective texture liking of bologna from RF45 were higher than FF15 (78.25 and 67.51, respectively; P < 0.01). Subjective toughness liking of bologna from RF30 and RF45 were higher compared to FF15 (77.21, 78.25, and 67.51, respectively; P < 0.01). There was no treatment effect for d 0 or d 14 TBARS (P = 0.94 and P = 0.27, respectively). Treatment did not affect percentage of linoleic acid (C18:n-6, P = 0.34). There was no treatment effect on calculated iodine value (P = 0.59). ConclusionAlthough results indicate feeding 45% RFMDGS had no effect on carcass characteristics, it did decrease fresh beef quality, increase processed beef quality, and had minimal effects on fatty acid composition.

Effects of Reduced-Fat Modified Distillers Grains with Solubles in Finishing Diets of Feedlot Steers on Fresh and Processed Beef Quality

ObjectivesThe impact of utilizing varying concentrations of reduced-fat modified distillers grains with solubles (RFMDGS) was evaluated using fifty crossbred (Angus × Gelbvieh × Holstein × Jersey) steers (initial body weight: 379 ± 32 kg) that were randomly assigned to one of four dietary treatments. Materials and MethodsDietary treatments consisted of: 14.93% RFMDGS of diet dry matter (DMD) with 0.74% corn oil DMD (FF15); 15.60% RFMDGS DMD (RF15); 30.84% RFMDGS DMD (RF30); and 46.27% RFMDGS DMD (RF45). All steers received Rumensin. Steers were fed dietary treatments for 181 d utilizing a Calan gate system then fed a common diet for 4 d before harvesting at a commercial abattoir. Hot carcass weight (HCW), 12th rib backfat (BF), ribeye area (REA), percent kidney, pelvic, and heart fat (KPH), and marbling score data were collected 24 h postmortem. Strip loins (IMPS #180) were collected for vacuum purge loss evaluation and fabricated into 2.54 cm steaks for drip loss, cook loss, Warner-Bratzler shear force (WBSF), and sensory evaluation (n = 122). Shoulder clods (IMPS # 114) were used to create ground beef and bologna. Thiobarbituric acid reactive substances (TBARS) analysis occurred utilizing ground beef while bologna samples were evaluated for sensory attributes (n = 108). Twelfth rib backfat was analyzed for fatty acid composition and calculated iodine value. All data was analyzed using PROC MIXED procedure in SAS (SAS Inst. Inc., Cary, NC). ResultsThere was no treatment effect for HCW (P = 0.96), BF (P = 0.63), REA (P = 0.62), KPH (P = 0.27), or marbling score (P = 0.67). All moisture loss attributes did not differ among treatments (P = 0.09). Warner-Bratzler shear force values for FF15 were greater compared to all other treatments (P = < 0.01). There was no treatment effect for overall liking (P = 0.15), flavor liking (P = 0.75), texture liking (P = 0.07), or off-flavor (P = 0.72) in steak sensory analysis. Subjective toughness values of steaks from FF15 were higher than RF15 (10.78 and 8.77, respectively; P = 0.01). Subjective juiciness values of steaks from FF15 were higher than RF45 (8.50 and 6.94, respectively; P = 0.03). There was no treatment effect for flavor liking or off-flavor in bologna sensory analysis. Subjective overall liking was higher in RF45 compared to FF15 bologna samples (78.14 and 71.63, respectively; P = 0.03). Subjective texture liking of bologna from RF45 were higher than FF15 (78.25 and 67.51, respectively; P < 0.01). Subjective toughness liking of bologna from RF30 and RF45 were higher compared to FF15 (77.21, 78.25, and 67.51, respectively; P < 0.01). There was no treatment effect for d 0 or d 14 TBARS (P = 0.94 and P = 0.27, respectively). Treatment did not affect percentage of linoleic acid (C18:n-6, P = 0.34). There was no treatment effect on calculated iodine value (P = 0.59). ConclusionAlthough results indicate feeding 45% RFMDGS had no effect on carcass characteristics, it did decrease fresh beef quality, increase processed beef quality, and had minimal effects on fatty acid composition.

Comparison of Sensory Characteristics, Fatty Acid Profiles, Proximate Analysis, and Shelf-Life Stability of Akaushi Beef, Commodity Prime Beef, and Top Choice Branded Beef

ObjectivesThe objective for this study was to compare Akaushi beef with commodity prime beef and top choice branded beef (TCB) looking at trained sensory panel attributes, tenderness, nutritional composition and shelf-life.Materials and MethodsStriploins (n = 106) were collected from 2 commercial beef plants. Beef type served as treatment [Akaushi top choice (Akaushi; n = 36), top choice branded (TCB; n = 36), and USDA low prime (prime; n = 34)]. Striploins were selected with marbling scores of Mt to Md for the top choice products and SLAB marbling for the prime product. Striploins were fabricated into 2.54-cm steaks and assigned to various laboratory analysis after 21, 28, and 35 d of wet ageing at 4°C. Steaks from the posterior end of the striploin were displayed for 4 d in an atmosphere consistent with a commercial retail case lighting and temperature and were then utilized for TBARS analysis. A trained sensory panel was used to evaluate common sensory attributes. Steak types were evaluated for tenderness using Warner-Bratzler Shear Force (WBSF), proximate analysis using a Foss Foodscan (Eden Prairie, MN), and fatty acid composition using gas chromatography. Differences between beef types and ageing treatments were analyzed using the mixed models procedure of SAS (SAS Inst. Inc., Cary, NC).ResultsAkaushi (21.8%) and prime (21.7%) had lower protein percentage compared to TCB (22.6%; P < 0.0001). TCB had the highest moisture percentage, followed by Akaushi, and prime (67.9, 67.1, and 64.3%, respectively; P < 0.0001). TCB (47.4) had the highest percent of composite saturated fatty acids, followed by prime (46.6) and Akaushi (42.8; P < 0.0001). When assessing composite monounsaturated fatty acid percentages, Akaushi (53.8) was the highest, followed by prime (49.7), and TCB (48.3; P < 0.0001). TCB (4.4) had the highest percent of composite polyunsaturated fatty acids followed by prime (3.7) and Akaushi (3.4; P < 0.0001). Akaushi had the highest lipid oxidation followed by TCB, and prime (P < 0.0001) averaging 0.5, 0.4, and 0.3 mg mal/kg of meat, respectively. Additionally, there was a difference among ageing treatments, (P < 0.0001), with 21d (0.4) and 28d (0.4) being similar, while 35d (0.5) was more oxidized. Akaushi and prime were similar for juiciness scoring 6.0 and 6.0, respectively on a scale of 1 to 8, and both were juicier than TCB (5.6; P < 0.05). Akaushi (6.2) was tenderer than TCB (5.8; P ≤ 0.05). Evaluating overall acceptability on a scale of 1 to 8, Akaushi and prime were similar (6.2 and 6.1, respectively), and both more favorable than TCB (5.8; P < 0.05). Average WBSF values were similar (P = 0.20) for TCB (2.8 kg), Akaushi (2.7 kg), and prime (2.5 kg).ConclusionResults show that while there were differences, all 3 beef types would be considered very acceptable to consumers when analyzing organoleptic properties. The fatty acid profile element was diverse, as TCB had the highest percentage of polyunsaturated fatty acids, and Akaushi had the highest percentage of monounsaturated fatty acids. Akaushi beef compares well to Prime and TCB when evaluating sensory and fatty acid profile attributes; this could benefit Akaushi producers if other factors do not impede economical beef production.

The Effects of Ractopamine and Hormonal Growth Promotants on Growth and Meat Quality of Crossbred Angus Steers

ObjectivesMeat tenderness is an important quality parameter that influences consumer preference. The cattle industry has over the years seen the emergence of feed additives and hormonal growth promotants in the form of β-adrenergic agonists (β-AA) and steroids, respectively. The objective of this study was to analyze the effect of hormonal growth implants and ractopamine on slaughter weight and meat quality parameters of steers selected for high (inefficient) and low (efficient) residual feed intake (RFI) performance.Materials and MethodsForty-eight crossbred Angus steers identified from individual GrowSafe data as high (n = 21) or low (n = 27) RFI cattle were randomly assigned to pens according to treatment (n = 12). Treatments included control (no ractopamine hydrochloride (RAC)/no steroids), RAC and steroids, steroids only, and RAC only in a 2x2x2 factorial design. Steers on steroid treatment received a first implant (200mg progesterone, 20mg estradiol benzoate and 29mg tylosin tartrate) at about 350 d of age and 450kg live weight and a terminal implant (120 mg trenbolone acetate and 24mg estradiol) at about 100 d before slaughter. RAC was fed to the appropriate group 28 d before slaughter at a rate of 200mg head–1d–1. Cattle were slaughtered at about 16 mo of age over 6 consecutive weeks by weight and back fat, with 1 animal per treatment represented in each kill for a total of 8 animals slaughtered per week. Hot carcass weights (HCW) were recorded. Gluteus medius (GM) muscles were obtained from the carcasses 3 d post mortem and halved for ageing, with one half aged a further 12 d under vacuum. After ageing at 4°C, muscle halves were assessed for pH, color, drip loss and Warner-Bratzler shear force (WBSF). For all data the experimental unit was the steer as the effect of ageing was not considered. Data was analyzed using the General Linear Model procedure in SAS (SAS Inst. Inc., Cary, NC) with RFI, steroids, RAC and their interactions as fixed factors with slaughter day used as a covariate. Mean differences were determined using Least Square Means and Tukey’s multiple comparisons.ResultsResults revealed no effect (P > 0.05) of RFI and RAC on slaughter weight (SW) but steroids increased (P < 0.0001) SW of steers. An interaction effect (P = 0.0381) was seen between RFI, steroids and RAC on HCW, where high RFI steers that were implanted with steroids and fed RAC had a higher HCW at 389.64 ± 8.70 kg than low RFI steers that were neither implanted nor fed RAC (325.68 ± 7.05kg). An interaction between RFI, steroids and RAC (P = 0.045) for drip loss was observed on muscles aged for 12 d, where high RFI steers that were implanted but not fed RAC had a higher drip loss (1.93 ± 0.23 g) than low RFI steers that were not implanted but feed RAC (0.63 ± 0.19g). Muscles from implanted steers had a higher mean WBSF value than muscles from non-implanted steers on d 12 post-mortem (P = 0.039), while high RFI steers that received RAC had the lowest mean WBSF (P = 0.015).ConclusionResults indicated that steroids compromised the development of tenderness during post mortem ageing in the GM. This suggests that the benefit of steroid use on slaughter and hot carcass weights will compromise tenderness of this muscle. Additional post mortem ageing beyond 12 d may be required. Conversely, the use of the β-AA RAC showed potential for decreasing cooked GM toughness in high RFI steers regardless of the ageing period.

Determination of Objective Analysis of Juiciness among Multiple Beef Muscles and Quality Grades

ObjectivesThe purpose of this study was to use a developed objective juiciness analyses including corresponding tenderness measurements to determine the juiciness among multiple beef muscles of various quality grades.Materials and MethodsTreatments were obtained from 5 different beef sub-primals: Strip loins (IMPS #180), inside rounds (IMPS #169), bottom rounds (IMPS #171B), shoulder clods (IMPS #114), and chuck rolls (IMPS #116). Sub-primals were also represented by 3 different USDA quality grades: Prime, Low Choice and Select; (n = 10/quality grade). All sub-primals were vacuum packaged, aged for 21dthen fabricated into 2.5 cm thick steaks from respective cuts: Adductor (AD), Biceps femoris (BF), Chuck Eye (CE), Infraspinatus (IF), Semimembranosus (SM), Serratus ventralis (SV), Longissimus lumborum (LD), and Triceps brachii (TB). The steaks were frozen (–20°C) until subsequent analyses. Several objective measures of juiciness and tenderness were evaluated on raw and cooked samples. Analysis techniques measured on raw samples included: pH and percentage fat, moisture, protein and collagen. Cooked techniques evaluated included: Warner-Bratzler shear force (WBSF), slice shear force (SSF), cook loss, and pressed juice percentage (PJP). For cooked analysis, each steak was cooked on a clam-shell grill to a medium degree of doneness (71°C), and the fiber orientation (45 or 90°) was determined before sampling. Analysis of PJP was evaluated using a compression-based juiciness method. Following SSF, a 1cm thick PJP slice was removed parallel with predetermined muscle fiber orientation (45 or 90°) and compressed on filter paper at 8 g for 30s. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC; ɑ = 0.05). Subprimal was experimental unit, and muscle, quality grade, muscle × quality grade were used as fixed effects. Carcass was used as a random effect.ResultsA muscle × quality grade interaction (P < 0.05) was detected for each chemical proximate measurement, as well as pH. Fat percentage for SV was greater (P < 0.05) than all other cuts in all quality grades, but similar (P > 0.05) to IF in the Select grade. Within Prime and Low Choice, moisture was greatest (P < 0.05) for TB and similar (P > 0.05) to AD. The pH was lowest (P < 0.05) for AD in all grades. The IF was highest (P < 0.05) in Choice and Select, but similar (P > 0.05) to Choice TB, LD and Select TB. A muscle × grade interaction (P < 0.05) was found for SSF. The BF across all quality grades was the toughest (P < 0.05). The SV was the most tender (P < 0.05) in Prime, however few differences were found in all other quality grades between muscles of AD, IF, LD, and SV. Quality grade and muscle affected (P < 0.05) WBSF and PJP. As quality grade increased, WBSF values decreased (P < 0.05). The SV and CE were more tender (P < 0.05) than AD, TB, and IF. The PJP was less (P < 0.05) for Prime and Choice than Select, while TB and SM were greater (P < 0.05) than IF and AD for the same trait.ConclusionObjective juiciness and tenderness measures among different beef cuts and quality grades cooked to the same degree of doneness indicated that there is a difference in the amount of juice that is released from various beef muscles.

Comparing Honduran and United States Consumers’ Sensory Perceptions of Honduran and U.S. Beef Loin Steaks

The objective of this study was to compare the eating quality characteristics of beef from the United States and Honduras and to assess the willingness of Honduran and U.S. consumers to pay for these products. All U.S. sourced strip loins from grain-finished cattle, aged 21 d, were selected to equally represent USDA Select (SEL; n = 6) and upper 2/3 (Top) Choice (TC; n = 6) quality grades. Additionally, strip loins (n = 6) from Honduran grass-finished (HGRASS) cattle and grain-finished (HGRAIN) cattle (n = 6) were collected from a commercial abattoir in Siguatepeque, Honduras and aged 21 d. Samples were evaluated on 8-point hedonic scales for flavor, tenderness, juiciness, and overall liking by 240 consumers in each country. Consumers indicated if each trait was acceptable, and willingness to pay for each sample was rated in U.S. dollars (or the Honduran Lempiras equivalent): $0, 3, 6, and 10 per 0.45 kg. Chemical composition and Warner-Bratzler shear force (WBSF) were also determined. The TC had greater (P 0.05) from HGRAIN. The HGRAIN had greater WBSF values than TC and SEL, which did not differ (P > 0.05); however, HGRASS was similar (P > 0.05) to all other treatments. The TC had greater tenderness and flavor liking scores (P < 0.05) than all other treatments, followed by SEL, HGRASS, and HGRAIN, with a significant difference between each treatment. Honduran consumers assigned greater ratings for tenderness and flavor liking when compared to U.S. consumers. The lowest rated treatment in both countries was Honduran grain-finished followed by Honduran grass-finished. Consumers in Honduras were willing to pay more for samples when compared to U.S. consumers. Consumers were also willing to pay a premium for products with greater palatability, regardless of the country of origin.

Relating Muscle Fiber Morphometrics and Protein Degradation to Meat Quality in a Multibreed Herd

ObjectivesBrahman and Brahman-influenced cattle provide integral adaptations that benefit the cattle herd in the sub-tropical United States. Their heat tolerance and parasite resistance make them ideal for warmer climates; however, they tend to exhibit less desirable carcass and palatability traits. When compared to Angus, Brahman are lower marbling, less tender, and have more connective tissue. The objective of this study is to determine influence of Brahman genetics on muscle metabolic phenotype and postmortem proteolysis.Materials and MethodsCattle used in this study were part of a long-term genetic study involving Angus, Brahman, and Angus-Brahman crossbreeding. Although these cattle represent a continuous spectrum of Angus-Brahman genetic variation, they were divided into 6 breed groups for analysis: Angus; 3/4 Angus, 1/4 Brahman; Brangus; 1/2 Angus, 1/2 Brahman; 1/4 Angus, 3/4 Brahman; and Brahman. Steers (n = 6 per breed group) were harvested and samples from longissimus lumborum muscles were collected at 0 h, 24 h, and 14 d post-mortem. Western blotting was used to assess proteolysis during the 14 d aging period, including degree of autolysis of the proteolytic enzyme, µ-calpain; content of the calpain inhibitor, calpastatin; and the extent of degradation of desmin. Tenderness was determined objectively by Warner-Bratzler shear force (WBSF). The data was analyzed using multivariate methods in JMP. Nonparametric correlations were used to calculate the relationships between 24 h µ-calpain autolysis, WBSF, citrate synthase activity, and breed group.ResultsAs the percentage of Brahman genetics increases, WBSF increase as expected (R = 0.45, P < 0.01). The degree of µ-calpain autolysis at 24 h decreases as WBSF values increase (R = -0.49, P < 0.01), and autolysis decreases as the percentage of Brahman increases (R = -0.43, P < 0.01). Brahman genetics tended to influence oxidative capacity (P = 0.06), as citrate synthase activity increased with greater percentage of Brahman genetics.ConclusionAs expected, Brahman influenced cattle produced tougher steaks, evidenced by higher WBSF and decreased protein degradation. Postmortem proteolysis and muscle fiber type will be utilized to establish predictors for the optimum breed group that provides desirable meat quality and palatability traits, while having enough Brahman influence to thrive in sub-tropical climates.