Relationships of slice shear force and Warner-Bratzler shear force of beef strip loin steaks as related to the tenderness gradient of the strip loin

Longitudinal and transversal intramuscular variation of muscle fiber and meat quality characteristics in bovine M. longissimus thoracis et lumborum

This study evaluates longitudinal and transversal intramuscular variations in muscle fiber and meat quality characteristics in bovine M. longissimus thoracis et lumborum (LTL). The LTL muscles (n = 5) from the left side of the beef carcass were cut at intervertebral segment intervals (between 1st thoracic vertebra (TV) and 6th lumbar vertebra (LV)). The pennation angle demonstrated an increasing trend from the anterior to posterior regions regardless of the medial (M-zone) and lateral (L-zone) regions (P < 0.05). The M -zone had a higher pennation angle than the L-zone in the TV and 1st LV (P < 0.05). The cross-sectional area (CSA) of muscle fibers, excluding type I, was larger in the posterior region than the anterior region (P < 0.05). A larger CSA of type I/IIA, IIA, IIAX, and IIX was observed on the lateral side than on the medial side of the 13th TV (P < 0.05). Fiber types were more oxidative (types I and IIA) in the anterior region and more glycolytic (types IIA/IIX and IIX) in the posterior region. Fat content was higher in the anterior region than in the posterior region (P < 0.05). The lowest redness, yellowness, and Warner-Bratzler shear force values were observed in the middle of the muscle, whereas the lightness value was lower in the posterior region regardless of the transversal region (P < 0.05). Therefore, bovine LTL muscles exhibit unique morphological properties and contribute to understanding meat quality associated with morphological and muscle fiber characteristics in relation to their intramuscular variations.

Consumer Perception of Beef Quality and How to Control, Improve and Predict It? Focus on Eating Quality

Quality refers to the characteristics of products that meet the demands and expectations of the end users. Beef quality is a convergence between product characteristics on one hand and consumers’ experiences and demands on the other. This paper reviews the formation of consumer beef quality perception, the main factors determining beef sensory quality, and how to measure and predict beef eating quality at scientific and industrial levels. Beef quality is of paramount importance to consumers since consumer perception of quality determines the decision to purchase and repeat the purchase. Consumer perception of beef quality undergoes a multi-step process at the time of purchase and consumption in order to achieve an overall value assessment. Beef quality perception is determined by a set of quality attributes, including intrinsic (appearance, safety, technological, sensory and nutritional characteristics, convenience) and extrinsic (price, image, livestock farming systems, commercial strategy, etc.) quality traits. The beef eating qualities that are the most valued by consumers are highly variable and depend mainly on the composition and characteristics of the original muscle and the post-mortem processes involved in the conversion of muscle into meat, the mechanisms of which are summarized in this review. Furthermore, in order to guarantee good quality beef for consumers in advance, the prediction of beef quality by combining different traits in scenarios where the animal, carcass, and muscle cuts can be evaluated is also discussed in the current review.

Effects of extended postmortem aging and intramuscular location on protein degradation, muscle fiber morphometrics, and tenderness of beef longissimus lumborum and semitendinosus steaks

The objective of this study was to determine effects of extended aging and intramuscular location on Warner-Bratzler shear force (WBSF), muscle fiber cross-sectional area (CSA), and protein degradation of semitendinosus (ST) and longissimus lumborum (LL) steaks. Left ST and LL were removed from 40 carcasses at 6 d postmortem. The ST was fabricated into five locations (LOC), with LOC 1 being most proximal and LOC 5 being most distal. The posterior LL was fabricated into 3 LOC, with LOC 1 being most anterior. Vacuum sealed ST steaks were aged 7, 14, 28, 56, or 112 d postmortem, while LL steaks were aged 7, 28, or 112 d postmortem at 2 ± 1 °C. A steak from each LOC was assigned to WBSF or laboratory analyses. There were no Day of Aging (DOA) × LOC interactions for all dependent variables (P > 0.06). There were DOA effects for ST and LL WBSF values and degraded 38-kDa desmin (DES; P < 0.01). Day-7 ST-steak WBSF value was greater than all other days (P < 0.01) and day-14 steaks had greater WBSF value than remaining days (P < 0.05). Day-28 ST-steak WBSF values were greater than day 56 and 112 (P < 0.01), which did not differ (P = 0.53). In the LL, day-7 steaks had greater WBSF values than the other two timepoints (P < 0.01) and day-28 steaks had greater (P < 0.01) WBSF values than day-112 steaks. Degraded ST 38-kDa DES content was less on day 7 and 14 compared to all other days (P < 0.03), but did not differ (P = 0.79) from each other. Days 28 and 56 38-kDa DES content was less than day 112 (P < 0.01), but did not differ (P = 0.34) from each other. Degraded LL 38-kDa DES content was less on day 7 than day 28 and 112 (P < 0.02), which did not differ (P = 0.67). There were LOC effects for only ST WBSF and muscle fiber CSA (P < 0.05). Semitendinosus steak LOC 1 and 2 had greater WBSF values than all other locations (P < 0.01), but did not differ (P = 0.32) from each other. Semitendinosus steak LOC 3 and 5 had greater WBSF values than LOC 4 (P < 0.01), but did not differ (P = 0.85) from each other. The CSA of all ST fiber types were largest in LOC 1 compared to all other fiber types (P < 0.01). The CSA of all LOC 2 and 3 fiber types was greater than LOC 4 and 5 (P < 0.01), but were not different from each other (P > 0.81), and LOC 4 had greater CSA than LOC 5 (P < 0.01). Steak aging WBSF value improvements seemed proteolysis catalyzed, while the ST intramuscular tenderness gradient was more likely due to muscle fiber CSA.

Transcriptome profiling analysis of muscle tissue reveals potential candidate genes affecting water holding capacity in Chinese Simmental beef cattle

Water holding capacity (WHC) is an important sensory attribute that greatly influences meat quality. However, the molecular mechanism that regulates the beef WHC remains to be elucidated. In this study, the longissimus dorsi (LD) muscles of 49 Chinese Simmental beef cattle were measured for meat quality traits and subjected to RNA sequencing. WHC had significant correlation with 35 kg water loss (r = − 0.99, p < 0.01) and IMF content (r = 0.31, p < 0.05), but not with SF (r = − 0.20, p = 0.18) and pH (r = 0.11, p = 0.44). Eight individuals with the highest WHC (H-WHC) and the lowest WHC (L-WHC) were selected for transcriptome analysis. A total of 865 genes were identified as differentially expressed genes (DEGs) between two groups, of which 633 genes were up-regulated and 232 genes were down-regulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment revealed that DEGs were significantly enriched in 15 GO terms and 96 pathways. Additionally, based on protein–protein interaction (PPI) network, animal QTL database (QTLdb), and relevant literature, the study not only confirmed seven genes (HSPA12A, HSPA13, PPARγ, MYL2, MYPN, TPI, and ATP2A1) influenced WHC in accordance with previous studies, but also identified ATP2B4, ACTN1, ITGAV, TGFBR1, THBS1, and TEK as the most promising novel candidate genes affecting the WHC. These findings could offer important insight for exploring the molecular mechanism underlying the WHC trait and facilitate the improvement of beef quality.

Low-Voltage Electrical Stimulation of Beef Carcasses Slows Carcass Chilling Rate and Improves Steak Color

Electrical stimulation (ES) is used in beef slaughter plants to improve tenderness; however, varying levels of low-voltage ES have not been well characterized. The objective was to evaluate the influence of two levels of low-voltage ES on temperature decline, pH, glycolytic potential, and meat quality. Forty-two beef carcasses were chosen from a commercial packing facility. One side of each carcass received either 40 or 80 volts of ES for 60 s at 45 min postmortem. The paired side of each carcass did not receive ES (Control). Temperature loggers were placed in the sirloin of 12 carcasses to record temperature decline. Longissimus muscle pH was measured at 1, 12, and 24 h, and 3 d postmortem. Strip steaks were fabricated for determination of meat quality. A treatment by time interaction was observed for carcass temperature decline (p < 0.001) where ES sides stayed warmer longer than Control sides. A treatment by time interaction was observed for pH decline with Control sides exhibiting an increased pH at 1 h postmortem (p < 0.001). Instrumental color values were increased for ES compared to Control sides (p < 0.001). These results indicate ES slows carcass temperature decline, hastens initial pH decline, and improves instrumental color. Similar results were observed between the ES treatments indicating either ES level may be used to achieve similar quality characteristics.

Meat and sensory eating quality of loin steaks from cattle slaughtered at different ages as a result of short, medium or long finishing systems

Context In the belief that feed costs and use of cereal grains are reduced, production systems based on grazed and conserved forage in which cattle are slaughtered at 30 to 36 months of age are increasingly advocated. Aims As there is a scarcity of information concerning meat quality traits of beef from such extended rearing systems, three finishing systems of different lengths (Short, 14–16 months; Medium, 20–24 months; Long, 31–34 months) were compared in which cattle were slaughtered at similar conformation and fat classification scores. Methods The experiment comprised a three (system) × two (gender) design with 24 Limousin cross-bred cattle (12 steers and 12 heifers) assigned to each system. Characteristics of the rib section (between and inclusive of the 5th and 10th ribs) and sensory properties of M. longissimus thoracis samples were then assessed. Key results Older (Long system) cattle had greater rib section and L. thoracis weights. L. thoracis was tougher in older (Long system) cattle when assessed by a trained sensory panel. Heifers had lower rib section weights than steers but neither rib section composition or meat toughness differed between genders. Gristle (visible connective tissue) in the rib section increased with system length and was associated with an increased perception of gristle on eating. Conclusions Overall meat quality was considered commercially acceptable regardless of system. Implications The likely increased greenhouse gas emissions but reduced utilisation of food resources from the Long system need to be considered in conjunction with the meat quality characteristics of the system.

Pork Loin Chop Quality and Muscle Fiber Characteristics as Affected by the Direction of Cut

In this study, the relationship between muscle fiber characteristics and meat quality of pork loin chops prepared using different directions of cut (vertical to the muscle length, M-Vertical; vertical or parallel to the muscle fiber orientation, F-Vertical or F-Parallel) was evaluated under different storage conditions (fresh, cold storage/aged, and freeze–thawed). Among the three groups, F-parallel displayed considerably larger size of muscle fibers, regardless of their type. This group also displayed an increase in discoloration in aged chops and a decrease in purge loss and tenderness than in other cut groups (p < 0.05). Freeze–thawing accelerated deterioration of meat quality, especially water-holding capacity and tenderness in all groups (p < 0.05), but was most prominent in F-Parallel. Therefore, to avoid excessive deterioration of fresh, aged, or frozen/thawed pork loin chops, it is important to consider the direction in which the chop is cut with respect to the muscle fiber orientation.

Muscle Fiber Characteristics on Chop Surface of Pork Loin (M. longissimus thoracis et lumborum) Associated with Muscle Fiber Pennation Angle and Their Relationships with Pork Loin Quality

The influence of muscle architecture on muscle fiber characteristics and meat quality has not been fully elucidated. In the present study, muscle fiber characteristics on the chop surface of pork loin (M. longissimus thoracis et lumborum, LTL), pennation angle degree, and meat quality were evaluated to understand the pork LTL architecture and its relationship with the loin chop quality. Muscle fiber pennation degree ranged from 51.33° to 69.00°, resulting in an ellipse-shaped muscle fiber on the surface of pork loin chop. The cross-sectional area (CSA) on the sections cut vertical to the muscle length (M-Vertical) was considerably larger (p<0.05) than that on the sections cut vertical to the muscle fiber orientation (F-Vertical) regardless of the fiber type. Pennation angle is positively correlated with CSAs of F-Vertical (p<0.05) and with Warner-Bratzler shear force (r=0.53, p<0.01). Besides the shear force, lightness and pH were positively correlated with the fiber composition and CSA of IIX fiber (p<0.05); however, the redness, yellowness, drip loss, and cooking loss were not correlated with the pennation angle and muscle fiber characteristics on the chop surface (p>0.05). These observations might help us in better understanding pork loin architecture and the relationship between the pennation angle, muscle fiber characteristics, and meat quality of pork loin chop.

Extending Aging of Beef Longissimus Lumborum From 21 to 84 Days Postmortem Influences Consumer Eating Quality

Our objective was to determine the effect of extending postmortem aging from 21 to 84 days on consumer eating quality of beef longissimus lumborum. Strip loins were collected from 108 carcasses. The longissimus lumborum muscle was isolated from strip loins and assigned to one of ten postmortem aging periods from 21 to 84 days (7-day increments) and balanced within four anatomical positions within the muscle. Consumer evaluations for tenderness, juiciness, flavor, and overall liking were conducted using untrained consumer sensory panels consisting of 1080 individual consumers, in accordance with the Meat Standards Australia protocols. These scores were then used to calculate an overall eating quality (MQ4) score. Postmortem aging had no effect (P > 0.05) on tenderness, but juiciness, flavor liking, overall liking, and MQ4 declined (P < 0.05) as aging period increased. Samples aged 21 to 42 days were most preferred having greater (P < 0.05) overall liking and greater (P < 0.05) MQ4 scores than samples aged 70 to 84 days postmortem. These results suggest that longissimus lumborum samples should not be wet-aged longer than 63 days to prevent potential negative eating experiences for consumers; however, altering storage conditions, specifically reducing temperature, could potentially allow for longer chilled storage without such negative effects on flavor and overall liking.

Cooking Method and USDA Quality Grade Affect Consumer Palatability and Flavor of Beef Strip Loin Steaks

Consumer sensory analysis (n = 288) was conducted, along with cooking loss, slice shear force (SSF), pressed juice percentage (PJP), and volatile compound analyses, to evaluate the effects of different dry heat cooking methods. Specifically, an electric clamshell grill (CLAM), flat top gas grill (FLAT), charbroiler gas grill (CHAR), and salamander gas broiler (SAL) were used to cook beef strip loin steaks from 4 USDA quality grades [Prime, Top (upper 2/3) Choice, Low (lower 1/3) Choice, and Select)] to determine the palatability. Cooking method and quality grade influenced (P < 0.01) consumer tenderness, juiciness, flavor liking, and overall liking. Steaks cooked on CHAR had greater (P < 0.05) flavor liking and subsequently greater overall liking than any other cooking method. Steaks cooked on FLAT were scored lower for tenderness and juiciness than any other cooking method (P < 0.05), whereas steaks cooked on CLAM had lower (P < 0.05) flavor liking scores than any other cooking method, excluding FLAT. Overall acceptance was greater (P < 0.05) for steaks cooked on CHAR compared to all other cooking methods, regardless of quality grade. Prime samples had greater scores than Low Choice and Select for tenderness, juiciness, flavor liking, and overall liking (P < 0.05), but Prime did not differ from Top Choice for all traits. No main effects or interactions influenced (P > 0.05) SSF or PJP. Both cooking method and quality grade impacted (P < 0.05) the headspace concentration of some volatile compounds in the alcohol, n-aldehyde, Strecker aldehyde, and furan groups. Cooking method also affected all pyrazines, and quality grade had an effect on 1 ketone (P < 0.05). These results indicate cooking method had a significant impact on consumer palatability ratings and objective measures of beef flavor, and those results were consistent across a range of quality grades.

Comparison of methods for measuring shear force and sarcomere length and their relationship with sensorial tenderness of longissimus muscle in beef

Slice shear force (SSF) and laser diffraction, considered faster methodologies, for measuring beef instrumental tenderness and sarcomere length, were compared with reference methodologies Warner-Bratzler shear force (WBSF) and phase contrast microscopy. Striploin samples (n = 74) were analyzed for pH, sarcomere length, instrumental tenderness, myofibrillar fragmentation index, and sensorial tenderness. Pearson's correlation measured the association of meat evaluation methods with residual analysis of the multivariate analysis of variance model. The n-dimensional profile to evaluated methods was presented by biplot to identify the behavior of the correlation between the methods (variables). There was moderate correlation between SSF and WBSF (r = .63; p < .01) and both presented moderate correlation with sensorial tenderness (r = - .62 and -.55, to SSF and WBSF, respectively; p < .01). However, WBSF was more efficient to classify samples as tender (68%) than SSF (47%), comparing with sensorial tenderness (80%). There was a moderate correlation for laser and microscopy for sarcomere length (r = .57; p < .01). Sarcomeres were shorter when measured by laser than microscopy. Either with low correlation coefficients, sarcomere measured by laser (r = .29; p < .05) presented higher correlation with sensorial tenderness than with microscopy (r = .22; p < .10). Results highlighted that SSF was faster and easier to run, while WBSF was more appropriate to classify samples by sensorial tenderness grades. Laser diffraction is more suitable to explain effects on tenderness; however, microscopy revealed results of sarcomere length that were more realistic, once laser can underestimate sarcomeres.

Comportamento mecânico e estrutural de diferentes cortes cárneos em teste de determinação da força de cisalhamento

Resumo Neste trabalho, foram avaliados os comportamentos mecânico e estrutural de diferentes cortes cárneos em testes de determinação da força de cisalhamento, com o objetivo de identificar possíveis diferenças que podem interferir negativamente na mensuração da maciez objetiva. Seis cortes cárneos: Contrafilé (Longissimus dorsi), Maminha (Tensor fasciae latae), Lagarto (Semitendinosus), Filé-mignon (Psoas major) e Picanha (Biceps femoris) bovinos, e Lombo suíno (Longissimus dorsi) foram analisados de acordo com o método Warner-Bratzler, usando um texturômetro equipado com lâmina de 1 mm de espessura. As superfícies cisalhadas foram analisadas por microscopia eletrônica de varredura e as curvas mecânicas geradas durante os testes foram estudadas. Diferentes comportamentos foram observados nas curvas mecânicas e na microestrutura dos cortes cárneos em estudo. Alguns cortes apresentaram picos máximos bem definidos, enquanto outros apresentaram curvas mais abertas com maior distribuição da força durante os testes. Os cortes também apresentaram diferenças quanto à altura dos picos, que variou entre diferentes cortes e até em um mesmo corte. Nas microestruturas, foram observados diferentes comportamentos como: fibras deformadas por tracionamento, fibras aglomeradas devido a forte compressão e irregularidades na espessura e formato de fibras. Assim, concluiu-se que o teste de determinação da força de cisalhamento utilizado envolve outros princípios, como compressão e elongação, dependendo do corte cárneo estudado.

Tenderness and sensory attributes of the longissimus lumborum muscles with different quality grades from Chinese fattened yellow crossbred steers

The objectives were to investigate intramuscular fat (IMF) content,Warner–Bratzler shear force(WBSF) and sensory attributes of Chinese fattened yellow crossbred steer beef with different quality grades, and to determine the relationship between WBSF and Chinese consumers' sensory tender. WBSF of grades A1 to A5 decreased from 50.6 N to 33.1 N with IMF % increased from4.26 to 24.55 (P b 0.05). Consumer panelists showed more likeability grades A4 and A5 with no difference between them. Grades A2 and A3 were slightly preferred (P b 0.05). Grade A1 was undesirable. A regression relationship between WBSF and sensory tender was found, which indicated that consumers disliked beef when WBSF N55.43 N and preferred those with WBSF b41.4 N. The range of 41.4 N to 55.43 N was intermediate. Hence, WBSF N55.43 & b41.4 N allow classification of tough and tender for beef tenderness for Chinese consumers, and grade A4 was recommended as suitable top grade.

Effects of stress by unfamiliar sounds on carcass and meat traits in bulls from three continental beef cattle breeds at different ageing times

One-hundred-and-twenty-four young bulls of three Continental beef cattle breeds were used to study the effect of pre-slaughter stress by unfamiliar sounds on carcass traits and quality characteristics of beef aged for three different periods. Stress due to unfamiliar noises had a moderately negative effect on carcass and meat quality. Carcasses from group Stressed had higher (P<0.05) values of pH0, pH24, a*, and Warner-Bratzler shear force, and lower (P<0.05) values of L*, b* and pressure losses than from Unstressed animals. There were significant differences (P<0.05) among breeds in L*, a* and pressure losses. The ageing time had a significant effect on chromatic variables, WBSF and pressure losses. The cooking losses were not significantly affected by any of the three factors discussed. These results emphasize the importance of implementing appropriate management practices during pre-slaughter handling of cattle in order to reduce any possible risk factor for stress, as well as the different sensitivity of the breeds to similar stimuli.

Combining two proven mechanical tenderness measurements in one steak

This research was performed to determine the true efficacy of measuring both Warner-Bratzler shear force (WBSF) and slice shear force (SSF) in the same steak. The objectives were to compare cooking methods commonly used in preparing steaks for WBSF and SSF procedures and compare them at different cooling times. United States Department of Agriculture select strip loins (n = 240) were aged for either 7 or 14 d to increase the variation in tenderness. Each strip loin was then frozen and cut into 2.54-cm steaks. Steaks were then cooked to an internal temperature of 71°C using a convection conveyor oven (conveyor), a convection oven, clamshell grill, or an open hearth grill. Steaks were allotted to 4 different cooling times to create the combinations of: WBSF 4 h/SSF 0 h, WBSF 4 h/SSF 4 h, WBSF 24 h/SSF 0 h, WBSF 24 h/SSF 24 h. Five 1.25-cm cores were used for WBSF and one 1- by 5-cm slice for SSF. The WBSF from steaks cooked with conveyor were tougher than convection oven cooked steaks [51.9 Newtons (N) vs. 46.1 N; P < 0.05]. However, SSF were tougher when cooked in oven compared with those cooked in conveyor (267.5 N vs. 237.2 N; P < 0.05). Correlations for WBSF and SSF performed in the same steak ranged from 0.51 to 0.88 (P < 0.0001). The WBSF 24 h/SSF 0 h and WBSF 4 h/SSF 4 h had the strongest relationships (0.88 and 0.82, respectively; P < 0.05) between WBSF and SSF when using clamshell method. Performing WBSF and SSF in the same steak was successful based on moderate to high correlation values but the magnitude of the relationship is dependent on the combination of cooking method and cooling time.