Meta-analysis of the relationships between beef tenderness and muscle characteristics

Effect of residual feed intake on meat quality in fattening Charolais bulls fed two contrasting diets

The selection of more efficient animals for breeding is of both economic and environmental interest to the industry. The aim of this study was to evaluate the influence of the animals' residual feed intake (RFI) ranking in interaction with the type of diet on the meat quality of Charolais beef cattle. Indeed, several biological mechanisms are associated with RFI, especially when animals are fed high starch-diets. It is therefore possible that quality parameters may show greater changes due to RFI in the context of high starch diets compared to high forage diets. An 84-day feed efficiency trial followed immediately by a second 112-day feed efficiency trial was conducted with a total of 100 animals fed either maize- or grass-diets for 196-days. At the end of the 84-day period, the 32 most divergent RFI animals (16 extreme RFI animals per diet, 8 RFI+ and 8 RFI-) were identified. They were slaughtered after 112-days of finishing. The Longissimus thoracis was characterised in terms of nutritional and sensory quality. RFI had no effect on lab colour, muscle shear force, total fat, fatty acid ratios and most of the total fatty acid content (especially n-3) irrespective of the diet. However, more efficient animals (RFI-) showed higher CLA contents compared to less efficient animals (RFI+) regardless of the diet and also a lower n6/n3 ratio only in animals fed the maize diets. Diet also had a significant effect on lipid and FA content as well as on FA composition.

Exploration of Microencapsulation of Arginine in Carnauba Wax (Copernicia prunifera) and Its Dietary Effect on the Quality of Beef

The objective of this exploratory study was to assess if microencapsulated arginine influences the physicochemical quality of beef. The study included three genetic groups: Angus, Hereford, and Angus × Hereford crossbreed. Two encapsulation systems were used with carnauba wax, at ratios of 3:1 and 2:1, carnauba wax:core (arginine), respectively. A control treatment was also included with no arginine addition. Encapsulated arginine with a 3:1 ratio increased redness by 19.66 at 28 d aged beef compared to the control and 2:1 ratio with values of 18.55 and 16.77, respectively (p = 0.01). Encapsulated arginine at a 3:1 ratio showed the lowest meat shear force values with 24.32 N at 28 d of ageing (p < 0.001). The Angus breed also had a low value of 24.02 N (p < 0.001). Finally, the highest values of intramuscular fat were observed with the inclusion of arginine in a 3:1 ratio. The fat value reached 2.12% with a 3:1 ratio (p = 0.002), while in the Angus breed it was 1.59%. The addition of carnauba wax-encapsulated arginine can improve meat quality. It enhances red color, tenderness, and marbling in bovine meat.

French consumer evaluation of eating quality of Angus x Salers beef: Effects of muscle cut, muscle slicing and ageing

Based on the Meat Standards Australia (MSA) methodology, the objectives of this study were to evaluate the eating quality of grass-fed Angus x Salers beef by French consumers, across different muscle cuts (m. triceps brachii caput longum, m. longissimus dorsi et thoracis and m. rectus abdominis), ageing times (5 and 14 days) and muscle slicing and grilling methods (being distinguished by 2 different sides on the grill), and to further quantify whether the MSA model could predict the eating quality of the meat produced by these lean crossbred animals. The results showed that French consumers can discern significant differences in eating quality traits across muscle cuts but not between ageing times and muscle slicing methods. In this study, the accuracy of eating quality score (MQ4)-assigned MSA grade was 64.5%. Due to the lack of MSA data on these lean crossbred animals, the prediction of eating quality from carcass characteristics was less accurate than usual. However, these results do indicate that the MSA sensory testing protocol, the MQ4 calculation and the MSA quality grades could be used to support a consumer-based quality grading system in France.

Across countries implementation of handheld near-infrared spectrometer for the on-line prediction of beef marbling in slaughterhouse

Only few studies have used Near-Infrared (NIR) spectroscopy to assess meat quality traits directly in the chiller. The aim of this study was therefore to investigate the ability of a handheld NIR spectrometer to predict marbling scores on intact meat muscles in the chiller. A total of 829 animals from 2 slaughterhouses in France and Italy were involved. Marbling was assessed according to the 3G (Global Grading Guaranteed) protocol using 2 different scores. NIR measurements were collected by performing 5 scans at different points of the Longissimus thoracis. An average MSA marbling score of 330-340 was obtained in the two countries. The prediction models provided a R² in external validation between 0.46 and 0.59 and a standard error of prediction between 83.1 and 105.5. Results did provide a moderate prediction of the marbling scores but can be useful in the European industry context to predict classes of MSA marbling.

Differences in carcass chilling rate underlie differences in sensory traits of pork chops from pigs with heavier carcass weights

Pork hot carcass weights (HCW) have been increasing 0.6 kg per year, and if they continue to increase at this rate, are projected to reach an average weight of 118 kg by the year 2050. This projection in weight is a concern for pork packers and processors given the challenges in product quality from heavier carcasses of broiler chickens. However, previous work demonstrated that pork chops from heavier carcasses were more tender than those from lighter carcasses. Therefore, the objective was to determine the effects of pork hot carcass weights, ranging from 90 to 145 kg with an average of 119 kg, on slice shear force and sensory traits of Longissimus dorsi chops when cooked to 63°C or 71°C, and to assess if differences in chilling rate can explain differences in sensory traits. Carcasses were categorized retrospectively into fast, medium, or slow chilling-rates based on their chilling rate during the first 17 h postmortem. Loin chops cut from 95 boneless loins were cooked to either 63°C or 71°C and evaluated for slice shear force and trained sensory panel traits (tenderness, juiciness, and flavor) using two different research laboratories. Slopes of regression lines and coefficients of determination between HCW and sensory traits were calculated using the REG procedure in SAS and considered different from 0 at P ≤ 0.05. As hot carcass weight increased, chops became more tender as evidenced by a decrease in SSF (63°C ß = -0.0412, P = 0.01; 71°C ß = -0.1005, P < 0.001). Further, HCW explained 25% (R 2 = 0.2536) of the variation in chilling rate during the first 5 h of chilling and 32% (R 2 = 0.3205) of the variation in chilling rate from 5 h to 13 h postmortem. Slow and medium-rate chilling carcasses were approximately 12 kg heavier (P < 0.05) than fast chilling carcasses. Slice shear force of chops cooked to 63° and 71°C was reduced in slow and medium chilling compared with fast chilling carcasses. Carcass temperature at 5 h postmortem explained the greatest portion of variation (R 2 = 0.071) in slice shear force of chops cooked to 63°C. These results suggest that carcasses tend to chill slower as weight increases, which resulted in slight improvements in sensory traits of boneless pork chops regardless of final degree of doneness cooking temperature.

Content and Solubility of Collagen and Their Relation to Proximate Composition and Shear Force of Meat from Different Anatomical Location in Carcass of European Beaver (Castor fiber)

The content and solubility of collagen in the muscle tissue and cooked meat from three anatomical locations (loin, hind leg and shoulder) in carcasses of adult male European beavers and relationships of collagen fractions with proximate composition and shear force were studied. Shoulder muscle tissue contained the highest amount of intramuscular fat, collagen/protein ratio, total and insoluble collagen, and the lowest percentage of soluble collagen. The cooked meat from hind leg contained the lowest amount of total, soluble and insoluble collagen. The percentage of collagen fractions in cooked meat was comparable in all cuts (p > 0.05). The toughest meat was from the shoulder, followed by the hind leg, and the tenderest meat was from the loin (p < 0.01). Shear force of cooked meat was correlated positively with the amount of total collagen, insoluble collagen and its percentage in muscle tissue (0.597, 0.594 and 0.499, p < 0.01), as well as negatively with percentage of soluble collagen (−0.594, p < 0.001). No correlations between the shear force and the content of total collagen and its fractions in cooked meat were found. In conclusion, our results indicate that the amount of total collagen and its fractions in raw muscle tissue of beaver is a better tenderness predictor for cooked meat than their values in heat-treated meat.

Impact of Kosher Slaughter Methods of Heifers and Young Bulls on Physical and Chemical Properties of Their Meat

This work aimed to comprehensively analyze the factors (slaughter method, gender, and muscle type) that determine the kosher status of beef and assess their influence on the selected quality characteristics of raw meat. The muscles were obtained from 40 carcasses of heifers and 40 carcasses of young bulls. In the first stage of the experiment, pH values were measured. The water, protein, fat, minerals, and collagen contents were determined. Then, the shear force, forced drip, and thermal drip were measured. The experimental results indicated that all the investigated parameters have an impact on the final quality of beef. Statistically significantly lower pH₁ values were noticed in the longissimus thoracic muscle of young bulls obtained through kosher slaughter methods. However, 24 and 48 h after slaughter, higher pH values were observed in the meat of young bulls obtained by the kosher slaughter method, where the meat samples were subjected to kosher treatment. The koshering process (salting and washing) resulted in a significant reduction in both forced and thermal drip values of the meat sample, but this decrease was not affected by gender.

Are muscle fiber types different between normal and dark-cutting beef?

Muscle fiber (MF) characteristics of Longissimus thoracis (LT) muscles from heifer (n = 11) and steer (n = 12) carcasses graded Canada AA (AA, normal, n = 4/sex) or dark-cutting (Canada B4) were examined and related to beef quality. Atypical (AB4, pH < 5.9, n = 4/sex) and typical (TB4, pH > 5.9, n = 3 and 4 for heifers and steers, respectively) dark-cutting carcasses were represented. Muscle fiber type proportions did not differ between AA, AB4 and TB4 muscles, although type I and IIB muscle fiber diameters were greater in TB4 than in AA LT. That AB4 muscle fiber proportions were not different from AA and TB4 muscles suggests that the increased MF diameter of TB4 muscle was due to water retained by muscle proteins at high ultimate pH, as evidenced by decreased cooking loss. Dark-cutting was therefore unrelated to muscle fiber proportions, and increased Type I and IIB diameters in dark cutting LT were likely driven by elevated intramuscular ultimate pH.

Meta-analysis of the relationship between collagen characteristics and meat tenderness

Meta-analysis methods were used to investigate the effects of collagen content, solubility and pyridinoline cross-link content on Warner-Bratzler shear force (WBSF) and sensory tenderness in major meat species. Data was collected from the literature on pork, beef and lamb and analyzed independently for each species. The beef data was categorized into subgroups according to muscle (loin and other muscle) and age (young, <18 months and old, ≥18 months). The results showed that in beef, collagen content and pyridinoline cross-link content were positively correlated with WBSF and negatively with sensory tenderness, while collagen solubility was negatively correlated with WBSF. The correlation coefficients were greater in other beef muscles than loin. Significant correlations between collagen content and tenderness attributes were observed in old beef animals. However, non-significant relationships and large variations were found in pork and lamb. More studies with various muscles and ages are required for an in-depth understanding of the relationship between collagen characteristics and meat tenderness.

The influence of age and sex on carcass characteristics and chemical composition of the longissimus thoracis et lumborum muscle in wild boars (Sus scrofa)

The aim of this study was to determine the influence of age and sex on carcass characteristics and the chemical composition of the longissimus thoracis et lumborum (LTL) muscle in wild boars (Sus scrofa). Carcass quality parameters varied significantly depending on age and sex, whereas the protein and collagen contents in the muscle were affected by animal age. The carcasses of male yearlings and adults were characterised by the highest processing suitability, which can be attributed to the highest percentage of lean meat in the carcass and a moderate fat and bone content. A higher fat content was found in carcasses of females from all age groups, and a lower bone content was found in yearlings and adult females. The protein content was the highest in the LTL muscle of adult boars, and the collagen content was the highest in piglets; thus, the chemical composition of the muscle was most desirable in adult wild boars and least desirable in piglets.

The use of conventional laboratory-based methods to predict consumer acceptance of beef and sheep meat: A review

Meat scientists often use objective, laboratory-based methods to understand the sensorial properties of red meat. These approaches are advantageous because of their reproducibility, low cost, rapid generation of data and technical ease - comparative to large scale consumer sensory panels. To enhance the value of these methods, effort has been applied to identify specific limits or thresholds that correspond to a consumer's acceptance or satisfaction with the quality of a meat product. From the literature, we observe there to be inconsistencies in these thresholds. This could stem from disparate laboratory methods, consumer panel procedures and demographics, the approach to statistical analysis, sample type and representativeness, and more. This paper aimed to review consumer thresholds, proposed in the literature, to provide insight into their validity and transferability to other studies. Investigations were limited to red meat (beef and sheep meat) and to non-spectroscopic methods that have been used to predict consumer acceptance of colour, tenderness, juiciness, flavour and overall liking.

Myosin sensitivity to thermal denaturation explains differences in water loss and shrinkage during cooking in muscles of distinct fibre types

The effect of thermal protein denaturation on the structure and quality of muscles of different fibre types is not well understood. Unaged masseter (100% type I fibres) and cutaneous trunci (93% type II fibres) muscles (N = 10) were assessed for their characteristics, protein denaturation, cooking loss, Warner- Bratzler shear force (WBSF) and shrinkage after heating at 50 °C - 85 °C with a rate of 5 °C/ min. Raw masseter had a higher pH, collagen and water content, shorter sarcomere, comparable fibre diameter, and shorter and wider fragments upon homogenization, than cutaneous trunci. In cutaneous trunci, at 55 °C - 60 °C, the lower transition temperature of myosin and the greater cumulative enthalpy resulted in greater cooking loss in muscle cuboids, and greater transverse, longitudinal and volume shrinkage in fibres and fibre fragments, than in masseter. Protein denaturation explained 71% variability in fibre fragment volume and 58% in cooking loss of both muscles, as well as 47% variability in WBSF of masseter.

Is meat from cull cows tougher?

Meat from cull cows is traditionally sold in Australia for mincemeat, but this study examined whether there is potential to add value by identifying meat of higher quality from older cattle. Dentition and ossification score were recorded for 173 Angus cattle of known age, ranging from 26 months to 12.6 years. Longissimus and semitendinosus muscles were sampled to assess the effect of chronological age on shear force and connective tissue. Age explained variation in shear force of the semitendinosus better than in the longissimus muscle, but had little effect on shear force values per se. At 2 days postmortem, 18% of the longissimus muscles were classified as tender reaching 65% as ageing extended to 14 days. Soluble collagen was a better predictor of age than total collagen. This study shows that the current practice of routinely selling meat from culled cows as mincemeat overlooks a valuable opportunity to grade and sell a significant proportion at higher price as prime cuts.

Physicochemical and histochemical characteristics of bovine longissimus lumborum muscle defected as muscular steatosis (massive adipocyte infiltration)

To understand muscular steatosis observed in beef carcasses, physicochemical and histochemical characteristics were compared between abnormal (massive fatty replaced) and normal regions of beef striploin. Fat content in the abnormal region (48.02%) was approximately twice than that in the normal region (22.01%). However, fatty acids did not show significant (P > 0.05) differences in their compositions between the two regions. Tenderness was significantly (P < 0.05) higher in the abnormal region. However, other meat quality traits were not significantly (P > 0.05) different between the two regions. Massive accumulation of adipocytes was accompanied by muscle fiber atrophy regardless of muscle fiber types. Without a change in total muscle fiber density, oxidative fiber composition was significantly increased, whereas glycolytic fiber composition was decreased (P < 0.05). These findings suggest that adipogenic transdifferentiation and muscle fiber type switching can occur within the muscle due to muscular steatosis.

Collagen, intramuscular fat and proteolysis affect Warner-Bratzler shear-force of muscles from Bos taurus breed types differently at weaning, after backgrounding on pasture, and after feedlotting

Context The texture of beef is highly important for the eating experience, and there is a continued interest in understanding the biochemical basis for the variation in texture between cattle and their meat cuts in order to improve and minimise variation in tenderness due to production and processing factors. Aims The present study aimed to investigate the impact of characteristics of meat on Warner-Bratzler shear-force (WBSF) as an indicator of texture of beef as affected by breed type, age/feeding phase, and muscle. Methods Seventy-five steers of three breed types (Angus, Hereford and Wagyu × Angus) were slaughtered after weaning 6 months old (n = 15), after backgrounding 17 months old (n = 30) and after feedlotting 25 months old (n = 30). At slaughter three muscles (M. supraspinatus, M. semitendinosus and M. longissimus lumborum) were sampled from each steer, and pH, intramuscular fat and collagen content, sarcomere length, and proteolysis (desmin degradation) were measured and used to explain the variation in WBSF after 7 and 14 days of aging. Key results Meat from Hereford and Angus steers had higher WBSF after 7 days of aging compared with Wagyu × Angus steers, but after 14 days of aging there was only a difference between Hereford and Wagyu × Angus in the M. supraspinatus and M. semitendinosus. The WBSF of the young weaned steers and steers slaughtered after backgrounding were dependent on the degree of proteolysis in the muscles, whereas for steers slaughtered after feedlotting the content of collagen was more important for the WBSF. The amount of intramuscular fat had a significant impact on the differences in WBSF within the specific muscle studied. In contrast to the general dogma that WBSF increase with age, WBSF decreased in M. semitendinosus and M. longissimus lumborum from the weaned 6-month-old steers to the 25-month-old steers finished in feed-lot, whereas in M. supraspinatus the older feed-lot finished steers had a higher WBSF. Conclusion The factors contributing to the Warner-Bratzler shear force of beef depends on the age/feeding phase of the animal and the muscle and less on the breed type. Implications Optimisation of texture in beef through breeding and production should address different traits dependent on the age/feeding phase of the slaughter animal.

Wagyu-Angus cross improves meat tenderness compared to Angus cattle but unaffected by mild protein restriction during late gestation

For the spring-calving beef herds, late gestation coincides with winter and early spring, when cows are dependent on feed supplements with low quality hay, which is hard to meet their nutrient requirements. However, the effects of deficiencies of metabolizable protein intake during late gestation on offspring beef quality are unclear. Wagyu cattle have excellent marbling, and insemination with Wagyu vs Angus semen is a practical option for beef producers to improve beef quality. To test, Angus cows (621 ± 73 kg) were selected and randomly separated into two groups. Each group was inseminated with either Angus or Wagyu semen. During the last 90 days of gestation, cows in each group were further separated and received either a low protein diet (85% of the NRC metabolizable protein requirement), which was a low quality hay-based diet common in northwestern region of the U.S., or an adequate protein diet (108% NRC requirement). All progeny was managed together and harvested at a final BW of 576.5 ± 16.6 kg. Wagyu-sired offspring had higher marbling scores and quality grades than Angus (P < 0.01). Protein supplementation did not affect Slice Shear Force (SSF) in either breeds (P = 0.60). However, Wagyu-sired cattle had lower SSF than Angus-sired (P < 0.01). In addition, Wagyu-sired cattle had higher intramuscular fat (P < 0.05) and total collagen content (P < 0.05), but Angus-sired had greater mature collagen cross-links, as shown by higher contents of Pyridinoline (P < 0.01) and Ehrlich Chromogen (P < 0.01). Consistently, the mRNA expression of enzymes catalyzing collagen cross-linking was higher in Angus-sired offspring, including Plod 1 (P < 0.05), Plod 2 (P = 0.08), and P4Hα 2 (P < 0.01). In conclusion, Wagyu-sired cattle had greater tenderness and marbling score compared to Angus-sired, which was associated with lower collagen cross-links. Feeding mature grass hay-based diet with relatively low protein content during late gestation had no major effect on beef quality of subsequent cattle.

Muscle fiber characteristics and postmortem quality of longissimus thoracis, psoas major and semitendinosus from Chinese Simmental bulls

Using Chinese Simmental cattle semitendinosus, psoas major, and longissimus thoracis samples, we assessed muscle fiber characteristics and postmortem quality. The type I, IIA, and IIB fiber diameters were greater in semitendinosus and longissimus thoracis relative to psoas major, with psoas major, semitendinosus, and longissimus thoracis having the highest respective percentages of type I, IIB, and IIA fibers. Psoas major had the highest R 248 and R 250 values and lowest R 258 values at 1- and 6-hr postmortem. Psoas major had the lowest Warner-Bratzler shear force (WBSF), hardness, and chewiness values. The trends of WBSF, hardness, and chewiness changes decreased with increasing aging time. Semitendinosus had higher changes in WBSF than psoas major, and the number % type I fibers was correlated negatively with % changes of WBSF. Therefore, muscles with a high proportion of type IIB fibers and a low proportion of type I had lower tenderness and higher tenderization rate. Further research should be done to seek the optimal composition of muscle fiber type in order to improve beef quality, as muscle fiber type has opposite effect of tenderness background and tenderization rate.

Visible and Near-Infrared Multispectral Features in Conjunction with Artificial Neural Network and Partial Least Squares for Predicting Biochemical and Micro-Structural Features of Beef Muscles

The objective of this study was to determine the potential of multispectral imaging (MSI) data recorded in the visible and near infrared electromagnetic regions to predict the structural features of intramuscular connective tissue, the proportion of intramuscular fat (IMF), and some characteristic parameters of muscle fibers involved in beef sensory quality. In order to do this, samples from three muscles (Longissimus thoracis, Semimembranosus and Biceps femoris) of animals belonging to three breeds (Aberdeen Angus, Limousine, and Blonde d’Aquitaine) were used (120 samples). After the acquisition of images by MSI and segmentation of their morphological parameters, a back propagation artificial neural network (ANN) model coupled with partial least squares was applied to predict the muscular parameters cited above. The results presented a high accuracy and are promising (R² test > 0.90) for practical applications. For example, considering the prediction of IMF, the regression model giving the best ANN model exhibited R²P = 0.99 and RMSEP = 0.103 g × 100 g⁻¹ DM.

Influence of collagen changes on the tenderness of yak rumen smooth muscle during storage

The aim of the present study was to investigate the influence of collagen changes on the tenderness of yak rumen smooth muscle during storage. Yak rumen smooth muscle was stored at 3 ± 1 °C for 7 d and the Warner–Bratzler shear force (WBSF); total, soluble, and insoluble collagen content (TCC, SCC); collagen solubility (CS); and histological structure were monitored. Label-free mass spectrometry was used to validate the changes in collagen. Collagen changes significantly influenced yak rumen smooth muscle tenderness. A significant positive relationship was found between WBSF and TCC, SCC, as well as CS. The label-free mass spectrometry results validated that the collagen of smooth muscle was degraded during storage. Histological analysis revealed that yak rumen smooth muscle structure was destroyed during storage. Smooth muscle underwent a similar change in tenderness as skeletal muscle, and the weakening of connective tissue was the main reason for smooth muscle tenderness development.

Research in Beef Tenderness and Palatability in the Era of Big Data

For decades, research has focused on predicting beef palatability using muscle biochemical traits, and various biomarkers. In these approaches, a precise definition of the variable to predict (tenderness assessed by panelists, untrained consumers, or shear force), and repeatability of the measurements are crucial for creating significant data resources for the derivation of robust predictive models, and rigorous validation testing. This “big data” approach also requires careful definition of traits and transparent principles for data sharing and management. As in other fields, meat science researchers should improve the Findability, Accessibility, Interoperability, and Reuse of data (known as the FAIR principles). Furthermore, with the rapid evolution of new measurement technologies, the traits that they measure must be consistently described, enhancing our ability to integrate these new measurements into existing description systems. For beef, strategic choices have been made in order to consider real consumers’ expectations, not well estimated correctly by lab approaches. This strategy has been successfully developed in Australia, which set up the “Meat Standards Australia” grading scheme, now partly adopted by the beef industry. The ambitions of the International Meat Research 3G Foundation is to develop beef ontology, to set up an international database with a huge number of consumers’ scores related to beef palatability and collected according to standard protocols. The foundation also aims to support the beef industry by offering an international predictive model of beef palatability, flexible enough to take into account any local livestock characteristics or regional consumer specificity. This approach is supported by the United Nations Economic Commission for Europe (UNECE), which is promoting development of regulations and norms, technical cooperation and exchange of best expertise and practices. This will substantially improve the transparency of data flow and price signaling between all participants of the value chain, from beef producers through to consumers at retail.

European conformation and fat scores of bovine carcasses are not good indicators of marbling

Marbling is one of the primary carcass attributes utilized in most beef grading systems for eating quality evaluation. In Europe, the current beef grading system is the EUROP grid, which is focused on carcass commercial value and production yield rather than eating quality estimation. The aim of this study was to investigate the relationship between marbling and the most common scores for carcass classification in Europe. If there are strong associations between marbling and European classification scores, marbling score may be estimated from the carcass characteristics. However, this study indicated that European classification scores explain only a slight proportion of the variance in marbling score (32%, 46%, 34% and 21% for the entire cattle group, young bulls, females and steers, respectively). Therefore, whereas the EUROP grid is well adapted to estimate yield, it does not reflect marbling at all. The European beef industry should take into account additional indicators related to beef palatability to assist the determination of the commercial value of carcasses.

The effects of graded levels of concentrate supplementation on colour and lipid stability of beef from pasture finished late-maturing bulls

Finishing late-maturing bulls on grass may alter the antioxidant/prooxidant balance leading to beef with higher susceptibility to lipid oxidation and a lower colour stability compared to bulls finished on cereal concentrates. In this context, lipid oxidation and colour stability of beef from late-maturing bulls finished on pasture, with or without concentrate supplements, or indoors on concentrate was assessed. Charolais or Limousin sired bulls (n = 48) were assigned to four production systems: (1) pasture only (P), (2) pasture plus 25% dietary DM intake as barley-based concentrate (PC25), (3) pasture plus 50% dietary DM intake as barley-based concentrate (PC50) or (4) a barley-based concentrate ration (C). Following slaughter and postmortem ageing, M. Longissimus thoracis et lumborum was subjected to simulated retail display (4°C, 1000 lux for 12 h out of 24 h) for 3, 7, 10 and 14 days in modified atmosphere packs (O2 : CO2; 80 : 20). Lipid oxidation was determined using the 2-thiobarbituric acid-reactive substances assay; α-tocopherol was determined by HPLC; fatty acid methyl esters were determined using Gas Chromatography. Using a randomised complete block design, treatment means were compared by either ANOVA or repeated measures ANOVA using the MIXED procedure of SAS. Total polyunsaturated fatty acid (PUFA) concentrations were not affected by treatment, n-3 PUFAs were higher (P < 0.001) and the ratio of n-6 to n-3 PUFAs was lower (P < 0.001) in muscle from P, PC25 and PC50 compared to C. α-Tocopherol concentration was higher in muscle from P compared to PC50 and C bulls (P = 0.001) and decreased (P < 0.001) in all samples by day 14. Lipid oxidation was higher in muscle from C compared to P bulls on day 10 and day 14 of storage (P < 0.01). Finishing on pasture without supplementation did not affect beef colour stability and led to lower lipid oxidation, possibly due to the higher α-tocopherol concentration compared to concentrate finished beef.

Evaluation of WBSF, Color, Cooking Loss of Longissimus Lumborum Muscle with Fiber Optic Near-Infrared Spectroscopy (FT-NIR), Depending on Aging Time

Near-infrared spectroscopy is a known technique for assessing the quality of compounds found in food products. However, it is still not widely used for predicting physical properties of meat using the online system. This study aims to assess the possibility of application of a NIR equipped with fiber optic system as an online measurement system to predict Warner⁻Bratzler shear force (WBSF) value, cooking loss (CL), and color of longissimus lumborum muscle, depending on aging time. The prediction model satisfactorily estimated the WBSF on day 1 and day 7 of aging as well as a* color parameter on day one and CL on day 21. This could be explained by the fact that during beef aging, the physicochemical structure of meat becomes more uniform and less differentiation of raw data is observed. There is still a challenge to obtain a verifiable model for the prediction of physical properties, using NIR, by utilizing more varied raw data.

Data from the Farmgate-to-Meat Continuum Including Omics-Based Biomarkers to Better Understand the Variability of Beef Tenderness: An Integromics Approach

This study is based on an integromic approach of 71 young bulls' data from the farmgate-to-meat continuum including omics-based biomarkers, to understand beef tenderness variability in two muscle cuts that differ by their contractile and metabolic properties. By the means of chemometrics using partial least-squares (PLS) and principal component regressions (PCR), important variables from a list of 49 that characterize four levels of the continuum (rearing factors-carcass-muscle-meat) were identified to explain tenderness of Longissimus thoracis (LT) and Semitendinosus (ST) muscles evaluated by a sensory panel and instrumental Warner-Bratzler shear force (WBSF). The PLS and PCR analyses validated 16 and 15 variables for LT and 12 and 14 for ST from the whole continuum to explain sensory tenderness and WBSF, respectively. Among the explanatory variables in the four models and in line with the role of apoptosis in tenderness determinism, HSP70-1A/B (a heat shock protein) was retained to explain beef tenderness irrespective of muscle and evaluation method. Similarly, dressing percentage from the carcass level was another robust predictor but in a muscle-dependent direction manner. HSP20, ENO3, and MyHC-I as three muscle protein biomarkers and dry matter intake (DMI) as a rearing factor were involved in three models to explain beef tenderness. This study highlighted also that several variables were muscle-specific irrespective of the evaluation method of tenderness. For LT muscle, six variables including three carcass traits (fatness score, fat carcass %, and muscle carcass %), two muscle biomarkers (HSP70-8 and MyHC-IIx/b), and one meat quality trait (pH_3h) were found. For ST muscle, five variables were validated from two rearing factors (average daily gain and feed efficiency) and three structural protein biomarkers (α-actin, MyBP-H, and CapZ-β). Finally, for WBSF only, lactate dehydrogenase chain B (LDH-B) was retained positively for LT and negatively for ST muscles. Overall, this trial showed that tenderness of LT and ST muscle cuts is influenced by variables belonging to the whole continuum with relationships that depend on both the muscle type and the evaluation method. It further highlighted the potential of integromic/chemometric approaches on the farmgate-to-meat continuum data to better understand the sophisticated biological processes that orchestrate the conversion of muscle into meat and tenderness determinism.

Role of myofibers, perimysium and adipocytes in horse meat toughness

Horse meat is a good source of iron with low cholesterol but consumers consider tenderness most important when purchasing meat. Myofibers and intramuscular connective tissue, the main structural components of muscle, play major roles in meat toughness. The effects of myofibers and perimysium characteristics on Warner-Bratzler Shear Force (WBSF) values of horse semimembranosus were investigated on muscles previously assessed as tough (mean WBSF 68.87 ± 3.21 N, n = 8) or tender (mean WBSF 46.21 ± 2.27 N, n = 8). Mean Type IIA myofiber diameter was significantly greater in tender than in tough muscles. Secondary thick perimysium was thicker and collagen fibers more loosely arranged in tender muscles than in tough. A negative correlation was observed between WBSF values and perimysium thickness and a trend between WBSF and intramuscular fat. Adipocytes in perimysium of tender muscles may have contributed to thickening of perimysium and loosened collagen fibers thus contributing to tenderness of the meat.

Effect of castration and carcass suspension method on the quality and fatty acid profile of beef from male dairy cattle

BACKGROUND

The use of bulls rather than steers for beef production offers some considerable advantages; however, the eating quality of bull beef is an issue of marketing concern. This study assessed the physicochemical characteristics of young Holstein-Friesian (HF) bull and steer beef. Steer carcasses were suspended by the Achilles tendon (AS) and by pelvic suspension (PS).

RESULTS

HF steer beef had higher redness, yellowness and chroma values, whereas bulls had higher ultimate pH and darker muscle. Warner-Bratzler shear force, cook loss at different ageing times, moisture, and insoluble and total collagen were higher for HF bull beef, whereas intramuscular fat, soluble collagen and collagen solubility were higher for steer beef. HF steer beef had a higher proportion of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA), whereas bull beef had higher proportions of polyunsaturated fatty acids (PUFA), PUFA/SFA and n-6/n-3 PUFA ratios. In comparison to AS, PS increased redness and chroma after 24 h blooming; PS improved tenderness up to 7 days of ageing and accelerated the ageing process.

CONCLUSION

For young dairy cattle, steer beef would likely have superior eating quality but a relatively less favourable nutritional fatty acid profile to bull beef. Suspension method affected the tenderness and colour intensity of dairy steer beef at different ageing times. © 2018 Society of Chemical Industry.

Effects of breed-production system on collagen, textural, and sensory traits of 10 European beef cattle breeds

In the current study the collagen, texture, and sensory characteristics of meat from 712 yearling males of 10 local Spanish and French beef breeds raised in their typical production systems were described. The breed-production system affected collagen and texture variables but affected sensory variables only slightly. There was a large amount of intra breed-production system variation for all the variables. French breeds had lower values for collagen solubility (~12%) than Spanish breeds (~40%). Stress (WB) varied from 36 N/cm² in Casina to 44 N/cm² in Salers, whereas compression stress at 80% ranged from 35 N/cm² in Asturiana de los Valles to 40 N/cm² in Salers. Oven cooking resulted in higher cooking losses (24%) than cooking on a grill (12%). Cooking losses increased as the grill temperature increased. Numerous significant correlations were found among variables. Carcass weight is associated with all the collagen and texture variables. Correlation coefficients among texture and collagen variables were statistically significant and these correlation coefficients were in general higher for solubility percentage than for total collagen content, highlighting the importance of the solubility of collagen rather than total collagen in determining meat textural properties.

PRACTICAL APPLICATIONS

To differentiate a product in the market, it is necessary to define its characteristics. Differentiation allows increasing the added value of products and, therefore, income of the farmers. In addition, it guarantees to the consumers that the product they purchase has the intrinsic and extrinsic quality features that they seek. For consumers, beef texture is one of the most important quality attributes sought, therefore, studying factors that can affect beef texture is a major interest for the industry.

Beef tenderness and intramuscular fat proteomic biomarkers: muscle type effect

Tenderness and intramuscular fat content are key attributes for beef sensory qualities. Recently some proteomic analysis revealed several proteins which are considered as good biomarkers of these quality traits. This study focuses on the analysis of 20 of these proteins representative of several biological functions: muscle structure and ultrastructure, muscle energetic metabolism, cellular stress and apoptosis. The relative abundance of the proteins was measured by Reverse Phase Protein Array (RPPA) in five muscles known to have different tenderness and intramuscular lipid contents: Longissimus thoracis (LT), Semimembranosus (SM), Rectus abdominis (RA), Triceps brachii (TB) and Semitendinosus (ST). The main results showed a muscle type effect on 16 among the 20 analyzed proteins. They revealed differences in protein abundance depending on the contractile and metabolic properties of the muscles. The RA muscle was the most different by 11 proteins differentially abundant comparatively to the four other muscles. Among these 11 proteins, six were less abundant namely enolase 3 (ENO3), phosphoglucomutase 1 (PGK1), aldolase (ALDOA), myosin heavy chain IIX (MyHC-IIX), fast myosin light chain 1 (MLC1F), triosephosphate isomerase 1 (TPI1) and five more abundant: Heat shock protein (HSP27, HSP70-1A1, αB-crystallin (CRYAB), troponin T slow (TNNT1), and aldolase dehydrogenase 1 (ALDH1A1). Four proteins: HSP40, four and a half LIM domains protein 1 (FHL1), glycogen phosphorylase B (PYGB) and malate dehydrogenase (MDH1) showed the same abundance whatever the muscle. The correlations observed between the 20 proteins in all the five muscles were used to construct a correlation network. The proteins the most connected with the others were in the following order MyHC-IIX, CRYAB, TPI1, PGK1, ALDH1A1, HSP27 and TNNT1. This knowledge is important for understanding the biological functions related to beef tenderness and intramuscular fat content.

Carcass characteristics of grass-fed crossbred bulls and steers slaughtered at two different ages

The aim of this study was to evaluate beef production potential and meat quality in young crossbred bulls and steers raised indoors and fed grass-based diets. One half of 96 bull calves were castrated at 2–3 wk of age. The calves were fed standard diets, and starting at 7 mo of age, they received grass silage supplemented with concentrates. At the end of the fattening period (18 and 21 mo of age), the animals were slaughtered, carcass quality was evaluated, and samples of musculus longissimus thoracis were collected to determine the proximate composition and meat quality. The semi-intensive feeding system contributed to higher daily gains (0.835 kg) in Holstein-Friesian (HF) × Hereford (HH) crosses. In comparison with steers, bulls were characterized by a higher dressing percentage (+1.33%), higher weight of five most valuable primal cuts (+6.7 kg), and higher lean meat content of three-rib cuts (+7.54%). Meat from steer carcasses, which had higher fat content was more tender and had desirable aroma, juiciness, and flavor. In semi-intensive production systems, steers performed better than bulls, and HF × HH crosses were more suitable than HF × Limousin (LM) and HF × Charolais (CH) crosses. Dairy-beef crosses should be slaughtered at 21 mo of age to improve carcass quality.

Effects of Marbling Texture on Muscle Fiber and Collagen Characteristics

The objective of this study was to evaluate the effects of marbling texture on muscle fiber morphometrics, adipocyte cross-sectional area, perimysial thickness, collagen solubility, and thermal transition temperature of perimysial collagen of beef strip loin steaks from 3 marbling scores. Beef strip loins (n = 117) were selected from three marbling scores [Top Choice (Modest00 – Moderate100 marbling), Low Choice (Small marbling), and Select (Slight marbling)] to equally represent 3 different marbling texture groups: fine, medium, and coarse, via visual appraisal. There were no marbling texture × marbling score interactions for all traits evaluated. Marbling texture impacted (P < 0.05) adipocyte cross-sectional area, where coarse steaks displayed larger adipocytes in comparison to fine marbled steaks, but medium marbled steaks were similar (P > 0.05) to both coarse and fine marbled steaks for the same trait. However, marbling texture did not impact (P > 0.05) perimysial thickness. Marbling texture did not affect collagen traits, as no differences (P > 0.05) were found among marbling texture treatments for soluble collagen, insoluble collagen, and total collagen concentrations. Furthermore, all marbling texture groups (fine, medium, and coarse) were similar (P > 0.05) for the peak thermal transition phase of the perimysial fraction of collagen. Marbling score affected adipocyte size, as Top Choice and Low Choice possessed larger (P < 0.05) adipocytes than Select steaks. There were no differences (P > 0.05) among marbling scores for fiber type; nor were differences found among marbling textures or marbling scores for fiber cross-sectional area. These results indicate that marbling texture does not contribute to differences in collagen characteristics or fiber cross-sectional area that may impact eating quality of beef strip loin steaks.

Identification of Biomarkers Associated with the Rearing Practices, Carcass Characteristics, and Beef Quality: An Integrative Approach

Data from birth to slaughter of cull cows allowed using a PCA-based approach coupled with the iterative K-means algorithm the identification of three rearing practices classes. The classes were different in their carcass characteristics. Old cows raised mainly on pasture have better carcass characteristics, while having an equivalent tenderness, juiciness, flavor, intramuscular fat content, and pHu to those fattened with hay or haylage. The Longissimus thoracis muscle of the cows raised on pasture (with high physical activity) showed greater proportions of IIA fibers at the expense of the fast IIX ones. Accordingly, the meat of these animals have better color characteristics. Superoxide dismutase (SOD1) and αB-crystallin quantified by Dot-Blot were the only other biomarkers to be more abundant in "Grass" class compared to "Hay" and "Haylage" classes. The relationships between the biomarkers and the 6 carcass and 11 meat quality traits were investigated using multiple regression analyses per rearing practices. The associations were rearing practice class and phenotype trait-dependent. ICDH and TP53 were common for the three classes, but the direction of their entrance was different. In addition, rearing practices and carcass traits were not related with Hsp70-Grp75 and μ-calpain abundances. The other relationships were specific for two or one rearing practices class. The rearing practices dependency of the relationships was also found with meat quality traits. Certain proteins were for the first time related with some beef quality traits. MyHC-IIx, PGM1, Hsp40, ICDH, and Hsp70-Grp75 were common for the three rearing practices classes and retained to explain at list one beef quality trait. A positive relationship was found between PGM1 and hue angle irrespective of rearing practices class. This study confirms once again that production-related traits in livestock are the result of sophisticated biological processes finely orchestrated during the life of the animal and soon after slaughter.

Multi-breed and multi-trait co-association analysis of meat tenderness and other meat quality traits in three French beef cattle breeds

Background

Studies to identify markers associated with beef tenderness have focused on Warner–Bratzler shear force (WBSF) but the interplay between the genes associated with WBSF has not been explored. We used the association weight matrix (AWM), a systems biology approach, to identify a set of interacting genes that are co-associated with tenderness and other meat quality traits, and shared across the Charolaise, Limousine and Blonde d’Aquitaine beef cattle breeds.

Results

Genome-wide association studies were performed using ~500K single nucleotide polymorphisms (SNPs) and 17 phenotypes measured on more than 1000 animals for each breed. First, this multi-trait approach was applied separately for each breed across 17 phenotypes and second, between- and across-breed comparisons at the AWM and functional levels were performed. Genetic heterogeneity was observed, and most of the variants that were associated with WBSF segregated within rather than across breeds. We identified 206 common candidate genes associated with WBSF across the three breeds. SNPs in these common genes explained between 28 and 30 % of the phenotypic variance for WBSF. A reduced number of common SNPs mapping to the 206 common genes were identified, suggesting that different mutations may target the same genes in a breed-specific manner. Therefore, it is likely that, depending on allele frequencies and linkage disequilibrium patterns, a SNP that is identified for one breed may not be informative for another unrelated breed. Well-known candidate genes affecting beef tenderness were identified. In addition, some of the 206 common genes are located within previously reported quantitative trait loci for WBSF in several cattle breeds. Moreover, the multi-breed co-association analysis detected new candidate genes, regulators and metabolic pathways that are likely involved in the determination of meat tenderness and other meat quality traits in beef cattle.

Conclusions

Our results suggest that systems biology approaches that explore associations of correlated traits increase statistical power to identify candidate genes beyond the one-dimensional approach. Further studies on the 206 common genes, their pathways, regulators and interactions will expand our knowledge on the molecular basis of meat tenderness and could lead to the discovery of functional mutations useful for genomic selection in a multi-breed beef cattle context.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-016-0216-y) contains supplementary material, which is available to authorized users.