Relationship between shear force and trained sensory panel tenderness ratings of 10 major muscles from Bos indicus and Bos taurus cattle

Using chemical intramuscular fat percentage to predict visual marbling scores in Australian beef carcasses

Meat Standards Australia (MSA) marbling score and AUS-MEAT marbling represent key determinants of carcass value in the Australian beef industry and are well recognised traits in national and international markets. However, with the emergence of objective measurement technologies there are opportunities to grade beef carcasses using objective traits such as chemical intramuscular fat (IMF%) but abrupt changes to MSA and AUS-MEAT grading practices would cause significant disruption to the industry. Therefore, the objective of the study was to develop and validate models that transform chemical IMF% into equivalent MSA marbling scores and AUS-MEAT marbling. The second objective was to compare IMF%-derived and grader-derived MSA marbling scores when used as input values in the MSA model to generate predicted eating quality scores (MQ4). Carcasses (n = 5513) from industry experiments across 7 years (2017-2023) were graded for MSA marbling and AUS-MEAT marbling and sampled for chemical IMF%. Data were utilised to develop IMF%-derived models for MSA marbling score (IMF-MSAMB) and AUS-MEAT marbling (IMF-AUMB). Calibration performance was maintained when cross-validated and independently validated. The IMF-MSAMB model described 91% of the variation in MSA marbling score (Residual Standard Error (RSEV) = 57.9), with a slope of 0.90 and very small bias of -0.54. Similarly, IMF-AUMB described 88% of the variation in grader AUS-MEAT marbling (RSEV = 0.68) with a slope very close to 1 (0.94) and negligible bias (0.06). In addition, predicted MQ4 scores were almost equivalent irrespective of which marbling input value was used, across a suite of cut and cook combinations. Therefore, there is an opportunity for models to assist transition to the use of chemical IMF% in place of visual marbling scores. This would enable grading technologies to be calibrated and validated against chemical IMF%, whilst minimising industry disruption.

USA millennial and non-millennial beef consumers perception of beef, pork, and chicken

Millennials have been shown to have distinctly different behaviors; however, factors affecting their liking of beef, pork and chicken has not been fully elucidated. As millennials are current and future animal protein consumers, the question of if they have different drivers of liking for beef, pork, and chicken has not been answered. Top loin steaks cooked to 58.3 or 80 °C; and pork loin chops and chicken breasts cooked to 62.7 or 80 °C were cooked on a flat grill. Beef bottom round roasts cooked to 58.3 or 80°; and pork inside ham roasts and chicken thighs were cooked to 62.7 or 80 °C in a Crock-pot®. A descriptive flavor and texture attribute panel and a consumer central location test in four cities were used to evaluated flavor and texture attributes. Consumers were either millennials or non-millennials, and light or heavy beef-eaters. Meat descriptive flavor and texture attributes differed by cooking method, cut, and internal temperature (P < 0.05). Consumers preferred grilled meat more than meat cooked in the Crock-pot® (P > 0.05). Consumers rated grill flavor, juiciness, and tenderness (P ≥ 0.05) higher in grilled meat. Light beef-eaters, those who ate beef 2 to 4 times per month, rated overall, flavor, and species flavor lower (P < 0.05) than heavy beef-eaters, but consumers liked beef regardless of generational segment or their consumption of beef; however, millennials rated overall, overall flavor, and tenderness liking slightly lower than non-millennials. These results indicate that millennials have similar drivers of liking as non-millennials across beef, pork, and chicken protein sources.

Automatic Quality Assessment of Pork Belly via Deep Learning and Ultrasound Imaging

Pork belly, prized for its unique flavor and texture, is often overlooked in breeding programs that prioritize lean meat production. The quality of pork belly is determined by the number and distribution of muscle and fat layers. This study aimed to assess the number of pork belly layers using deep learning techniques. Initially, semantic segmentation was considered, but the intersection over union (IoU) scores for the segmented parts were below 70%, which is insufficient for practical application. Consequently, the focus shifted to image classification methods. Based on the number of fat and muscle layers, a dataset was categorized into three groups: three layers (n = 1811), five layers (n = 1294), and seven layers (n = 879). Drawing upon established model architectures, the initial model was refined for the task of learning and predicting layer traits from B-ultrasound images of pork belly. After a thorough evaluation of various performance metrics, the ResNet18 model emerged as the most effective, achieving a remarkable training set accuracy of 99.99% and a validation set accuracy of 96.22%, with corresponding loss values of 0.1478 and 0.1976. The robustness of the model was confirmed through three interpretable analysis methods, including grad-CAM, ensuring its reliability. Furthermore, the model was successfully deployed in a local setting to process B-ultrasound video frames in real time, consistently identifying the pork belly layer count with a confidence level exceeding 70%. By employing a scoring system with 100 points as the threshold, the number of pork belly layers in vivo was categorized into superior and inferior grades. This innovative system offers immediate decision-making support for breeding determinations and presents a highly efficient and precise method for assessment of pork belly layers.

Descriptive beef flavor and texture attributes relationships with consumer acceptance of US light beef eaters

Consumer acceptance and overall liking has been shown to be related to beef instrumental and trained sensory attributes related to beef flavor, tenderness, and juiciness. Our objective was to understand the relationships between descriptive beef flavor and texture attributes, Warner-Bratzler shear force (WBSF), and consumer liking attributes for light US beef eaters. It is not known if light beef eaters have different drivers of overall liking. Treatments were created to differ in beef flavor and texture by utilizing different beef cuts (Choice top loin, high pH top loin, Select top sirloin, Choice tenderloin steaks, and Select and Choice bottom rounds roasts) cooked to 58 °C or 80 °C. Cooking methods included either a George Forman grill, food-service grill, or crock-pot. Cooking method, cut, and internal temperature impacted beef descriptive flavor and texture attributes, WBSF and consumer liking ratings (P ≤ 0.05) similarly. Descriptive juiciness and tenderness attributes were highly related to each other and with consumer juiciness and tenderness liking ratings. Consumer overall liking was closely related to descriptive fat-like, overall sweet, sweet and salty attributes. Musty/moldy, liver-like, and sour aromatic attributes were negatively associated with consumer liking. Overall flavor accounted for 85% of the variation in overall liking and tenderness liking contributed an additional 4%. While light beef eaters used different parts of the scale, they rated beef across treatments similarly. When beef flavor and texture descriptive attributes differed, consumer liking was impacted for light beef eaters.

Extended Storage of Beef Steaks Using Thermoforming Vacuum Packaging

Extended storage duration often results in negative quality attributes of fresh or frozen beef steaks. This study focused on evaluating the fresh and cooked meat quality of beef steaks stored using vacuum packaging for 63 days. Steaks 2.54 cm thick were packaged into one of three thermoforming films VPA (250 µ nylon/EVOH/enhanced polyethylene coextrusion), VPB (250 µ nylon/EVOH/enhanced polyethylene coextrusion), or VPC (125 µ nylon/EVOH/enhanced/polyethylene coextrusion). Steaks placed in VPA were lighter (L*) and redder (a*) in surface color (p < 0.05) as the display period increased, whereas steaks packaged in VPB and VPC became darker. Yellowness, hue angle (Hue°), and chroma (C*) values were greater (p < 0.05) in steaks using VPC film as the storage period increased. Calculated spectral values of red to brown were greater (p < 0.05) for steaks in VPA and VPB than in VPC. However, steaks placed in VPC films contained greater (p < 0.05) forms of metmyoglobin and oxymyoglobin and lower calculated relative values of deoxymyoglobin. In addition, packaging treatment altered (p > 0.05) lipid oxidation, but storage time had a greater (p < 0.05) influence on purge loss, cook loss, and Warner-Bratzler shear force (WBSF). Current results suggest that the use of vacuum packaging for extended storage of beef steaks (>60) days is plausible.

Effects of in-the-bag dry-ageing on meat quality, palatability and volatile compounds of low-value beef cuts

This study evaluated the effects of in-the-bag dry-ageing (BDA) (21 and 42 d) on meat quality, palatability, and volatile compounds of clod heart, brisket, and flat iron cuts from steers. In all cuts, BDA increased moisture losses (P < 0.05), but this did not reduce the juiciness of 21 d BDA versus wet-aged (WA) steaks. In clod heart, BDA increased overall tenderness at 21 d compared to 21 d WA (P < 0.01). Regardless of ageing period, BDA of clod heart increased beef flavour and salty taste and decreased sour-dairy and stale/cardboard flavours and concentrations of volatile compounds derived from lipid oxidation compared to WA (P < 0.05). In brisket, BDA increased salty taste and fatty aroma and reduced bloody/serumy flavour, whereas decreased beef and buttery flavours and intensified some unpleasant aromas/flavours (P < 0.05) for both ageing periods. The BDA of flat iron increased several undesirable aromas/flavours and decreased sweet taste and beef and buttery flavours (P < 0.05), regardless of ageing period. Overall, BDA for 42 d decreased meat quality and palatability and increased concentrations of volatile compounds from lipid oxidation, especially in flat iron cuts. Value could be recovered by customizing BDA periods by cut.

The Colour, Composition and Eating Quality of Beef from Late- or Early-Maturing Suckler Bulls Finished at Pasture with or without Concentrate Supplementation

Carcasses from pasture-finished early-maturing (EM), rather than late-maturing (LM), breed bulls may be more suited to meet the minimum carcass fatness classification of 2+ (6.0 on a 15-point scale) required for some markets. The comparative colour and eating quality of beef from grass-fed bulls of different maturities are unknown. Sixty yearling suckler-bred bulls were assigned to a 2 (maturities: EM and LM) × 2 (finishing strategies: grass only (G0) or grass + 4.0 kg concentrate daily (GC)) factorial design. Bulls were at pasture from 7 April, concentrates were introduced (or not) 97 days later, and bulls were slaughtered at 192 d post-turnout (approximately 19 mo of age). Carcass fat scores averaged 5.02, 6.20, 6.33 and 7.30 for LMG0, LMGC, EMG0 and EMGC bulls, respectively. Muscle colour did not differ between treatments. Muscle from LM had lower intramuscular fat concentration, collagen solubility and a tendency (p < 0.1) towards lower ratings for tenderness, texture, and acceptability of 14 d aged beef. Concentrate supplementation decreased the ratings for muscle tenderness but ratings for acceptability were not affected. Achieving the minimum carcass fatness was therefore not required to produce beef of acceptable eating quality and suckler bulls can access the “grass-fed” beef market.

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.

Assessment of indigenous Shaka cattle structural indices reared in Shaka zone, south west Ethiopia

The study encompassed quantitative traits of the Shaka cattle reared in Shaka zone, Anderacha and Masha weredas of south western, Ethiopia. The study covered quantitative parameters which were taken from 240 cows and 120 bulls from randomly slected120 households. The means for the quantitative traits were compared using Duncan’s Multiple Range test, the values were considered significant at P < 0.05 and P < 0.01. The results of morphometrical measurements of bulls reared at Masha wereda had wider (P < 0.05) values for their pelvic width and the Chest Depth for the bulls aged ≥7 years was higher (P < 0.01). While the canon bone circumference was also wider when compared to the bulls reared at Anderacha wereda. Contrary the bulls aged ≤5 years and reared at Anderacha wereda had higher (P < 0.05) for Body Weight, Height at Withers and Chest Depth. Morphometrical measurement for cows ≤5 year age group and reared at Masha wereda have longer (P < 0.05) Neck Length and for cows ≥7 years have wider (P < 0.05) Hock Bone Circumference and Pelvic Width. Contrary the cows aged ≤5 years raised at Anderacha wereda has wider (P < 0.05) for Cannon Bone Circumference, and (P < 0.01) for Chest Girth, higher Body Weight, Rump Length, Ear Length, Neck Circumference and Chest Depth. Among the cows aged ≥7 years have longer (P < 0.01) face length and deeper (P < 0.05) Chest. There is a significant difference in the length index (LI2) and body ratio (BR) (P < 0.05) throughout the research locations, with Anderacha wereda having the higher result, and Masha wereda having the higher depth index (DI) and transverse pelvic index (TPI) (P < 0.05).The results of body indices of both sex indicate that, the cattle is suited for grazing in the forest areas and are of dual type.

Physicochemical composition, fatty acid profile and sensory attributes of meat (longissimus lumborum muscle) from Nellore and Nellore-cross bulls

This study aimed to compare the physicochemical characteristics, fatty acid composition, and sensory attributes of the meat from three genetic groups: Nellore (Nell), ½ Nellore × ½ Angus (NeAn), and ¼ Nellore × ¼ Angus × ½ Senepol (NASe). Longissimus lumborum muscle from 30 slaughtered bulls with a body weight of 549 ± 32.5 kg was used. The water holding capacity was greater for the Nell and NeAn groups than for the NASe group. Meat samples from the NASe group exhibited a higher L* index than those from the NeAn group and lower a* and b* color indexes than those from the Nell group. The meat fatty acid profiles showed that the Nell group had higher concentrations of 12:0, 14:0, 18:1 t11, 14:1 c9, 16:1 c9, 18:1 c9, 18:1 c11, 18:2 c9, t11 (conjugated linoleic acid (CLA)), and 20:3 n-6 polyunsaturated fatty acid (PUFA) than the NeAn and NASe groups. The total saturated (ΣSFA), unsaturated (ΣUFA), and monounsaturated (ΣMUFA) fatty acid concentrations were higher and the ΣPUFA:ΣSFA ratio was lower in the Nell group than in the NeAn group. The Δ⁹-desaturase C16 activity was significantly higher in the Nell and NASe groups than in the NeAn group. The atherogenicity index (AI) tended to be lower in the crossbreeds than in the Nell breed. The NASe group presented meat with better tenderness, juiciness, and overall acceptance than the Nell and NeAn groups and was therefore the best genetic group for beef production of the tested groups.

Influence of intrinsic and extrinsic factors on the sensory perception and intention to purchase buffalo meat by consumers in Southeast Brazil

Abstract This study aimed to evaluate the effect of extrinsic factors (meat type, price, and nutritional claims) on purchase intention and the perception of intrinsic factors (tenderness, juiciness and flavor) in buffalo loin in a region of Brazil where the marketing of buffalo meat is not common. Photos of the steaks were treated and labels were designed to simulate the retail purchase process, with the effects of extrinsic factors being evaluated through conjoint analysis. Sensory tests of difference from control, purchase intention, and overall acceptance were performed for intrinsic factors. Regarding the purchase process, a determining factor was the price, with buffalo meat having a better purchase intention when associated with a lower price. The lowest price also proved to be more important than the presence of nutritional information for most respondents, however, nutritional information was necessary for consumers characterized over 50 years old. Good acceptance was perceived after tasting buffalo meat, even with less tenderness and juiciness compared to Nellore, and only a minority respondents were willing to pay more for it. The buffalo meat presents a potential option for the consumer, when offered in association with marketing strategies that emphasize nutritional and/or sensory information, such as tenderness and juiciness.

Palatability Traits of Sirloin Cap Steaks From Four USDA Quality Grades

Sirloin cap steaks from 4 different USDA quality grades were evaluated to determine the effect of marbling on eating experience. Top sirloin cap steaks (N = 60) of 4 different quality grades (Prime, Top Choice, Low Choice, and Select) were evaluated in the current study. Top sirloin butts were collected, and the biceps femoris was removed, trimmed, and sliced into twelve 2.54-cm-thick steaks. The steaks from each subprimal were aged for 28 d and designated for either trained sensory panels, consumer sensory panels, Warner-Bratzler shear force, or moisture and fat determination. The Prime steaks were rated the highest (P &lt; 0.05) for overall liking and were higher (P &lt; 0.05) for flavor liking than Low Choice and Select steaks within the consumer panels. However, all quality treatments were similar (P &gt; 0.05) in juiciness and tenderness for the consumer panels. Additionally, a similar (P &gt; 0.05) percentage of samples from each treatment were rated acceptable for tenderness, juiciness, flavor liking, and overall liking, with each trait having greater than 70% of samples rated acceptable. Also, Prime steaks were rated the highest (P &lt; 0.05) for sustained juiciness and overall tenderness within the trained sensory panels. Similarly, Prime steaks were rated higher (P &lt;0.05) for initial juiciness than the Low Choice and Select treatments but were similar (P &gt; 0.05) to Top Choice. These results indicate that USDA quality grades impact the eating quality of sirloin cap steaks, especially within the Prime grade, and could provide an opportunity for refined marketing and added economic value for the cut.

Relationship Between Meat Quality, Carcass Characteristics, and Protein Abundance of HSPβ1, HSPA, and DJ1 in Beef Longissimus thoracis Pre-Rigor or After 14 Days’ Aging

This study evaluated associations of heat shock proteins (HSP) and an oxidative stress protein, protein deglycase (DJ1), with beef quality and tenderness. Samples from the longissimus thoracis (N = 99) were collected pre-rigor (day 0) and after 14-d aging. Warner-Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), and a trained sensory panel were used to determine meat quality. Protein abundance of DJ1 and 2 HSP—HSPβ1 and HSPA—were assessed. Regression analyses demonstrated that DJ1 abundance after 14 d of aging is a predictor of WBSF (P &lt; 0.001), MFI (P = 0.02), and sensory panel tenderness (P &lt; 0.001). Abundance of HSPβ1 after 14 d of aging is also a predictor of MFI (P = 0.03). Additionally, abundance of both HSPβ1 and DJ1 pre-rigor are predictors of juiciness (P &lt; 0.05). Abundance of HSPβ1 pre-rigor was correlated with WBSF (R = 0.67), sensory panel tenderness (R = −0.44), juiciness (R = −0.30), and umami (R = −0.20). Abundance of DJ1 pre-rigor was also correlated with WBSF (R = 0.72), sensory panel tenderness (R = −0.44), juiciness (R = − 0.24), and umami (R = −0.31). After 14-d aging, HSP β 1 abundance was cor- related with WBSF (R = 0.66), sensory panel tenderness (R = −0.34), juiciness (R = −0.34), umami (R = −0.33), and brown/ roasted (R = −0.30). Abundance of DJ1 after 14-d aging was also correlated with WBSF (R = 0.68), sensory panel tenderness (R = −0.41), juiciness (R = −0.21), and umami (R = −0.28). These results demonstrate that abundance of HSPβ1 and DJ1 both pre-rigor and after 14 d of aging are correlated with meat tenderness and end-product quality as assessed by a trained sensory panel. Regression analyses further reveal that abundance of DJ1 and HSPβ1 after 14 d of aging is causative in development of beef tenderness and juiciness, respectively. Taken together, these results suggest that abundance of DJ1 is a predictor of tenderness, whereas abundance of HSPβ1 is related to meat quality but cannot be used to predict tenderness.

Effect of pelvic suspension and post-mortem ageing on the quality of three muscles from Holstein Friesian bulls and steers

BACKGROUND

The use of bulls rather than steers from the dairy herd offers a more profitable and environmentally friendly option; however, the beef eating quality from bulls is an issue of concern. This study assessed the effect of two tenderization techniques - pelvic suspension and ageing - on three different muscles of Holstein Friesian males from two different production systems.

RESULTS

The results indicate that a production system based on steers slaughtered at 24 months (S24) produced beef with better eating quality than from bulls slaughtered at 19 months (B19) when tenderization techniques were not applied. Instrumental texture of longissimus thoracis and gluteus medius muscles was improved with ageing and/or pelvic suspension, with both tenderization techniques exerting greater impact on B19 meat. No differences were found in semitendinosus muscle due to suspension method, whereas ageing for longer than 14 days decreased its instrumental tenderness. Sensory results indicate that, after 14 days of ageing, panellists still preferred meat from S24, and they could differentiate between pelvic and traditional suspension.

CONCLUSION

Tenderization methodologies should be optimized for each production system and muscle; however, both panel and instrumental texture results indicate that eating quality of beef from either production systems is acceptable after 14 days of ageing, or even earlier if the suspension method is applied. © 2020 Society of Chemical Industry.

Comparative analyses of copy number variations between Bos taurus and Bos indicus

BACKGROUND

Bos taurus and Bos indicus are two main sub-species of cattle. However, the differential copy number variations (CNVs) between them are not yet well studied.

RESULTS

Based on the new high-quality cattle reference genome ARS-UCD1.2, we identified 13,234 non-redundant CNV regions (CNVRs) from 73 animals of 10 cattle breeds (4 Bos taurus and 6 Bos indicus), by integrating three detection strategies. While 6990 CNVRs (52.82%) were shared by Bos taurus and Bos indicus, large CNV differences were discovered between them and these differences could be used to successfully separate animals into two subspecies. We found that 2212 and 538 genes uniquely overlapped with either indicine-specific CNVRs and or taurine-specific CNVRs, respectively. Based on FST, we detected 16 candidate lineage-differential CNV segments (top 0.1%) under selection, which overlapped with eight genes (CTNNA1, ENSBTAG00000004415, PKN2, BMPER, PDE1C, DNAJC18, MUSK, and PLCXD3). Moreover, we obtained 1.74 Mbp indicine-specific sequences, which could only be mapped on the Bos indicus reference genome UOA_Brahman_1. We found these sequences and their associated genes were related to heat resistance, lipid and ATP metabolic process, and muscle development under selection. We further analyzed and validated the top significant lineage-differential CNV. This CNV overlapped genes related to muscle cell differentiation, which might be generated from a retropseudogene of CTH but was deleted along Bos indicus lineage.

CONCLUSIONS

This study presents a genome wide CNV comparison between Bos taurus and Bos indicus. It supplied essential genome diversity information for understanding of adaptation and phenotype differences between the Bos taurus and Bos indicus populations.

Prediction of consumer palatability in beef using visual marbling scores and chemical intramuscular fat percentage

With development of objective technologies that can predict chemical intramuscular fat percentage (IMF%), there is a need to understand the relationships between existing marbling traits, IMF% and eating quality. This study utilised historical carcass data (n = 9641 observations) from the Meat Standards Australia (MSA) industry research dataset and included MSA grading data, chemical IMF% data and weighted composite eating quality scores (MQ4). Several analyses were performed to assess the prediction of MQ4 by MSA marbling, M. longissimus thoracis et lumborum (striploin) IMF% and cut specific IMF%. Results demonstrated that there was similar precision between chemical IMF% (R² = 0.32, RSE = 11.8) and MSA marbling (R² = 0.28, RSE = 11.9) in the prediction of grilled 14 day aged striploin MQ4, with similar results across other cut by cook by days aged combinations. These results support the development of objective technologies that predict chemical IMF% in parallel with MSA marbling for carcass grading and the prediction of eating quality.

Muscle, Ageing and Temperature Influence the Changes in Texture, Cooking Loss and Shrinkage of Cooked Beef

This study aimed to quantify the effect of muscle, ageing and cooking temperature on the texture, cooking loss and shrinkage of cooked beef. Cuboids from unaged (1 day post mortem) and aged (14 days post mortem) semitendinosus, biceps femoris and psoas major muscles, from both sides of five beef carcasses, were cooked at four different cooking temperatures (50, 60, 70 and 80 °C) for 30 min. and their Warner-Bratzler shear force (WBSF), cooking loss and shrinkage (longitudinal and transverse) were quantified. The WBSF was reduced by ageing in the muscles at the specific cooking temperatures: psoas major (cooked at 50, 60 and 80 °C), semitendinosus (70 and 80 °C) and biceps femoris (80 °C). The cooking loss was 3% greater in aged compared to unaged muscles. The longitudinal shrinkage was greatest in psoas major at 80 °C amongst the muscle types and it was reduced by ageing in psoas major (70 and 80 °C) and biceps femoris (80 °C). The transverse shrinkage was reduced by ageing only in biceps femoris, across all temperatures; and the diameter of homogenized fibre fragments from semitendinosus and biceps femoris was reduced more by cooking at 50 °C in unaged compared to aged condition. WBSF was related to transverse shrinkage, and cooking loss was related to longitudinal shrinkage. The effect of muscle type on the physical changes occurring during cooking of beef is dependent on ageing and cooking temperature.

Genetic parameters associated with meat quality of Nellore cattle at different anatomical points of longissimus: Brazilian standards

The present study estimated genetic parameters and evaluated the genetic and phenotypic correlations between meat quality characteristics of Nellore cattle evaluated at different anatomical points of the longissimus. Data from 1329 Nellore young bulls were used to evaluate, in the 5th and 12th ribs, marbling score (MAR), shear force (SF), cooking weight losses (CWL) and intramuscular fat (IMF). In addition, the subcutaneous fat thickness was measured at the 12th rib (SFT₁₂) and between the last lumbar and the first sacral vertebrae (SFT_LR), in the separation of loin and round. Results yielded moderate heritability coefficients for evaluated characteristics, except CWL. High genetic correlations (0.61) were found between measurements of SFT₁₂ and SFT_LR. MAR, IMF and SF were evaluated at the 5th and 12th rib. Meat quality and subcutaneous fat thickness measured at different anatomical points of the longissimus are genetically correlated and can be used in genetic selection programs to improve meat quality characteristics in Nellore cattle.

Quality of three muscles from suckler bulls finished on concentrates and slaughtered at 16 months of age or slaughtered at 19 months of age from two production systems

There is a requirement in some beef markets to slaughter bulls at under 16 months of age. This requires high levels of concentrate feeding. Increasing the slaughter age of bulls to 19 months facilitates the inclusion of a grazing period, thereby decreasing the cost of production. Recent data indicate few quality differences in longissimus thoracis (LT) muscle from conventionally reared 16-month bulls and 19-month-old bulls that had a grazing period prior to finishing on concentrates. The aim of the present study was to expand this observation to additional commercially important muscles/cuts. The production systems selected were concentrates offered ad libitum and slaughter at under 16 months of age (16-C) or at 19 months of age (19-CC) to examine the effect of age per se, and the cheaper alternative for 19-month bulls described above (19-GC). The results indicate that muscles from 19-CC were more red, had more intramuscular fat and higher cook loss than those from 16-C. No differences in muscle objective texture or sensory texture and acceptability were found between treatments. The expected differences in composition and quality between the muscles were generally consistent across the production systems examined. Therefore, for the type of animal and range of ages investigated, the effect of the production system on LT quality was generally representative of the effect on the other muscles analysed. In addition, the data do not support the under 16- month age restriction, based on meat acceptability, in commercial suckler bull production.

Contribution of connective tissue components, muscle fibres and marbling to beef tenderness variability in longissimus thoracis, rectus abdominis, semimembranosus and semitendinosus muscles

BACKGROUND

The present study aimed to identify relationships between components of intramuscular connective tissue, proportions of the different fiber types, intramuscular fat and sensory tenderness of beef cooked at 55 °C. Accordingly, four muscles differing in their metabolic and contractile properties, as well as in their collagen content and butcher value, were obtained from dairy and beef cattle of several ages and sexes and were then used to create variability.

RESULTS

Correlation analyses and/or stepwise regressions were applied on Z-scores to identify the existing and robust associations. Tenderness scores were further categorized into tender, medium and tough classes using unsupervised learning methods. The findings revealed a muscle-dependant role with respect to tenderness of total and insoluble collagen, cross-links, and type IIB + X and IIA muscle fibers. The longissimus thoracis and semitendinosus muscles that, in the present study, were found to be extreme in their tenderness potential were also very different from each other and from the rectus abdominis (RA) and semimembranosus (SM). RA and SM muscles were very similar regarding their relationship for muscle components and tenderness. A relationship between marbling and tenderness was only present when the results were analysed irrespective of all factors of variation of the experimental model relating to muscle and animal type.

CONCLUSION

The statistical approaches applied in the present study using Z-scores allowed identification of the robust associations between muscle components and sensory beef tenderness and also identified discriminatory variables of beef tenderness classes. © 2020 Society of Chemical Industry.

Meat and sensory quality of major muscles from Angus, Charolais, and Angus crossbred steers with high and low residual feed intake

Effects of residual feed intake (RFI) and genetic group on growth, carcass, and meat quality characteristics of bovine longissimus lumborum (LL), triceps brachii (TB), semimembranosus (SM), and gluteus medius (GM) muscles were investigated using 72 purebred Angus, purebred Charolais, and Angus crossbred steers (n = 24 per genetic group) classified as either high (inefficient) or low (efficient) RFI (n = 12 high and low RFI steers within genetic group). There was no RFI effect (P > 0.05) on growth, carcass, and meat quality measurements except high RFI steers had the highest dry matter intake (P < 0.05), and low RFI TB was rated as having reduced beef flavour intensity and sustained juiciness (P < 0.05). Purebred Angus and Charolais LL and GM had lower shear force values (P < 0.05) than Angus crossbreds and ageing reduced mean shear force values except in TB. For TB, SM, and GM, Angus crossbred steers had the highest mean beef flavour intensity scores, and Charolais SM and TB were less tender than those of Angus crossbred (P < 0.05). Overall, RFI did not influence most meat quality traits; therefore, low RFI animals may contribute to reducing feed costs or environmental impact without compromising meat quality and palatability.

Consumer Palatability of Beef Muscles From Australian and US Production Systems With or Without Enhancement

The objective was to assess the consumer (n = 360) palatability and satisfaction of enhanced (7%) and nonenhanced Australian grain-fed, Australian grass-fed, and US grain-fed beef from 2 beef muscles. Strip loin (longissimus lumborum [LL]) and top sirloin butt (gluteus medius [GM]) subprimals were collected from 12 Australian grass-fed, 12 Australian grain-fed, and 12 US grain-fed (USDA Choice) carcasses. In addition, tenderloin (psoas major) and eye of round (semitendinosus) subprimals were collected from the same US carcasses to serve as anchors for high and low palatability. All subprimals were aged until 29 to 32 d postmortem. All fabrication and enhancement occurred in Lubbock, Texas. Data were analyzed initially as a randomized complete design and subsequently as a split-split plot design, with the main effects of country of origin/diet (Australian grain-fed, Australian grass-fed, and US grain-fed), muscle (LL and GM), and enhancement (0% or 7%) and all potential interactions as fixed effects. Enhancement significantly improved palatability in both LL and GM steaks as evidenced by greater (P &lt; 0.05) consumer ratings for tenderness, juiciness, flavor liking, overall liking, and satisfaction. Enhancing LL steaks resulted in consumer responses that were comparable or superior to consumer responses for psoas major samples. Similarly, enhancing GM steaks resulted in consumer responses that were comparable or superior to nonenhanced LL samples. Consumers reacted least favorably to nonenhanced Australian grass-fed beef as they rated all palatability traits lowest (P &lt; 0.05) for both LL and GM samples. However, enhancing grassfed beef resulted in consumer responses that were similar (P &gt; 0.05) to nonenhanced grain-fed beef. This response to enhancement was observed in consumer scores for both LL and GM samples. Consumers could not detect differences (P &gt; 0.05) in tenderness, juiciness, flavor, overall liking, or satisfaction between grain-fed beef from Australia and the US.

Single-nucleotide polymorphisms for matrix metalloprotease-1 can affect perimysial strength and intramuscular fat content but not growth rate of cattle

Context Single-nucleotide polymorphisms (SNPs) in the gene coding for matrix metalloprotease-1 (MMP-1) are known to affect the level of intramuscular fat found in cattle. As well as a signalling molecule affecting adipogenesis, MMP-1 is a major collagenase involved in the turnover of connective tissue. Aims The aim of the work was to assess whether SNPs in the gene for MMP-1 may affect the mechanical properties of intramuscular connective tissue, and therefore meat texture. Methods Allelic frequencies of three SNPs for MMP-1 were determined in a group of black Aberdeen Angus cattle whose growth characteristics had been traced for 450 days before slaughter. Associations between the alleles of each of the three SNPs and growth rate, killing out percentage, half-carcass weight, intramuscular fat content, cooking loss, strength of perimysium in cooked M. semitendinosus and Warner–Bratzler peak force of cooked M. longissimus dorsi were studied. Key results None of the SNPs studied had any effect on growth curves, and only one SNP (ss77831914) showed differences in half-carcass weight between alleles. Carcass yield and killing out percentage showed a small difference between alleles of ss7783924. No effects were found on the Warner–Bratzler peak force of M. longissimus dorsi cooked to 70°C. Two SNPs (ss77831914 and ss77831924) showed significant differences between alleles in the raw strength of perimysium in M. semitendinosus and the amount of intramuscular fat. Conclusions Commonly occurring SNPs of the major collagenase MMP-1 can affect the strength of intramuscular connective tissue as well as intramuscular fat content. Although these differences in connective tissue strength do not influence Warner–Bratzler measures of toughness at a cooking temperature of 70°C, they may contribute to differences in toughness in low-temperature, long-time cooking. Implications Because none of the SNPs had effects on the growth curves of the cattle studied, selection of animals with the relevant alleles of SNPs ss77831914 ss77831924 could be used to produce more tender meat without affecting carcass yield.

Alternative cutting methods and dry aging reduce the shear force of hot boned beef striploin in Bos indicus cattle

Hot boning (HB) is an economical processing technique often resulting in poorer meat quality and tenderness. This study tested a method of partial HB, where the short loin section was removed from the hot carcass and chilled, with the striploin remained in the skeletal system. Thirty six yearling Bos indicus steers carcasses were subjected to either low, high or no electrical stimulation and each side allocated to a cutting treatment of HB, partial HB and conventional (Achillies hung). Striploins were divided into 3 and aged for 5, 14 and 28 days. Warner Bratzler Shear force (WBSF) and sarcomere length were tested. Partial HB resulted in greater tenderization without aging compared to HB. However, optimized electrical stimulation was a requirement. Treatment did not influence sarcomere length. The study also tested the impact of Dry aging of HB striploins, which resulted in further increases in tenderness at 28 days of aging compared to wet aged product, reducing WBSF by 9 N.

Evaluation of Beef Top Sirloin Steaks of Four Quality Grades Cooked to Three Degrees of Doneness

The objective of this study was to evaluate the impact of USDA quality grade on beef eating quality of top sirloin steaks when cooked to multiple degrees of doneness (DOD). Beef top sirloin butts (N = 60; 15/quality grade) were collected to equally represent 4 quality grades [Prime, Top Choice (modest00 to moderate100), Low Choice, and Select]. Steaks were assigned to 1 of 3 DOD: rare (60°C), medium (71°C), and well-done (77°C). Steaks were allocated to either consumer sensory analysis, trained sensory analysis, fat and moisture analysis, or Warner-Bratzler shear force (WBSF). There were no interactions (P > 0.05) for all consumer ratings of palatability traits, indicating increases in DOD had the same impact across all quality grades. Prime steaks had greater (P < 0.05) juiciness ratings than all other quality grades, except for Top Choice. As DOD increased, consumer ratings and the percentage of steaks rated acceptable for each palatability trait decreased (P < 0.05; rare > medium > well-done). There was a quality grade × DOD interaction (P < 0.05) for trained sensory panel juiciness scores. When cooked to medium, Prime and Top Choice steaks were rated higher (P < 0.05) for juiciness than Low Choice and Select steaks, while there were no differences at all other DOD. Similar to consumer ratings, trained panel ratings of tenderness decreased (P < 0.05) as DOD increased (rare > medium > well-done). Lastly, there was no quality grade by DOD interaction (P > 0.05) for Warner-Bratzler shear force. These results indicate that regardless of the DOD top sirloin steaks are cooked to, quality grade had minimal impact on palatability. Therefore, it is unnecessary for consumers, retailers, and foodservice to pay premium prices for higher quality top sirloin steaks, as the same eating experience will be provided.

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.

Suckler Bulls Slaughtered at 15 Months of Age: Effect of Different Production Systems on the Fatty Acid Profile and Selected Quality Characteristics of Longissimus Thoracis

The objective was to compare the quality of beef from bulls reared in typical Irish indoor systems or in novel grass-based systems. Bulls were assigned to one of the following systems: (a) grass silage plus barley-based concentrate ad libitum (CON); (b) grass silage ad libitum plus 5 kg of concentrate (SC); (c) grazed grass without supplementation (G0); (d) grazed grass plus 0.5 kg of the dietary dry matter intake as concentrate (GC) for (100 days) until slaughter (14.99 months). Carcass characteristics and pH decline were recorded. Longissimus thoracis was collected for analytical and sensory analysis. Lower carcass weight, conformation and fatness scores were found for grazing compared to CON and SC groups. CON bulls had highest intramuscular fat and lighter meat colour compared with grazing bulls. The SC meat (14 days aged) was rated higher for tenderness, texture, flavour and acceptability compared with grazing groups. CON saturated and monounsaturated fatty acid (FA) concentration was highest, conversely, omega-3 FA concentration was higher for GC compared with CON, while no differences were found in polyunsaturated FA. In conclusion, while market fatness specification was not reached by grazed grass treatments, beef eating quality was not detrimentally affected and nutritional quality was improved.

Evaluating the Relationship of Animal Temperament to Carcass Characteristics and Meat Quality

The purpose of this study was to compare meat quality and sensory characteristics of steaks from longissimus dorsi of steers with different temperaments. Calves (n = 49; 314kg) were processed and scored for temperament according to Beef Improvement Federation Guidelines and divided into three groups: Docile (D), Restless (R) and Nervous-Flighty (NF). Steers were housed with access to pasture then transferred to a research feedlot until harvest and processed with carcass data recorded. Striploins were wet-aged for 14 d before, frozen and were then cut into 2.54 cm steaks, and individually vacuum packed. Instrumental color was measured on thawed and tray overwrapped steaks on d 0, 1, 2, 3, 5, and 7 of simulated retail display. The CIE L*, a*, and b* color values were collected and oxymyoglobin, hue angle and saturation index values were calculated. A 7-member trained sensory panel evaluated steak samples for myofibrillar tenderness, connective tissue amount, overall tenderness, juiciness, and beef flavor intensity. The NF group had reduced (P < 0.05) hot carcass weight compared to the other groups. The D and R groups were lighter (L*; P < 0.05), and R group yellower (b*; P < 0.05) and greater (P < 0.05) in hue angle than the other groups. No difference (P > 0.05) between groups for redness (a*), saturation index, and oxymyoglobin ratio were observed. Display time affected color with d 0 being redder (a*; P < 0.05), yellower (b*; P < 0.05), greater (P < 0.05) saturation index, and greater (P < 0.05) oxymyoglobin ratio than d 7. Steaks from D and R groups were more tender (P < 0.05) in myofibrillar tenderness, had less (P < 0.05) perceived connective tissue, were overall more tender (P < 0.05), and more (P < 0.05) juicy than steaks from the NF group. There was no difference (P > 0.05) in off-flavor between the temperament groups. Temperament had minimal effect on carcass characteristics except hot carcass weight. Sensory panelists detected differences between temperament groups.

Critical Review on the Utilization of Handheld and Portable Raman Spectrometry in Meat Science

Traditional methods for the determination of meat quality-relevant parameters are rather time-consuming and destructive, whereas spectroscopic methods offer fast and non-invasive measurements. This review critically deals with the application of handheld and portable Raman devices in the meat sector. Some published articles on this topic tend to convey the impression of unrestricted applicability of mentioned devices in this field of research. Furthermore, results are often subjected to over-optimistic interpretations without being underpinned by adequate test set validation. On the other hand, deviations in reference methods for meat quality assessment and the inhomogeneity of the meat matrix pose a challange to Raman spectroscopy and multivariate models. Nonetheless, handheld and portable Raman devices show considerable potential for some applications in the meat sector.

Effects of hormonal growth promotants on beef quality: a meta-analysis

Benefits of hormonal growth promotants (HGPs) include production efficiency, profit, and reduced environmental effects for beef cattle. Questions remain about effects of HGP on beef quality, particularly on measures of toughness such as Warner-Bratzler shear force (WBSF), tenderness, and other taste-panel attributes of beef. The objective of this meta-analysis was to assess the effects of HGP on beef quality using the results of randomized controlled trials identified from 3 searched databases. Thirty-one experiments with 181 treatment comparisons were used to evaluate the effects of HGP on WBSF and sensory measures of beef quality. Experiments varied in design, used many different hormonal treatments and combinations, which were single or repeated, in different breeds and sex groups of cattle, with or without electrical stimulation, and with different lengths of time on feed and beef aging. The effects of multiple treatment comparisons in experiments were evaluated using robust regression models and compared to Knapp-Hartung and permutation meta-analytical methods. Increased WBSF was associated with HGP treatment. Use of multiple HGP implants was associated with an increase in WBSF of 0.248 kg (95% CI = 0.203 to 0.292). Effects of a single implant only increased WBSF by 0.176 kg (95% CI = 0.109 to 0.242). Aging of beef did not alter the association of HGP with increased WBSF (P = 0.105); however, the point direction was toward a reduced effect with aging (standardized mean difference [SMD] = -0.005 per day aged). While aging lowered WBSF, it did not reduce the SMD between HGP treatment and reference groups. Comparisons using trenbolone acetate did not differ in WBSF from those using other implants (P > 0.15). The findings on sensory panel tenderness differ from those using WBSF as HGP treatment was not associated with reduced tenderness (P > 0.3) and multiple HGP treatments improved tenderness (SMD = 0.468) compared to a single implant. Further, juiciness, flavor, and connective tissue were not associated with HGP use, whereas there was a marked 5.5-point decrease in the Meat Standards Australia meat quality 4 score, albeit with limited experiments. In general, the true variance of experiments, tau2 (τ2) was low (<0.1), but heterogeneity, I2 was high (>50%) indicating that much of the variance was due to factors other than measurement error. More targeted studies on the role of HGP in influencing beef quality are needed.

Using microwave cooking to evaluate tenderness and its relationship to sensory analysis

This study evaluated a microwave (Mw) cooking method for determining beef toughness using the Warner-Bratzler slice shear force (WBsSF) protocol. Longissimus thoracis muscles were aged for 1, 10, 19, and 28 days at 4C. They were then either cooked on a clam-shell grill until reaching an internal temperature of 72C, in a Mw for 100 s at maximum power (Mw100) or for 140 s at 60% of maximum power (Mw60). Cooking loss and shear force (SF) values were higher in Mw samples than in grilled ones. SF assessment by grill and Mw100 were able to discriminate tenderness by aging times in the same way as the sensory panel. The SF measured in a grilled sample had higher repeatability (R = .74) and correlation with sensory scores (r = -.79) than Mw100 (R = .61; r = -.62) and Mw60 (R = .51; r = -.53). Mw100 can be considered as an appropriate alternative for the WBsSF protocol. PRACTICAL APPLICATIONS: Tenderness is the most important attribute for consumers. Many studies have evaluated tenderness in meat and different protocols for cooking. This work was intended to optimize and evaluate the use of the microwave as a cooking method for shear force determination, against a standard protocol and establish the correlation to sensory tenderness.

The Effect of Finishing Diet on Consumer Perception of Enhanced and Non-Enhanced Honduran Beef

The effects of experimental finishing diets and enhancement were tested to determine if they could improve Honduran beef palatability. Fifteen enhanced (ENH) and non-enhanced (NE) paired loins from 7 different finishing diets (n = 210 loins) were fed to Honduran consumers (n = 288). Diets consisted of a grass-finished control (CON) or diets with the inclusion of distiller’s dry grain (DDG), palm kernel meal (PKM), PKM replication (PKMR), sorghum (SORG), soybean meal and corn (SBMC), or sugarcane (SC). An interaction (P < 0.01) occurred between diet and enhancement to influence scores for all palatability traits, willingness to pay (WTP), and acceptability of traits. Consumers found enhanced samples were more tender (P < 0.05) than NE counterparts, excluding ENH- and NE-CON (P > 0.05). Without enhancement, CON was rated more tender (P < 0.05) than all other treatments, except PKMR. All ENH samples were juicier (P < 0.05) and had a flavor that was liked more (P < 0.05) than NE counterparts. Diet alone resulted in similar (P > 0.05) juiciness scores between CON, DDG, PKM, and PKMR; however, CON was rated juicier (P < 0.05) than all other treatments. Among NE samples, flavor liking scores were not different (P > 0.05) between CON, DDG, PKM, PKMR, and SBMC, and CON was liked more (P < 0.05) than SORG and SC. All enhanced steaks, except CON, had greater overall liking scores and WTP values (P < 0.05) than NE counterparts. Diet alone resulted in similar (P > 0.05) overall liking and WTP values between CON, DDG, PKM, PKMR, and SBMC, while SORG and SC were liked less overall (P < 0.05) than CON, which reduced (P < 0.05) WTP values. Experimental diets in conjunction with enhancement were able to improve the consumers’ perception of palatability traits, acceptability, and WTP.

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) fat percentage than SEL and HGRASS, but did not differ (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.

Effects of hormonal growth promotants on beef quality: a meta-analysis

Benefits of hormonal growth promotants (HGPs) include production efficiency, profit, and reduced environmental effects for beef cattle. Questions remain about effects of HGP on beef quality, particularly on measures of toughness such as Warner-Bratzler shear force (WBSF), tenderness, and other taste-panel attributes of beef. The objective of this meta-analysis was to assess the effects of HGP on beef quality using the results of randomized controlled trials identified from 3 searched databases. Thirty-one experiments with 181 treatment comparisons were used to evaluate the effects of HGP on WBSF and sensory measures of beef quality. Experiments varied in design, used many different hormonal treatments and combinations, which were single or repeated, in different breeds and sex groups of cattle, with or without electrical stimulation, and with different lengths of time on feed and beef aging. The effects of multiple treatment comparisons in experiments were evaluated using robust regression models and compared to Knapp-Hartung and permutation meta-analytical methods. Increased WBSF was associated with HGP treatment. Use of multiple HGP implants was associated with an increase in WBSF of 0.248 kg (95% CI = 0.203 to 0.292). Effects of a single implant only increased WBSF by 0.176 kg (95% CI = 0.109 to 0.242). Aging of beef did not alter the association of HGP with increased WBSF (P = 0.105); however, the point direction was toward a reduced effect with aging (standardized mean difference [SMD] = -0.005 per day aged). While aging lowered WBSF, it did not reduce the SMD between HGP treatment and reference groups. Comparisons using trenbolone acetate did not differ in WBSF from those using other implants (P > 0.15). The findings on sensory panel tenderness differ from those using WBSF as HGP treatment was not associated with reduced tenderness (P > 0.3) and multiple HGP treatments improved tenderness (SMD = 0.468) compared to a single implant. Further, juiciness, flavor, and connective tissue were not associated with HGP use, whereas there was a marked 5.5-point decrease in the Meat Standards Australia meat quality 4 score, albeit with limited experiments. In general, the true variance of experiments, tau2 (τ2) was low (<0.1), but heterogeneity, I2 was high (>50%) indicating that much of the variance was due to factors other than measurement error. More targeted studies on the role of HGP in influencing beef quality are needed.

Evaluation of the contribution of tenderness, juiciness, and flavor to the overall consumer beef eating experience

The objectives of this study were to evaluate the contribution of tenderness, juiciness, and flavor to the overall consumer beef eating experience and to evaluate the risk of overall palatability failure due to the unacceptable level of one or more of these traits. Data from 11 previously conducted studies representing a wide range of treatments and levels of eating quality that included more than 1,500 beef samples and 1,800 consumers were compiled and analyzed for this study. Results of a multivariate regression indicated that tenderness, flavor, and juiciness accounted for 43.4%, 49.4%, and 7.4%, respectively, of overall palatability (P < 0.05; R² > 0.99). Additionally, the odds of a steak being rated unacceptable overall when tenderness, juiciness, or flavor were rated unacceptable were 2.2 to 1 (69%), 1.9 to 1 (66%), and 3.3 to 1 (77%), respectively. This indicated overall palatability was 7.2, 6.5, and 12.3 times more likely to be rated unacceptable if tenderness, juiciness, or flavor, respectively, was also rated unacceptable. Additionally, the percentage of samples rated acceptable for each palatability trait increased (P < 0.05) as quality grade increased. More than 88% of USDA Prime samples were rated acceptable for each palatability trait, whereas only 74.8–77.3% of USDA Select samples were rated acceptable for each palatability trait. Marbling score accounted for 14–16% of the variation (P < 0.01) in consumer palatability scores for each trait and intramuscular fat percentage accounted for 17–21% of the variation in each trait (P < 0.01). Logistic equation models for the predicted probability of an acceptable rating for each palatability trait based on intramuscular fat percentage accounted for only a minimal amount of variation (P < 0.01; R² ≤ 0.09). Results of this study indicate the relative contribution of tenderness, juiciness, and flavor to overall beef palatability. They provide evidence that the failure of even a single palatability trait dramatically increases the likelihood of overall palatability failure, indicating that no single palatability trait is most important, as beef palatability is dependent upon the acceptance of all three traits: tenderness, juiciness, and flavor.

Effect of the inclusion of natural additives on animal performance and meat quality of crossbred bulls (Angus × Nellore) finished in feedlot

The objective of this study was to evaluate the influence a finishing diet containing natural additives fed for 94 days on animal performance, carcass, and meat quality characteristics of crossbred bulls (1/2 Angus × 1/2 Nellore). Forty-eight bulls (initial BW 318 ± 4.7 kg and initial age 22 months) were used in a completely randomised design. Bulls were fed one of four diets: (1) CON – Control; (2) CCO – addition of 4 g/animal.day of a mix of essential oils from castor bean and cashew; (3) MIX – addition of 4 g/animal.day of a mix of essential oils (oregano oils, castor bean, cashew); (4) YST – addition of 4 g/animal.day of yeast. Bulls were finished in feedlot (in individual pens) and slaughtered at an average weight of 469 ± 6.7 kg. Final BW, hot carcass weight and average daily gain were greater (P < 0.05) in MIX diet than in the three other diets. However, DM intake, G : F, fat thickness, longissimus muscle area, marbling, and meat colour were similar (P > 0.05) among the four diets. The carcass conformation score was higher (P < 0.05) for bulls that were fed with the YST diet and similar for the three other diets. Meat from CCO had a reduced (P < 0.05) cooking loss when compared with CON diet. Shear force from MIX diet had lesser values (P < 0.05) than meat from YST diet, and it was similar among CON and CCO diets. There was no diet effect (P > 0.05) on lipid oxidation, moisture, ash, and total lipids contents. C14:0, C14:1 n-9, C16:0, C18:1 n-9, C18:1 n-7 and C18:3 n-6 fatty acids in intramuscular fat from the longissimus muscle were affected by the inclusion of additives in the diets. SFA, MUFA, PUFA, n-3 and n-6 fatty acid percentages, and the ratios PUFA : SFA and n-6 : n-3 were similar (P > 0.05) among diets. In conclusion, adding a mix of oregano, castor bean, and cashew oils in the diet improved the performance of the bulls, but meat characteristics did not significantly change.