The associations between proteomic biomarkers and beef tenderness depend on the end-point cooking temperature, the country origin of the panelists and breed

In-depth exploration of the high and normal pH beef proteome: First insights emphasizing the dynamic protein changes in Longissimus thoracis muscle from pasture-finished Nellore bulls over different postmortem times

This study aimed to evaluate for the first time the temporal dynamic changes in early postmortem proteome of normal and high ultimate pH (pHu) beef samples from the same cattle using a shotgun proteomics approach. Ten selected carcasses classified as normal (pHu < 5.8; n = 5) or high (pHu ≥ 6.2; n = 5) pHu beef from pasture-finished Nellore (Bos taurus indicus) bulls were sampled from Longissimus thoracis muscle at 30 min, 9 h and 44 h postmortem for proteome comparison. The temporal proteomics profiling quantified 863 proteins, from which 251 were differentially abundant (DAPs) between high and normal pHu at 30 min (n = 33), 9 h (n = 181) and 44 h (n = 37). Among the myriad interconnected pathways regulating pH decline during postmortem metabolism, this study revealed the pivotal role of energy metabolism, cellular response to stress, oxidoreductase activity and muscle system process pathways throughout the early postmortem. Twenty-three proteins overlap among postmortem times and may be suggested as candidate biomarkers to the dark-cutting condition development. The study further evidenced for the first time the central role of ribosomal proteins and histones in the first minutes after animal bleeding. Moreover, this study revealed the disparity in the mechanisms underpinning the development of dark-cutting beef condition among postmortem times, emphasizing multiple dynamic changes in the muscle proteome. Therefore, this study revealed important insights regarding the temporal dynamic changes that occur in early postmortem of high and normal muscle pHu beef, proposing specific pathways to determine the biological mechanisms behind dark-cutting determination.

Effects of dietary Allium mongolicum Regel powder supplementation on the growth performance, meat quality, antioxidant capacity and muscle fibre characteristics of fattening Angus calves under heat stress conditions

The aim of this study was to investigate the effects of dietary Allium mongolicum Regel powder (AMRP) supplementation on the growth performance, meat quality, antioxidant capacity and muscle fibre characteristics of fattening Angus calves. Growth performance data and longissimus thoracis (LT) samples were collected from four groups of fattening Angus, which were fed either a basal diet (CON) or a basal diet supplemented with an AMRP dose of 10 (LAMR), 15 (MAMR), or 20 g/animal/day AMRP (HAMR) for 120 days before slaughter. AMRP addition to the feed improved growth performance and meat quality and altered muscle fibre type. Some responses to AMRP supplementation were dose dependent, whereas others were not. Together, the results of this study demonstrated that dietary supplementation with 10 g/animal/day AMRP was the optimal dose in terms of fattening calf growth performance, while 20 g/animal/day AMRP supplementation was the optimal dose in terms of meat quality.

Effect of Dry Aging of Pork on Microbiological Quality and Instrumental Characteristics

Meat aging is an important process that affects the quality of meat and is traditionally used mainly for beef. However, in recent years, there has been an increasing demand for pork products subjected to dry aging. The aim of this study was to compare selected parameters (microbiological quality, instrumental analyses of texture and color of meat, weight loss) of pork neck and loin with bone and skin together subjected to dry aging for 14 days. The microbiological profile (total viable psychrotrophic count, Enterobacteriaceae, psychrotrophic lactic acid bacteria, Pseudomonas spp.) on the surface of the meat with the skin and the lateral cutting surfaces without skin was compared on the first day after slaughter and after 14 days of dry aging. The results of this study demonstrated that dry aging did not significantly deteriorate the microbiological profile. Statistically significant weight losses were observed after 14 days of aging. The dry aging of pork had no significant effect on lightness (L*), redness (a*), and shear force. Significant differences were observed for yellowness (b*) and meat hardness (p < 0.05).

The application of omics technologies for understanding tropical plants-based bioactive compounds in ruminants: a review

Finding out how diet impacts health and metabolism while concentrating on the functional qualities and bioactive components of food is the crucial scientific objective of nutritional research. The complex relationship between metabolism and nutrition could be investigated with cutting-edge "omics" and bioinformatics techniques. This review paper provides an overview of the use of omics technologies in nutritional research, with a particular emphasis on the new applications of transcriptomics, proteomics, metabolomics, and genomes in functional and biological activity research on ruminant livestock and products in the tropical regions. A wealth of knowledge has been uncovered regarding the regulation and use of numerous physiological and pathological processes by gene, mRNA, protein, and metabolite expressions under various physiological situations and guidelines. In particular, the components of meat and milk were assessed using omics research utilizing the various methods of transcriptomics, proteomics, metabolomics, and genomes. The goal of this review is to use omics technologies-which have been steadily gaining popularity as technological tools-to develop new nutritional, genetic, and leadership strategies to improve animal products and their quality control. We also present an overview of the new applications of omics technologies in cattle production and employ nutriomics and foodomics technologies to investigate the microbes in the rumen ecology. Thus, the application of state-of-the-art omics technology may aid in our understanding of how species and/or breeds adapt, and the sustainability of tropical animal production, in the long run, is becoming increasingly important as a means of mitigating the consequences of climate change.

Meat Quality in Katerini and Podolian Young Bulls Raised on Pasture: A Comparison between Organic Production Systems in Greek and Italian Environments

Local and typical agri-food products (TAP) are receiving increasing interest from consumers, since they are perceived as genuine, healthy and tasty because they are produced under environmentally friendly farming systems. This has aroused a renewed interest among breeders from the inner regions of Italy and Greece toward autochthonous animal populations, such as Greek Katerini and Italian Podolian cattle. Twenty animals were used, divided into two homogeneous groups of ten subjects per each genotype. Animals were fed only on natural pasture and were slaughtered at 18 months of age. Meat from the Katerini young bulls showed a lower a* value, higher moisture and was leaner, and its fat was richer in n-3 fatty acids and had a better n-6/n-3 ratio. Meat from Podolian young bulls was more tender and showed a higher redness value and a significantly greater MUFA concentration. This preliminary study provides a contribution to the local actors and relevant authorities to develop a conservation program for the endangered Katerini breed based on the nutritional and sensorial characterization of its products.

Plasma metabolomic profiling in two rabbit lines divergently selected for intramuscular fat content

This study provides a thorough comparison of the plasma metabolome of two rabbit lines divergently selected for intramuscular fat content (IMF). The divergent selection led to a correlated response in the overall adiposity, turning these lines into a valuable animal material to study also the genetics of obesity. Over 900 metabolites were detected, and the adjustment of multivariate models, both discriminant and linear, allowed to identify 322 with differential abundances between lines, which also adjusted linearly to the IMF content. The most affected pathways were those of lipids and amino acids, with differences between lines ranging from 0.23 to 6.04 standard deviations, revealing a limited capacity of the low-IMF line to obtain energy from lipids, and a greater branched-chain amino acids catabolism in the high-IMF line related to its increased IMF content. Additionally, changes in metabolites derived from microbial activity supported its relevant role in the lipid deposition. Future research will focus on the analysis of the metabolomic profile of the cecum content, and on the integration of the several -omics datasets available for these lines, to help disentangle the host and microbiome biological mechanisms involved in the IMF deposition.

Quantitative proteomics analysis on the meat quality of processed pale, soft, and exudative (PSE)-like broiler pectoralis major by different heating methods

This study aims to assess and compare the influences of different heating methods on the quality characteristics of pale, soft, and exudative (PSE)-like and normal (NOR) pectoralis major through quantitative proteomic analysis. A total of 632 proteins were identified, and there were 84, 89, 50, and 43 differentially abundant proteins (DAPs) between processed PSE and NOR samples after four thermal treatments, including boiling (BO), steaming (ST), roasting (RO), and microwaving (MV), respectively, where moist heating conditions led to more different protein abundance. Processed PSE muscles resulted in significant changes in structural proteins related to myofibrillar and connective tissue, which could be associated with their structural instability and degraded quality. Collagen, tropomyosin, myoglobin, and hemoglobin could be potential indicators of PSE muscles color stability and variation during thermal processing. The quantitative proteomic analysis will help correlate molecular changes with processed meat quality towards future optimization of PSE poultry meat processing.

Meat Quality and Muscle Tissue Proteome of Crossbred Bulls Finished under Feedlot Using Wet Distiller Grains By-Product

Wet distiller grains (WDG) are a corn by-product rich in protein and fiber that can be used in feedlot diets. This study evaluated F1 Angus-Nellore bulls fed on a control diet vs. WDG (n = 25/treatment). After a period of 129 days on these feeds, the animals were slaughtered and Longissimus thoracis samples were collected for both a meat quality evaluation and gel-based proteomic analyses. A greater ribeye area (99.47 cm²) and higher carcass weight (333.6 kg) (p < 0.05) were observed in the WDG-finished cattle compared to the control (80.7 cm²; 306.3 kg). Furthermore, there were differences (p < 0.05) in the intramuscular fat between the WDG and control animals (IMF = 2.77 vs. 4.19%), which led to a significant decrease (p < 0.05) in saturated fatty acids (FA). However, no differences (p > 0.10) were observed in terms of tenderness, evaluated using Warner–Bratzler shear force (WBSF). The proteomic and bioinformatic analyses revealed substantial changes in the biological processes, molecular functions, and cellular components of the WDG-finished cattle compared to the control. Proteins related to a myriad of interconnected pathways, such as contractile and structural pathways, energy metabolism, oxidative stress and cell redox homeostasis, and transport and signaling. In this experiment, the use of WDG supplementation influenced the protein expression of several proteins, some of which are known biomarkers of beef quality (tenderness and color), as well as the protein–protein interactions that can act as the origins of increases in muscle growth and reductions in IMF deposition. However, despite the effects on the proteome, the tenderness, evaluated by WBSF, and fatty acid profile were not compromised by WDG supplementation.

Proteomics Unveils Post-Mortem Changes in Beef Muscle Proteins and Provides Insight into Variations in Meat Quality Traits of Crossbred Young Steers and Heifers Raised in Feedlot

Proteomics has been widely used to study muscle biology and meat quality traits from different species including beef. Beef proteomics studies allow a better understanding of the biological processes related to meat quality trait determination. This study aimed to decipher by means of two-dimensional electrophoresis (2D-PAGE), mass spectrometry and bioinformatics the changes in post-mortem muscle with a focus on proteins differentially expressed in the Longissimus thoracis (LT) muscle of immunocastrated young heifers and steers. Carcass traits, chemical composition, pH, instrumental color (L*, a*, b*), cooking loss and Warner-Bratzler shear force (WBSF) of meat from F1 Montana-Nellore cattle were also evaluated. Backfat thickness (BFT) and intramuscular fat content (IMF) were 46.8% and 63.6% higher in heifers (p < 0.05), respectively, while evaporation losses (EL) were 10.22% lower compared to steers. No differences (p > 0.05) were observed for tenderness evaluated by WBSF (3, 10, and 17 days post-mortem), pH, and color traits (L*, a* and b*) between the experimental groups. The study revealed several proteins to be differentially expressed proteins in heifers compared steers (p < 0.05). In heifers, proteins involved in nutrient transport (TF, ALB, and MB), energy metabolism (ALDOA, GAPDH, and PKM), and oxidative stress and response to stress (HSPA8 and CA3) were associated with a greater BFT and IMF deposition. The higher expression of these proteins indicated greater oxidative capacity and lower glycolytic activity in the LT muscle of heifers. In steers, there was greater abundance of protein expression related to muscle contraction and proteins of structure (ACTA1, TPM2 and TNNT3), energy metabolism (ENO1, ENO3, PYGM, PGM1 and TPI1) and ATP metabolism (ATP5F1B, PEBP1 and AK1), indicating greater glycogenolysis in LT muscle, suggesting a shift in the glycolytic/oxidative fibers of steers.

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.

Comparative Study on Muscle Fiber Types of Longissimus Dorsi of Xinjiang Brown Cattle and Angus Cattle of Different Months

The longissimus dorsi muscle of Xinjiang brown cattle and Angus cattle at the age of 3, 7, 12, and 24 months under the same feeding and management conditions were selected to explore the differences of muscle 4 fiber types in this study. The muscle histological and molecular biological reasons for the quality difference between Xinjiang brown cattle and Angus beef were discussed. The morphology of the muscle was compared by ATP enzyme staining and SDH enzyme staining, and its gene expression was detected by qRT-PCR. The mRNA expression levels of Myhc-I in 3-month-old Xinjiang brown cattle were significantly higher than those in Angus cattle of the same age ( $P<0.01$ ). The 4 fiber types of 7-month-old Xinjiang brown cattle were significantly lower than those of Angus cattle of the same age ( $P<0.01$ ). The expression level of type I and IIb in 12-month-old Xinjiang brown cattle was significantly higher than that in 12-month-old Angus cattle ( $P<0.05$ ). Type I and IIa of 24-month-old Xinjiang brown cattle were significantly lower than those of Angus cattle of the same age ( $P<0.05$ ). However, in our study, the basic characteristics of longissimus dorsi of Xinjiang brown cattle and Angus cattle, such as color, pH, shearing force, and other characteristics were not detected, which is lacking in this aspect. Overall, with the increase of age, the growth trend of muscle fiber morphology of Xinjiang brown cattle and Angus cattle is roughly the same, but from the point of view of muscle fiber types, the Xinjiang brown cattle are more suitable for the production of early fat calves and to make some reference for improving the quality of beef cattle in China.

DIA-based quantitative proteomic analysis on the meat quality of porcine Longissimus thoracis et lumborum cooked by different procedures

A DIA-based quantitative proteomic strategy was used to investigate the effects of different cooking procedures (steaming and boiling) on pork meat quality. Results showed that steamed meats had higher redness, cohesion, springiness, but lower lightness, yellowness, shear force, hardness, chewiness and cooking loss than boiled meats. In total of 1608 proteins were identified and 103 proteins exhibited significant difference (fold change > 1.5, P < 0.05). These DAPs mainly involved in protein structure, metabolic enzyme, protein turnover and oxidation stress. ALDOC, PVALB, PPP1R14C, AMPD1, CRYAB and SOD1 were validated as potential indicators of color variations in cooked meat. CFL1, COL1A1, COL3A1, RTN4, NRAP, NT5C3A, and SOD1 might be potential biomarker for texture changes of cooked meats. Moreover, these validated proteins exhibited significant (P < 0.05) correlation with cooking loss and could be serve as candidate predictors for cooking loss changes of meats in different cooking procedures.

Meat tenderness: advances in biology, biochemistry, molecular mechanisms and new technologies

Meat tenderness is an important quality trait critical to consumer acceptance, and determines satisfaction, repeat purchase and willingness-to-pay premium prices. Recent advances in tenderness research from a variety of perspectives are presented. Our understanding of molecular factors influencing tenderization are discussed in relation to glycolysis, calcium release, protease activation, apoptosis and heat shock proteins, the use of proteomic analysis for monitoring changes, proteomic biomarkers and oxidative/nitrosative stress. Each of these structural, metabolic and molecular determinants of meat tenderness are then discussed in greater detail in relation to animal variation, postmortem influences, and changes during cooking, with a focus on recent advances. Innovations in postmortem technologies and enzymes for meat tenderization are discussed including their potential commercial application. Continued success of the meat industry relies on ongoing advances in our understanding, and in industry innovation. The recent advances in fundamental and applied research on meat tenderness in relation to the various sectors of the supply chain will enable such innovation.

Review on characteristics of trained sensory panels in food science

Sensory analysis has been, is, and will be one of the most important methods in judging food quality. As such, it is an evaluation tool involving human subjects with specific skills to conduct assigned series of tests. This review outlines main characteristics of 179 trained panels published in 16 selected scientific journals in the last 12 months, as well as training methods used for panelists, and type of sensory studies employed. The results reveal that two thirds of the panels have between eight and twelve members, with gender data provided in half of the papers. Overall duration of their initial training is presented only in around 20% of reviewed publications. When provided, duration was below 2 hr per session involving up to 10 sessions. One third of papers confirmed to have conducted training of the panel for methods employed, while almost half used experienced human subjects with no further data. Around 12% of all manuscripts have validated training of their sensory panel, while 20% of papers covered at least one criterion for assessment of their panels' performance. The majority of papers (80%) used descriptive methods, mainly with intensity scales. It is of note that 15% of papers used hedonic tests typical for consumer studies. Almost half of the scholars conducted their research in triplicates (41.3%) while almost one quarter (24%) provided no data on this subject. Type of food analyzed has no effects on the quality of data provided regarding panels, training, sensory methods, and replications.

A Proteomic Study for the Discovery of Beef Tenderness Biomarkers and Prediction of Warner-Bratzler Shear Force Measured on Longissimus thoracis Muscles of Young Limousin-Sired Bulls

Beef tenderness is of central importance in determining consumers’ overall liking. To better understand the underlying mechanisms of tenderness and be able to predict it, this study aimed to apply a proteomics approach on the Longissimus thoracis (LT) muscle of young Limousin-sired bulls to identify candidate protein biomarkers. A total of 34 proteins showed differential abundance between the tender and tough groups. These proteins belong to biological pathways related to muscle structure, energy metabolism, heat shock proteins, response to oxidative stress, and apoptosis. Twenty-three putative protein biomarkers or their isoforms had previously been identified as beef tenderness biomarkers, while eleven were novel. Using regression analysis to predict shear force values, MYOZ3 (Myozenin 3), BIN1 (Bridging Integrator-1), and OGN (Mimecan) were the major proteins retained in the regression model, together explaining 79% of the variability. The results of this study confirmed the existing knowledge but also offered new insights enriching the previous biomarkers of tenderness proposed for Longissimus muscle.

Histochemical Characterisation and Gene Expression Analysis of Skeletal Muscles from Maremmana and Aubrac Steers Reared on Grazing and Feedlot Systems

Simple Summary

Muscle fibre types and sizes are important factors affecting muscle growth potential and meat quality. Their variability depends on some factors like muscle type, animal breed, physical activity, and they could be going through morphological or metabolic modifications, throughout animal life. Two muscles from Maremmana, an autochthonous breed from Tuscany (Italy), was compared to those from Aubrac, a breed from the Massif Central (France), under histochemical and gene expression points of view. Both these breeds were poorly studied, and the results identified Maremmana muscles were more oxidative in comparison to Aubrac. Moreover, steers of each breed were proportionally divided and reared on grazing or feedlot systems. Conversely to what was expected, the voluntary physical activity on pasture, another aspect poorly studied, influenced neither histochemical characteristics nor the gene expression.

Abstract

This study aimed to characterise the fibre composition of Triceps brachii (TB) and Semimembranosus (SM) muscles from 20 Maremmana (MA) and 20 Aubrac (AU) steers, and the effect of grazing activity in comparison with feedlot system. The histochemical method was performed with the m-ATPase method with an acid pre-incubation, thus allowing to distinguish type I, IIA, and IIB fibres. Additionally, on total RNA extracted from SM muscle, the expressions of atp1a1, mt-atp6, and capn1 genes were evaluated, in order to find potential associations with muscle fibre histochemical characteristics. In SM muscle, the MA steers had the greater frequency of oxidative fibres (type I and IIA) and the higher atp1a1 expression, in comparison to AU steers. Conversely, AU steers had a greater frequency of type IIB fibres, and the higher capn1 expression. A similar histochemical pattern was observed in TB muscle. The grazing activity was probably insufficient to determine differences both for fibre proportion and size, and gene expressions, except for mt-atp6 expression that was surprisingly highest in feedlot MA in comparison to other steers. These findings further the knowledge of muscle properties belonging to these breeds, and the effect of voluntary physical activity since few studies were available in this regard.

Dry-aging of beef as a tool to improve meat quality. Impact of processing conditions on the technical and organoleptic meat properties

Meat consumers are demanding products of higher and consistent quality, with a distinctive flavor and aroma, able to provide a particular sensorial experience when consuming beef. The impact of all the factors affecting the final eating quality, known as the farm to fork approach, has been extensively studied in the last decades. This includes genetic factors, production system, transport, carcass intervention, aging, packaging and cooking method, among others. Aging is, one of the most important steps in producing high quality tender beef. During this step, flavor is developed and the meat is tenderized. Dry-aging although considered a traditional method, is currently attracting attention from consumers, producers and researchers because of the characteristics of the final products in terms of flavor, aroma and texture. This chapter will describe the series of biochemical changes, which combined with the loss of water, generates a final product that is highly appreciated by niche consumers. This will include the changes that the muscle undergoes to be transformed to meat, the main factors driving the dry-aging process and how the flavor and aroma compounds are generated during this process.

Insights on meat quality from combining traditional studies and proteomics

Following a century of major discoveries on the mechanisms determining meat colour and tenderness using traditional scientific methods, further research into complex and interactive factors contributing to variations in meat quality is increasingly being based on data-driven "omics" approaches such as proteomics. Using two recent meta-analyses of proteomics studies on beef colour and tenderness, this review examines how knowledge of the mechanisms and factors underlying variations in these meat qualities can be both confirmed and extended by data-driven approaches. While proteomics seems to overlook some sources of variations in beef toughness, it highlights the role of post-mortem energy metabolism in setting the conditions for development of meat colour and tenderness, and also points to the complex interplay of energy metabolism, calcium regulation and mitochondrial metabolism. In using proteomics as a future tool for explaining variations in meat quality, the need for confirmation by further hypothesis-driven experimental studies of post-hoc explanations of why certain proteins are biomarkers of beef quality in data-driven studies is emphasised.

Molecular signatures of beef tenderness: Underlying mechanisms based on integromics of protein biomarkers from multi-platform proteomics studies

Over the last two decades, proteomics have been employed to decipher the underlying factors contributing to variation in the quality of muscle foods, including beef tenderness. One such approach is the application of high-throughput protein analytical platforms in the identification of meat quality biomarkers. To broaden our understanding about the biological mechanisms underpinning meat tenderization across a large number of studies, an integromics study was performed to review the current status of protein biomarker discovery targeting beef tenderness. This meta-analysis is the first to gather and propose a comprehensive list of 124 putative protein biomarkers derived from 28 independent proteomics-based experiments, from which 33 robust candidates were identified worthy of evaluation using targeted or untargeted data-independent acquisition proteomic methods. We further provide an overview of the interconnectedness of the main biological pathways impacting tenderness determination after multistep analyses including Gene Ontology annotations, pathway and process enrichment and literature mining, and specifically discuss the major proteins and pathways most often reported in proteomics research.

Protein Array-Based Approach to Evaluate Biomarkers of Beef Tenderness and Marbling in Cows: Understanding of the Underlying Mechanisms and Prediction

This study evaluated the potential of a panel of 20 protein biomarkers, quantified by Reverse Phase Protein Array (RPPA), to explain and predict two important meat quality traits, these being beef tenderness assessed by Warner-Bratzler shear force (WBSF) and the intramuscular fat (IMF) content (also termed marbling), in a large database of 188 Protected Designation of Origin (PDO) Maine-Anjou cows. Thus, the main objective was to move forward in the progression of biomarker-discovery for beef qualities by evaluating, at the same time for the two quality traits, a list of candidate proteins so far identified by proteomics and belonging to five interconnected biological pathways: (i) energy metabolic enzymes, (ii) heat shock proteins (HSPs), (iii) oxidative stress, (iv) structural proteins and (v) cell death and protein binding. Therefore, three statistical approaches were applied, these being Pearson correlations, unsupervised learning for the clustering of WBSF and IMF into quality classes, and Partial Least Squares regressions (PLS-R) to relate the phenotypes with the 20 biomarkers. Irrespective of the statistical method and quality trait, seven biomarkers were related with both WBSF and IMF, including three small HSPs (CRYAB, HSP20 and HSP27), two metabolic enzymes from the oxidative pathway (MDH1: Malate dehydrogenase and ALDH1A1: Retinal dehydrogenase 1), the structural protein MYH1 (Myosin heavy chain-IIx) and the multifunctional protein FHL1 (four and a half LIM domains 1). Further, three more proteins were retained for tenderness whatever the statistical method, among which two were structural proteins (MYL1: Myosin light chain 1/3 and TNNT1: Troponin T, slow skeletal muscle) and one was glycolytic enzyme (ENO3: β-enolase 3). For IMF, two proteins were, in this trial, specific for marbling whatever the statistical method: TRIM72 (Tripartite motif protein 72, negative) and PRDX6 (Peroxiredoxin 6, positive). From the 20 proteins, this trial allowed us to qualify 10 and 9 proteins respectively as strongly related with beef tenderness and marbling in PDO Maine-Anjou cows.

The Profiling of DNA Methylation and Its Regulation on Divergent Tenderness in Angus Beef Cattle

Beef is an essential food source in the world. Beef quality, especially tenderness, has a significant impact on consumer satisfaction and industry profit. Many types of research to date have focused on the exploration of physiological and developmental mechanisms of beef tenderness. Still, the role and impact of DNA methylation status on beef tenderness have yet to be elucidated. In this study, we exhaustively analyzed the DNA methylation status in divergent tenderness observed in Angus beef. We characterized the methylation profiles related to beef tenderness and explored methylation distributions on the whole genome. As a result, differentially methylated regions (DMRs) associated with tenderness and toughness of beef were identified. Importantly, we annotated these DMRs on the bovine genome and explored bio-pathways of underlying genes and methylation biomarkers in beef quality. Specifically, we observed that the ATP binding cassette subfamily and myosin-related genes were highly methylated gene sets, and generation of neurons, regulation of GTPase activity, ion transport and anion transport, etc., were the significant pathways related with beef tenderness. Moreover, we explored the relationship between DNA methylation and gene expression in DMRs. Some methylated genes were identified as candidate biomarkers for beef tenderness. These results provide not only novel epigenetic information associated with beef quality but offer more significant insights into meat science, which will further help us explore the mechanism of muscle biology.

Cooking loss in retail beef cuts: The effect of muscle type, sex, ageing, pH, salt and cooking method

The aim of the study was to compare cooking losses in beef (striploin and cube roll) during various cooking methods (grilling, roasting, broiling) in two different cooking devices (convection oven and clamshell grill). A total of 400 samples of meat were cooked (an internal temperature of more than 70 °C) and analysed. Cooking losses of slices of striploin ranged between 24.5% and 34.8%, with losses of 25.9-35.8% when whole cuts of meat were roasted. Losses fell within similar ranges (24.7-33.7%) for cube roll. Beef after 21 days of dry ageing showed generally lower cooking losses. Principal component analysis confirmed a strong negative correlation between cooking losses and salt content, saltiness and juiciness, which were positively correlated with one another. The majority of the sensory properties were positively correlated with pH, while their relationship with Warner-Bratzler (WB) test was negative. Roasting in a convection oven would seem to be the most suitable method of cooking striploin, followed by broiling in a convection oven, with grilling in last place. The highest score for the majority of sensory properties and the lowest WB values were recorded in meat roasted in a convection oven, particularly in the meat of bulls aged for 21 days.

Measuring quantitative proteomic distance between Spanish beef breeds

Estimates of quantitative proteomic distance between populations have not been reported to date. Here, quantitative proteomic distances between three Spanish bovine breeds (Asturiana de los Valles, AV; Retinta, RE; and Rubia Gallega, RG) were estimated from two-dimensional electrophoresis profiles of meat samples of longissimus thoracis muscle at 2 h post-mortem. Statistically significant distances were detected between AV/RG and the most genetically different RE breed, using the novel QD measure of quantitative proteomic distance. In total, 18 differentially abundant myofibrillar and sarcoplasmic proteins/isoforms contributing to proteomic distances between breeds were confidently identified by tandem mass spectrometry. The fast skeletal myosin regulatory light chain 2 followed by other five interacting proteins exhibited the most pronounced relative change between breeds. In addition, most differentially represented proteins could be associated with variations in meat tenderness. Therefore, they could be candidate biomarkers for molecular breeding programs and authentication of the three Spanish beef breeds.

Muscle Fiber Properties in Cattle and Their Relationships with Meat Qualities: An Overview

The control of meat quality traits constitutes an important target for any farm animal production, including cattle. Therefore, better understanding of the biochemical properties that drive muscle development and final outcomes constitutes one of the main challenging topics of animal production and meat science. Accordingly, this review has focused on skeletal muscle fibers in cattle and their relationships with beef qualities. It aimed to describe the chemical and structural properties of muscle fibers as well as a comprehensive review of their contractile and metabolic characteristics during the life of the animal. The existing methods for the classification of muscle fibers were reviewed, compared, and discussed. Then, the different stages of myogenesis in cattle were defined. The main factors regulating fetal and postnatal growth and the plasticity of muscle fibers were evidenced, especially the role of myostatin growth factor and the impact of nutritional factors. This review highlights that the knowledge about muscle fibers is paramount for a better understanding of how to control the muscle properties throughout the life of the animal for better management of the final eating qualities of beef. Accordingly, the associations between bovine muscle fibers and different meat eating qualities such as tenderness, pH decline, and color traits were further presented.

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.

Beef Tenderness Prediction by a Combination of Statistical Methods: Chemometrics and Supervised Learning to Manage Integrative Farm-To-Meat Continuum Data

This trial aimed to integrate metadata that spread over farm-to-fork continuum of 110 Protected Designation of Origin (PDO)Maine-Anjou cows and combine two statistical approaches that are chemometrics and supervised learning; to identify the potential predictors of beef tenderness analyzed using the instrumental Warner-Bratzler Shear force (WBSF). Accordingly, 60 variables including WBSF and belonging to 4 levels of the continuum that are farm-slaughterhouse-muscle-meat were analyzed by Partial Least Squares (PLS) and three decision tree methods (C&RT: classification and regression tree; QUEST: quick, unbiased, efficient regression tree and CHAID: Chi-squared Automatic Interaction Detection) to select the driving factors of beef tenderness and propose predictive decision tools. The former method retained 24 variables from 59 to explain 75% of WBSF. Among the 24 variables, six were from farm level, four from slaughterhouse level, 11 were from muscle level which are mostly protein biomarkers, and three were from meat level. The decision trees applied on the variables retained by the PLS model, allowed identifying three WBSF classes (Tender (WBSF ≤ 40 N/cm²), Medium (40 N/cm² < WBSF < 45 N/cm²), and Tough (WBSF ≥ 45 N/cm²)) using CHAID as the best decision tree method. The resultant model yielded an overall predictive accuracy of 69.4% by five splitting variables (total collagen, µ-calpain, fiber area, age of weaning and ultimate pH). Therefore, two decision model rules allow achieving tender meat on PDO Maine-Anjou cows: (i) IF (total collagen < 3.6 μg OH-proline/mg) AND (µ-calpain ≥ 169 arbitrary units (AU)) AND (ultimate pH < 5.55) THEN meat was very tender (mean WBSF values = 36.2 N/cm², n = 12); or (ii) IF (total collagen < 3.6 μg OH-proline/mg) AND (µ-calpain < 169 AU) AND (age of weaning < 7.75 months) AND (fiber area < 3100 µm²) THEN meat was tender (mean WBSF values = 39.4 N/cm², n = 30).