Associations between the rumen microbiota and carcass merit and meat quality in beef cattle.

The rumen microbiota is important for energy and nutrient acquisition in cattle, and therefore its composition may also affect carcass merit and meat quality attributes. In this study, we examined the associations between archaeal and bacterial taxa in the rumen microbiota of beef cattle and 12 different attributes, including hot carcass weight (HCW), dressing percentage, ribeye area (REA), intramuscular fat content, marbling score, fat thickness, yield grade, moisture content, purge loss, and shear force. There were significant correlations between the relative abundance of certain archaeal and bacterial genera and these attributes. Notably, Selenomonas spp. were positively correlated with live weight and HCW, while also being negatively correlated with purge loss. Members of the Christensenellaceae R-7, Moryella, and Prevotella genera exhibited positive and significant correlations with various attributes, such as dressing percentage and intramuscular fat content. Ruminococcaceae UCG-001 was negatively correlated with live weight, HCW, and dressing percentage, while Acidaminococcus and Succinivibrionaceae UCG-001 were negatively correlated with intramuscular fat content, moisture content, and marbling score. Overall, our findings suggest that specific changes in the rumen microbiota could be a valuable tool to improve beef carcass merit and meat quality attributes. Additional research is required to better understand the relationship between the rumen microbiota and these attributes, with the potential to develop microbiome-targeted strategies for enhancing beef production. KEY POINTS: • Certain rumen bacteria were associated with carcass merit and meat quality • Moryella was positively correlated with intramuscular fat in beef carcasses • Acidaminococcus spp. was negatively correlated with marbling and intramuscular fat.

Biomagnification and temporal trends (1990-2021) of perfluoroalkyl substances in striped dolphins (Stenella coeruleoalba) from the NW Mediterranean sea.

Poly- and Perfluoroalkyl Substances (PFAS) are a well-known class of pollutants which can bioaccumulate and biomagnify with a vast majority being highly persistent. This study aims to determine the biomagnification rates of PFAS in sexually mature striped dolphins and to assess temporal trends on PFAS concentrations over the past three decades (1990-2021) in the North-Western Mediterranean Sea. Thirteen and 17 of the 19 targeted PFAS were detected in the samples of the dolphins' digestive content and liver, respectively, at concentrations ranging between 43 and 1609 ng/g wet weight, and 254 and 7010 ng/g wet weight, respectively. The most abundant compounds in both types of samples were linear perfluorooctanesulfonic acid (n-PFOS) and perfluorooctanesulfonamide (FOSA), which were present in all samples, followed by perfluoroundecanoic acid (PFUnDA), perfluorotridecanoic acid (PFTrDA) and perfluorononanoic acid (PFNA). Long-chain PFAS (i.e., PFCAs C ≥ 7 and PFSAs C ≥ 6) biomagnified to a greater extent than short-chain PFAS, suggesting a potential effect on the health of striped dolphins. Environmental Quality Standards concentrations set in 2014 by the European Union were exceeded in half of the samples of digestive content, suggesting that polluted prey may pose potential health risks for striped dolphins. Concentrations of most long-chain PFAS increased from 1990 to 2004-2009, then stabilized during 2014-2021, possibly following country regulations and industrial initiatives. The current study highlights the persistent presence of banned PFAS and may contribute to future ecological risk assessments and the design of management strategies to mitigate PFAS pollution in marine ecosystems.

Prediction of primal and retail cut weights, tissue composition and yields of youthful cattle carcasses using computer vision systems; whole carcass camera and/or ribeye camera.

The application of two computer vision systems (CVS) was evaluated to predict primal and retail cut composition in youthful beef carcasses. Left carcass sides from a total of 634 animals were broken down into primal cuts, scanned using dual-energy x-ray absorptiometry for the prediction of tissue composition and fabricated into retail cuts. Cold carcass camera (CCC) images led to higher R2 values than hot carcass camera (HCC) images. The CVS coefficients of prediction for the primal cut weights ranged from 0.61 to 0.97. For the primal cut tissue composition predictions, R2 values ranged from 0.09 for Brisket HCC bone prediction to 0.82 for Chuck CCC fat prediction. Retail cut weight estimations had similar R2 values, ranging from 0.10 for IMPS 112 (Ribeye roll-denuded ribeye) to 0.99 for IMPS 113C (semi-boneless chuck) both using CCC. The results suggest the feasibility of CVS technologies to predict beef primal and retail cuts weights together with tissue composition, and yield percentages.

Towards improving classification of Canadian dark-cutting beef carcasses: Consumer sensory evaluation.

This study evaluated whether different colour intensities of ribeye steaks from dark-cutting (B4 grade) beef carcasses (Dark-B4DK/Moderate-B4MD) were similar in appearance and eating quality to steaks from normal (N) carcasses of lower marbling grades (AA or A) as assessed by consumers. The B4MDAAA and B4DK/MDAA had similar raw appearance and eating quality to N carcasses with a one quality downgrade for marbling (P > 0.1), potentially supporting a B4MDAAA and B4DK/MDAA re-class to NAA and NA grades, respectively. Cooked B4DKAAA steaks had greater juiciness and tenderness acceptability (P < 0.01) and similar appearance, flavour and overall acceptability and purchase intent compared to NAA steaks (P > 0.1). However, consumers perceived greater marbling and lower colour acceptability (P < 0.01) in raw B4DKAAA compared to NAA steaks, lowering the purchase intent scores of B4DKAAA steaks (P < 0.01). These results suggest merit for continuing a B4DKAAA segregated grade, unless the superior eating quality of B4DKAAA could offset its poorer raw appearance through consumer education or modified atmosphere packaging.

A Comparison of Fresh Pork Colour Measurements by Using Four Commercial Handheld Devices.

The objective of this study was to evaluate the performance of different low-cost instruments to measure pork colour in comparison to Minolta spectrophotometers and industry subjective standards. Canadian pork colour standards and commercial meat (252 loin chops and 46 tenderloins) were measured using two Minolta (CM 700D) spectrophotometers, four Nix sensors (two Nix Pro II and two Nix QC), and four Spectro devices (two Spectro 1 and two Spectro 1 Pro). Using Bland-Altman plots, all hand-held devices revealed similar performance on colour coordinates, except for the Nix Pro II, which had more variability on a* value, and Spectro 1 Pro on b* value, when compared to Minolta measurements. Low RSD values (< 5%) were obtained from repeated measurements on Canadian colour standards. The trend of colour coordinates on colour scores (0-6) were similar for all four commercial instruments, except for a* from Nix Pro and b* from Spectro 1. The correlation coefficients between subjective standards and colour coordinates from the Nix and Spectro devices were slightly higher than the Minolta spectrophotometers. Even though Nix and Spectro 1 series instruments generated different absolute colour coordinate values on meat samples, these pocket-size instruments presented great reliability to measure pork surface colour. However, operational limitations of the instruments, such as the internal calibration time between samples for the Spectro 1 series, should also be considered.

Carcass and Primal Composition Predictions Using Camera Vision Systems (CVS) and Dual-Energy X-ray Absorptiometry (DXA) Technologies on Mature Cows.

This study determined the potential of computer vision systems, namely the whole-side carcass camera (HCC) compared to the rib-eye camera (CCC) and dual energy X-ray absorptiometry (DXA) technology to predict primal and carcass composition of cull cows. The predictability (R2) of the HCC was similar to the CCC for total fat, but higher for lean (24.0%) and bone (61.6%). Subcutaneous fat (SQ), body cavity fat, and retail cut yield (RCY) estimations showed a difference of 6.2% between both CVS. The total lean meat yield (LMY) estimate was 22.4% better for CCC than for HCC. The combination of HCC and CCC resulted in a similar prediction of total fat, SQ, and intermuscular fat, and improved predictions of total lean and bone compared to HCC/CCC. Furthermore, a 25.3% improvement was observed for LMY and RCY estimations. DXA predictions showed improvements in R2 values of 26.0% and 25.6% compared to the HCC alone or the HCC + CCC combined, respectively. These results suggest the feasibility of using HCC for predicting primal and carcass composition. This is an important finding for slaughter systems, such as those used for mature cattle in North America that do not routinely knife rib carcasses, which prevents the use of CCC.

Evaluation of RNA quality and functional transcriptome of beef longissimus thoracis over time post-mortem.

Evaluating RNA quality and transcriptomic profile of beef muscle over time post-mortem may provide insight into RNA degradation and underlying biological and functional mechanisms that accompany biochemical changes occurring post-mortem during transformation of muscle to meat. RNA was extracted from longissimus thoracis (LT) sampled from British Continental crossbred heifer carcasses (n = 7) stored at 4°C in an abattoir drip cooler at 5 time points post-mortem, i.e., 45 min (0 h), 6 h, 24 h, 48 h, and 72 h. Following RNA-Sequencing, processed reads were aligned to the ARS-UCD1.2 bovine genome assembly. Subsequent differential expression (DE) analysis identified from 51 to 1434 upregulated and 27 to 2256 downregulated DE genes at individual time points compared to time 0 h, showing a trend for increasing counts of both upregulated and downregulated genes over time. Gene ontology and biological pathway term enrichment analyses on sets of DE genes revealed several processes and their timelines of activation/deactivation that accompanied or were involved with muscle transformation to meat. Although the quality of RNA in refrigerated LT remained high for several days post-mortem, the expression levels of several known biomarker genes for meat quality began to change from 24 h onwards. Therefore, to ensure accuracy of predictions on meat quality traits based on the expression levels of those biomarker genes in refrigerated beef muscle tissue, it is crucial that those expression measurements be made on RNA sampled within 24 h post-mortem. The present study also highlighted the need for more research on the roles of mitochondrial genes and non-coding genes in orchestrating muscle tissue processes after death, and how pre-mortem immune status might influence post-mortem meat quality.

Effect of Feeding Barley, Corn, and a Barley/Corn Blend on Beef Composition and End-Product Palatability.

This study evaluated the relationship among palatability attributes, volatile compounds, and fatty acid (FA) profiles in meat from barley, corn, and blended (50:50, barley and corn) grain-fed steers. Multiple correspondence analysis with three dimensions (Dim) explained 62.2% of the total variability among samples. The Dim 1 and 2 (53.3%) separated pure from blended grain-fed beef samples. Blended grain beef was linked to a number of volatiles including (E,E)-2,4-decadienal, hexanal, 1-octen-3-ol, and 2,3-octanedione. In addition, blended grain-fed beef was linked to fat-like and rancid flavors, stale-cardboard, metallic, cruciferous, and fat-like aroma descriptors, and negative categories for flavor intensity (FI), off-flavor, and tenderness. A possible combination of linoleic and linolenic acids in the blended diet, lower rumen pH, and incomplete biohydrogenation of blended grain-fed polyunsaturates could have increased (p ≤ 0.05) long-chain n-6 fatty acids (LCFA) in blended grain-fed beef, leading to more accumulation of FA oxidation products in the blended than in barley and corn grain-fed meat samples. The Dim 3 (8.9%) allowed corn separation from barley grain beef. Barley grain-fed beef was mainly linked to alkanes and beef positive FI, whereas corn grain-fed beef was associated with pyrazines, in addition to aldehydes related to n-6 LCFA oxidation.

Enhancing the Nutritional Value of Red Meat through Genetic and Feeding Strategies.

Consumption of red meat contributes to the intake of many essential nutrients in the human diet including protein, essential fatty acids, and several vitamins and trace minerals, with high iron content, particularly in meats with high myoglobin content. Demand for red meat continues to increase worldwide, particularly in developing countries where food nutrient density is a concern. Dietary and genetic manipulation of livestock can influence the nutritional value of meat products, providing opportunities to enhance the nutritional value of meat. Studies have demonstrated that changes in livestock nutrition and breeding strategies can alter the nutritional value of red meat. Traditional breeding strategies, such as genetic selection, have influenced multiple carcass and meat quality attributes relevant to the nutritional value of meat including muscle and fat deposition. However, limited studies have combined both genetic and nutritional approaches. Future studies aiming to manipulate the composition of fresh meat should aim to balance potential impacts on product quality and consumer perception. Furthermore, the rapidly emerging fields of phenomics, nutrigenomics, and integrative approaches, such as livestock precision farming and systems biology, may help better understand the opportunities to improve the nutritional value of meat under both experimental and commercial conditions.

Rapid and non-destructive determination of lean fat and bone content in beef using dual energy X-ray absorptiometry.

Dual energy X-ray absorptiometry (DXA) was evaluated for its accuracy in predicting total lean, fat and bone in beef carcass sides and primal cuts. Left carcass sides (n = 316) were broken down into primal cuts, scanned using DXA and then dissected to fat, lean and bone. The DXA estimates for bone, lean and fat from the primals (n = 237) were used to calibrate partial least squares regression (PLSR) models for predicting tissue weights. Models were validated using 79 additional carcass sides, which were broken into primals, scanned using DXA, and subsequently dissected to fat, lean and bone. Models were highly accurate for predicting tissue weights for the entire carcass side (lean R2 = 0.991, fat R2 = 0.985 and bone R2 = 0.941) and within most primal cuts. Results suggest DXA technology can be utilized to accurately predict carcass tissue composition for whole carcass sides and within most primals.

A Review of the Principles and Applications of Near-Infrared Spectroscopy to Characterize Meat, Fat, and Meat Products.

Consumer demand for quality and healthfulness has led to a higher need for quality assurance in meat production. This requirement has increased interest in near-infrared (NIR) spectroscopy due to the ability for rapid, environmentally friendly, and noninvasive prediction of meat quality or authentication of added-value meat products. This review includes the principles of NIR spectroscopy, pre-processing methods, and multivariate analyses used for quantitative and qualitative purposes in the meat sector. Recent advances in portable NIR spectrometers that enable new online applications in the meat industry are shown and their performance evaluated. Discrepancies between published studies and potential sources of variability are discussed, and further research is encouraged to face the challenges of using NIRS technology in commercial applications, so that its full potential can be achieved.

Detection by real time PCR of walnut allergen coding sequences in processed foods.

A quantitative real-time PCR (RT-PCR) method, employing novel primer sets designed on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences, was set up and validated. Its specificity, sensitivity, and applicability were evaluated. The DNA extraction method based on CTAB-phenol-chloroform was best for walnut. RT-PCR allowed a specific and accurate amplification of allergen sequence, and the limit of detection was 2.5pg of walnut DNA. The method sensitivity and robustness were confirmed with spiked samples, and Jug r 3 primers detected up to 100mg/kg of raw walnut (LOD 0.01%, LOQ 0.05%). Thermal treatment combined with pressure (autoclaving) reduced yield and amplification (integrity and quality) of walnut DNA. High hydrostatic pressure (HHP) did not produce any effect on the walnut DNA amplification. This RT-PCR method showed greater sensitivity and reliability in the detection of walnut traces in commercial foodstuffs compared with ELISA assays.

Pork as a Source of Omega-3 (n-3) Fatty Acids.

Pork is the most widely eaten meat in the world, but typical feeding practices give it a high omega-6 (n-6) to omega-3 (n-3) fatty acid ratio and make it a poor source of n-3 fatty acids. Feeding pigs n-3 fatty acids can increase their contents in pork, and in countries where label claims are permitted, claims can be met with limited feeding of n-3 fatty acid enrich feedstuffs, provided contributions of both fat and muscle are included in pork servings. Pork enriched with n-3 fatty acids is, however, not widely available. Producing and marketing n-3 fatty acid enriched pork requires regulatory approval, development costs, quality control costs, may increase production costs, and enriched pork has to be tracked to retail and sold for a premium. Mandatory labelling of the n-6/n-3 ratio and the n-3 fatty acid content of pork may help drive production of n-3 fatty acid enriched pork, and open the door to population-based disease prevention polices (i.e., food tax to provide incentives to improve production practices). A shift from the status-quo, however, will require stronger signals along the value chain indicating production of n-3 fatty acid enriched pork is an industry priority.

The elimination of an adult segment by the Hox gene Abdominal-B.

Hox gene activity leads to morphological diversity of organs or structures in different species. One special case of Hox function is the elimination of a particular structure. The Abdominal-B Hox gene of Drosophila melanogaster provides an example of such activity, as this gene suppresses the formation of the seventh abdominal segment in the adult. This elimination occurs only in males, and is characteristic of more advanced Diptera. The elimination requires the differential expression or activity of genes that are downstream Abdominal-B, or that work together with it, and which regulate cell proliferation or cell extrusion. Here, we review the mechanisms responsible for such elimination and provide some new data on processes taking place within this segment.

The scope for manipulating the polyunsaturated fatty acid content of beef: a review.

Since 1950, links between intake of saturated fatty acids and heart disease have led to recommendations to limit consumption of saturated fatty acid-rich foods, including beef. Over this time, changes in food consumption patterns in several countries including Canada and the USA have not led to improvements in health. Instead, the incidence of obesity, type II diabetes and associated diseases have reached epidemic proportions owing in part to replacement of dietary fat with refined carbohydrates. Despite the content of saturated fatty acids in beef, it is also rich in heart healthy cis-monounsaturated fatty acids, and can be an important source of long-chain omega-3 (n-3) fatty acids in populations where little or no oily fish is consumed. Beef also contains polyunsaturated fatty acid biohydrogenation products, including vaccenic and rumenic acids, which have been shown to have anticarcinogenic and hypolipidemic properties in cell culture and animal models. Beef can be enriched with these beneficial fatty acids through manipulation of beef cattle diets, which is now more important than ever because of increasing public understanding of the relationships between diet and health. The present review examines recommendations for beef in human diets, the need to recognize the complex nature of beef fat, how cattle diets and management can alter the fatty acid composition of beef, and to what extent content claims are currently possible for beef fatty acids.

Effect of vacuum ageing on quality changes of lamb steaks from early fattening lambs during aerobic display.

The effects of vacuum ageing on the quality changes of lamb steaks during retail display were assessed. Biceps femoris and Quadriceps femoris muscles from thirty early fattening lambs fed barley straw and concentrate or alfalfa and concentrate were used. Half of the muscles were vacuum aged for three weeks (VA), and the other half were not aged (control). Control and VA muscles were sliced and aerobically displayed. Weight loss, pH, aldehyde contents, instrumental color characteristics and color acceptance were measured at display days 1, 3, 7 and 14. At day 1 redness was higher in VA lamb. However, redness of VA lamb decreases more rapidly during further storage. Redness and color acceptance decreased in VA lamb from day 3, whereas in not-aged lamb the decrease was observed from day 7 onwards. From days 7 to 14 a drop of color acceptance accompanied by an increase in pH and a decrease in lightness was observed in control and VA lamb.

Detection of almond allergen coding sequences in processed foods by real time PCR.

The aim of this work was to develop and analytically validate a quantitative RT-PCR method, using novel primer sets designed on Pru du 1, Pru du 3, Pru du 4, and Pru du 6 allergen-coding sequences, and contrast the sensitivity and specificity of these probes. The temperature and/or pressure processing influence on the ability to detect these almond allergen targets was also analyzed. All primers allowed a specific and accurate amplification of these sequences. The specificity was assessed by amplifying DNA from almond, different Prunus species and other common plant food ingredients. The detection limit was 1 ppm in unprocessed almond kernels. The method's robustness and sensitivity were confirmed using spiked samples. Thermal treatment under pressure (autoclave) reduced yield and amplificability of almond DNA; however, high-hydrostatic pressure treatments did not produced such effects. Compared with ELISA assay outcomes, this RT-PCR showed higher sensitivity to detect almond traces in commercial foodstuffs.

Quality characteristics of a dry-cured lamb leg as affected by tumbling after dry-salting and processing time.

The aim of this study was to evaluate selected quality characteristics of a dry-cured lamb leg with different tumbling treatments after salting. The characteristics were measured at different processing times. Three batches of dry-cured lamb legs (nine legs per batch) were prepared with no-, short- and long-tumbling treatments, and microbial counts, NaCl, aw, proximate composition, pH, free fatty acids, water soluble nitrogen, volatile compounds, texture and colour were evaluated at days 1, 22 and 71 of processing. Furthermore, a descriptive sensory analysis (flavour and texture) was performed in the final product (day 71). Time-related changes were observed for most of the characteristics studied. The effect of tumbling was only observed for the sensory attribute pastiness that was higher in tumbled legs. Methyl-branched butanal was only detected in tumbled legs.

A Novel Proteomic Analysis of the Modifications Induced by High Hydrostatic Pressure on Hazelnut Water-Soluble Proteins.

Food allergies to hazelnut represent an important health problem in industrialized countries because of their high prevalence and severity. Food allergenicity can be changed by several processing procedures since food proteins may undergo modifications which could alter immunoreactivity. High-hydrostatic pressure (HHP) is an emerging processing technology used to develop novel and high-quality foods. The effect of HHP on allergenicity is currently being investigated through changes in protein structure. Our aim is to evaluate the effect of HHP on the protein profile of hazelnut immunoreactive extracts by comparative proteomic analysis with ProteomeLab PF-2D liquid chromatography and mass spectrometry. This protein fractionation method resolves proteins by isoelectric point and hydrophobicity in the first and second dimension, respectively. Second dimension chromatogram analyses show that some protein peaks present in unpressurized hazelnut must be unsolubilized and are not present in HHP-treated hazelnut extracts. Our results show that HHP treatment at low temperature induced marked changes on hazelnut water-soluble protein profile.

Real Time PCR to detect hazelnut allergen coding sequences in processed foods.

A quantitative RT-PCR method, employing novel primer sets designed on Cor a 9, Cor a 11 and Cor a 13 allergen-coding sequences has been setup and validated. Its specificity, sensitivity and applicability have been compared. The effect of processing on detectability of these hazelnut targets in complex food matrices was also studied. The DNA extraction method based on CTAB-phenol-chloroform was the best for hazelnut. RT-PCR using primers for Cor a 9, 11 and 13 allowed a specific and accurate amplification of these sequences. The limit of detection was 1 ppm of raw hazelnut. The method sensitivity and robustness were confirmed with spiked samples. Thermal treatments (roasting and autoclaving) reduced yield and amplificability of hazelnut DNA, however, high-hydrostatic pressure did not affect. Compared with an ELISA assay, this RT-PCR showed higher sensitivity to detected hazelnut traces in commercial foodstuffs. The RT-PCR method described is the most sensitive of those reported for the detection of hazelnut traces in processed foods.