Driving forces shaping the microbial ecology in meat packing plants

Meat production is a complex system, continually receiving animals, water, air, and workers, all of which serve as carriers of bacteria. Selective pressures involved in different meat processing stages such as antimicrobial interventions and low temperatures, may promote the accumulation of certain residential microbiota in meat cutting facilities. Bacteria including human pathogens from all these sources can contaminate meat surfaces. While significant advancements have been made in enhancing hygienic standards and pathogen control measures in meat plants, resulting in a notable reduction in STEC recalls and clinical cases, STEC still stands as a predominant contributor to foodborne illnesses associated with beef and occasionally with pork. The second-and third-generation sequencing technology has become popular in microbiota related studies and provided a better image of the microbial community in the meat processing environments. In this article, we reviewed the potential factors influencing the microbial ecology in commercial meat processing facilities and conducted a meta-analysis on the microbiota data published in the last 10 years. In addition, the mechanisms by which bacteria persist in meat production environments have been discussed with a focus on the significant human pathogen E. coli O157:H7 and generic E. coli, an indicator often used for the hygienic condition in food production.

Evaluation of long-term supplementation of a Bacillus subtilis direct-fed microbial and enzymatically hydrolyzed yeast cell culture product used alone or in combination on Clostridia, Clostridium perfringens, Escherichia coli, and Salmonella prevalence in beef steers

The objective was to determine the influence of long-term supplementation (258 d) of a direct-fed microbial (DFM) and/or yeast cell wall (YCW) product on bacterial populations in beef steers. Single-sourced Charolais × Red Angus steers (n = 256; body weight = 246 ± 1.68 kg) were used in a randomized complete block design and blocked by location into one of four treatments: 1) fed no DFM and no YCW (Control); 2) fed only the DFM (DFM; Certillus CP B1801 Dry, 28 g/steer d-1 ); 3) fed only the YCW (YCW; Celmanax; 18 g/steer d-1 ); and 4) fed the DFM and the YCW (DFM+YCW). Steers were vaccinated for respiratory and clostridial diseases and treated for internal and external parasites at processing and individually weighed on days 1, 14, 42, 77, 105, 133, 161, 182, 230, and 258. To determine bacterial prevalence, fecal samples were collected on days 1, 14, 77, 133, 182, and 230 and environmental (pen area, feed, and water) samples were collected at the beginning of the week when cattle were weighed. No treatment × day interactions or treatment effects (P > 0.05) were observed between treatment groups at any sampling days for the bacterial populations. Samples on days 1, 133, and 182 had greater (P < 0.05) Clostridia levels compared to the other sampling points but were not different from each other. Clostridia levels were also greater (P < 0.05) on day 77 compared to days 14 and 230. Samples on days 77 and 230 had greater (P < 0.05) Clostridium perfringens levels compared to the other sampling points but were not different (P > 0.05) from each other. Samples on days 1 and 14 had lower (P < 0.05) total Escherichia coli levels compared to the other sampling points but were not different (P > 0.05) from each other. Escherichia coli levels on day 77 were higher (P < 0.05) compared to days 133, 182, and 230. Little Salmonella prevalence (1.5%) was observed throughout the study. This study had greater levels of Clostridia compared to small and large commercial feedlots in the Church and Dwight research database, but C. perfringens, total and pathogenic E. coli, and Salmonella prevalence were notably lower. Collectively, there were no appreciable treatment influences on bacterial populations. These data further indicate a low pathogenic bacterial challenge at the trial site, which could partially explain the lack of differences with DFM or YCW supplementation. The DFM and YCW used alone or in combination cannot be expected to show additional benefits when animals are relatively unstressed with a low pathogenic bacterial challenge.

Kansas beef bulls with chronic anaplasmosis demonstrate satisfactory breeding soundness outcomes at breeding soundness examination

OBJECTIVE

The objectives of this study were to evaluate the prevalence of chronic Anaplasma marginale infection in beef bulls from eastern Kansas and compare breeding soundness parameters between A marginale-infected and uninfected bulls. We hypothesized that bulls with chronic anaplasmosis would have inferior breeding soundness exam (BSE) outcomes as a result of persistent A marginale infection or the consequence of initial clinical disease compared to uninfected bulls.

ANIMALS

535 client-owned beef bulls from eastern Kansas undergoing routine BSE.

METHODS

Complete BSEs were conducted by participating veterinarians according to the second edition of the Society for Theriogenology Manual for Breeding Soundness Examination of Bulls. Blood samples were collected for PCV determination and analysis of A marginale infection status via quantitative PCR and cELISA. Logistic and linear regression methods were used to evaluate factors associated with A marginale infection status and BSE parameters.

RESULTS

Prevalence of chronic A marginale infection was 46% (245/535) among bulls. Unsatisfactory BSE outcome was not statistically associated with chronic anaplasmosis in this study population, although more bulls with chronic anaplasmosis had unsatisfactory BSE outcomes (15.0 ± 2.4% vs 12.0 ± 2.2%).

CLINICAL RELEVANCE

Chronic anaplasmosis is prevalent among eastern Kansas breeding bulls; however, no negative association between chronic anaplasmosis and breeding soundness at time of BSE was observed.

Total Selenium Level and Its Distribution between Organs in Beef Cattle in Different Selenium Status

The aim of this study was to determine the Se concentration in the main tissues of beef cattle and to evaluate the differences in tissue distribution between animals with different selenium status. Selenium concentration was determined in the serum, longissimus dorsi muscle, semitendinosus muscle, kidney, heart, liver, spleen and lungs of cows, heifers and beef bulls, using spectrofluorimetric method. Despite receiving supplementation, 55.6% animals demonstrated an optimal Se level, while 44.4% were deficient. The mean serum Se concentration was significantly higher (p < 0.05) in animals with a normal Se status than in Se-deficient animals. Differences in Se tissue distribution were observed between Se-deficient animals and those with normal Se status. The organs most susceptible to Se deficiency are the semitendinosus muscle, lungs, heart and liver. In both normal and Se-deficient animals, significantly higher Se concentrations were observed in the kidney than other organs (p < 0.05), and the lowest in the muscles. As Se deficiencies can be found among supplemented animals, the level of Se should be monitored in beef cattle in order to detect possible Se deficiencies, which may have negative health effects for animals and reduce the value of animal products as a source of Se in the human diet.

Utilization of Hyperspectral Imaging with Chemometrics to Assess Beef Maturity

There is a growing demand from consumers for more assurance in premium food products such as beef and especially steak. The quality of beef steak is primarily dictated by the maturation which ultimately influences its taste and flavor. These enhanced qualities have resulted in steak becoming a premium product that consumers are willing to pay a premium price for. A challenge, however, is analyzing the maturity of beef by traditional analytical techniques. Hyperspectral imaging (HSI) is a methodology that is gaining traction mainly due to miniaturization, improved optics, and software. In this study, HSI was applied to wet aged beef supplied at various stages of maturity, with spectral data generated using a portable hyperspectral camera. Two trials were conducted over a five-month period: (i) proof of principle and (ii) a bespoke sampling trial for the industry. With the support of industry participation, all samples were sourced from a highly reputable UK/Ireland supplier. To enhance data interpretation, the spectral data collected were combined with multivariate analysis. A range of chemometric models were generated using unsupervised and supervised methods to determine the maturity of the beef, and external validation was performed. The external validation showed good accuracy for "unknown samples" tested against the model set and ranged from 74 to 100% for the different stages of maturity (20, 30, and 40 days old). This study demonstrated that HSI can detect different maturity timepoints for beef samples, which could play an important role in solving some of the challenges that the industry faces with ensuring the authenticity of their products. This is the first time that portable HSI has been coupled with chemometric modeling for assessing the maturity of beef, and it can serve as a model for other food authenticity and quality applications.

Feeding Pellets Containing Agro-Industrial Waste Enhances Feed Utilization and Rumen Functions in Thai Beef Cattle

The objective of this research was to investigate the effects of citric waste fermented with yeast waste pellet (CWYWP) supplementation on feed intake, rumen characteristics, and blood metabolites in native Thai beef cattle that are fed a rice-straw-based diet. Four native male Thai beef cattle (1.0-1.5 years old) with an initial body weight (BW) of 116 ± 16 kg were held in a 4 × 4 Latin square design within 21-day periods. The animals were assigned to receive CWYWP supplementation at 0%, 2%, 4%, and 6% of the total dry matter (DM) intake per day. The results indicate that feeding beef cattle with CWYWP leads to a linear increase in the total intake as well was the intake of crude protein (CP) and the digestibility of CP, with the maximum levels observed at 6% CWYWP supplementation (p < 0.05). Rumen characteristics, including pH, blood urea-nitrogen concentration, and protozoal population, showed no significant alterations in response to the varying CWYWP dosages (p > 0.05). In addition, the CWYWP supplementation resulted in no significant changes in the concentration of ammonia-nitrogen, remaining within an average normal range of 10.19-10.38 mg/dL (p > 0.05). The inclusion of 6% CWYWP resulted in the highest population of ruminal bacteria (p < 0.05). Additionally, the CWYWP supplementation led to a statistically significant increase in the mean propionic acid concentration as compared to the group that did not receive the CWYWP supplementation (p < 0.05). In conclusion, this experiment demonstrates that supplementing Thai native beef cattle with CWYWP at either 4% or 6% DM per day can enhance their total CP intake as well as the CP digestibility and rumen bacterial population, and can increase propionate concentration.

Does transport stress have any effect on carcass quality of Nellore cattle (Bos taurus indicus) in Brazil? - A case study

With the increasing concomitant demands for Brazilian beef and in particular high-quality beef, there is a need for observational studies of the effects of pre- and post-slaughter practices on beef carcass traits. We hypothesized in our case study that pre-slaughter transport of bovines over significant distances would induce stress in animals, and that this would reduce carcass quality because of higher pH resulting from long-distance transportation. To test this hypothesis, 30,230 Nellore carcasses from a private slaughterhouse were evaluated 24 h postmortem. Analysis showed correlations between animal maturity, ultimate pH, distance, and carcass weight. More precisely, there was a slight positive correlation between ultimate pH and weight (but not with transportation distance) and a slight positive correlation between maturity and weight. A linear regression model (R2 = 0.016) failed to show distance having a significant effect on ultimate pH (P = 0.63), while carcass weight significantly affected ultimate pH (P < 0.001) with a low coefficient of 0.0003. Maturity negatively affected ultimate pH also (P < 0.001) but with also a small effect (-0.0008). Results (from 95% confidence intervals of variance of the random effects and of the random errors) showed that the variability within farms was higher than between farms. The linear mixed model showed that maturity had a significant effect on carcass weight value (P < 0.001) with a large coefficient of 2.90. The R2 of the linear mixed model was 46.03%. In conclusion, while weight and maturity both affect ultimate pH, long distances did not significantly impact ultimate pH and therefore the beef quality from Nellore cattle. This could be because of low stress during transport, as well as the physical characteristics of the Nellore breed that favor greater resistance to tropical climatic conditions.

Beef Intake Is Associated with Higher Nutrient Intake and Nutrient Adequacy in U.S. Adolescents, NHANES 2001-2018

Nutrient adequacy among adolescents is of concern due to higher nutrient requirements for their developing bodies as well as the gap between the current nutrient intake and the recommendations. The objective of this study was to determine beef intake and assess the relationship between beef consumption and nutrient intake and nutrient adequacy in male and female adolescents, 14-18 years of age. Dietary recalls collected during the What We Eat in America (WWEIA) portion of the National Health and Nutrition Examination Survey (NHANES) cycles 2001-2018 were utilized to determine beef intake. Usual nutrient intakes were determined with the National Cancer Institute method in conjunction with day 1 and day 2 total nutrient files. Nutrient adequacy was assessed by calculating the percentage of the population below the estimated average requirement (EAR) or above the adequate intake (AI). The average beef intake of male and female adolescent beef consumers was 57.9 ± 2.4 and 46.8 ± 2.2 g with a 90th percentile of 82.3 ± 4.3 and 67.8 ± 3.5 g, respectively. Compared to non-consumers, beef consumers had a 10% or higher intake of calcium, iron, phosphorus, potassium, total choline, vitamin B12, and zinc. Over 50% of the adolescent population (regardless of beef consumption) had intakes below the EAR for calcium, magnesium, and vitamins A, C, D, and E. The percentage of the beef-consuming population below the EAR was lower for calcium, copper, folate, iron, phosphorus, zinc, and vitamins B12 and B6 as compared to non-consumers. Additionally, the portion of the population above the AI for sodium was higher in female beef consumers as compared to non-consumers. We estimate approximately 900,000 to 1,400,000, 400,000-700,000, 200,000-600,000, and 200,000-400,000 fewer adolescents to be below the EAR for zinc, phosphorus, vitamin B12, and iron, respectively if beef non-consumers were to consume beef. This study suggests beef can help increase the nutrient intake and nutrient adequacy in the diets of adolescents, helping to close important gaps for this nutritionally vulnerable population. While recommendations to reduce beef intake are widely prevalent, this could result in unintended nutritional consequences regarding under-consumed nutrients including those of public health concern important for adolescent health.

Combining Feature Selection Techniques and Neurofuzzy Systems for the Prediction of Total Viable Counts in Beef Fillets Using Multispectral Imaging

In the food industry, quality and safety issues are associated with consumers' health condition. There is a growing interest in applying various noninvasive sensorial techniques to obtain quickly quality attributes. One of them, hyperspectral/multispectral imaging technique has been extensively used for inspection of various food products. In this paper, a stacking-based ensemble prediction system has been developed for the prediction of total viable counts of microorganisms in beef fillet samples, an essential cause to meat spoilage, utilizing multispectral imaging information. As the selection of important wavelengths from the multispectral imaging system is considered as an essential stage to the prediction scheme, a features fusion approach has been also explored, by combining wavelengths extracted from various feature selection techniques. Ensemble sub-components include two advanced clustering-based neuro-fuzzy network prediction models, one utilizing information from average reflectance values, while the other one from the standard deviation of the pixels' intensity per wavelength. The performances of neurofuzzy models were compared against established regression algorithms such as multilayer perceptron, support vector machines and partial least squares. Obtained results confirmed the validity of the proposed hypothesis to utilize a combination of feature selection methods with neurofuzzy models in order to assess the microbiological quality of meat products.

The Intrinsic and Instrumental Values of Blockchain to Provide Beef Traceability in Hong Kong, South Korea, and the United States

Although previous research has identified that consumers are willing to pay for traceability, it remains unknown which types of traceability information might have the highest value, and whether consumers have an intrinsic value for blockchain technology above and beyond the instrumental value of providing traceability. A choice experiment was conducted with over 1500 consumers in Hong Kong, South Korea, and the U.S. In all three countries, consumers were willing to pay premiums for beef with traceability related to all parts of the supply chain, country of origin, and temperature history; however, the preference ordering of beef from different countries varied across Hong Kong, South Korea, and the U.S. The intrinsic value of using blockchain to deliver traceability information differed by country and by attribute, and consumers in the U.S. were most sensitive to the information describing blockchain technology. Even when traceability conveys negative information, such as temperature rising above safe levels for a short period, we find that consumers prefer knowing to not knowing, suggesting uncertainty and ambiguity aversion.

Mitigation of the U.S. agrifood sector's contribution to human and planetary health: a case study

The relationship of the United States (U.S.) agrifood sector to climate change is bidirectional; cattle production for beef consumption generates methane and nitrous oxide, both of which are potent greenhouse gases (GHGs). These gases contribute to global warming which in turn increase the frequency and strength of adverse catastrophic events, which compromise the food supply. Increased GHGs also affect crop yields and the micronutrient content of crops, which adversely affect the prevalence of food and nutrition insecurity, particularly in low- and middle-income countries. Because the U.S. is a major contributor to global warming, we have a special responsibility to reduce our contribution to the generation of GHGs. The dilemma is that beef is a highly nutritious and desirable food, with excess consumption in the U.S. and under consumption in other parts of the world, but a desirable source of nutrients in low- and middle-income countries (LMICs). Reductions in fossil fuels have been a major focus of concern, and the agrifood system has been largely ignored. Policy changes to reduce beef consumption have been resisted at the highest levels of government. Furthermore, shifts to more plant-based diets have been contentious. Successful reductions in beef consumption will require individual, institutional, municipal, and state initiatives. Building the political will for change will require a compelling communication campaign that emphasizes the unsustainable contribution of beef consumption to climate change and land and water use.

Investigation of the Suitability of a Combination of Ethyl-Να-dodecanyl-L-arginat_HCl (LAE) and Starter Culture Bacteria for the Reduction of Bacteria from Fresh Meat of Different Animal Species

Meat can be contaminated with (pathogenic) microorganisms during slaughter, dissection and packaging. Therefore, preservation technologies are frequently used to reduce the risk of (fatal) human infections due to the consumption of meat. In this study, we first investigated, if the application of ethyl-Nα-dodecanyl-L-arginate hydrochloride (LAE) and the starter culture bacteria Staphylococcus carnosus and Lactobacillus sakei, either single or in combination, influences the bacteria number on pork, chicken meat and beef, inoculated with Brochothrix (Br.) thermosphacta (all meat species) or Salmonella (S.) Typhimurium (pork), Campylobacter (C.) jejuni (chicken) and Listeria (L.) monocytogenes (beef), before packaging under modified atmosphere and on days 7 and 14 of storage. To evaluate effects of the treatment on the appearance during storage, additionally, the physicochemical parameters color and myoglobin redox form percentages were analyzed. LAE regularly resulted in a significant reduction of the number of all bacteria species on day 1 of storage, whereas up to day 14 of storage, the preservation effect did not persist in nearly all samples, except in the beef with Br. thermosphacta. However, with the starter culture bacteria on day 1, only L. monocytogenes on beef was significantly reduced. Interestingly, on day 7 of storage, this reducing effect was also found with S. Typhimurium on pork. Br. thermosphacta, which was principally not influenced by the starter culture bacteria. The combinatory treatment mainly resulted in no additional effects, except for the S. Typhimurium and Br. thermosphacta results on pork on day 7 and the Br. thermosphacta results on beef on day 14. The physicochemical parameters were not influenced by the single and combinatory treatment. The results indicate that LAE was mainly responsible for the antimicrobial effects and that a combination with starter culture bacteria should be individually evaluated for the meat species.

Higher Muscle Protein Synthesis Rates Following Ingestion of an Omnivorous Meal Compared with an Isocaloric and Isonitrogenous Vegan Meal in Healthy, Older Adults

BACKGROUND

Plant-derived proteins are considered to have fewer anabolic properties when compared with animal-derived proteins. The anabolic properties of isolated proteins do not necessarily reflect the anabolic response to the ingestion of whole foods. The presence or absence of the various components that constitute the whole-food matrix can strongly impact protein digestion and amino acid absorption and, as such, modulate postprandial muscle protein synthesis rates. So far, no study has compared the anabolic response following ingestion of an omnivorous compared with a vegan meal.

OBJECTIVES

This study aimed to compare postprandial muscle protein synthesis rates following ingestion of a whole-food omnivorous meal providing 100 g lean ground beef with an isonitrogenous, isocaloric whole-food vegan meal in healthy, older adults.

METHODS

In a randomized, counter-balanced, cross-over design, 16 older (65-85 y) adults (8 males, 8 females) underwent 2 test days. On one day, participants consumed a whole-food omnivorous meal containing beef as the primary source of protein (0.45 g protein/kg body mass; MEAT). On the other day, participants consumed an isonitrogenous and isocaloric whole-food vegan meal (PLANT). Primed continuous L-[ring-13C6]-phenylalanine infusions were applied with blood and muscle biopsies being collected frequently for 6 h to assess postprandial plasma amino acid profiles and muscle protein synthesis rates. Data are presented as means ± standard deviations and were analyzed by 2 way-repeated measures analysis of variance and paired-samples t tests.

RESULTS

MEAT increased plasma essential amino acid concentrations more than PLANT over the 6-h postprandial period (incremental area under curve 87 ± 37 compared with 38 ± 54 mmol·6 h/L, respectively; P-interaction < 0.01). Ingestion of MEAT resulted in ∼47% higher postprandial muscle protein synthesis rates when compared with the ingestion of PLANT (0.052 ± 0.023 and 0.035 ± 0.021 %/h, respectively; paired-samples t test: P = 0.037).

CONCLUSIONS

Ingestion of a whole-food omnivorous meal containing beef results in greater postprandial muscle protein synthesis rates when compared with the ingestion of an isonitrogenous whole-food vegan meal in healthy, older adults. This study was registered at clinicaltrials.gov as NCT05151887.

Dietary Exposure and Risk Assessment of Beta-Agonist Residues in Commercial Beef and Pork in Taiwan

Beta-agonists (β-agonists) in meat products in one's diet raise concerns about the possibility of foodborne illness. It may also lead to discomfort, such as headaches and occasional irregular heartbeats, which might be linked to a heightened concern for cardiovascular issues. Taiwan's high demand for meat and reliance on imported meat products from certain countries where β-agonists are permitted has raised concerns. Recent import border checks and monitoring of meat products in the market have revealed the concentration of non-compliance with β-agonist residue regulations, which is ten ppb. This study aims to analyze the concentration of β-agonist residues in meat products sold in Taiwan and assess the current levels of exposure and dietary risk for consumers. The study analyzed 1415 samples of domestically produced and imported livestock products from supermarkets, traditional markets, and bulk stores in New Taipei City between 2019 and 2023. The samples were analyzed using the method for detecting 21 β-agonists based on the Taiwan Food and Drug Administration's specifications. Estimated daily intake (EDI) of β-agonists for different age groups and the target hazard quotient (THQ) were used to assess dietary exposure and risk. The results showed that all 1415 samples were compliant with regulations. Among them, 43 beef samples showed residues of ractopamine originating from the United States, with residue concentrations ranging from 1 to 10 μg/kg and an average residue concentration of 3.3 ± 1.9 μg/kg. Under average consumption, the highest EDI for the exposed population was observed in the 6-12 age group, with values of 0.1469 μg/kg/day, 0.0734 μg/kg/day, and 0.0242 μg/kg/day for the three residue concentrations (maximum detected residue, maximum allowable residue, and average detected residue, respectively). The THQs for ractopamine in imported beef samples were all less than 1, indicating no health hazards at the current intake levels of each age group and the residue concentrations in commercially available beef. Despite the findings, traders need to acknowledge regulatory variations between Taiwan and exporting countries when importing meat products. Traders should provide inspection reports to monitor β-agonist residue levels in imports or explore sourcing beef from countries with β-agonist bans.

A survey of Kansas beef producers and consumers who participate in business-to-consumer marketing of beef

Following the coronavirus disease 2019 (COVID-19) pandemic, producer and consumer interest in business-to-consumer (B2C) beef sales increased. The objective of the current study was to assess current B2C beef producer and consumer attitudes and understandings of the B2C beef marketing process in order to identify knowledge gaps and strategies to improve producer/consumer interactions. Both producers and customers of local beef were recruited using a large online platform (https://shopkansasfarms.com), and descriptive statistics were used to summarize the data. In total, 41 B2C beef producers and 174 consumers who had either previously participated in B2C marketing or intended to participate were surveyed. Most producers (69.8%) only produced beef and produced only a small number (1 to 20 head) of animals per year. Many (43.9%) reported selling 100% of beef directly to consumers, while 29.3% reported selling less than 20% through this channel. Almost all (97.3%) of the producers indicated that increased sales directly to consumers would be desirable, with most (87.1%) considering this marketing channel as the most profitable. Marketing beef in smaller portions, including portioned cuts, was popular, reported by more than 62% of producers, while whole carcass sales were lower. Word-of-mouth (91.3%) and social media (65.8%) were the most popular forms of advertisement used by producers and more than one-third of producers (38.9%) reported having trouble with customers regarding a sale. Over 60% of consumers indicated they had purchased B2C beef less than 5 times, with more than 73% indicating that more than 75% of their beef purchased was local. Low take-home weights, portion sizes, and quality were among consumers' most cited troubles. Lack of freezer space (25%), price (24.9%), and quantity of product (41.7%) were reported as the largest barriers to consumer participation in B2C marketing. Both consumers and producers indicated that consumer testimonials would be the most beneficial in improving producer/consumer interactions, with educational materials from government sources viewed as the least beneficial. These results provide a baseline for B2C beef marketing and provide insight into impactful strategies to use to assist in this process.

Increased Cattle Feeding Precision from Automatic Feeding Systems: Considerations on Technology Spread and Farm Level Perceived Advantages in Italy

Automation reduces the impact of farming on climate change and helps farmers adapt to its financial impact. Automatic feeding systems (AFSs) increase the ruminant's feeding precision and ease operators' workload. Such systems exist on a spectrum, requiring varied levels of operator support and installation complexity. A recent survey on farmers pointed out that those already running an AFS and those willing to buy one appreciate its ease of use, the resulting animal welfare, and the resulting overall benefits (increased production, farm profitability, and reduced feed waste). Whether technologically complex or not, studies have confirmed the benefits that farmers perceive to be underlying the remarkable reduction in the environmental impact of feeding operations (AFSs are electrically powered), the increase in animal welfare resulting from reduced conflicts around accessing the feed bunk, and the constant availability of fresh feed. However, their introduction should follow accurate and holistic structural and economic planning for existing and newly built facilities. The availability of public subsidies plays an essential role in pushing farmers to adopt the most modern digital technologies, whose benefits may even increase when farmers couple them with interconnected sensors to monitor animals' physiological states.

Microbiological Quality of Australian Beef, Sheep and Pork Carcases, Cuts and Offals

A one-year survey was undertaken of the microbiological quality of carcases and the derived primal cuts, manufacturing meat and offals at twelve Australian export establishments (six beef, three sheep/lamb and three pork). A total of 27,157 microbiological results for aerobic plate count (APC) and generic Escherichia coli were gathered, 15,155 from beef, 8405 from sheep and 3597 from pig establishments. The mean log10 APCs on beef, sheep and pig carcases were 0.84, 1.60 and 1.30 log10 cfu/cm2, respectively. For primals, the mean log10 APC was higher for beef but was similar for sheep and pork primals, with 'outside' cuts having higher counts. For manufacturing meat, the concentration was 2-3 log10 cfu/g, irrespective of species. The prevalence (%) of generic E. coli from beef, sheep and pork was 2.3, 28.4 and 5.4 on carcases; 7.0, 20.6 and 3.2 on primals; and 5.8, 33.6 and 6.1 on manufacturing meat, respectively. The mean log10 APCs of beef, sheep and pork offal were 3.23, 3.18 and 3.37 log10 cfu/g, with tripes and tongues having APCs 1-2 log10 units higher than organ offals. The results reflect improvements in total bacterial loadings compared with previous national baseline surveys.

Marinades Based on Natural Ingredients as a Way to Improve the Quality and Shelf Life of Meat: A Review

Marinating is a traditional method of improving the quality of meat, but it has been modified in response to consumer demand for "clean label" products. The aim of this review is to present scientific literature on the natural ingredients contained in marinades, the parameters of the marinating process, and certain mechanisms that bring about changes in meat. A review was carried out of publications from 2000 to 2023 available in Web of Science on the natural ingredients of meat marinades: fruit and vegetables, seasonings, fermented dairy products, wine, and beer. The review showed that natural marinades improve the sensory quality of meat and its culinary properties; they also extend its shelf life. They affect the safety of meat products by limiting the oxidation of fats and proteins. They also reduce biogenic amines and the formation of heterocyclic aromatic amines (HAAs) and polycyclic aromatic hydrocarbons (PAHs). This is possible due to the presence of biologically active substances and competitive microflora from dairy products. However, some marinades, especially those that are acidic, cause a slightly acidic flavour and an unfavourable colour change. Natural compounds in the ingredients of marinades are accepted by consumers. There are no results in the literature on the impact of natural marinades on the nutritional value and health-promoting potential of meat products, so it can be assumed that this is a future direction for scientific research.

Effects of Silage Type and Feeding Intensity on Carcass Traits and Meat Quality of Finishing Holstein-Friesian Bulls

The study aimed at evaluating the influence of silage type (grass silage-GS, and maize silage-MS) and energy level in the feed portion on animals' performance, carcass value and the quality of Holstein-Friesian bull meat. The animals were reared using intensive (I) feeding, 1.02 feed units for meat production (UFV)/kg dry matter (DM), and semi-intensive (SI) feeding, 0.94 UFV/kg DM. Thirty-two HF bulls with an average live weight of 530 kg were assigned to four feeding groups. The proportions (g/kg DM) of feed in the diets were as follows: group GS-I, GS 500, concentrate 500; group GS-SI, GS 700, concentrate 300; group MS-I, MS 500, concentrate 500; and group MS-SI, MS 700, concentrate 300. After 4 months of the finishing phase, bulls were slaughtered and samples of the longissimus lumborum muscle were collected. The silage type did not affect performance, carcass value or meat quality. However, in the intensive feeding, a 33% increase (p < 0.01) in daily weight gain and a reduction in the feed conversion ratio compared to semi-intensive feeding were noted. The carcasses of bulls fed intensively received higher scores for conformation and fatness than the carcasses of bulls fed semi-intensively. The meat of I group bulls had a higher intramuscular fat content and received higher juiciness, tenderness, taste and overall acceptability scores.

Measuring the Phytochemical Richness of Meat: Effects of Grass/Grain Finishing Systems and Grapeseed Extract Supplementation on the Fatty Acid and Phytochemical Content of Beef

Grass-finished beef (GFB) can provide beneficial bioactive compounds to healthy diets, including omega-3 polyunsaturated fatty acids (n-3 PUFAs), conjugated linoleic acid (CLA), and secondary bioactive compounds, such as phytochemicals. The objective of this study was to compare fatty acids (FAs), micronutrients, and phytochemicals of beef fed a biodiverse pasture (GRASS), a total mixed ration (GRAIN), or a total mixed ration with 5% grapeseed extract (GRAPE). This was a two-year study involving fifty-four Red Angus steers (n = 54). GFB contained higher levels of n-3 PUFAs, vitamin E, iron, zinc, stachydrine, hippuric acid, citric acid, and succinic acid than beef from GRAIN and GRAPE (p < 0.001 for all). No differences were observed in quantified phytochemicals between beef from GRAIN and GRAPE (p > 0.05). Random forest analysis indicated that phytochemical and FA composition of meat can predict cattle diets with a degree of certainty, especially for GFB (5.6% class error). In conclusion, these results indicate that GFB contains higher levels of potentially beneficial bioactive compounds, such as n-3 PUFAs, micronutrients, and phytochemicals, compared to grain-finished beef. Additionally, the n-6:n-3 ratio was the most crucial factor capable of separating beef based on finishing diets.

The Oxidative and Color Stability of Beef from Steers Fed Pasture or Concentrate during Retail Display

Beef production in Uruguay is based on pasture (~85%) or concentrate (~15%), resulting in differences in meat quality. The objective of this study was to compare the oxidative stability and color of beef from these two systems during refrigerated retail display. For these purposes, the Semimembranosus muscle was removed from ten Aberdeen Angus steers raised and fed on pasture (130 days prior to slaughter) and from another ten steers fed concentrate (100 days prior to slaughter), sliced. The muscles were placed in a refrigerated showcase for 3, 6, and 9 days. The contents of β-carotene, α-tocopherol, and fatty acids were determined before the meat was placed on display. Lipid and protein oxidation, color, and heme iron content were determined before and during display. The meat from pasture-fed steers had a lower intramuscular fat content (1.78 ± 0.15 vs. 4.52 ± 0.46), lower levels of monounsaturated fatty acids, a lower n-6/n-3 ratio, less lipid and protein oxidation, lower L* and a* values, and higher levels of α-linolenic acid, DHA, total n-3, β-carotene, and α-tocopherol. In conclusion, the meat from pasture-fed steers was more stable during retail display from an oxidative point of view, which may be due to its higher levels of antioxidant compounds such as β-carotene and α-tocopherol and had a healthier fatty acid profile for consumers.

Antimicrobial Effects and Antioxidant Activity of Myrtus communis L. Essential Oil in Beef Stored under Different Packaging Conditions

The aim of this study was to assess the antimicrobial effects of myrtle (Myrtus communis L.) essential oil (EO) on pathogenic (E. coli O157:H7 NCTC 12900; Listeria monocytogenes ATCC BAA-679) and spoilage microbiota in beef and determine its minimum inhibitory concentration (MIC) and antioxidant activity. The behavior of LAB, Enterobacteriaceae, Pseudomonas spp., and fungi, as well as total mesophilic (TM) and total psychotropic (TP) counts, in beef samples, was analyzed during storage at 2 and 8 °C in two different packaging systems (aerobiosis and vacuum). Leaves of myrtle were dried, its EO was extracted by hydrodistillation using a Clevenger-type apparatus, and the chemical composition was determined using chromatographical techniques. The major compounds obtained were myrtenyl acetate (15.5%), β-linalool (12.3%), 1,8-cineole (eucalyptol; 9.9%), geranyl acetate (7.4%), limonene (6.2%), α-pinene (4.4%), linalyl o-aminobenzoate (5.8%), α-terpineol (2.7%), and myrtenol (1.2%). Myrtle EO presented a MIC of 25 µL/mL for E. coli O157:H7 NCTC 12900, E. coli, Listeria monocytogenes ATCC BAA-679, Enterobacteriaceae, and E. coli O157:H7 ATCC 35150 and 50µL/mL for Pseudomonas spp. The samples packed in aerobiosis had higher counts of deteriorative microorganisms than samples packed under vacuum, and samples with myrtle EO presented the lowest microbial contents, indicating good antimicrobial activity in beef samples. Myrtle EO is a viable natural alternative to eliminate or reduce the pathogenic and deteriorative microorganisms of meat, preventing their growth and enhancing meat safety.

Prevalence and characterization of quinolone-resistant Escherichia coli isolated from retail raw beef and poultry meat in Egypt

Objective

The goal of this study was to look at quinolone-resistant (QR) Escherichia coli (E. coli) from retail beef and poultry meat in Egypt by looking at the QR mechanisms in the resistant strains.

Materials and Methods

In total, 120 samples of raw poultry meat (n = 60) and beef meat (n = 60) were purchased from Mansoura retail stores between January and March 2021, and evaluated microbiologically for E. coli. Then, an antimicrobial sensitivity test was applied to all isolates. The prevalence of QR E. coli with concern for the QR determinants, including quinolone resistance-determining regions (QRDRs) mutations, the plasmid-mediated quinolone resistance gene (PMQR), and the efflux pump activity were determined.

Results

The total prevalence of E. coli was 34.2% (41/120). Noticeably, the prevalence of E. coli in poultry meat (40%, 24/60) was higher than that of beef (28%, 17/60). All strains were assessed for their antimicrobial susceptibility using the disc diffusion technique; the highest rate of resistance (100%) was displayed to clindamycin and cefuroxime, followed by ampicillin (97.6%), doxycycline (92.7%), amoxicillin-clavulanate (92.7%), nalidixic acid (NA) (80.5%), sulfamethoxazole/trimethoprim (70.7%), chloramphenicol (63.4%), gentamicin, and azithromycin (58.5% each). Multiple antimicrobial resistance (strains resistant to three or more antimicrobial classes) was displayed by 97.6% of E. coli isolates. Regarding QR, 37 isolates could resist at least one of the examined quinolones. Regarding PMQR genes, qnrS was determined in 70% (7/10) of QR E. coli, while qnrA, qnrB, and qnrD were not identified. While the mutations determined regions of QR in the resistant E. coli isolates, S83L was the most prevalent in gyrase subunit A either alone or combined with D87N and D87Y, and three isolates of QR E. coli isolates revealed a topoisomerase IV subunit mutation harboring S80I. 20% of the isolates displayed efflux activity, as NA showed a considerable difference between its zones of inhibition.

Conclusion

The high prevalence of antimicrobial-resistant E. coli, with concern for QR strains harboring different resistance mechanisms in poultry meat and beef, threatens the public's health. Thus, standard manufacturing procedures and adequate hygiene conditions must be followed in all phases of meat preparation, production, and consumption, and public knowledge should be improved.

Influence of Ageing Time and Method on Beef Quality and Safety

The effectiveness of dry ageing with regard to retaining meat quality is still subject to debate. At 4 d post mortem, samples of boneless strip loins were excised from young Charolais carcasses and then stored for a further 26 d in a cooler, either vacuum-packaged (VP) or dried-aged (DA). Loin samples were also dissected 7 d post mortem as a control treatment (CT). Chemical, instrumental and microbiological data (n = 18) were determined in longissimus dorsi and underwent ANOVA to estimate the differences in the ageing fixed factor split into two orthogonal contrasts: control vs. aged and VP vs. DA. Ageing loss (both surface dehydration and water purge) was greater in DA compared to VP samples, resulting in the lowest moisture content and highest crude protein and fat percentage in DA loins. The ageing method did not affect meat surface colour, except for redness, which had the lowest value in DA samples. Meat tenderness improved a similar amount following both VP and DA ageing treatments. Compared to the control, prolonged ageing raised both the peroxide value and the total microbial count, especially in DA samples, though both remained within the recommended limits. In summation, both ageing methods improved beef meat tenderisation, preserving its shelf life.

Sous-Vide as an Alternative Method of Cooking to Improve the Quality of Meat: A Review

Sous-vide (SV) is a method of cooking previously vacuum-packed raw materials under strictly controlled conditions of time and temperature. Over the past few years, scientific articles have explored the physical, biochemical, and microbiological properties of SV cooking. In this review, we provide a critical appraisal of SV as an alternative method of meat cooking, including the types of methods, types of SV meat products, and effects of SV parameters on the meat quality and the mechanisms of transformation taking place in meat during SV cooking. Based on the available data, it can be concluded that most research on the SV method refers to poultry. The yield of the process depends on the meat type and characteristics, and decreases with increasing temperature, while time duration does not have an impact. Appropriate temperatures in this method make it possible to control the changes in products and affect their sensory quality. Vacuum conditions are given a minor role, but they are important during storage. The limited number of studies on the approximate composition of SV meat products makes it challenging to draw summarizing conclusions on this subject. The SV method allows for a higher microbiological quality of stored meat than conventional methods. The literature suggests that the SV method of preparing beef, pork, and poultry has many advantages.