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The objective of this exploratory study was to assess the changes on lipidome and metabolome profiling of Longissimus lumborum bull muscle with different ultimate pH (pHu) and aging periods. The bull muscles classified as normal, intermediate, or high pHu were collected from a Brazilian commercial slaughterhouse, cut into steaks, individually vacuum-packaged, and aged for 3 days (3-d) or 21 days (21-d) at 2 °C. Muscle extracts were analyzed for the profiles of both lipids, by mass spectrometry (via direct flow-injection), and metabolites, by nuclear magnetic resonance, with downstream multivariate data analysis. As major results, pairwise comparisons identified C12:0 and C14:0 acylcarnitines as potential biomarkers of the intermediate pHu-muscle, which are related to lipid catabolism for alternative energy metabolism and indicate less protein breakage postmortem. Interestingly, the concentration of arginine at early postmortem aging (3-d) may influence the previously reported improved tenderness in normal and high pHu-muscles. Moreover, upregulation of fumarate, formate, and acetate with increased pHu muscle at 21-d aging indicate more intense tricarboxylic acid cycle, amino acid degradation, and pyruvate oxidation by reactive oxygen species, respectively. These three compounds (fumarate, formate, and acetate) discriminated statistically the muscle with high pHu at 21-d aging. The normal pHu-muscle showed higher concentrations of glycogenolysis and glycolysis metabolites, including glucose, mannose, and pyruvate. Hence, our results enhance knowledge of postmortem biochemical changes of beef within different pHu groups aged up to 21 days, which is essential to understand the mechanisms underpinning bull meat quality changes.

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This study aimed to evaluate the thermal performance and meat quality in broilers reared in positive pressure tunnel ventilation (PP) and negative pressure tunnel ventilation (NP) in production houses. 320 Cobb broilers (40 broilers per house) were used. Pectoralis major muscles from 40 broilers (10 broilers per house) were randomly selected and analysed for L* (lightness), a* (redness), b* (yellowness), pH, drip loss (DL), cooking loss (CL) and shear force (SF). Air temperature and humidity of the transportation and slaughterhouse waiting room were recorded in the last week of rearing. Subsequently, the enthalpy comfort index (ECI) was calculated. Air temperature and ECI were higher (p < 0.05) in positive pressure sheds, whereas relative humidity was higher (p < 0.001) in negative pressure sheds. There was no statistically significant difference between the enthalpy comfort index during transport and lairage (p > 0.005). Meat quality defects (high L*, DL, CL, SF) were found in PP and NP. It was observed that b* was higher in PP, although pH and CL were higher in NP. Differences in pH, b* and CL indicate that broilers from PP had a higher level of heat stress. In conclusion, differences in pH, b*value and cooking loss in breast broilers indicate that birds in PP had a higher level of heat stress. Additional studies investigating pre-slaughter handling methods to minimise injuries and heat stress are recommended in order to improve animal welfare and meat quality.

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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.

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Objectives: The spread of extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) and carbapenem-resistant Enterobacterales (CRE) has resulted in increased morbidity, mortality, and health care costs worldwide. To identify the factors associated with ESCrE and CRE colonization within hospitals, we enrolled hospitalized patients at a regional hospital located in Guatemala. Methods: Stool samples were collected from randomly selected patients using a cross-sectional study design (March-September, 2021), and samples were tested for the presence of ESCrE and CRE. Hospital-based and household variables were examined for associations with ESCrE and CRE colonization using lasso regression models, clustered by ward (n = 21). Results: A total of 641 patients were enrolled, of whom complete data sets were available for 593. Colonization with ESCrE (72.3%, n = 429/593) was negatively associated with carbapenem administration (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.11-0.42) and positively associated with ceftriaxone administration (OR 1.61, 95% CI 1.02-2.53), as was reported hospital admission within 30 days of the current hospitalization (OR 2.84, 95% CI 1.19-6.80). Colonization with CRE (34.6%, n = 205 of 593) was associated with carbapenem administration (OR 2.62, 95% CI 1.39-4.97), reported previous hospital admission within 30 days of current hospitalization (OR 2.58, 95% CI 1.17-5.72), hospitalization in wards with more patients (OR 1.05, 95% CI 1.02-1.08), hospitalization for ≥4 days (OR 3.07, 95% CI 1.72-5.46), and intubation (OR 2.51, 95% CI 1.13-5.59). No household-based variables were associated with ESCrE or CRE colonization in hospitalized patients. Conclusion: The hospital-based risk factors identified in this study are similar to what has been reported for risk of health care-associated infections, consistent with colonization being driven by hospital settings rather than community factors. This also suggests that colonization with ESCrE and CRE could be a useful metric to evaluate the efficacy of infection and prevention control programs in clinics and hospitals.

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This study aimed to investigate the incorporation of micronized salt (MS) to reduce sodium content in fresh sausages while preserving technological, chemical, textural, and sensory characteristics. Four treatments were prepared: control (C) with 2.0% regular salt; M2.0% with 2.0% micronized salt; M1.5% with 1.5% micronized salt; and M1.0% with 1.0% micronized salt, containing 1004, 1133, 860, and 525 mg of sodium/100 g of product, respectively. To characterize the samples, analyses of sodium content, cooking loss, relative myoglobin content, and instrumental color were carried out. The sensory analysis was performed using the Temporal-Check-All-That-Apply (TCATA) method. Half of the micronized salt treatment was mixed with the fat during the processing of the fresh sausages. It was possible to achieve a 50% reduction in sodium (M1.0%) in the fresh sausages without negative effects on most technological, chemical, and textural parameters, which did not differ from the control treatment (C). Conversely, "chewiness" decreased in M2.0% compared to the control (C) due to mixing micronized salt with the fat. The sodium reduction did not impact the temporal sensory profile and overall liking. Therefore, using micronized salt in fresh sausages reduces sodium content without affecting sensory traits and product stability.

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Bos taurus indicus bulls are very susceptible to pre-slaughter stress, which directly impacts the decline in muscle pH, leading to darker meat. The aim was to investigate the effect of succinate and atmosphere on the color stability of Nellore (Bos taurus indicus) Longissimus lumborum steaks classified by ultimate pH (pHu): normal pHu (5.40 ≤ pHu ≤ 5.79) and high pHu (pHu ≥ 5.80). The experimental treatment systems were: (i) vacuum packaging without succinate injection, (ii) HiOx-MAP (80 % O2 + 20 % CO2), and (iii) HiOx-MAP (80 % O2 + 20 % CO2) enhanced with sodium succinate injection (pH 5.4). Steaks from all treatment systems were stored at 4 °C for 14 days and tested for instrumental color, myoglobin content, oxygen consumption (OC), metmyoglobin-reducing activity (MRA), lipid oxidation, and microbiological analysis. High and normal pHu vacuum-packaged steaks exhibited greater color stability due to higher MRA. High and normal pHu steaks packaged with HiOx-MAP or HiOx-MAP enhanced with succinate showed improved color due to lower deoxymyoglobin content (%DMb) and OC up to the eighth day of storage. Still, succinate injection promoted increased (P < 0.05) lipid oxidation in normal pHu steaks and reduced MRA after 14 days. These findings emphasize the intricate interplay between pHu and packaging systems on Bos taurus indicus meat quality. Further research in this area could contribute to a better understanding of meat color abnormalities and provide insights into potential meat preservation and enhancement strategies.

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Despite the relatively high occurrence of bovine meat with intermediate to high ultimate pH (pHu), there is a lack of studies focused on the effects of long-term conventional air-blasting freezing storage on quality parameters of commercial beefs of Zebu Nellore (Bos indicus) with varying pHu ranges. The objective of this work was to evaluate the influence of pHu ranges [normal (≤5.79), intermediate (5.80 to 6.19), and high (≥6.20)] and long-term frozen storage on quality parameters of aged Longissimus dorsi beefs of Zebu Nellore (Bos indicus). The aging conditions were set at 2 °C for 14 days, while the freezing conditions were set at - 20 °C, and samples were collected after 3, 6, 9, and 12 months of storage. The results indicated that the pHu influenced meat quality parameters, as well as the chemical forms of myoglobin, which changed throughout the frozen storage, leading to a brighter red color, especially for the normal pHu beef samples, likely due to increased oxymyoglobin content. Frozen storage improved tenderness, with high pHu beef samples being the more tender after 12 months, potentially due to lower protein oxidation, as measured by the carbonyl content. Increased drip loss was observed over freezing time, with a concomitant decrease in protein solubility, especially for myofibrillar and sarcoplasmic proteins, which differed among the pHu ranges. These findings are valuable for determining freezing time as a preservation strategy to maintain beef quality within different pHu ranges.

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This study estimates the shelf life of vacuum packed beef meat (three muscles: striploin (longissimus thoracis et lumborum, LTL), tenderloin (psoas major, PM) and outside chuck (trapezius thoracis, TT)) at refrigeration temperatures (0 °C-10 °C) based on modelling the growth of two relevant groups of spoilage microorganisms: lactic acid bacteria (LAB) and Enterobacteriaceae. The growth models were developed combining a two-step and a one-step approach. The primary modelling was used to identify the parameters affecting the growth kinetics, guiding the definition of secondary growth models. For LAB, the secondary model included the effect of temperature and initial pH on the specific growth rate. On the other hand, the model for Enterobacteriaceae incorporated the effect of temperature on the specific growth rate and the lag phase; as well as the effect of the initial pH on the specific growth rate, the lag phase and the initial microbial count. We did not observe any significant effect of the type of muscle on the growth kinetics. Once the equations were defined, the models were fitted to the complete dataset using a one-step approach. Model validation was carried out by cross-validation, mitigating the impact of an arbitrary division between training and validation sets. The models were used to estimate the shelf life of the product, based on the maximum admissible microbial concentration (7 log CFU/g for LAB, 5 log CFU/g for Enterobacteriaceae). Although LAB was the dominant microbiota, in several cases, both LAB and Enterobacteriaceae reached the critical concentration practically at the same time. Furthermore, in some scenarios, the end of shelf life would be determined by Enterobacteriaceae, pointing at the potential importance of non-dominant microorganisms for product spoilage. These results can aid in the implementation of effective control measures in the meat processing industry.

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BACKGROUND: We estimated the prevalence of colonization with extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) and carbapenem-resistant Enterobacterales (CRE) from a hospital and associated communities in western Guatemala. METHODS: Randomly selected infants, children, and adults (<1, 1-17, and ≥18 years, respectively) were enrolled from the hospital (n = 641) during the coronavirus disease 2019 (COVID-19) pandemic, March to September 2021. Community participants were enrolled using a 3-stage cluster design between November 2019 and March 2020 (phase 1, n = 381) and between July 2020 and May 2021 (phase 2, with COVID-19 pandemic restrictions, n = 538). Stool samples were streaked onto selective chromogenic agar, and a Vitek 2 instrument was used to verify ESCrE or CRE classification. Prevalence estimates were weighted to account for sampling design. RESULTS: The prevalence of colonization with ESCrE and CRE was higher among hospital patients compared to community participants (ESCrE: 67% vs 46%, P < .01; CRE: 37% vs 1%, P < .01). Hospital ESCrE colonization was higher for adults (72%) compared with children (65%) and infants (60%) (P < .05). Colonization was higher for adults (50%) than children (40%) in the community (P < .05). There was no difference in ESCrE colonization between phase 1 and 2 (45% and 47%, respectively, P > .05), although reported use of antibiotics among households declined (23% and 7%, respectively, P < .001). CONCLUSIONS: While hospitals remain foci for ESCrE and CRE colonization, consistent with the need for infection control programs, community prevalence of ESCrE in this study was high, potentially adding to colonization pressure and transmission in healthcare settings. Better understanding of transmission dynamics and age-related factors is needed.

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NO2 is one of the main greenhouse gases, which is mainly generated by the combustion of fossil fuels. In addition to its contribution to global warming, this gas is also directly dangerous to humans. The present work reports the structural and gas sensing properties of the CaCu3Ti4O12 compound prepared by the sol-gel technique. Rietveld refinement confirmed the formation of the pseudo-cubic CaCu3Ti4O12 compound, with less than 4 wt% of the secondary phases. The microstructural and elemental composition analysis were carried out using scanning electron microscopy and X-ray energy dispersive spectroscopy, respectively, while the elemental oxidation states of the samples were determined by X-ray photoelectron spectroscopy. The gas sensing response of the samples was performed for different concentrations of NO2, H2, CO, C2H2 and C2H4 at temperatures between 100 and 300 °C. The materials exhibited selectivity for NO2, showing a greater sensor signal at 250 °C, which was correlated with the highest concentration of nitrite and nitrate species on the CCTO surface using DRIFT spectroscopy.