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Natural plant extracts have been widely used in the food industry in recent years as natural colourants, antioxidants and antimicrobials due to consumer health concerns. In this study, the effects of different levels of black carrot water extract (BCWE) (control without BCWE, 100, 200 and 300 ppm) on metmyoglobin (MetMb), lipid oxidation, colour and microbial counts of vacuum‐packed ground beef were evaluated during chilled storage for 15 days. MetMb, pH, lipid oxidation, redness (a*) values and microbial counts of ground beef were significantly (p < 0.01) affected by BCWE treatment. During storage, the lowest lipid oxidation values were determined in the BCWE groups (p < 0.05). BCWE groups had higher a* values and lower MetMb content at the end of storage than control. BCWE contributed to reduce the growth of Enterobacteriaceae. The 200‐ppm BCWE group had approximately 2 log units lower Enterobacteriaceae counts at the end of storage compared to the control. These results showed that the anthocyanin‐rich BCWE is a promising natural additive to overcome the problems in vacuum‐packed ground meat. Consequently, 200‐ppm BCWE can be recommended for use in vacuum‐packed ground beef to prevent discolouration, lipid oxidation and microbial growth during chilled storage. [ABSTRACT FROM AUTHOR]

L. monocytogenes, which is recognized among the leading foodborne pathogen has been identified as the causative agent of listeriosis, which causes important symptoms such as abortion, septicemia, and meningitis. In the first stage of our study, the effectiveness of VIDAS LMO2 and ISO 11290:1 methods, which are frequently used today in the diagnosis of this pathogen, were compared in artificially contaminated samples. In the second stage, the presence of L. monocytogenes in ground beef samples sold in the market was revealed by both methods. According to the data achieved in the study, the relative sensitivity, specificity, accuracy, false positive, and false negative of the VIDAS LMO2 method against ISO 11290-1:2017 was found 99.236%, 73,684%, 90%, 0.263%, and 0.007% in ground beef, respectively. Although no significant difference was detected between the two methods, VIDAS LMO2 was found to be superior in terms of analysis time. Since it is known that rapid and reliable diagnosis is very important in food poisoning, the VIDAS method can be preferred more desirable due to this superiority. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the food safety efficacy of common antimicrobial interventions at and above required uptake levels for processing aids on the reduction of Shiga-toxin producing E. coli (STEC) and Salmonella spp. through spray and dip applications. Beef trim was inoculated with specific isolates of STEC or Salmonella strains. Trim was intervened with peracetic or lactic acid through spray or dip application. Meat rinses were serially diluted and plated following the drop dilution method; an enumerable range of 2–30 colonies was used to report results before log transformation. The combination of all treatments exhibits an average reduction rate of 0.16 LogCFU/g for STEC and Salmonella spp., suggesting that for every 1% increase in uptake there is an increase of 0.16 LogCFU/g of reduction rate. There is a statistical significance in the reduction rate of Shiga-toxin producing Escherichia coli in relation to the uptake percentage (p < 0.01). The addition of explanatory variables increases the R2 of the regression for STEC, where all the additional explanatory variables are statistically significant for reduction (p < 0.01). The addition of explanatory variables increases the R2 of the regression for Salmonella spp., but only trim type is statistically significant for reduction rate (p < 0.01). An increase in uptake percentages showed a significant increase in reduction rate of pathogens on beef trimmings.

The objective of this study was to compare the quality characteristics of current plant-based protein ground beef alternatives (GBA) to ground beef (GB) patties of varying fat percentages. Fifteen different production lots (n = 15/fat level) of 1.36 kg GB chubs of 3 different fat levels (10%, 20%, and 27%) were collected from retail markets in the Manhattan, KS area. Additionally, GBA products including a foodservice GBA (FGBA), a retail GBA (RGBA), and a traditional soy protein–based GBA (TGBA) currently available through commercial channels were collected. Consumers (n = 120) evaluated sample appearance, juiciness, tenderness, overall flavor liking, beef flavor liking, texture liking, and overall liking. Additionally, samples were evaluated for color, texture profile, shear force, pressed juiciness percentage (PJP), pH, and fat and moisture percentage. All 3 GB samples rated higher (P < 0.05) than the 3 GBA samples for appearance liking, overall flavor liking, beef flavor liking, and overall liking by consumers. Similar results were found with trained sensory panelists, which rated the GBA as less (P < 0.05) juicy, softer (P < 0.05), and lower (P < 0.05) for beef flavor and odor intensity and higher (P < 0.05) for off-flavor intensity than the GB. Moreover, the GBA had less (P < 0.05) change in shape through cooking and a lower (P < 0.05) percentage of cooking loss and cooking time than the GB. Also, the GBA all had lower (P < 0.05) shear force and PJP values than the GB. The color of the GBA differed (P < 0.05) from the GB, with the GB samples being more (P < 0.05) red in the raw state. These results indicate that the GBA provide different eating and quality experiences than GB and should thus be considered as different products by consumers and retailers.

ABSTRACT A low initial contamination level of the meat surface is the sine qua non to extend the subsequent shelf life of ground beef for as long as possible. Therefore, the short- and long-term effects of a pregrinding treatment with electrolyzed water (EW) on the microbiological and physicochemical features of Piedmontese steak tartare were here assessed on site, by following two production runs through storage under vacuum packaging conditions at 4°C. The immersion of muscle meat in EW solution at 100 ppm of free active chlorine for 90 s produced an initial surface decontamination with no side effects or compositional modifications, except for an external color change that was subsequently masked by the grinding step. However, the initially measured decontamination was no longer detectable in ground beef, perhaps due to a quick recovery by bacteria during the grinding step from the transient oxidative stress induced by the EW. We observed different RNA-based metataxonomic profiles and metabolomic biomarkers (volatile organic compounds [VOCs], free amino acids [FAA], and biogenic amines [BA]) between production runs. Interestingly, the potentially active microbiota of the meat from each production run, investigated through operational taxonomic unit (OTU)-, oligotyping-, and amplicon sequence variant (ASV)-based bioinformatic pipelines, differed as soon as the early stages of storage, whereas microbial counts and biomarker dynamics were significantly distinguishable only after the expiration date. Higher diversity, richness, and abundance of Streptococcus organisms were identified as the main indicators of the faster spoilage observed in one of the two production runs, while Lactococcus piscium development was the main marker of shelf life end in both production runs. IMPORTANCE Treatment with EW prior to grinding did not result in an effective intervention to prolong the shelf life of Piedmontese steak tartare. Our RNA-based approach clearly highlighted a microbiota that changed markedly between production runs but little during the first shelf life stages. Under these conditions, an early metataxonomic profiling might provide the best prediction of the microbiological fate of each batch of the product.

With the emergence of clade 2.3.4.4b H5N1 highly pathogenic avian influenza virus (AIV) infection of dairy cattle and its subsequent detection in raw milk, coupled with recent AIV infections affecting dairy farm workers, experiments were conducted to affirm the safety of cooked ground beef related to AIV because such meat is often derived from cull dairy cows. Specifically, retail ground beef (percent lean:fat = ca. 80:20) was inoculated with a low pathogenic AIV (LPAIV) isolate to an initial level of 5.6 log 10 50% egg infectious doses (EID 50 )  per 300 g patty. The inoculated meat was pressed into patties (ca. 2.54 cm thick, ca. 300 g each) and then held at 4 °C for up to 60 min. In each of the two trials, two patties for each of the following three treatments were cooked on a commercial open-flame gas grill to internal instantaneous temperatures of 48.9 °C (120°F), 62.8 °C (145°F), or 71.1 °C (160°F), but without any dwell time. Cooking inoculated ground beef patties to 48.9 °C (ave. cooking time of ca. 15 min) resulted in a mean reduction of ≥2.5 ± 0.9 log 10 EID 50 per 300 g of ground beef as assessed via quantification of virus in embryonating chicken eggs (ECEs). Likewise, cooking patties on a gas grill to 62.8 °C (ave. cooking time of ca. 21 min) or to the USDA FSIS recommended minimum internal temperature for ground beef of 71.1 °C (ave. cooking time of ca. 24 min) resulted in a reduction to nondetectable levels from initial levels of ≥5.6 log 10 EID 50 per 300 g. These data establish that levels of infectious AIV are substantially reduced within inoculated ground beef patties (20% fat) using recommended cooking procedures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Inc.)

Salmonella is estimated to be the leading bacterial cause of U.S. domestically acquired foodborne illness. Large outbreaks of Salmonella attributed to ground beef have been reported in recent years. The demographic and sociodemographic characteristics of infected individuals linked to these outbreaks are poorly understood. We employed a retrospective case-control design; case-patients were people with laboratory-confirmed Salmonella infections linked to ground beef-associated outbreaks between 2012 and 2019, and controls were respondents to the 2018-2019 FoodNet Population Survey who reported eating ground beef and denied recent gastrointestinal illness. We used county-level CDC/ATSDR Social Vulnerability Index (SVI) to compare case-patient and controls. Case-patient status was regressed on county-level social vulnerability and individual-level demographic characteristics. We identified 376 case-patients and 1,321 controls in the FoodNet sites. Being a case-patient was associated with increased overall county-level social vulnerability (OR: 1.21 [95% CI: 1.07-1.36]) and socioeconomic vulnerability (OR: 1.24 [1.05-1.47]) when adjusted for individual-level demographics. Case-patient status was not strongly associated with the other SVI themes of household composition and disability, minority status and language, and housing type and transportation. Data on individual-level factors such as income, poverty, unemployment, and education could facilitate further analyses to understand this relationship., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Inc.)

In the present study, firstly, various properties of lyophilized water extracts (LBCWE) produced from fresh black carrot were determined. LBCWE was observed to be a rich source of monomeric anthocyanins (1188.40 ± 17.38 mg C3G/100 g; n = 4) and phenolics (2733.83 ± 17.78 mg GAE/100 g, n = 4). Secondly, ground beef containing LBCWE (Control, 100, 200 and 300 ppm) and packaged in HiOx-MAP (80% O2 + 20% CO2) was evaluated in terms of lipid oxidation, metmyoglobin (MetMb), color, pH and microbial counts during storage at 2.0 ± 0.5 °C for 12 days. By increasing level of LBCWE, the pH, lipid oxidation, MetMb and microbial counts were decreased (P < 0.01). The LBCWE significantly affected the color and microbial count parameters (P < 0.01). The highest redness and lowest microbial growth during storage was in the 300 ppm LBCWE group (P < 0.05). On the 12th day of storage, Pseudomonas and Enterobactericeae decreased 1.24 log and 1.46 log units in this group according to control. The shelf life of ground beef can be extended by 3 days with MAP + 300 ppm extract application. [ABSTRACT FROM AUTHOR]

The objective of this study was to analyze the effects of rosemary (RSM) and green tea (GT) added to groundbeef to extend shelf life. Four antioxidant treatments were used: control, 2,500 ppm RSM, 300 ppm GT, and 2,500 ppm RSM + 300 ppm GT (RSM + GT). Patties from each treatment (n = 42) were randomly packaged into one of 3 types: polyvinyl chloride (PVC) overwrap, modified atmospheric packaging (MAP), or master packages (MP). Packages of MAP and MP were flushed with 0.4% CO, 69.6% nitrogen (N2), and 30% carbon dioxide (CO2). Patties in PVC and MAP were placed directly into display cases for 7 d, and MP patties were placed in dark storage for 7 d and then in display cases for another 7 d. Instrumental and subjective color, lipid oxidation, and sensory panel scores were measured. In MAP, patties with GT had increased (P < 0.05) a* and chroma values by day 6 of retail display. In MP at 3 d of retail display, GT patties exhibited increased (P < 0.05) L* values (lighter), display color (deeper red), and surface discoloration (greater discoloration) scores compared with RSM + GT patties. However, GT and RSM patties were not different (P > 0.05) for these parameters. Trained sensory panelists did not detect a difference between control and GT patties for the green-hay attribute; however, RSM patties had highly detectable (P < 0.05) green-hay flavor. Panelists were unable to detect any differences (P > 0.05) for rancid or fatty flavors regardless of treatment. Patties in MAP were more color stable than those in PVC after 6 d of retail display. In conclusion, patties in MP with GT showed positive instrumental and objective color measurements, as well as lipid oxidation values after 3 d of display, combined with undetectable flavor, warranting further research.

A new DNA microarray test kit has been developed to detect foodborne pathogens in various food matrices. This study focuses on evaluating the PathogenDx microarray-based system to detect Salmonella in ground beef and verify critical parameters that could interfere with the method's effectiveness, such as enrichment incubation time, ground beef fat content, inclusivity, exclusivity, and analytical sensitivity. Sample preparation protocols were evaluated at 6, 8, 12, 18, and 24 h enrichment times at varying bacterial levels to identify optimal conditions to detect the invA gene using the PathogenDx microarray. An 8 h enrichment step was selected based on 100% detection when initial inoculum levels were ≥5 CFU/g, and fractional detection was achieved when the concentration was as low as 1 CFU/g. Thus, the detection of Salmonella using the PathogenDx microarray system can be conducted in 12.5 h, including sample preparation, labeling PCR, hybridization, and analysis. Regarding fat content, there was no significant difference in detection rates of PathogenDx protocol among the highest and lowest commercially sold lean-to-fat ratios of ground beef. Inclusivity and exclusivity experiments showed that Salmonella was correctly identified 100% of the time. Using the ground beef matrix, PathogenDx method is comparable to the United States Department of Agriculture's Microbiology Laboratory Guidebook methodology for detection, which correctly identified Salmonella in 100% of the samples. Salmonella was detected between 93.33 and 100% when ground beef was inoculated with 1 and 5 CFU/g, respectively. • PathogenDx microarray-based system effectively detects Salmonella in ground beef. • Fat content in ground beef does not affect the ability of the system to detect Salmonella. • Salmonella can be detected in ground beef when the microorganism is present at levels as low as 1 CFU/g. • Specificity and sensitivity are nearly 100%. • The effectiveness of this method is comparable to FSIS MLG for Salmonella at a fraction of the time. [ABSTRACT FROM AUTHOR]

• Establishment Salmonella share relative to own mean predicts recalls better than Salmonella share. • Salmonella shares at ground beef standard makes establishment 12 percent more likely to have recall. • Establishments with multiple recalls have high Salmonella shares and may need a food safety audit by FSIS. • Typical ground beef establishments with recalls have Salmonella shares 80 percent greater than the mean. • Establishments with firm initiated recalls or are small have industry average Salmonella shares. The Food Safety and Inspection Service (FSIS) initiated 1,073 recalls of meat and poultry products that could cause severe illness or death over 2000–2019. These recalls led to substantial drops in demand that vary by the characteristics of the recall (Zhou and Liu, 2023) and incentivized firms to invest in food safety (Ollinger and Houser, 2020). Following Zhou and Liu (2023) and Ollinger and Houser (2020) , this paper examines differences in food safety process control for establishments with different recall characteristics and contrasts that performance with establishments without recalls. Results show that (1) Salmonella share relative to an establishment's own mean Salmonella share outperforms Salmonella share alone in estimating the likelihood of a recall, (2) 27 percent rather than 12 percent of establishments would have failed to meet the Salmonella standard if a proposed but not yet mandated more stringent standard had been in effect, and (3) most establishments return to normal operating conditions after a recall, but establishments with multiple recalls struggle to regain control of food safety, suggesting they may benefit from an audit of their food safety systems by FSIS or an auditor. [ABSTRACT FROM AUTHOR]

Shiga toxin-producing Escherichia coli (STEC) can be life-threatening and lead to major outbreaks. The prevention of STEC-related infections can be provided by control measures at all stages of the food chain. The growth performance of E. coli O157:H7 at different temperatures in raw ground beef spiked with cocktail inoculum was investigated using machine learning (ML) models to address this problem. After spiking, ground beef samples were stored at 4, 10, 20, 30 and 37 °C. Repeated E. coli O157 enumeration was performed at 0–96 h with 21 times repeated counting. The obtained microbiological data were evaluated with ML methods (Artificial Neural Network (ANN), Random Forest (RF), Support Vector Regression (SVR), and Multiple Linear Regression (MLR)) and statistically compared for valid prediction. The coefficient of determination (R2) and mean squared error (MSE) are two essential criteria used to evaluate the model performance regarding the comparison between the observed value and the prediction made by the model. RF model showed superior performance with 0.98 R2 and 0.08 MSE values for predicting the growth performance of E. coli O157 at different temperatures. MLR model predictions were obtained further from the observed values with 0.66 R2 and 2.7 MSE values. Our results indicate that ML methods can predict of E. coli O157:H7 growth in ground beef at different temperatures to strengthen food safety professionals and legal authorities to assess contamination risks and determine legal limits and criteria proactively. [ABSTRACT FROM AUTHOR]

Food irradiation is becoming increasingly popular in many countries for preserving and extending the shelf life of foods, which creates a demand for express methods for the detection of absorbed doses. This paper proposes an innovative method for the estimation of the dose absorbed by X-rayed beef samples using a reaction-based optical sensing technique that was proposed earlier by our team for the estimation of the dose absorbed by raw potatoes. Potato and beef samples were exposed to X-ray irradiation at 100 and 1000 Gy and then extracted by water at 23 °C for 24 h or 60/70 °C for 1 h. The resulting solutions were introduced to the reaction mixtures of dyes (carbocyanines, Rhodamines, or Crystal Violet) with oxidants (hypochlorite, bromate, or hydrogen peroxide). The fluorescence intensity and absorbance of the mixtures were periodically measured photographically using visualizers. The data were processed using linear discriminant analysis (LDA) and k-nearest neighbors algorithm (kNN). Using the most efficient individual reactions, the doses can be recognized with a 90–100% accuracy, and the combinations of up to 5 reactions can improve the accuracy to 100%. The protocol is simple and rapid: sample extraction time and indicator reactions take not more than 1 h each. The proposed method potentially has a wide area of applications ranging from plants to animal products. • A simple chemical method for estimating doses is developed. • No prior knowledge about irradiation markers is required. • 1-Hour extraction of irradiated samples with water is sufficient. • 100% accuracy of dose estimation (0, 100, 1000 Gy) is achieved. [ABSTRACT FROM AUTHOR]

Shiga toxin-producing Escherichia coli (STEC) can cause from watery diarrhea to severe diseases, such as thrombocytopenic purpura (TP) or hemolytic uremic syndrome (HUS). Ruminants are the main reservoir; most of the time humans are infected through the ingestion of contaminated meat. The goal of this study was the detection of stx1 and stx2 genes through the standardization of a real time PCR method that uses SYBR green, and then we used this method to analyze the presence of STEC in ground beef from butcheries of the metropolitan zone of Asuncion, Paraguay. We analyzed 48 ground beef samples from 24 butcheries. They were processed by standard methods of culture and DNA extraction. Real-time PCR reactions were standardized for the detection of stx1 and stx2. Both genes were detected in the 48 samples studied. The concordance between this method and a conventional PCR technique was excellent, showing kappa concordance indexes of 0.76 for stx1 and 0.87 for stx2. Even though the high levels of contaminated ground beef detected, all the isolates were LEE negatives and O157 negatives, which are less related to outbreaks and severe diseases. The most common virulence profile was stx1/stx2/saa/exhA. With this finding, we have proven the need for preventive procedures in the slaughter process and the handling process of meat products.

Abstract We examine the impact of food labels that make unsupported claims of food safety and labels that provide information to support such claims on consumer choices and examine consumers’ willingness to pay for beef products with these different food safety labeling cues. Empirical results from a survey of grocery shoppers in a Midwestern city in the USA show that more than two thirds of respondents who received a label with unsubstantiated food safety claims chose this option and were willing to pay the highest price premium for it, compared to the less preferred labeling options that provided information to support food safety claims.

Antibiotics used during food animal production account for approximately 77% of U.S. antimicrobial consumption by mass. Ground beef products labeled as raised without antibiotics (RWA) are perceived to harbor lower levels of antimicrobial-resistant bacteria than conventional (CONV) products with no label claims regarding antimicrobial use. Retail ground beef samples were obtained from six U.S. cities. Samples with an RWA or U.S. Department of Agriculture Organic claim (n = 299) were assigned to the RWA production system. Samples lacking these claims (n = 300) were assigned to the CONV production system. Each sample was cultured for the detection of five antimicrobial-resistant bacteria. Genomic DNA was isolated from each sample, and a quantitative PCR assay was used to determine the abundance of 10 antimicrobial resistance (AMR) genes. Prevalence of tetracycline-resistant Escherichia coli (CONV, 46.3%; RWA, 34.4%; P < 0.01) and erythromycin-resistant Enterococcus (CONV, 48.0%; RWA, 37.5%; P = 0.01) was higher in CONV ground beef. Salmonella was detected in 1.2% of samples. The AMR gene blaCTX-M (CONV, 4.1 log-normalized abundance; RWA, 3.8 log-normalized abundance; P < 0.01) was more abundant in CONV ground beef. The AMR genes mecA (CONV, 4.4 log-normalized abundance; RWA, 4.9 log-normalized abundance; P = 0.05), tet(A) (CONV, 3.9 log-normalized abundance; RWA, 4.5 log-normalized abundance; P < 0.01), tet(B) (CONV, 3.9 log-normalized abundance; RWA, 4.5 log-normalized abundance; P < 0.01), and tet(M) (CONV, 5.4 log-normalized abundance; RWA, 5.8 log-normalized abundance; P < 0.01) were more abundant in RWA ground beef. Although these results suggest that antimicrobial use during U.S. cattle production does not increase human exposure to antimicrobial-resistant bacteria via ground beef, quantitative microbiological risk assessments are required for authoritative determination of the human health impacts of the use of antimicrobial agents during beef production. [ABSTRACT FROM AUTHOR]

Featured Application: The increase in health-conscious consumers and awareness in the prevention of diseases through diet opens a new market opportunity to improve meat products with functional ingredients such as Moringa oleifera leaves powder (MOLP). Meat products can be developed by enhancing their nutritional value either by decreasing fat content and/or incorporating new and functional ingredients such as MOLP. However, the meat industry encounters a serious challenge in maintaining traditional quality and reasonable cost of the formulated meat products. This study evaluated the influence of MOLP on the nutritional and technological properties, lipid oxidation, microbial growth, and sensory analysis of ground beef during cold storage. Moringa oleifera leaves powder improved the nutritional and technological properties and inhibited lipid oxidation in ground beef. Therefore, MOLP could be utilised by meat processors as a functional ingredient to enhance the quality attributes of ground beef. The utilisation of Moringa oleifera leaves powder (MOLP) to improve the nutritional properties and inhibit lipid oxidation and the proliferation of microorganisms in ground beef during cold storage was examined. The effects of 0.2, 0.4, 0.6, and 0.8% MOLP on the nutritional properties (proximate composition, total phenolic and total flavonoid content), thiobarbituric acid reactive substances (TBARS), microbial composition, physicochemical characteristics (pH value, colour attributes, and cooking properties), and sensory analysis of ground beef were investigated. The findings showed that ash, protein, polyphenolic compounds, pH, colour, and microbial growth increased significantly, while moisture, fat content, and TBARS decreased significantly, with an increase in the concentration of MOLP during cold storage. Moderate levels (0.2 and 0.4%) of MOLP did not affect the sensory attributes of stored ground beef. Evidently, MOLP can be utilised as a natural preservative in ground beef to improve the nutritional value and inhibit lipid oxidation. [ABSTRACT FROM AUTHOR]

Verotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin–producing E. coli) is a significant cause of foodborne illnesses around the world. Due to the serological and genomic diversity of VTEC, methods of detection for VTEC in food samples require detection of verotoxin or its gene vt (also known as stx). The current taxonomy of vt identifies three vt1 (a, c, d) and seven vt2 (a to g) subtypes. PCR detection of vt is convenient and rapid, but protocols may not detect all currently identified variants or subtypes of vt. The Health Canada Compendium of Analytical Methods protocol for the analysis of food for VTEC is MFLP-52. MFLP-52 includes a VT Screening PCR that is used to determine the presumptive presence of VTEC by the detection of vt in food enrichments and to differentiate VTEC from other isolates. The VT Screening PCR was developed prior to the establishment of the current vt taxonomy. An evaluation of VT Screening PCR for detection of the 10 established vt subtypes was performed, and it was discovered that the method could not detect subtypes vt1d and vt2f. Additional primers and a modified protocol were developed, and the modified VT Screening PCR was tested against an inclusivity panel of 50 VTEC strains, including representatives of 10 vt subtypes, and an exclusivity panel of 30 vt-negative E. coli from various sources, to ensure specificity. The reliability of MFLP-52 with the modified VT Screening PCR was assessed by analysis of four priority food matrices (ground beef, lettuce, cheese, and apple cider) inoculated with a VTEC strain at 2 to 5 CFU/25 g. The modified VT Screening PCR was determined to be able to detect all 10 vt subtypes and reliably detect the presence of VTEC in all tested food enrichments. [ABSTRACT FROM AUTHOR]

A total of 482 veal cutlet, 555 ground veal, and 540 ground beef samples were purchased from retail establishments in the mid-Atlantic region of the United States over a noncontiguous 2-year period between 2014 and 2017. Samples (325 g each) were individually enriched and screened via real-time PCR for all seven regulated serogroups of Shiga toxin–producing Escherichia coli (STEC). Presumptive STEC-positive samples were subjected to serogroup-specific immunomagnetic separation and plated onto selective media. Up to five isolates typical for STEC from each sample were analyzed via multiplex PCR for both the virulence genes (i.e., eae, stx1 and/or stx2, and ehxA) and serogroup-specific gene(s) for the seven regulated STEC serogroups. The recovery rates of non-O157 STEC from veal cutlets (3.94%, 19 of 482 samples) and ground veal (7.03%, 39 of 555 samples) were significantly higher (P < 0.05) than that from ground beef (0.93%, 5 of 540 samples). In contrast, only a single isolate of STEC O157:H7 was recovered; this isolate originated from 1 (0.18%) of 555 samples of ground veal. Recovery rates for STEC were not associated with state, season, packaging type, or store type (P > 0.05) but were associated with brand and fat content (P < 0.05). Pulsed-field subtyping of the 270 viable and confirmed STEC isolates from the 64 total samples testing positive revealed 78 pulsotypes (50 to 80% similarity) belonging to 39 pulsogroups, with ≥90% similarity among pulsotypes within pulsogroups. Multiple isolates from 43 (67.7%) of 64 samples testing positive had an indistinguishable pulsotype. STEC serotypes O26 and O103 were the most prevalent serogroups in beef and veal, respectively. These findings support related findings from regulatory sampling studies over the past decade and confirm that recovery rates for the regulated STEC serogroups are higher for raw veal than for raw beef samples, as was observed in the present study of meat purchased at food retailers in the mid-Atlantic region of the United States. Higher recovery rates of regulated STEC serogroups were found in raw veal than in beef. Recovery of STEC was not associated with state, season, packaging, or store type. Recovery of STEC was associated with brand and fat content. The most prevalent STEC serogroups in beef and veal were O26 and O103, respectively. STEC with the same pulsotype had the same virulence profile. [ABSTRACT FROM AUTHOR]

The objectives of the present work were (1) to determine the total polyphenol content (TPC), total flavonoid content (TFC), and oxygen radical absorbance capacity (ORAC) of citrus fibre, and (2) to predict, by attenuated total reflection (ATR)-Fourier transform infrared spectroscopy (FTIR), the oxidative stability of ground beef made with different levels (i.e., 0, 1, 3, and 5%) of citrus fibre (CF) during 1, 3, 5, or 7 days of refrigerated storage. The TPC, TFC, and ORAC values of citrus fibre were 3.753 ± 0.49 mg/g, 2.825 ± 0.008 mg/g, and 10.036 ± 1.94 μmol/g in dry basis, respectively. The citrus fibre pH was 4.45 ± 0.075. To monitor lipid oxidation, the peaks at 2924, 2853, and 1743 cm-1 were useful. Principal component analysis (PCA) was applied at a 5% significance level between 1780 - 1700 cm-1. The results of the present work demonstrated that the addition of citrus fibre at higher levels (i.e., 3 and 5%) had a pro-oxidative effect on ground beef meatballs. FTIR helped to predict oxidation in meat products. [ABSTRACT FROM AUTHOR]

The goal of this research is to evaluate the influence of the polyphenols extract of Polygonum multiflorum Thunb. root on the lipid oxidation, chemical properties and sensory characteristics of ground beef during frozen storage. Beef was ground in aqueous solutions of polyphenols extract at different concentrations: 830, 415, 277, 208 and 166 mg GAE/L, polyphenols solution/sample ratio is 1/20 (v/w). Then, the ground beef was stored for up to 100 days at -20±2oC. The best oxidation inhibitor for ground beef was at the highest polyphenols concentration of 830 mg GAE/L. All quality parameters (pH, PoV, MDA, color parameter and sensory evaluation) of the treated sample and of the control sample display significant differences (p<0.05) during storage period. For this reason, it was concluded that the polyphenols extract of Polygonum multiflorum Thunb. root could be used as an alternative source of natural antioxidant in beef processing. [ABSTRACT FROM AUTHOR]

Over 20% of E. coli O157 illnesses and over 5% of Salmonella illnesses are estimated to be attributable to beef consumption in the United States. Irradiating ground beef is one possible method to reduce disease burden. We simulated the effect of ground beef irradiation on illnesses, hospitalizations, deaths, and direct healthcare costs from ground beef-associated E. coli O157 and Salmonella illnesses in the United States. To estimate the fraction of illnesses, hospitalizations, deaths, and direct healthcare costs preventable by ground beef irradiation, we multiplied the disease burden attributable to ground beef; the estimated percentage of ground beef sold that is not currently irradiated; the percentage of unirradiated ground beef that would be irradiated; and the percentage reduction in risk of illness after irradiation. We multiplied this fraction by estimates of burden and direct healthcare costs to calculate the numbers or amounts averted. Model inputs were obtained from the literature and expert opinion. We used Monte Carlo simulation to incorporate uncertainty in inputs into model estimates. Simulation outcomes were summarized with means and 95% uncertainty intervals (UI). Irradiating 50% of the currently unirradiated ground beef supply would avert 3,285 (95% UI: 624-9,977) E. coli O157 illnesses, 135 (95% UI: 24-397) hospitalizations, 197 (95% UI: 34-631) hemolytic uremic syndrome cases, 2 (95% UI: 0-16) deaths, and $2,972,656 (95% UI: $254,708-$14,496,916) in direct healthcare costs annually. For Salmonella, irradiation would avert 20,308 (95% UI: 9,858-38,903) illnesses, 400 (95% UI: 158-834) hospitalizations, 6 (95% UI: 0-18) deaths, and $7,318,632 (95% UI: $1,436,141-$26,439,493) in direct healthcare costs. Increasing ground beef irradiation could reduce E. coli O157 and Salmonella burden in the United States. Additional studies should assess whether targeted irradiation of higher-risk ground beef products could prevent similar numbers of illnesses with less total product irradiated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Inc.)

Ground beef can be a reservoir for a variety of bacteria, including spoilage organisms, and pathogenic foodborne bacteria. These bacteria can exhibit antimicrobial resistance (AMR) which is a public health concern if resistance in pathogens leads to treatment failure in humans. Culture-dependent techniques are commonly used to study individual bacterial species, but these techniques are unable to describe the whole community of microbial species (microbiome) and the profile of AMR genes they carry (resistome), which is critical for getting a holistic perspective of AMR. The objective of this study was to characterize the microbiome and resistome of retail ground beef products labeled as coming from conventional or raised without antibiotics (RWA) production systems. Sixteen ground beef products were purchased from 6 retail grocery outlets in Fort Collins, CO, half of which were labeled as produced from cattle raised conventionally and half of products were from RWA production. Total DNA was extracted and isolated from each sample and subjected to 16S rRNA amplicon sequencing for microbiome characterization and target-enriched shotgun sequencing to characterize the resistome. Differences in the microbiome and resistome of RWA and conventional ground beef were analyzed using the R programming software. Our results suggest that the resistome and microbiome of retail ground beef products with RWA packaging labels do not differ from products that do not carry claims regarding antimicrobial drug exposures during cattle production. The resistome predominantly consisted of tetracycline resistance making up more than 90% of reads mapped to resistance gene accessions in our samples. Firmicutes and Proteobacteria predominated in the microbiome of all samples (69.6% and 29.0%, respectively), but Proteobacteria composed a higher proportion in ground beef from conventionally raised cattle. In addition, our results suggest that product management, such as packaging type, could exert a stronger influence on the microbiome than the resistome in consumer-ready products. Metagenomic analyses of ground beef is a promising tool to investigate community-wide shifts in retail ground beef. Importantly, however, results from metagenomic sequencing must be carefully considered in parallel with traditional methods to better characterize the risk of AMR in retail products.

With current meat industry efforts focused on improving environmental influencers, adopting sustainable packaging materials may be an easier transition to addressing the sustainability demands of the meat consumer. With the growing popularity of vacuum-packaged meat products, the current study evaluated instrumental surface color on fresh ground beef using vacuum packaging films, recycle-ready film (RRF), standard barrier (STB) and enhanced barrier (ENB). Ground beef packaged using ENB barrier film was lighter (L*), redder (a*) and more vivid (chroma) than all other packaging treatments during the simulated display period (p < 0.05). By day 12 of the simulated retail display, the ground beef surface color became lighter (L*), more yellow (b*), less red (a*), less vivid (chroma) and contained greater forms of calculated metmyoglobin, oxymyoglobin (p < 0.05). The current results suggest that barrier properties of vacuum packaging film for ground beef are pivotal for extending the surface color during fresh shelf-life conditions.

The beef consumption by Brazilian population has increased in recent years. However, the processing of this product can facilitate its contamination by microorganisms and trigger outbreaks of food infections. Based on the previous information, the present study aimed to evaluate the hygienic sanitary quality of ground beef marketed in 20 butcheries in the city of Sarandi, PR. Samples of 50 grams of the product were collected in each establishment. Then, the presence of total and thermotolerant coliforms was evaluated by Most Probable Number technique and Salmonella spp. by the growth in a specific medium. The presence of thermotolerant coliform was observed in all sample analyzed, but in none of them had growth of Salmonella spp. The presence of Escherichia coli in foods indicate a failure in the hygienic sanitary procedures, emphasizing the importance of implementing tools that promote improvement in the good hygiene practices, to reduce the contamination index of these products and to increase the quality of customer’s life.

Escherichia coli O157:H7 is well known for many foodborne outbreaks that lead to fatal infections in human being worldwide. The objective of this study was to develop a rapid and sensitive method for detection of EHEC O157:H7 from ground beef using a method that combined immunomagnetic separation (IMS) with loop-mediated isothermal amplification (LAMP). The EHEC O157:H7 cells were separated with Dynabeads coated with anti- EHEC O157:H7 after a short enrichment for 4 h. Then, EHEC O157:H7 was identified by LAMP assay for amplifying and detecting the rfbE gene, which is highly conserved in all EHEC O157:H7 strains and exhibits strain-specifi c gene expression. The LAMP method results analyzed with real time turbidity measurements showed a high specificity and sensitivity, with a positive detection rate of amplifi cation of EHEC O157:H7 DNA diluted to a minimum equivalent concentration of 1.8 × 101 CFU/mL, which was 10 times more sensitive than the conventional PCR assay. The IMS followed with LAMP could capture and detect a bacterial concentration as low as 3×101 CFU/mL from the meat samples, which was close to the sensitivity of LAMP assay with pure culture. IMS combined with realistic LAMP method is a simple, rapid, highly specific gene amplifi cation technology that is suitable for implementing as a screening assay in basic laboratory and field test for detecting food contamination.

Ground beef can be a reservoir for a variety of bacteria, including spoilage organisms, and pathogenic foodborne bacteria. These bacteria can exhibit antimicrobial resistance (AMR) which is a public health concern if resistance in pathogens leads to treatment failure in humans. Culture-dependent techniques are commonly used to study individual bacterial species, but these techniques are unable to describe the whole community of microbial species (microbiome) and the profile of AMR genes they carry (resistome), which is critical for getting a holistic perspective of AMR. The objective of this study was to characterize the microbiome and resistome of retail ground beef products labeled as coming from conventional or raised without antibiotics (RWA) production systems. Sixteen ground beef products were purchased from 6 retail grocery outlets in Fort Collins, CO, half of which were labeled as produced from cattle raised conventionally and half of products were from RWA production. Total DNA was extracted and isolated from each sample and subjected to 16S rRNA amplicon sequencing for microbiome characterization and target-enriched shotgun sequencing to characterize the resistome. Differences in the microbiome and resistome of RWA and conventional ground beef were analyzed using the R programming software. Our results suggest that the resistome and microbiome of retail ground beef products with RWA packaging labels do not differ from products that do not carry claims regarding antimicrobial drug exposures during cattle production. The resistome predominantly consisted of tetracycline resistance making up more than 90% of reads mapped to resistance gene accessions in our samples. Firmicutes and Proteobacteria predominated in the microbiome of all samples (69.6% and 29.0%, respectively), but Proteobacteria composed a higher proportion in ground beef from conventionally raised cattle. In addition, our results suggest that product management, such as packaging type, could exert a stronger influence on the microbiome than the resistome in consumer-ready products. Metagenomic analyses of ground beef is a promising tool to investigate community-wide shifts in retail ground beef. Importantly, however, results from metagenomic sequencing must be carefully considered in parallel with traditional methods to better characterize the risk of AMR in retail products. [ABSTRACT FROM AUTHOR]

The performance of three chromogenic agar media for detection of the "top seven" Shiga toxin–producing Escherichia coli (STEC) in beef was compared. Samples of retail ground beef were inoculated with STEC O26, O45, O103, O111, O121, O145, or O157 at geometric mean (±standard error of the mean) levels of 0, 48 (±1), 420 (±1), 4,100 (±1), or 45,000 (±1) CFU/10 g and enriched 1:10 (90 mL) in EC broth (40°C for 6 h). Following enrichment, aliquots of broth culture were treated by immunomagnetic separation with one of three pools of beads against the seven STEC serogroups: pool I, O26, O45, and O121; pool II, O103, O111, and O145; and pool III, O157. After immunomagnetic separation, 50 μL of washed bead suspensions in buffered peptone water were spiral plated onto modified Rainbow Agar O157 (mRBA), CHROMagar STEC (CS), or modified Possé differential medium (mPossé2) and incubated at 37°C for 18 h. Up to six isolated colonies were picked from each spiral plate based on expected colony phenotypes for STEC on the respective media, and isolate identity was confirmed with an 11-plex PCR assay targeting the O serogroups and virulence genes. Overall, mRBA had the highest sensitivity (99.2%), correctly detecting a significantly higher proportion of STEC serogroups than either CS (79.4%; P < 0.05) or mPossé2 (91.7%; P < 0.05). mRBA also had the highest negative predictive value (90.0%), correctly identifying a significantly higher proportion of true-negative samples compared with CS (25.7%; P < 0.05) and mPossé2 (46.2%; P < 0.05). However, mRBA also had the lowest analytical specificity of 83.2% (P < 0.05), yielding the lowest proportion of colonies tested that were STEC positive (3,548 of 4,263) compared with 97.7% (3,607 of 3,693) for mPossé2 and 98.0% (2,875 of 2,935) for CS. Reduced specificity results in more work and higher expense due to the increased number of colonies that must be tested. Further improvements in agar culture media for non-O157 STEC isolation are needed. The performance of various chromogenic agars for STEC isolation was compared. Modified Rainbow Agar O157 was the most sensitive but also the least specific. CHROMagar STEC and modified Possé differential medium were the most specific. Lower specificity suggests that more work and higher expense will be incurred. Improvements in agar culture media for non-O157 STEC isolation are still needed. [ABSTRACT FROM AUTHOR]

This study aimed to determine the frequency of contamination, serovar diversity, and multilocus sequence typing (MLST) of Salmonella enterica (SE) in lymph nodes and ground beef. A total of 1,545 samples from 400 beef carcasses were analyzed. Samples included peripheral (PLN) and deep lymph nodes (DLN), lean and fatty ground beef obtained in warm (April-July) and cold (September-December) seasons during 2017 and 2018. The pure isolates were subjected to complete genome sequencing. With these data, the in silico prediction of serovars and the MLST profile was performed. In total, 78 SE isolates were obtained (5% of the total analyzed samples). The frequency of contamination was associated with the type of sample (X2=23.7, P<0.0001) and the time of year (X2=20.3, P<0.0001), being higher in PLN (9.7%) and during the warm season (7.0%). The predominant serovars were Anatum and Reading (each one with n= 23), Typhimurium (n= 11), and London (n= 9). The MLST profile of strains of the Typhimurium (ST 19 and 34) and Kentucky (ST 198) serovars has been previously reported in isolates involved in clinical cases. It was concluded that lymph nodes and ground beef are reservoirs of SE of public health importance, especially during the warm months of the year. Therefore, it is necessary to establish measures to prevent dissemination throughout the production chain of strains associated with apparently healthy animals. [ABSTRACT FROM AUTHOR]

We evaluated high pressure processing to lower levels of Shiga toxin–producing Escherichia coli (STEC) and Listeria monocytogenes inoculated into samples of plant or beef burgers. Multistrain cocktails of STEC and L. monocytogenes were separately inoculated (∼7.0 log CFU/g) into plant burgers or ground beef. Refrigerated (i.e., 4°C) or frozen (i.e., −20°C) samples (25 g each) were subsequently exposed to 350 MPa for up to 9 or 18 min or 600 MPa for up to 4.5 or 12 min. When refrigerated plant or beef burger samples were treated at 350 MPa for up to 9 min, levels of STEC were reduced by ca. 0.7 to 1.3 log CFU/g. However, when refrigerated plant or beef burger samples were treated at 350 MPa for up to 9 min, levels of L. monocytogenes remained relatively unchanged (ca. ≤0.3-log CFU/g decrease) in plant burger samples but were reduced by ca. 0.3 to 2.0 log CFU/g in ground beef. When refrigerated plant or beef burger samples were treated at 600 MPa for up to 4.5 min, levels of STEC and L. monocytogenes were reduced by ca. 0.7 to 4.1 and ca. 0.3 to 5.6 log CFU/g, respectively. Similarly, when frozen plant and beef burger samples were treated at 350 MPa up to 18 min, reductions of ca. 1.7 to 3.6 and ca. 0.6 to 3.6 log CFU/g in STEC and L. monocytogenes numbers, respectively, were observed. Exposure of frozen plant or beef burger samples to 600 MPa for up to 12 min resulted in reductions of ca. 2.4 to 4.4 and ca. 1.8 to 3.4 log CFU/g in levels of STEC and L. monocytogenes, respectively. Via empirical observation, pressurization did not adversely affect the color of plant burger samples, whereas appreciable changes in color were observed in pressurized ground beef. These data confirm that time and pressure levels already validated for control of STEC and L. monocytogenes in ground beef will likely be equally effective toward these same pathogens in plant burgers without causing untoward effects on product color. Pathogens were more barotolerant in plant burgers than in ground beef. HPP treatment did not change the color of plant-sourced protein. There were appreciable changes in color of ground beef after pressurization. [ABSTRACT FROM AUTHOR]

The viability of Shiga toxin--producing Escherichia coli (STEC), Salmonella, and Listeria monocytogenes within plant- and beef-based burgers was monitored during storage and cooking. When inoculated (ca. 3.5 log CFU/g) into 15-g portions of plantor beef-based burgers, levels of STEC and Salmonella decreased slightly (≤0.5-log decrease) in both types of burgers when stored at 4°C, but increased ca. 2.4 and 0.8 log CFU/g, respectively, in plant-based burgers but not beef-based burgers (≤1.2-log decrease), after 21 days at 10°C. For L. monocytogenes, levels increased by ca. 1.3 and 2.6 log CFU/g in plant burgers after 21 days at 4 and 10°C, respectively, whereas pathogen levels decreased slightly (≤0.9-log decrease) in beef burgers during storage at 4 and 10°C. Regarding cooking, burgers (ca. 114 g each) were inoculated with ca. 7.0 log CFU/g STEC, Salmonella, or L. monocytogenes and cooked in a sauté pan. Cooking plant- or beef-based burgers to 62.8°C (1458F), 68.3°C (155°F), or 73.9°C (165°F) delivered reductions ranging from ca. 4.7 to 6.8 log CFU/g for STEC, ca. 4.4 to 7.0 log CFU/g for L. monocytogenes, and ca. 3.5 to 6.7 log CFU/g for Salmonella. In summary, the observation that levels of all three pathogens increased by ca. 1.0 to ca. 2.5 log CFU/g in plant-based burgers when stored at an abusive temperature (10°C) highlights the importance of proper storage (4°C) to lessen risk. However, because all three pathogens responded similarly to heat in plant-based as in beef-based burgers, well-established cooking parameters required to eliminate STEC, Salmonella, or L. monocytogenes from ground beef should be as effective for controlling cells of these same pathogens in a burger made with plant-sourced protein. [ABSTRACT FROM AUTHOR]

The aims of this study were to evaluate the prevalence of Salmonella spp., including S. Enteritidis and S. Typhimurium, their antibiotic resistance profiles, and the presence/absence of class 1 integron (intI1) in 50 raw ground beef and 50 raw, meatball samples collected in the Samsun Province, Turkey. For the detection of Salmonella, conventional culture technique and PCR assay were used. The antibiotic resistance profiles of the isolates against nine antibiotics were tested. Salmonella spp. was detected in 20 (n = 86 isolates) samples, namely 12 ground beef and 8 meatball samples. Salmonella Enteritidis (n = 12; 24 isolates) or S. Typhimurium (n = 3; 6 isolates) was detected in 15 (75.00%, n = 30 isolates) samples. At least one species-specific gene (oriC or invA) was detected in the isolates. All isolates were sensitive to two of the third-generation cephalosporins and also nalidixic acid. There was a different level of multidrug resistance (MDR) between S. Enteritidis and Typhimurium isolates. Class 1 integron was detected in four samples (n = 7 isolates); seven isolates were S. Enteritidis and four out of the seven S. Enteritidis isolates were also MDR. In conclusion, the presence of Salmonella, particularly S. Enteritidis and S. Typhimurium, in ground beef and meatballs may cause foodborne infections. The presence of antibiotic-resistant Salmonella and S. Enteritidis with the Cls1integron is important for horizontal antibiotic gene transfer. [ABSTRACT FROM AUTHOR]

Fresh beef storage in the retail setting can be presented in a variety of packaging methods, and identifying an alternative such as vacuum packaging to current traditional methods could potentially increase shelf life and reduce meat waste. The objective of this study was to identify the influence of packaging film and lean trimming sources on fresh ground beef surface color during a simulated retail display period. There were no differences (p > 0.05) in surface color redness (a*), yellowness (b*), chroma, or hue angle regardless of packaging film or lean trimmings. However, thiobarbituric acid reactive substances (TBARS) were greater (p < 0.05) for packages containing a greater percentage of CULL beef trimmings regardless of packaging film. In addition, pH values of ground beef packages did not differ (p > 0.05) among packaging film or lean trimming blends. Visual color did not differ (p > 0.05) throughout the simulated retail display period regardless of beef trimmings or packaging film. Microbial spoilage organisms were greater (p < 0.05) after the simulated display period. These results suggest that ground beef presented in a simulated retail setting using an alternative packaging platform, such as vacuum packaging, is plausible.

Blended meat/plant products are capturing industry market space at the retail counter for value-added beef products. Plant protein ingredients can be added to meat formulations to create appealing and functional products. Ground beef was combined with one of three plant protein inclusion treatments: control, pea, oat, or rice, along with 5% textured vegetable protein (TVP) and 1.5% soy protein concentrate then formed into 226 g patties containing up to 10% plant-based proteins. Patties were analyzed for fresh and cooked characteristics throughout a 5- or 7-day retail display. The inclusion of plant-based proteins negatively affected the instrumental tenderness values which were greater (p < 0.01) in plant-inclusion patties compared to the control patties. The inclusion of plant proteins increased (p = 0.01) the cooking yield of patties compared to the control. Cooking time was longer (p = 0.04) for oat patties compared to the control patties. Cooked color values for vegetable inclusion patties did not affect (p = 0.12) lightness (CIE L*) values; however, redness (CIE a*) was greater (p < 0.01) for rice than all other treatments and yellowness (CIE b*) values were greater (p < 0.01) for all protein treatments compared to the control. Rice improved (p < 0.01) fresh a* values on day 5 of display compared to the control; whereas pea decreased (p = 0.04) values compared to the control. There was a treatment × day interaction (p < 0.01) on lipid oxidation values with a reduction in values on day 3 for all vegetable proteins compared to the control and on day 7 lipid oxidation was reduced (p ≤ 0.03) for oat patties.

The relationships between the lipid content, lipid oxidation, and discoloration rate of ground beef during a simulated retail display were characterized in this study. A total of 276 batches of ground beef were manufactured with inside rounds and subcutaneous fat from 138 beef carcasses at different targeted levels of lean:fat. There was a total of four different targeted grind levels during the manufacture of the ground beef, and the lipid content for the samples used in this study ranged from 2% to 32% total lipid. Fatty acid composition was determined based on subcutaneous fat, whereas the proximate composition of moisture and total lipids, instrumental color, visual discoloration, and lipid oxidation measured as thiobarbituric acid reactive substances were evaluated on ground beef patties during 7 days of simulated retail at 4 °C display under LED lights. Analysis for the correlation and the creation of linear regression models indicated that lipid content played a more critical role in the discoloration rate compared to lipid oxidation and fatty acid composition. Lipid oxidation could be more reliably predicted by lipid content and instrumental color compared to visual discoloration. Overall, ground beef formulated with greater lipid content is expected to experience greater rates of lipid oxidation and discoloration during retail display.

Abstract Background Enterohemorrhagic Escherichia coli (EHEC) are zoonotic agents associated with outbreaks worldwide. Growth of EHEC strains in ground beef could be inhibited by background microbiota that is present initially at levels greater than that of the pathogen E. coli. However, how the microbiota outcompetes the pathogenic bacteria is unknown. Our objective was to identify metabolic pathways of EHEC that were altered by natural microbiota in order to improve our understanding of the mechanisms controlling the growth and survival of EHECs in ground beef. Results Based on 16S metagenomics analysis, we identified the microbial community structure in our beef samples which was an essential preliminary for subtractively analyzing the gene expression of the EHEC strains. Then, we applied strand-specific RNA-seq to investigate the effects of this microbiota on the global gene expression of EHEC O2621765 and O157EDL933 strains by comparison with their behavior in beef meat without microbiota. In strain O2621765, the expression of genes connected with nitrate metabolism and nitrite detoxification, DNA repair, iron and nickel acquisition and carbohydrate metabolism, and numerous genes involved in amino acid metabolism were down-regulated. Further, the observed repression of ftsL and murF, involved respectively in building the cytokinetic ring apparatus and in synthesizing the cytoplasmic precursor of cell wall peptidoglycan, might help to explain the microbiota’s inhibitory effect on EHECs. For strain O157EDL933, the induced expression of the genes implicated in detoxification and the general stress response and the repressed expression of the peR gene, a gene negatively associated with the virulence phenotype, might be linked to the survival and virulence of O157:H7 in ground beef with microbiota. Conclusion In the present study, we show how RNA-Seq coupled with a 16S metagenomics analysis can be used to identify the effects of a complex microbial community on relevant functions of an individual microbe within it. These findings add to our understanding of the behavior of EHECs in ground beef. By measuring transcriptional responses of EHEC, we could identify putative targets which may be useful to develop new strategies to limit their shedding in ground meat thus reducing the risk of human illnesses.

The study examined the leaf extracts of Moringa oleifera and Bidens pilosa for presence of bioactive phytochemicals and their antioxidant activities on pH and lipid oxidation of fresh ground beef during 6 days cold storage. The results revealed that B. pilosa leaf extract contained higher amount of bioactive compounds and antioxidant contents (p 0.05). The antioxidant activities of the extracts indicate that M. oleifera and B. pilosa leaf can be used as nutraceuticals or preservative agents in food industry.

The concept of «ideal product» is proposed for the study of mass transfer during partial freezing of food products by freezing plate. The ideal product is a product, in which number of factors affecting the «real product» (meat) are excluded. These factors include chemical composition of meat, quality grade of raw material (NOR, DFD, PSE), cryoscopic temperature that determines the degree of water transformation into ice, the phenomenon of osmosis, rate of freezing, etc. By using the concept of «ideal product» and its implementation in a physical experiment, it is proved that the “piston effect” causing the migration of moisture is due to frozen crust formation during partial freezing of the body. During partial freezing of the product by freezing plate, «ideal» and «real» food environment is transformed from closed system into open one with inflow of moisture to unfrozen part of the body. In the «ideal product», there is an expulsion of unfrozen moisture from freezing front, so the water appears on the body surface. Thus, the displacement of moisture increases by the same law, according to which the thickness (weight) of frozen layer increases. During partial freezing of ground meat, moisture does not appear on the surface of the product, but hydrates the unfrozen part of meat. The reason of this phenomenon is the expulsion of water during formation of frozen crust and water-binding capacity of meat.

The objective of this study was to evaluate the chemical composition, consumer liking, and consumer acceptability of ground beef with 2 finishing diets. Three ground beef treatments were used in this study and included grass-fed, grain-fed Angus, and grain-fed commodity beef. Ground beef samples were evaluated for consumer sensory response, pH, proximate composition, and fatty acid composition. Grain-fed samples were rated higher (P < 0.01) for overall liking compared to grass-fed samples. Consumers found tenderness and juiciness similar (P > 0.05) for all 3 types of ground beef. Consumers preferred (P < 0.05) Angus over grass-fed ground beef with a flavor acceptability of 83.3 and 73.9%, respectively; and 94.9 and 82.5%, respectively, for overall acceptability. Commodity ground beef had a similar (P > 0.05) flavor acceptability and overall acceptability to Angus and grass-fed ground beef. Grass-fed, Angus, and commodity ground beef were similar (P > 0.05) for moisture, fat, and protein content. Commodity ground beef had a higher pH (P < 0.05) than Angus and grass-fed ground beef. Samples of ground beef from the 2 grain-fed treatments had greater (P < 0.05) total saturated fatty acids (SFA) than grass-fed samples; however, ground beef from grass-fed cattle had higher monounsaturated fatty acids (MUFA; P < 0.01) than the grain-fed treatments. Total polyunsaturated fatty acids (PUFA) was similar (P > 0.01) across all treatments. Omega-3 fatty acids were found in the greatest (P < 0.05) proportions in samples from grass-fed beef. Additionally, the omega-6:omega-3 ratio for grass-fed ground beef was lower (P < 0.05) than grain-fed source. Angus and commodity ground beef were more palatable, and there was no evidence of higher PUFA in grass-fed ground beef.

Abstract Ground bovine meat is commonly consumed by the population of Brazil. However, it constitutes an excellent medium for the multiplication of microorganisms due to available nutrients and handling practices prior to consumption. Here, we examined 100 samples of ground beef for the presence of diarrheagenic Escherichia coli (DEC) pathotypes by PCR, and characterized isolates by analyzing their adherence to HEp-2 cells, serotype, antimicrobial susceptibility, and phylogeny. Enteroaggregative E. coli was detected in five (5%) meat samples, Shiga toxin-producing E. coli in three (3%), and atypical enteropathogenic E. coli in two (2%). According to the phylogeny, six isolates (60%) were classified in group A, two (20%) in group B1, and two (20%) in group E. The detected serotypes were O3:H2, O93:H9, O93:H46, O105ab:H7, O152:H8, O156:H10, and O175:H7. The antimicrobial susceptibility testing showed that one sample (10%) was resistant to ampicillin, two (20%) to sulfamethoxazole-trimethoprim, and two (20%) to cephalothin. Based on these results, bovine ground meat for human consumption can serve as a reservoir of DEC, which emphasizes the importance of appropriate hygienic-sanitary conditions during handling at every stage from slaughter to table.

The utilisation of Moringa oleifera leaves powder (MOLP) to improve the nutritional properties and inhibit lipid oxidation and the proliferation of microorganisms in ground beef during cold storage was examined. The effects of 0.2, 0.4, 0.6, and 0.8% MOLP on the nutritional properties (proximate composition, total phenolic and total flavonoid content), thiobarbituric acid reactive substances (TBARS), microbial composition, physicochemical characteristics (pH value, colour attributes, and cooking properties), and sensory analysis of ground beef were investigated. The findings showed that ash, protein, polyphenolic compounds, pH, colour, and microbial growth increased significantly, while moisture, fat content, and TBARS decreased significantly, with an increase in the concentration of MOLP during cold storage. Moderate levels (0.2 and 0.4%) of MOLP did not affect the sensory attributes of stored ground beef. Evidently, MOLP can be utilised as a natural preservative in ground beef to improve the nutritional value and inhibit lipid oxidation.

A predictive mathematical model of the effect of temperature (10–47 °C) on the growth of Escherichia coli O157:H7 in natural contaminated ground beef was developed. The estimated values for the cardinal parameters T min , T max , T opt and the optimum maximum specific growth rate (μ opt) of E. coli O157:H7 were found to be 3.36, 46.87, 43.16 °C and 1.385/h, respectively. The developed model was further validated against observed growth of E. coli O157:H7 in ground beef at non – isothermal chilling conditions by using two periodically changing temperature profiles with temperature ranging from 0 to 15 °C. Overall the model predicted satisfactorily the growth of E. coli O157:H7 in ground beef at dynamic temperature conditions. The model was combined with temperature data collected from ground beef chill chain in Greece in order to assess the growth of the pathogen from purchase of the product at retail to consumption. Retail storage average temperature from 50 retail cabinets in Greek super markets ranged from 0.1 to 7.4 °C with a mean of 3.2 °C and a mean standard deviation of 1.7 °C. The predicted growth of the pathogen after 7 days of storage at retail ranged between 0 and 2.03 log 10 CFU/g, with an average growth to 0.31 log 10 CFU/g. The growth of the pathogen during transportation from retail to domestic refrigerators ranged between 0.03 and 0.45 log 10 CFU/g, with an average growth to 0.16 log 10 CFU/g. The average temperature of 160 domestic refrigerators ranged from −2.7 to 18.1 °C. Differences in the temperature among the shelves of the refrigerators were observed. The predicted growth of E. coli O157:H7 in ground beef stored in domestic refrigerators for 1 day ranged between 0.00 and 2.3 log 10 CFU/g. For a scenario storage of ground beef in retail for 3 days, transportation from retail domestic refrigerators over a period of 6 h and storage in domestic refrigerators for 3 days the 99th percentile of the total growth was 4.83 log 10 CFU/g for storage at the upper self of the domestic refrigerator. The data and models provided in the present work can be further used in a quantitative risk assessment model of E. coli O157:H7 in ground beef consumed in Greece. Unlabelled Image • A predictive model was developed for Escherichia coli O157:H7 growth in ground beef. • Validation at dynamic temperature conditions showed a good performance of the model. • Data on temperature conditions during ground beef storage in the Greek chill chain were collected. • The model was combined with temperature data to predict the growth of the pathogen. • Data and models can be used for risk assessment of E.coli O157:H7 in ground beef consumed in Greece. [ABSTRACT FROM AUTHOR]

Shiga toxin-producing Escherichia coli (STEC) can cause from watery diarrhea to severe diseases, such as thrombocytopenic purpura (TP) or hemolytic uremic syndrome (HUS). Ruminants are the main reservoir; most of the time humans are infected through the ingestion of contaminated meat. The goal of this study was the detection of stx1 and stx2 genes through the standardization of a real time PCR method that uses SYBR green, and then we used this method to analyze the presence of STEC in ground beef from butcheries of the metropolitan zone of Asuncion, Paraguay. We analyzed 48 ground beef samples from 24 butcheries. They were processed by standard methods of culture and DNA extraction. Real-time PCR reactions were standardized for the detection of stx1 and stx2. Both genes were detected in the 48 samples studied. The concordance between this method and a conventional PCR technique was excellent, showing kappa concordance indexes of 0.76 for stx1 and 0.87 for stx2. Even though the high levels of contaminated ground beef detected, all the isolates were LEE negatives and O157 negatives, which are less related to outbreaks and severe diseases. The most common virulence profile was stx1/stx2/saa/exhA. With this finding, we have proven the need for preventive procedures in the slaughter process and the handling process of meat products. [ABSTRACT FROM AUTHOR]