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Abstract: This study aimed to evaluate the potential of near infrared spectroscopy (NIRS) as a fast and non-destructive tool for detecting and quantifying different adulterants in fresh and frozen-thawed minced beef. Partial least squares regression (PLSR) models were built under cross validation and tested with different independent data sets, yielding determination coefficients (R P 2) of 0.96, 0.94 and 0.95 with standard error of prediction (SEP) of 5.39, 5.12 and 2.08% (w/w) for minced beef adulterated by pork, fat trimming and offal, respectively. The performance of the developed models declined when the samples were in a frozen-thawed condition, yielding R P 2 of 0.93, 0.82 and 0.95 with simultaneous augments in the SEP of 7.11, 9.10 and 2.38% (w/w), respectively. Linear discriminant analysis (LDA), partial least squares-discriminant analysis (PLS-DA) and non-linear regression models (logistic, probit and exponential regression) were developed at the most relevant wavelengths to discriminate between the pure (unadulterated) and adulterated minced beef. The classification accuracy resulting from both types of models was quite high, especially the LDA, PLS-DA and exponential regression models which yielded 100% accuracy. The current study demonstrated that the VIS-NIR spectroscopy can be utilized securely to detect and quantify the amount of adulterants added to the minced beef with acceptable precision and accuracy. [Copyright &y& Elsevier]

Abstract: A survey of diarrhoeagenic Escherichia coli (DEC) was carried out on 21 minced beef and 21 boerewor (a traditional South African fresh sausage) samples purchased from 30% of butcheries in the Bloemfontein District of South Africa. The samples were cultivated on standard plate count agar for aerobic plate counts and chromocult coliform agar for coliform and E. coli counts without enrichment. Diarrhoeagenic E. coli were isolated after enrichment in MacConkey broth followed by cultivation on chromocult coliform agar. The resultant E. coli colonies were selected and serotyped using the slide agglutination test for DEC. Eight (38.10%) minced beef samples were positive for DEC. The 8 positive samples consisted of 5 (23.81%) EPEC and 1 each (4.76%) of EIEC, EAggEC, and VTEC. A total of 100 isolates were serotyped (5 from each sample) and these comprised 6 (6%) EPEC serotypes (3×O18; 1×O125; and 1×O142), and 1 (1%) each of EIEC (1×O128ac), EAggEC (1×O44) and VTEC (1×O26). Boerewors had 6 (28.57%) samples that were positive for DEC. EPEC and VTEC were the virotypes that were isolated at 23.81% (5/21) and 4.76% (1/21) respectively. A total of 105 isolates were serotyped (5 from each sample) and these comprised 7 (6.66%) EPEC (3×O18, 2×O125, 1×O55 and 1×O142); and 1 (0.95%) VTEC (1×O26). EPEC were the most frequent virotype while VTEC were the most virulent virotype recovered from both products. No E. coli O157:H7 were recovered. [Copyright &y& Elsevier]

Abstract: This study examined the effect of adding essential oils of hyssop and coriander at the highest concentration (0.02% v/w) sensorially acceptable to a panel of assessors on the microbiological and biochemical characteristics of stored ground beef. Vacuum-packed meat was stored at 0.5±0.5°C and 6±1°C for 15days. The greatest beneficial effect of both additives was in inhibiting the development of undesirable sensory changes (extending acceptability by up to 3days) and the growth of Enterobacteriaceae (by up to approximately 1–2 log cycles compared with the controls). The effect on lactic acid bacteria, total viable bacterial count and other groups of microorganisms investigated was minor (up to 1 log cycle) and similar for both oils. Neither did these additives significantly affect amino nitrogen levels, protease activity, the proportions of meat pigments, protein electropherograms and pH levels. This indicates the limited effect of these essential oils in the concentrations applied on preserving vacuum-packed minced beef. [Copyright &y& Elsevier]

Essential oils (EOs) extracted by hydrodistillation from leaf parts of Algerian Eucalyptus globulus, Myrtus communis and Satureja hortensis were analyzed by gas chromatography/mass spectrometry (GC/MS). The main components of EOs obtained were γ-terpinene (94.48%), 1,8-cineole (46.98%) and carvacrol (46.10%), respectively, for E. globulus, M. communis and S. hortensis. The in vitro antimicrobial activity of the EOs was evaluated against Staphylococcus aureus CECT 4459 and Escherichia coli O157:H7 CECT 4267 using the agar diffusion technique. Results revealed that E. globulus and S. hortensis EOs had more antibacterial effects than that from M. communis. Minimal inhibitory concentrations (MIC) showed a range of 0.05–0.22% (volume by volume [v/v]). Sensitivity of gram-positive S. aureus was much higher than that of gram-negative E. coli. Plant EOs were added to minced beef (two-fold MIC value) at 0.10–0.44%, experimentally inoculated with the same pathogens at a level of 5 × 105 colony forming units (cfu)/g and stored at 5 ± 2 °C. Results showed that the EOs of E. globulus and S. hortensis had remarkable antibacterial properties, higher than that of M. communis, against S. aureus and E. coli. Indeed, a reduction of 5.8 log cfu/g (70.74% of reduction) was recorded after 7 days of storage for S. hortensis against E. coli. However, regarding S. aureus, both S. hortensis and E. globulus caused a highly significant (p < 0.05) decrease of microbial counts, most evident after 5 days of storage; S. aureus numbers were 3.50 and 2.50 cfu/g, respectively, corresponding to a reduction of 2.20 and 3.20 log cfu/g (38.60 and 56.14% of reduction) after 1 week of storage. Sensory evaluation revealed that the aroma of minced beef meat treated with EOs was acceptable by panelists at the levels used. [ABSTRACT FROM PUBLISHER]

The present study was undertaken to determine the incidence and distribution of Salmonella species in selected meat and chicken products purchased from retail supermarkets in Assiut, Egypt. Atotal of 75 samples including 25 samples each of minced frozen beef, frozen chicken legs and frozen chicken fillets were collected over a 7-month period between January and July 2009 and examined for the presence of Salmonella species. In addition, 28 children stool cultures were collected from hospitalized children resident in Pediatric University Hospital with diarrhea or fever. Out of the total 75 meat samples examined, Salmonella was detected in 5 (20%) of minced frozen beef, 9 (36%) of frozen chicken leg and 13 (52%) of frozen chicken fillet samples analyzed. Regarding the examined 28 children stool cultures, 3 (10.71 %) were found Salmonella positive. Of the total 30 Salmonella positive samples from all examined samples, five selected Salmonella isolates were further identified using multiplex PCR (m-PCR). Two serovars were the dominant serovar identified was Salmonella entrica subsp. entrica serovar Enteritidis (2 chicken leg isolates and 2 chicken breast fillets) followed by Salmonella entrica subsp. entrica serovar Kentucky (one minced beef isolate). The public health hazards of Salmonella were discussed and the suggestive measures to protect the consumers and improve the quality of meat and chicken products were given. [ABSTRACT FROM AUTHOR]

Abstract: Meat freshness has been monitored by various microbiological, chemical and sensorial indices. However, these methods are slow and not suited to automation. Infrared spectroscopy is one of the most convenient analytical tools which could be used to monitor the evolution of food quality. The aim of this work was to investigate the ability of both NIR (Near Infrared) and MIR (Mid Infrared) spectroscopy to follow meat freshness decay. The minced beef was packaged in high-oxygen modified atmosphere (30% CO2 and 70% O2) and stored at three temperatures. Spectra were collected by Fourier-Transformation (FT)-NIR and FT-IR instruments. PCA, applied to the data, was able to discriminate samples on the basis of storage time and temperature. The modelling of PC scores versus time allowed the setting of the time of initial freshness decay for the samples (6–7days at 4.3°C, 2–3days at 8.1°C and less than 1day at 15.5°C). [Copyright &y& Elsevier]

The effect of various concentrations of sage (Saliva oficinalis) on the microbial quality and the shelf-life of minced beef mixed with soyprotein was investigated. For this purpose, minced beef mixed with soyprotein samples were divided into four groups. First group was kept as a control group, others ones were treated with 0.1%, 0.3% and 0.5% sage extract. All samples were stored at 4°C and microbiological evaluation was conducted at intervals of 0, 1, 3, 5 and 7 days post-storage for aerobic, anaerobic, enterobacteriaceae, yeast-mould, Bacillus cereus and Staphylococcus aureus counts. Minced beef pose a risk of food-borne infection or intoxication due to existence and growth of B. cereus and S. aureus. Sage extract concentration of 0.3% and 0.5%, signiicantly reduced aerobic, anaerobic, enterobacteriaceae, yeast-mould, B. cereus and S. aureus counts in the samples. Control and 0.1% sage groups did not comply with the Egyptian Standards Criteria for total aerobic counts when compared to other groups within the seven days of shelf-life. The results indicated that 0.3% and 0.5% sage extract improved the microbiological quality and prolonged the shelf-life of the minced beef mixed with soyprotein to seven days of retail displayed when stored at 4°C. [ABSTRACT FROM AUTHOR]

Aims: To investigate the influence of aerobic or vacuum pack storage of beef trimmings on the microbiology, colour and odour of subsequently produced mince. Methods and Results: Trimmings stored aerobically for 7 or 10 days and in vacuum packs for 7, 10, 14 or 22 days at 0 or 5°C were minced, stored aerobically at 0 or 5°C for up to 7 days and examined daily to determine Total viable, Pseudomonas, Lactic acid bacteria, Brochothrix thermosphacta, and Enterobacteriaceae counts, colour and odour. Mincing reduced counts, particularly of Pseudomonas, B. thermosphacta and Enterobacteriaceae, probably because of the action free radicals released from muscle and bacterial cells. Storage of vacuum-packed trimmings for 22 days resulted in improved mince colour and inhibition of the growth of Pseudomonas. Conclusions: The shelf life of mince from trimmings is directly influenced by the trimmings storage conditions, and longer-term vacuum storage of trimmings produced improvements in mince quality. Significance and Impact of the Study: There appears to be no scientific rationale for limiting the storage of vacuum packaging beef trimmings to 15 days, prior to mince production, as stated in EU 835/2004. This study identifies advantages in storing trimmings in vacuum packs for at least 21 days prior to mincing, in terms of improved mince quality. [ABSTRACT FROM AUTHOR]

The present research was conducted to check the presence of Listeria spp. in some meat and chicken products purchased from retail supermarkets in Assiut (Egypt). A total of 100 samples including 25 samples each of minced frozen beef, luncheon, frozen chicken legs and frozen chicken breast fillets were collected over a 7-month period between January and July 2009 and analyzed for the presence of Listeria spp. In addition, 28 stool cultures examined for Listeria spp. from hospitalized children resident in Assiut Pediatric University Hospital with diarrhea or fever. Out of the total 100 meat samples examined, Listeria spp. were detected in 8 (32%) of minced frozen beef, 8 (32%) of luncheon, 13 (52%) of frozen chicken leg and 14 (56%) of frozen chicken fillet samples analyzed, respectively. Regarding the examined 28 stool cultures from hospitalized children with underlying disease in Assiut Univ. hospital, 2 (7.14%) were found positive for Listeria spp. For identification of L. monocytogenes using polymerase chain reaction (PCR), two primers were selected to detect 217-pb fragment ofthe prfA (transcriptional activator of the virulence factor) gene for L. monocytogenes. 13 selected Listeria isolates displayed beta-haemolysis on sheep blood agar and positive CAMP test were further identified using PCR. PCR results showed that L. monocytogenes were confirmed in one of minced imported frozen meat examined, two of luncheon samples and two of frozen chicken legs with the total incidence of 5 isolates (5%) from the total 100 examined food samples. This suggests the presence of a significant public health hazard linked to the consumption of these meat and chicken products sold in Assiut city contaminated with L. monocytogenes. The public health significance of these pathogens as well as recommended sanitary measures was discussed. [ABSTRACT FROM AUTHOR]

Abstract: Verocytotoxin-producing Escherichia coli (VTEC) are foodborne pathogens that cause outbreaks linked to consumption of meat and raw milk. In this note the authors report results obtained from a survey conducted on minced beef and raw bovine milk samples using a Multiplex PCR (M-PCR) for the detection of eae, stx 1, stx 2 and hlyA genes as a screening step followed by a colony blot hybridization (CBH) technique for the isolation of the VTEC. Of 100 minced beef and 123 raw milk samples, 13 (13%) and 7 (5.7%) were positive in the M-PCR and among these 9 and 3 strains were isolated using CBH, respectively. All isolates showed the presence of the stx 2 gene, single or in association with the other investigated genes. None of the isolates belonged to the O157, O26, O91, O103, O111 and O145 serogroups. The study showed that the use of M-PCR for the screening of samples coupled with a sensitive and specific detection technique, could improve the possibility of detection of VTEC strains in foods. Moreover, the presence of VTEC in minced beef and in raw milk confirms their important role as putative vehicles of infection to humans. Stringent control of these foodstuffs is essential for food safety purposes. [Copyright &y& Elsevier]

Abstract: The aims were: (1) to follow the freshness decay of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures (4.3, 8.1 and 15.5°C) by applying traditional methods (microbiological counts, color evaluation, thiobarbituric acid assay TBA, headspace gas composition) and e-nose; (2) to model the decay kinetics to obtain information about the maximum shelf life as function of storage conditions. The minced beef, packaged in modified atmosphere was supplied by a manufacturer at the beginning of its commercial life. The study demonstrated the ability of the traditional methods to describe the kinetics of freshness decay. The modeling of the experimental data and the comparison with microbiological or chemical thresholds allowed the setting, for each index, of a stability time above which the meat was no longer acceptable. The quality decay of meat was also evaluated by the headspace fingerprint of the same set of samples by means of a commercial e-nose. A clear discrimination between “fresh” and “old” samples was obtained using PCA and CA, determining at each temperature a specific range of stability time. The mean value of the stability times calculated for each index was 9days at 4.3°C (recommended storage temperature), 3–4days at 8.1°C (usual temperature in household refrigerators) and 2days at 15.5°C (abuse temperature). Resolution of the stability times allowed calculation of mean Q10 values, i.e. the increase in rate for a 10°C increase in temperature. The results show that the Q 10 values from the traditional methods (3.6–4.0 range) overlapped with those estimated with e-nose and color indexes (3.4 and 3.9, respectively). [Copyright &y& Elsevier]

Aims: The present study aimed to assess the Arcobacter contamination on bovine carcasses postevisceration and postcooling in two slaughterhouses and in ready-to-eat minced beef. Methods and Results: Carcasses ( n = 247) were sampled at four sites in two slaughterhouses and 100 minced beef samples were collected at retail. Isolation was performed by a quantitative and qualitative Arcobacter selective method, and the isolates were identified by multiplex PCR, after which a part of them were characterized by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Although arcobacters were isolated from 37% of the bovine carcasses postevisceration with the chest and the foreleg as most contaminated sites, cooling the carcasses for at least 24 h reduced the incidence of Arcobacter (7%) on the carcass surface significantly. Arcobacter butzleri was the species most frequently isolated, although co-contamination with multiple species also occurred. At retail, arcobacters were present in 9% of the minced beef samples, with Arcobacter butzleri as the dominant species. Conclusions: Forced air cooling of bovine carcasses for at least 24 h decreased the number of positive carcasses, but did not eliminate all arcobacters. Significance and Impact of the study: This study demonstrates that maintaining good hygiene practices throughout the food supply chain is crucial to ensure safe food products at the consumer level. [ABSTRACT FROM AUTHOR]

Copyright of Revista Veterinaria is the property of Universidad Nacional del Nordeste and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Fourier transform infrared (FTIR) spectroscopy was exploited to measure biochemical changes within fresh minced beef in an attempt to rapidly monitor beef spoilage. Minced beef packaged either aerobically, under modified atmosphere and using an active packaging were held from freshness to spoilage at 0, 5, 10, and 15°C. Frequent FTIR measurements were collected directly from the sample surface using attenuated total reflectance, in parallel the total viable counts of bacteria, the sensory quality and the pH were also determined. Principal components analysis allowed illuminating the wavenumbers potentially correlated with the spoilage process. Qualitative interpretation of spectral data was carried out using discriminant factorial analysis and used to corroborate sensory data and to accurately determine samples freshness and packaging. Partial least-squares regressions permitted estimates of bacterial loads and pH values from the spectral data with a fit of R 2 =0.80 for total viable counts and fit of R 2 =0.92 for the pH. Obtained results demonstrated that a FTIR spectrum may be considered as a metabolic fingerprint and that the method in tandem with chemometrics represents a powerful, rapid, economical and non-invasive method for monitoring minced beef freshness regardless the storage conditions (e.g. packaging and temperature). [Copyright &y& Elsevier]

Copyright of MESO is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Oxygen-enriched modified atmosphere packaging (MAP) represents an important means to stabilize meat colour but may lead to an increase in lipid oxidation, influencing the acceptability and safety of the product. In this work, the effect on cholesterol and lipid susceptibility to oxidation was investigated in commercial minced beef held under MAP (80% O2/20% CO2). Cholesterol oxidation products (COPs), peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) were determined, before and after pan frying, at 1, 8 and 15 days since packaging under refrigerated storage (3–4°C). 7α-Hydroxycholesterol, 7β-hydroxycholesterol and 7-ketocholesterol were the more abundant COPs identified. COPs significantly increased in raw beef during storage: after 1, 8 and 15 days since packaging COPs were at the levels of 10.4, 30.7 and 60.5μg/g of fat, respectively. Cooking did not affect cholesterol oxidation in freshly packaged minced beef but led to a rise in COPs amount with respect to raw muscle after 8 and 15 days of storage. The trend in cholesterol oxidation reflected the progressive increase in lipid peroxidation rate brought by MAP conditions. [Copyright &y& Elsevier]

Objectives: Thyrotoxicosis is produced by excessive quantities of thyroid hormone. Its most common causes involve inflammation of the thyroid gland. Much more rarely, thyrotoxicosis is due to exogenous intake of thyroid hormones or iodide compounds. Few outbreaks are documented. In 2003 to early 2004, doctors in Minas, Uruguay noted a sharp increase in the incidence of thyrotoxicosis in a neighbourhood, with multiple cases within families. The objective of this study was to identify the source of the outbreak. Study design: A case--control study was conducted following surveillance and environmental inspection. Methods: Case patients were symptomatic residents of Minas with documented thyroid-stimulating hormone concentrations <0.1 µUI/ml or <0.49 µUI/ml and elevated free triiodothyronine or free thyroxine. Control subjects were frequency matched with case patients by barrio of residence and age. Case patients, control subjects and persons who prepared and purchased household food were interviewed using a standard questionnaire. Odds ratios adjusted (AOR) for age and gender were calculated by logistic regression in SUDAAN to account for neighbourhood and family clustering. Results: Fifty-nine case patients aged 9-74 years (median 39 years) were identified. Of the 56 interviewed, 52% were women and 71% resided in one barrio. Case patients were more likely than control subjects to eat minced beef at least weekly and purchase it from Butcher A [AOR 6.1 ; 95% confidence interval (Cl) 2.61-14.46], and were more likely to eat chorizo at Least weekly and purchase it from Butcher B (AOR 11.6; 95% Cl 1.30-102.27). One beef supplier selling meat cuts containing thyroid gland was identified. Conclusions: The most likely cause of this outbreak of thyrotoxicosis was consumption of minced beef and chorizo contaminated with thyroid gland. Tight regulation and oversight of slaughter, processing, and sates of meat and meat products are imperative for prevention of future outbreaks. [ABSTRACT FROM AUTHOR]

Abstract: The antimicrobial effect of thyme essential oil (EO) at supplementation levels of 0.3%, 0.6% or 0.9%, nisin at 500 or 1000IU/g, and their combination, on Escherichia coli O157:H7 was examined in both tryptic soy broth (TSB) and minced beef meat. EO at 0.3% possessed a weak antibacterial activity against the pathogen in TSB, whereas at 0.9% showed unacceptable organoleptic properties in minced meat. Thus, only the level of 0.6% of EO was further examined against the pathogens in minced meat. Treatment of minced beef meat with EO at 0.6% showed an inhibitory activity against E. coli O157:H7 during storage at 10°C, but not at 4°C. Treatment of minced beef meat or TSB with nisin at 500 or 1000IU/g did not show any antibacterial activity against E. coli O157:H7. The combination of EO at 0.6% and nisin at 500 or 1000IU/g showed an additive effect against the pathogen, which was higher during storage at 10°C than at 4°C. [Copyright &y& Elsevier]

Abstract: The effect of preservatives on microbial quality, pH, drip-loss, roasting-loss, colour, and sensorial properties of modified atmosphere packaged (70% O2 and 30% CO2) minced beef (M. semimembranosus) stored at (2±0.5°C) for 12days was investigated. Beef cubes (approx. 20×20×20mm size) were immersed in solutions of 2% and 5% lactic acid, 2% lactic acid combined with 0.5% sodium ascorbate, 20% potassium lactate and 20% potassium sorbate before mincing. Addition of lactic acid was associated with pH drop, which increased drip-loss and roasting-loss. Application of all additives inhibited aerobic micro-organisms (103–104 CFUg−1 on day 12) compared to reference sample (9×105 CFUg−1 on day 12). Lactic acid discoloured samples, while sodium ascorbate seemed to improve colour stability. Despite good visual colour characteristics, potassium sorbate treated samples were organoleptically unacceptable with massive off-flavour. [Copyright &y& Elsevier]

Abstract: The antimicrobial effect of thyme essential oil (EO) at 0.3%, 0.6%, or 0.9%, nisin at 500 or 1000IU/g, and their combination against Listeria monocytogenes was examined in both tryptic soy broth (TSB) and minced beef meat. Thyme EO at 0.3% possessed a weak antibacterial activity against the pathogen in TSB, whereas at 0.9% showed unacceptable organoleptic properties in minced meat. Thus, only the level of 0.6% of EO was further examined against the pathogen in minced meat. Treatment of minced beef meat with nisin at 500 or 1000IU/g showed antibacterial activity against L. monocytogenes, which was dependent on the concentration level of nisin and the strains used. Treatment of minced beef meat with EO at 0.6% showed stronger inhibitory activity against L. monocytogenes than treatment with nisin at 500 or 1000IU/g. All treatments showed stronger inhibitory activity against the pathogens at 10°C than at 4°C. The combined addition of EO at 0.6% and nisin at 500 or 1000IU/g showed a synergistic activity against the pathogen. Most efficient among treatments was the combination of EO at 0.6% with nisin at 1000IU/g, which decreased the population of L. monocytogenes below the official limit of the European Union recently set at 2logcfu/g, during storage at 4°C. [Copyright &y& Elsevier]

Aims: To provide information on detection of Shiga toxin-producing Escherichia coli (STEC) in retail-minced beef using an approach combining (i) PCR-based techniques and automated immunoassay for stx screening and detection of the five major serogroups associated with human infection, and (ii) immunomagnetic separation (IMS) and colony hybridization assays for bacterial strain isolation. Methods and Results: Twenty-seven out of 164 minced beef samples were stx-positive by PCR-ELISA, nine of which were also positive by real-time PCR for at least one marker of the five main serogroups tested (O26, O103, O111, O145 and O157). Two E. coli O103 stx-negative strains were isolated from two out of 10 IMS and nine STEC strains that did not belong to the five main serogroups were isolated by colony hybridization. Conclusions: PCR techniques are applicable for rapid screening of samples containing both an stx gene and an O-group marker of the five main pathogenic STEC serogroups. Isolation of STEC strains belonging to the main non-O157 serogroups remains difficult. Significance and Impact of the Study: This study presents an evaluation of a multi-faceted approach for the detection of the most frequently reported human pathogenic STEC serogroups. The advantages and limits of this strategy are presented. [ABSTRACT FROM AUTHOR]

Abstract: Verocytotoxin-producing Escherichia coli (VTEC) non-O157 serogroups are among the most important emerging food-borne pathogen groups. In particular, the O26 serogroup is able to cause a large spectrum of illnesses in humans which have a significant public health impact as they may range from haemorrhagic colitis (HC) to haemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). It is known that VTEC organisms are associated with animal reservoirs, i.e. ruminants, and foods of animal origin, especially undercooked meat and raw milk, are often involved in outbreaks. In this study, 250 minced beef samples collected at retail outlets in southern Italy were tested for the presence of E. coli O26 and the isolates were characterized and studied for their antimicrobial resistance properties. Three minced beef samples (1.2%) tested positive for E. coli O26; one isolate per positive sample was characterized. One isolate harboured the genes encoding for virulence factors intimin (eaeA) and enterohaemolysin (hlyA), while none presented verocytotoxin-encoding genes (stx1 and stx2) and all were negative at the verotoxicity assay. All the isolates showed resistance properties to at least four antimicrobial agents tested and two were multi-drug resistant (MDR). Although no verocytotoxin-encoding genes were found in the isolates, the presence of potentially pathogenic E. coli O26 strains in minced beef points to the need for proper hygiene during meat production to reduce the risk of food-borne illnesses and transmission of MDR organisms via foods to humans. This paper is the first report on the presence and characterization of E. coli O26 in minced beef marketed in Italy. [Copyright &y& Elsevier]

Abstract: An Arrhenius model and survival analysis are introduced to analyze data based on consumers acceptance or rejection of samples stored at different times and different temperatures. Sample data comprises 60 consumers who observed raw minced beef samples stored at 2°C, 9°C and 19°C, with seven different storage times for each temperature, answering yes or no as to whether they would accept the samples. An activation energy of 15.3kcal/mol was estimated from this censored data set, and shelf-life predictions for temperatures outside the tested temperature range were obtained. In the present study it was found that experimental storage at three temperatures was necessary to obtain satisfactory shelf-life estimations for temperatures outside the tested range. [Copyright &y& Elsevier]

Abstract: This study compared an immuno-magnetic separation (IMS)/culture method and a real-time PCR method to detect Verocytotoxigenic Escherichia coli (VTEC) serovar O26 and/or O111 in minced beef. A total of 65 samples were examined, 40 of which were frozen beef samples previously established as containing E. coli O157, and 25 were samples of fresh minced beef, purchased from butcher shops in the Dublin area. After selective enrichment, all samples were (a) subjected to IMS, plated on differential media and identified as E. coli O26 or O111 using biochemical and immuno-logical methods; and (b) subjected to DNA extraction and real-time PCR analysis using primers and probes against E. coli O111 and O26 serovar specific genes, and verotoxin genes. Overall, from the 65 minced beef samples collected, three were positive for E. coli O26 by real-time PCR, with only one of these samples positive for E. coli O26 by the culture method. One sample was positive for E. coli O111 by both real-time PCR and the culture method. The two samples found positive for E. coli O26 by real-time PCR method but not by culture method belonged to the group of frozen beef samples, indicating that the previously developed culture method for the detection of E. coli O26 may not be suitable for the detection of freeze injured cells. In conclusion, this study highlights the role of beef meat in the transmission of non-O157 VTEC. The results of the study emphasize that the analyses for emergent pathogens should be included in food safety surveillance systems and that the development of standard methods for the detection of E. coli O26 and O111 in routine food testing is needed in order to reduce the consumer exposure to contaminated food. [Copyright &y& Elsevier]

Abstract: This study investigated the prevalence and numbers of Enterobacteriaceae in minced beef and beef burgers purchased from supermarkets and butcher shops in the Republic of Ireland (RoI). Samples (n=1303) collected between June 2001 and April 2002 from every county in the RoI (∼60 per county) were examined for the presence of Enterobacteriaceae using method BS 5763. Overall, in the 43 beef products in which E. coli O157:H7 was present the Enterobacteriaceae counts ranged from 0.52 to 6.98log10 cfug−1. There was no correlation between the number of Enterobacteriaceae and the presence of E. coli O157:H7. There were no significant differences between Enterobacteriaceae numbers in fresh, unpackaged, minced beef samples from butcher shops and supermarkets, or in fresh, unpackaged, beef burgers from butcher shops and supermarkets. However, there were significant differences among the numbers of Enterobacteriaceae detected in different minced beef products. The numbers of Enterobacteriaceae in fresh, unpackaged, minced beef (6.54–6.98log10 cfug−1) were considerably higher than in preprepared or prepackaged minced beef (2.95–3.62log10 cfug−1). [Copyright &y& Elsevier]

Abstract: Ohmic heating is an alternative fast heating method for food products. In this study, the tylose samples having different salt concentrations and minced beef samples having different fat contents were heated at five different voltage gradients in the range of 10–50V/cm. The electrical conductivity–temperature relationships were observed to be linear below 55–60°C for all voltage gradients applied. It was found that the tylose samples having 0.5% and 0.67% salt contents gave similar ohmic heating rates and the electrical conductivity variations with the minced beef samples having higher and lower fat contents, respectively. The system performance coefficients for tylose samples were in the range of 0.41–0.53, and those of the minced beef samples were in the range of 0.36–0.48. The predictions of the mathematical model for the system performance coefficient were found to be very accurate (P<0.01). [Copyright &y& Elsevier]

s.b. o'brien, g. duffy, d. daly, j.j. sheridan, i.s. blair and d.a. mcdowell. 2005. To assess the detection and recovery rates achieved with commonly used cultural methods for the enumeration and recovery of Escherichia coli O157:H7 from minced beef and bovine hide. Minced beef and bovine hide were inoculated with varying concentrations (log10 1·58–2·58 CFU g−1 and log10 2·42–4·49 CFU 100 cm2 respectively) of E. coli O157:H7 and recovered using a direct plate method or an enrichment/immunomagnetic separation (IMS) method and then plated onto SMAC or SMAC-CT in both cases. The direct plate method detected the pathogen consistently from minced beef samples with an average recovery of 69·2–91·2%. From faecal material on the bovine hide the recovery of the pathogen ranged from 1·80 to 64·5% with fresh faeces depending on the inocula while from dried faeces on hide the results ranged from no recovery at all to 25·1%. Enrichment/IMS recovered E. coli O157:H7 at all inocula levels tested in minced beef while the pathogen was only detected consistently at an average inocula level of log10 2·73 CFU 100 cm2 from fresh faeces and log10 4·49 CFU 100 cm2 from dried faeces on bovine hide. The direct count enumeration method for E. coli O157:H7 underestimated the numbers of pathogens present. The enrichment/IMS procedure consistently detected the pathogen from minced beef but did not always detect E. coli O157:H7 from faeces on bovine hide. Overall this study highlights that any microbial data, used in either predictive microbiology or risk assessment, must take account of the sensitivity and associated performance of the methods employed, in order to make an accurate reflection of the true microbiology of the examined sample. [ABSTRACT FROM AUTHOR]

In this study, enrichment procedures and two recovery methods, a membrane surface adhesion technique and an immunomagnetic separation (IMS), were compared for use in conjunction with a multiplex polymerase chain reaction (PCR) method with a view to describing a fast (24 h) and economical test for detection of Escherichia coli O157:H7 in meat samples. The study showed no significant difference between three different enrichment media (BHI, E. coli (E.C.) broth+novobiocin, modified tryptone soya broth (mTSB)+novobiocin) or two incubation temperatures (37 or 41.5 °C) for growth of E. coli O157:H7 in minced beef. Minced beef samples inoculated with E. coli O157:H7 at 40 cfu g−1 were incubated at 37 °C for 16 h in E.C. broth+novobiocin reaching numbers of (log107.82–8.70). E. coli O157:H7 were recovered by attachment to polycarbonate membranes immersed in the enriched cultures for 15 min or by immunomagnetic separation. Subsequent treatment of recovered membranes or IMS beads with lysis buffer and phenol/chloroform/isoamyl alcohol was used to extract the DNA from the extracted E. coli O157:H7 cells. The results show when E. coli O157:H7 was present at high levels in the enriched meat sample (log109.6–7.5 cfu ml−1; >16-h enrichment), the membrane and IMS techniques recovered similar levels of the pathogen and the microorganism was detectable by PCR using both methods. At lower levels of E. coli O157:H7 (log106.4), only the IMS method could recover the pathogen but at levels below this neither method could recover sufficient numbers of the pathogens to allow detection. The conclusion of the study is that with sufficient enrichment time (16 h) the membrane surface adhesion membrane extraction method used in combination with multiplex PCR has the potential for a rapid and economical detection method. [Copyright &y& Elsevier]

A total of 3879 samples of foodstuffs were examined for the presence of Verocytotoxin-producing Escherichia coli O157 (VTEC O157). The survey was conducted by 9 of the 10 Italian Veterinary Public Health Laboratories. Samples were collected between May 2000 and September 2001 in 14 regions and comprised 931 minced beef specimens and 2948 dairy products (DP) with less than 60 days of ripening. The DP included 657 pasteurised and 811 unpasteurised bovine DP, 477 pasteurised and 502 unpasteurised ovine DP, and 501 water-buffalo''s milk mozzarella cheese. Samples were collected at retail level, from plants processing minced beef and dairy plants and from farms directly manufacturing cheeses. All the samples were tested using a sensitive procedure based on ISO/DIS 16654:1999 (later ISO 16654:2001), which includes an immunomagnetic separation step. A preliminary inter-laboratory trial was organised with artificially contaminated samples to assess the ability of all the participating laboratories to isolate E. coli O157 by the established procedure.VTEC O157 was isolated from four (0.43%) of the minced beef samples, collected in four different regions and during different months, but was not detected in any of the dairy products. E. coli O157 VT-eae+ was isolated from one raw cow''s milk cheese. This survey provided national data on the presence of VTEC O157 in foodstuffs, demonstrating a low prevalence of the organism. The survey also encouraged updating of knowledge and procedures on VTEC O157 in laboratories with official responsibility for microbiological testing of foods of animal origin. [Copyright &y& Elsevier]