References of "Delhalle, Laurent"
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See detailChilling of heavy carcasses from double muscled cattle: time-temperature evolution and predictive modelling of growth of Listeria monocytogenes and Clostridium perfringens
Delhalle, Laurent ULg; Collignon, Bertrand; Dehard, Sandrine ULg et al

Poster (2010, August)

The time/temperature combination during carcass chilling is of concern in order to avoid bacterial growth. The chilling speed is lower in carcasses with high muscular development such as large cattle from ... [more ▼]

The time/temperature combination during carcass chilling is of concern in order to avoid bacterial growth. The chilling speed is lower in carcasses with high muscular development such as large cattle from the Belgian Blue breed. Three slaughterhouses were selected for temperature and pH measurements during the chilling process at 6 different days on 4 half carcasses in order to obtain representative data from heavy carcasses with high muscular development. Predictive microbiology was used to evaluate the potential growth of Listeria monocytogenes and Clostridium perfringens on the surface and in the depth of the carcasses. The gamma concept was chosen as secondary model taking into account the effect of temperature, pH and water activity on the selected bacteria during the chilling process. The predicted growth potential of Listeria monocytogenes is influenced by the different environmental conditions of the selected slaughterhouses and could reach 1.4 log CFU/cm² after the chilling process. The potential growth of Clostridium perfringens is limited due to unfavourable conditions during the first hours and to low temperature later. It can be concluded that when the initial level of contaminating bacteria is not excessive the speed at which the carcass is currently chilled is sufficient to limit the growth of these two pathogens and to ensure the product quality [less ▲]

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See detailLa microbiologie prévisionnelle : un nouvel outil de maîtrise de la qualité microbiologique des denrées alimentaires
Delhalle, Laurent ULg; Clinquart, Antoine ULg; Daube, Georges ULg

in Food Science and Law (2010), 2

Les nouveaux outils de microbiologie prévisionnelle permettent de mieux comprendre et de maîtriser le comportement des micro-organismes dans la chaîne alimentaire. La législation européenne récente, dont ... [more ▼]

Les nouveaux outils de microbiologie prévisionnelle permettent de mieux comprendre et de maîtriser le comportement des micro-organismes dans la chaîne alimentaire. La législation européenne récente, dont le but est garantir un niveau élevé de sécurité sanitaire des aliments proposés au consommateur, mentionne cette méthodologie comme outil de référence. Les autorités en charge de la gestion de la santé publique et les industriels ont maintenant à leur disposition des outils leur permettant de comprendre les flux de contamination dans la chaîne alimentaire, de fixer une date limite de consommation, d’optimaliser les processus de transformation et de conservation, et de proposer des aliments sûrs aux consommateurs. Cette discipline offre la possibilité, à travers ses modèles et ses concepts, d’exploiter des données issues d’expérimentations réalisées au laboratoire ou en production et de les convertir en applications qui permettent d’évaluer la stabilité et la sécurité d’une denrée alimentaire. [less ▲]

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See detailModeling Microbial Cross-contamination in Quick Service Restaurants by Means of Experimental Simulations With Bacillus Spores
Baptista Rodrigues, Ana Lúcia ULg; Crevecoeur, Sébastien ULg; Dure, Remi et al

Poster (2010)

Cross contamination has been frequently mentioned as being in the origin of a wide range of food borne outbreaks. Handling of food is one of the ways through which cross contamination may occur. For many ... [more ▼]

Cross contamination has been frequently mentioned as being in the origin of a wide range of food borne outbreaks. Handling of food is one of the ways through which cross contamination may occur. For many different reasons, quick service restaurants are particularly at risk. Due to its importance, cross contamination via the hands should be taken into consideration when carrying out a quantitative risk assessment. The main goal of this study was to determine transfer rates of bacteria to and via the hands, reduction rates of two hand sanitizing procedures and to apply the results to a quantitative microbial risk assessment model. According to our results, handling of a portion of raw minced meat contaminated at 4.104 cfu leads to the presence of 24 cfu on both hands, 3 cfu on ready-to-eat product (RTE) manipulated with unwashed hands, 1 cfu on RTE manipulated with wiped hands and absence on RTE manipulated with washed hands. This study provides adequate quantitative data for quantitative microbial risk assessment. [less ▲]

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See detailChilling of carcasses from double muscled cattle: time-temperature evolution and predictive modelling of growth of Listeria monocytogenes and Clostridium perfringens
Delhalle, Laurent ULg; Collignon, Bertrand; Dehard, Sandrine ULg et al

Poster (2010)

The time/temperature combination during carcass chilling is of concern in order to avoid bacterial growth. The chilling speed is lower in carcasses with high muscular development such as large cattle from ... [more ▼]

The time/temperature combination during carcass chilling is of concern in order to avoid bacterial growth. The chilling speed is lower in carcasses with high muscular development such as large cattle from the Belgian Blue breed. Three slaughterhouses were selected for temperature and pH measurements during the chilling process at 6 different days on 4 half carcasses in order to obtain representative data from heavy carcasses with high muscular development. Predictive microbiology was used to evaluate the potential growth of Listeria monocytogenes and Clostridium perfringens on the surface and in the depth of the carcasses. The gamma concept was chosen as secondary model taking into account the effect of temperature, pH and water activity on the selected bacteria during the chilling process. The predicted growth potential of Listeria monocytogenes is influenced by the different environmental conditions of the selected slaughterhouses and could reach 1.4 log CFU/cm² after the chilling process. The potential growth of Clostridium perfringens is limited due to unfavourable conditions during the first hours and to low temperature later. It can be concluded that when the initial level of contaminating bacteria is not excessive the speed at which the carcass is currently chilled is sufficient to limit the growth of these two pathogens and to ensure the product quality. [less ▲]

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See detailDéveloppement d'un modèle tertiaire pour la prédiction de la croissance de Listeria monocytogenes et Salmonella spp. dans la viande hachée de porc
Delhalle, Laurent ULg; Adolphe, Ysabelle ULg; Jasick, Adeline ULg et al

in Viandes et Produits Carnés (2010), Hors-série

Tertiary models are proposed in order to predict the growth of Listeria monocytogenes and Salmonella spp. in pork minced meat packaged under stretch film. The models have been calculated from challenge ... [more ▼]

Tertiary models are proposed in order to predict the growth of Listeria monocytogenes and Salmonella spp. in pork minced meat packaged under stretch film. The models have been calculated from challenge-tests at 8°C (L. monocytogenes) and 12°C (Salmonella), the meat being artificially contaminated at 2 log cfu pathogen/g. In a second step, they have been validated at 5, 8 and 10°C for L. monocytogenes (r² : 0.94, 0.98 and 0.95) and 8, 10 and 12°C for Salmonella (r³ : 0.80, 0.92 and 0.98). [less ▲]

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See detailDéveloppement d'une méthodologie pour l’appréciation quantitative des risques appliquée à Salmonella dans la viande de porc en Belgique
Delhalle, Laurent ULg

Doctoral thesis (2009)

Following the European legislation on control of Salmonella and other zoonotic agents, effective measures must be taken to detect and control these agents at all stages of the food chain. Therefore, the ... [more ▼]

Following the European legislation on control of Salmonella and other zoonotic agents, effective measures must be taken to detect and control these agents at all stages of the food chain. Therefore, the Belgian FPS Public Health, Food Chain Safety and Environment has decided to fund a research project involving institutions grouped under a consortium in order to develop a Quantitative Microbial Risk Assessment (QMRA) on human salmonellosis following consumption of minced pork meat. To achieve this goal, preliminary steps were necessary. The first task was a survey on available data at all stages of the production chain from public authorities and food business operators. A database was carried out summarizing the working practices in different companies and the microbiological results of the whole production chain. The aim was to study the sources of contamination of pork meat from the slaughterhouse to the preparation at consumer's home. Thanks to collected data, a QMRA model has been built taking into account the production flow. The objective of the model is to provide options to reduce the risk of human salmonellosis due to consumption of minced pork meat. The scenarios were developed on the international situation and the literature to simulate concrete and realistic opportunities to improve the microbiological quality of pork meat. The potential risk factors of contamination associated with production parameters, technical facilities and methods for cleaning/disinfection were evaluated in the 10 largest Belgian slaughterhouses. The results showed high variability concerning Salmonella contamination among these slaughterhouses, with prevalence ranging from 2.6 to 34.3%. The results of linear and logistic regressions revealed that some working practices such as scalding steam, second flaming after polishing and cleaning/disinfection of the splitter machine several times a day are beneficial to reduce contamination by Salmonella. These data were the basis for modelling the slaughter process of pigs in Belgium. Production stages after the slaughterhouse were also studied. The results of bacteriological analysis of seven cutting plants, four minced meat plants of the four largest retailers in Belgium were collected using data from official and self-monitoring. The Salmonella prevalence in cutting meat varies from 0% to 50%. The prevalence of Salmonella in minced meat at the retail level varies from 0.3% to 4.3%. Salmonella concentrations on the carcasses, the meat and minced meat were estimated from semi-quantitative data and were equal to -3.40 ± 2.04 log CFU/cm ², -2.64 ± 1.76 log CFU/g and -2.35 ± 1.09 log CFU/g, respectively. These data provided the basis to build the model for the cutting, mincing, distribution and storages stages of pork meat chain in Belgium. A QMRA model was then developed on the basis of collected data. After validation, scenarios of risk mitigation have been implemented. The number of human salmonellosis due to consumption of minced pork meat in Belgium was estimated at 15,376 cases per year. The results showed that the risk of human salmonellosis could be reduced significantly with efforts made by food business operators, but also by consumers. Following the model, 25% reduction of carcass prevalence at the slaughterhouse would decrease from 45.7% the number of human salmonellosis cases in Belgium. Consumers should also be aware of good hygiene practices during preparation of the meat in household’s kitchen to avoid cross contamination between foods. Following the model, cross-contamination with raw foods during the preparation of meals generates 14,693 cases of salmonellosis each year and the lack of cooking only 683 cases. The number of cases of human salmonellosis could be reduced by improving the food preparation habits in the kitchen to avoid cross contamination. The results of this research are useful for food business operators and public health officials involved in the production of pork. The QMRA presented in this thesis were used to obtain an overview of the Belgian food chain andalso to make recommendations along the production chain. However, these results must be taken with care because, at present time, the application of QMRA in the meat industry has a recurring problem of lack of data. States and companies should undertake studies and provide a better assessment of the situation of the food chain "from farm to fork". [less ▲]

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See detailQuantifying hand cross contamination in food.
Rodrigues, Ana; Dure, Rémi ULg; Delhalle, Laurent ULg et al

Poster (2009, June)

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See detailMETZOON : Development of a quantitative microbial risk assessment for human salmonellosis through household consumption of fresh minced pork méat in Belgium.
Bollaerts, Kaatje; Messens, Winy; Delhalle, Laurent ULg et al

in Risk Analysis : An Official Publication of the Society for Risk Analysis (2009), 29(6), 820-840

A quantitative microbial risk assessment according to the Codex Alimentarius Principles is conducted to evaluate the risk on human salmonellosis through household consumption of fresh minced pork meat in ... [more ▼]

A quantitative microbial risk assessment according to the Codex Alimentarius Principles is conducted to evaluate the risk on human salmonellosis through household consumption of fresh minced pork meat in Belgium. The quantitative exposure assessment is carried out by building a modular risk model, called the METZOON-model, which covers the pork production from farm to fork. In the METZOON-model, the food production pathway is split up in six consecutive modules: (1) primary production, (2) transport & lairage, (3) slaughterhouse, (4) post-processing, (5) distribution & storage and (6) preparation & consumption. All the modules are developed to resemble as closely as possible the Belgian situation making use of the available national data. Several statistical refinements and improved modeling techniques are proposed. The model produces highly realistic results. The baseline predicted number of annual salmonellosis cases is 20513 [st. dev. 9061.45]. The risk is estimated higher for the susceptible population [est. 4.713 × 10−5; st. dev. 1.466 × 10−5] compared to the normal population [est. 7.704 × 10−6; st. dev. 5.414 × 10−6] and is mainly due to cross contamination via cook’s hands and only for a small extent to undercooking. [less ▲]

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See detailSalmonella surveillance and control at post harvest in the Belgian pork meat chain.
Delhalle, Laurent ULg; Saegerman, Claude ULg; Farnir, Frédéric ULg et al

in Food Microbiology (2009), 26

Salmonella remains the primary cause of reported bacterial food borne disease outbreaks in Belgium. Pork and pork products are recognized as one of the major sources of human salmonellosis. In contrast ... [more ▼]

Salmonella remains the primary cause of reported bacterial food borne disease outbreaks in Belgium. Pork and pork products are recognized as one of the major sources of human salmonellosis. In contrast with the primary production and slaughterhouse phases of the pork meat production chain, only a few studies have focussed on the post-harvest stages. The goal of this study was to evaluate Salmonella and Escherichia coli contamination at the Belgian post-harvest stages. E. coli counts were estimated in order to evaluate the levels of faecal contamination. The results of bacteriological analysis from seven cutting plants, four meat-mincing plants and the four largest Belgian retailers were collected from official and self-monitoring controls. The prevalence of Salmonella in the cutting plants and meat-mincing plants ranged from 0% to 50%. The most frequently isolated serotype was Salmonella typhimurium. The prevalence in minced meat at retail level ranged from 0.3% to 4.3%. The levels of Salmonella contamination estimated from semi-quantitative analysis of data relating to carcasses, cuts of meat and minced meat were equal to 3.40 2.04 log CFU/cm2, 2.64 1.76 log CFU/g and 2.35 1.09 log CFU/g, respectively. The E. coli results in meat cuts and minced meat ranged from 0.21 0.50 to 1.23 0.89 log CFU/g and from 1.33 0.58 to 2.78 0.43 log CFU/g, respectively. The results showed that faecal contamination still needs to be reduced, especially in specific individual plants. [less ▲]

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See detailLes Salmonelles au niveau de la production primaire de porcs.
Korsak Koulagenko, Nicolas ULg; Delhalle, Laurent ULg; Daube, Georges ULg

Article for general public (2008)

La problématique des Salmonella spp. en filière animale, quelle que soit la spéculation envisagée, apparaît simple. De nombreux guides et ouvrages y ont été consacrés et, en théorie, il semble aisé de ... [more ▼]

La problématique des Salmonella spp. en filière animale, quelle que soit la spéculation envisagée, apparaît simple. De nombreux guides et ouvrages y ont été consacrés et, en théorie, il semble aisé de s’en débarrasser ou d’empêcher son introduction dans un élevage ou dans un atelier d’engraissement. En pratique, toutefois, la situation est différente et il est constaté que le micro-organisme peut contaminer la chaîne alimentaire en de multiples endroits, que ce soit au stade de la production primaire, dans le secteur abattage et transformation ou bien chez le consommateur. Pour arriver à développer une filière porcine « Salmonella-free », il faut une collaboration complète de tous les acteurs d’une filière, ce qui signifie qu’elle doit être intense et soutenue dans le temps. [less ▲]

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See detailSalmonella dans la filière porcine : de l'abattoir au consommateur
Delhalle, Laurent ULg; Korsak Koulagenko, Nicolas ULg; Daube, Georges ULg

Article for general public (2008)

Suite aux accords internationaux et à la modification de la législation européenne, l’analyse de risque est devenue une démarche systématique pour la maîtrise de la sécurité de la chaîne alimentaire ... [more ▼]

Suite aux accords internationaux et à la modification de la législation européenne, l’analyse de risque est devenue une démarche systématique pour la maîtrise de la sécurité de la chaîne alimentaire. L’analyse de risque permet de donner des réponses concrètes aux responsables de la santé, aux vétérinaires et aux industriels. Cette discipline permet de déterminer le risque pour une population donnée face à un danger, d’estimer le nombre de cas liés suite à l’ingestion d’une denrée contaminée, de simuler les conséquences d’un accident dans la chaîne alimentaire et de présenter les mesures de prévention efficaces. Elle permet également de proposer des scénarii possibles afin de réduire le nombre de cas et les coûts associés, d’évaluer l’effet de l’implémentation de mesures de gestion comme des critères de performance (par exemple des niveaux admissibles de contamination microbienne) ou des critères de traitement (par exemple une durée ou une température à une étape donnée), etc. L’analyse de risque peut être un guide quantitatif utile pour les prises de décision si elle s'appuie sur des études scientifiques solides et si elle est complétée par des décisions industrielles, sociales et politiques qui prennent en compte les limites de cette méthode. Actuellement, le Département des Sciences des Denrées alimentaires de la Faculté Vétérinaire de l’Université de Liège associés avec d’autres partenaires réalisent une évaluation quantitative de risque concernant Salmonella dans la filière porcine (projet METZOON). Le modèle développé simule la contamination par Salmonella de l’ensemble de la filière à partir de l’élevage de porc jusqu’à la consommation de la viande par la population. Le modèle fait appel aux résultats des plans de surveillance de l’AFSCA et à l’ensemble des études réalisées en Belgique sur les salmonelles dans la filière porcine. Plusieurs industriels ont également collaboré à cette étude. Le but est d’identifier les actions ayant le plus d’efficacité pour réduire la contamination de la chaîne alimentaire. En conclusion, le nombre de salmonelloses humaines a diminué ces dernières années en Belgique. L’implémentation des méthodes HACCP et des bonnes pratiques d’hygiène dans l’industrie, une meilleure surveillance des aliments par les autorités publiques, les campagnes de vaccination des poules pondeuses en production primaire sont les raisons essentielles de la diminution. Mais l’ensemble des acteurs de la filière doivent être conscients de leur responsabilité dans le but d’obtenir une viande indemne de salmonelles. Les bonnes pratiques de fabrication doivent être respectées tout au long de la chaîne de production, en accord avec les principes HACCP, avec des contrôles fréquents sur tous les points critiques. Une traçabilité complète de l’origine de la viande ou des produits de viande est nécessaire pour permettre aux autorités publiques et aux épidémiologistes d’établir l’origine d’épidémies et ainsi réagir au plus vite. Ce n’est qu’avec une collaboration continue de tous les acteurs que nous pourrons produire une viande sans salmonelles. [less ▲]

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See detailReducing human salmonellosis in Belgium from minced pork meat with quantitative risk assessment scenarios
Delhalle, Laurent ULg; Bollaerts, K.; Messens, W. et al

Poster (2008, May)

Detailed reference viewed: 15 (2 ULg)