123 research outputs found

    Sanitation Assessment of Food Contact Surfaces and Lethality of Moist Heat and a Disinfectant Against Listeria Strains Inoculated on Deli Slicer Components

    Get PDF
    The overall objectives of this study were to: evaluate the efficacy of different cleaning cloth types and cloth-disinfectant combinations in reducing food contact surface contamination to acceptable levels; determine the optimum moist heat and moist heat + sanitizer treatments that can significantly reduce the number of Listeria strains on deli slicer components; and investigate if the moist heat treatment used in this study induced the viable-but-non-culturable (VBNC) state in Listeria cells. The efficacy of wiping cloths was measured using ATP-bioluminescence and total plate count methods using four different wiping cloths and silver dihydrogen citrate sanitizer on food contact surfaces. The lethality study of moist heat and silver dihydrogen citrate disinfectant against Listeria strains was done using deli slicer components and the viable-but-non-culturable state of Listeria strains subjected to sub-lethal moist heat and silver dihydrogen citrate disinfectant stresses was measured using BacLight bacterial viability test kit. In the first study we demonstrated that the cleaning effects of wiping cloths on food contact surfaces can be enhanced when used with the SDC sanitizer and stated that the ATP-B measurements can be used for real-time hygiene monitoring in the public sector with inclusion of microbial contamination testing (total plate count) for more reliable measure of cleanliness. In the moist heat lethality study, the internal moist heat only treatment and both the internal and external moist heat + disinfectant treatments yielded non-detectable levels of Listeria strains on stainless steel and cast aluminum coupons. Moist heat only and moist heat + disinfectant treatments at 150 °F (66°C) and at least 20% relative humidity (RH) for 5 h was adequate to attain non-detectable levels of a Listeria strains cocktail on both stainless steel and cast aluminum deli meat slicer components. The BacLight bacterial viability test demonstrated that the moist heat treatment applied in this study was effective in inactivating Listeria strains. However, the absence of growth on nutrient agar plates and detection of live cells by the viability test demonstrated that the sub-lethal temperature used in this study could induce the VBNC state in Listeria strains

    Efficient scheduling of batch processes in continuous processing lines

    Get PDF
    This thesis focuses mainly on the development of efficient formulations for scheduling in industrial environments. Likewise, decisions over the processes more related to advanced process control or production planning are included in the scheduling; in this way, the schedule obtained will be more efficient than it would be if the additional restrictions were not considered. The formulations have to emphasize obtaining online implementations, as they are planned to be used in real plants. The most common scheduling problems handled in the industrial environments are: the assignment of tasks to units, the distribution of production among parallel units and the distribution of shared resources among concurrent processes. Most advances in this work are the result of a collaborative work.Departamento de Ingeniería de Sistemas y AutomáticaDoctorado en Ingeniería Industria

    Salubrité des légumes en conserve par traitement thermique combiné à l'électro-activation : analyse de l'efficacité du système et détermination des économies d'énergie

    Get PDF
    La salubrité et la qualité des aliments en conserve dépendent toujours des paramètres appliqués lors de la stérilisation (le temps, les températures). L'application de températures élevées peut détériorer la qualité des produits et augmenter les coûts énergétiques associés au procédé de stérilisation. De plus, l’attente des consommateurs se dirige, de nos jours, vers des produits sains et frais, ce qui encourage les chercheurs à découvrir de nouvelles approches et techniques pour améliorer la conservation des aliments. Les technologies émergentes combinées à d'autres approches classiques ont démontré des résultats probants (effet barrière ou «hurdle effect ») quant à la préservation de produits non acidifiés. Récemment, des études sur l'électro-activation (EA) ont mis en évidence son fort potentiel antibactérien applicable pour une large gamme de produits alimentaires. En outre, cette technologie a été reconnue comme étant sécuritaire et peu coûteuse. Le but de ce projet était d'étudier l'EA comme une barrière efficace afin de préserver les qualités nutritionnelles des aliments tout en réduisant les barèmes de stérilisation et les coûts de production dans un respect total de la salubrité du produit. Le premier objectif était d'étudier les propriétés des solutions électro-activées (SEA) ainsi que la dynamique de leurs modifications en fonction de plusieurs paramètres comme la densité de courant appliqué au système, le temps d'excitation, le type de sels utilisés, la concentration en sel et les configurations du réacteur d’électro-activation. De plus, les paramètres optimaux comme le pH, le potentiel redox et la résistance électrique du système, qui est un indice d’efficacité énergétique, ont été déterminés pour la production des SEA à l'aide de la méthode de surface de réponse. Par la suite, les SEA optimisés ont été étudiés sur la corrosivité dans des boîtes de conserve en métal et les résultats obtenus ont montré que la SEA n'a aucun effet significatif sur l'oxydation des contenants de maïs en conserve. Le deuxième objectif a permis de mettre en évidence l'activité sporicide des SEA. En effet, l’étude a montré que les SEA ont une forte capacité d'inhibition de la croissance des spores de Clostridium sporogenes et de Geobacillus stearothermophilus. La combinaison de traitements modérés (T ≤ 100 °C) avec différentes SEA dans la purée de légumes a entraîné une destruction importante ou totale des spores de C. sporogenes. Une diminution considérable de la résistance à la chaleur de G. stearothermophilus a été également observée. Un effet synergique d’une grande efficacité a été obtenu lorsque la SEA a été utilisée en combinaison avec un traitement thermique lors de la stérilisation. Sur le plan pratique, cela résulte en une modification significative des barèmes de stérilisation en utilisant des températures modérées. Le troisième objectif consistait à étudier l'effet combiné des SEA et de la stérilisation à des températures modérées sur la qualité des conserves. Des petits pois et du maïs en grain ont été utilisés comme légumes modèles. L'analyse organoleptique a montré qu'un temps de stérilisation écourté conserve mieux les attributs sensoriels du produit. En plus, les températures de stérilisation utilisées avec les SEA étaient adéquates pour la préservation de la vitamine C qui est utilisée comme indicateur de préservation de la qualité. Aussi, la différence entre la technologie de stérilisation utilisant l’effet combiné de barrières composées de SEA et d’un traitement thermique modéré, comparativement à la technologie de stérilisation classique, laisse entrevoir la possibilité de réaliser d'importantes économies énergétiques. De plus, il sera possible de préserver la qualité nutritionnelle du produit et tout cela sans compromettre sa salubrité. Finalement, ce projet a apporté une contribution significative aux connaissances applicables à l’amélioration de la technologie classique de mise en conserve des légumes via une meilleure compréhension du comportement des spores thermophiles sous l'action des SEA combinées à des températures nettement inférieures à celles utilisées dans le procédé conventionnel de stérilisation des légumes en conserve.The safety and quality of low-acid canned food always depends on the parameters of sterilization. However, high temperatures may lead to a deterioration of product quality and to an increase of energy costs. In addition, today’s the increase of consumer demand for more «fresh-like» foods is challenging researchers to discover innovative approaches and techniques to improve methods of food preservation. Emerging technologies in combination with classical approaches exhibited high effectiveness (hurdle effect) in preservation of low-acid products. Recently, electro-activation (EA) convincing results by demonstrating high antibacterial potential on food products at large scale; furthermore, it has been recognized as a safe and an inexpensive hurdle. Taking sense from the hurdle approach, the aim of this project was to study EA as an effective and potent hurdle, so that it could result in a decrease in sterilization temperatures, thereby decreasing energy costs, increasing food quality and ensuring sterility. The first objective was to study the properties of EA solutions as well as the dynamics of their changes using variety of parameters (current density, excitation time, type and concentration of salts, configurations). In addition, by using the response surface methodology the optimum parameters (pH, redox potential, resistance) for the production of EA solutions (EAS) were found. Thereafter, the optimized EAS were studied for corrosiveness in canned containers showing no significant oxidizing effect on container filled with canned corn which was within the acceptable limits according to the stipulated regulations. The next objective focused on its sporicidal activity. The study showed that EAS has strong inhibiting capacity on the growth of Clostridium sporogenes and Geobacillus stearothermophilus spores. The combination of mild treatments (≤100°C) and EAS in vegetable puree resulted in significant or total destruction of putrefactive spores of C. sporogenes. A considerable decrease in heat-resistance of G. stearothermophilus was also observed. A synergistic effect was observed when EAS was used in combination with heat treatment during sterilisation, which allows changing the temperatures of sterilization. Thus, the last objective investigated the combined effect of EAS and sterilization at mild temperatures on the quality of canned peas and corn. The sensorial analysis showed that a shorter sterilization time increase the preservation of sensorial attributes. Indeed, the lowest temperatures appeared to be more favourable for vitamin C preservation. Nevertheless the difference between classical sterilization and hurdle technologies using EAS displayed significant energy savings and quality preservation. Overall, this project proposed a new approach to improve food canning technology; furthermore, it allowed a better understanding of the thermal behaviour of thermophilic spores under action of EAS as well as expands the scientific knowledge of EA technology

    Managing occupational hazards confronting healthcare workers

    Get PDF
    The primary goal of this thesis is to identify, evaluate, and control occupational hazards that may exist in health care facilities. Due to the complex nature of health care facilities, healthcare workers are always challenged by an imposing group of occupational hazards. The magnitude and diversity of these hazards, and the constantly changing nature of government regulations make it difficult to guarantee absolute protection and accuracy of the material contained herein. However, awareness of the risks, compliance with basic preventive measures, and adequate interventions are all essential components to consider in protecting healthcare workers. Therefore, potential health effects of various hazards such as back injuries, heat, noise, infectious hazards, pharmaceutical hazards, chemicals, exposure to radiation, and prevalent psychosocial (stress) problems are reviewed, and rational approaches to managing and preventing these problems are offered. This thesis also presents a broad overview of hospital safety programs, and job safety analyses; it offers assistance in understanding and complying with regulations and guidelines issued by the Centers for Disease Control and Prevention (CDC), the Occupational Safety and Health Administration (OSHA), the National Institute for Occupational Safety and Health (NIOSH), and the Joint Commission on Accreditation of Healthcare Organizations (JCAHO)

    Advances in Sterilization and Decontamination: a Survey

    Get PDF
    Recent technical advances made in the field of sterilization and decontamination and their applicability to private and commercial interests are discussed. Government-sponsored programs by NASA produced the bulk of material presented in this survey. The summary of past and current research discussed is detailed to enhance an effective transfer of technology from NASA to potential users

    Halal certification for an industrial machine intended to come in contact with food

    Get PDF
    Halal Certification is a worldwide recognition that the products are permissible under Islamic law. These products are thus edible, drinkable or usable by Muslims. It can be extended to industrial machinery and tools. This Certification must be issued by a Notified Body under the supervision of an IMAM. Focus of the Certification are GMPs and Food Contact Materials and Articles. Four main phases to achieve Certification (the scheme is the same of ISO 14001, ISO 18001 and ISO 9001): Pre-Audit - The activity is to evaluate the documentation describing our internal system. Audit - The activity is to evaluate how the Organization works in coherence with the documentation. Issue of Certification - Released by an accredited Imam. System verifications - The Certification has to be revised and confirmed every year by the Notified Body and after three years a new complete audit has to be carried out

    Monoclonal Antibody Production Via Fluidized Bioreactor Technology

    Get PDF
    Monoclonal antibodies (mAbs) are biologically identical antibodies created by homogenous immune cells originating from the same parent cell. MAbs target a specific epitope of an antigen on a cell’s surface, allowing it to neutralize the antigen. This unique characteristic has made them a key tool in the biopharmaceutical industry for the production of therapeutic drugs. One of these drugs is Rituxan® (rituximab), a mAb drug for the treatment of various cancers and autoimmune diseases. Currently, most mAb products are grown via cell suspension technology in stirred tank bioreactors. However, we have found that by using an integrated bioprocessing model, including conventional cell suspension culture tanks and fluidized bioreactor technology, overall product yield per day is increased by about 7-fold for the production of Rituxan®. Additionally, an economic analysis shows the fluidized bioreactor process is more profitable. Furthermore, though it requires a higher initial investment than the stirred tank process, the differential present worth of the fluidized bioreactor process in comparison to the stirred tank process is $13 billion. Overall, for the production of Rituxan®, the use of fluidized bioreactor technology is a more productive and lucrative process than the conventional stirred tank process

    Aptamer Based Lab-on-a-chip Biosensor for Selective Detection of Foodborne Pathogen, Listeria Spp., in Food Products

    Get PDF
    This research investigated impedimetric lab-on-a-chip biosensors for selective detection of foodborne pathogen, Listeria spp., using aptamers. Listeria was chosen as a model target due to its impact on the agricultural and food industries. The overall research goal of this project is to bridge the gap to address the need for real-time, highly sensitive and reliable biosensing platforms to meet the demands of on-site analysis of food products. The research objective was to develop a miniaturized aptamer biosensor that was designed and fabricated to carry out the detection of the bacteria in a simple and practical way. Miniaturization of the sensor enhanced the sensitivity and response time and allowed integration of various functionalities as a lab-on-a-chip platform. The research methods utilized the bottom-up approach of nanotechnology and dielectrophoresis techniques to improve the performance of miniaturized sensor. Pt-IMEs were functionalized with internalin A aptamers for selective binding of internalins in the cell membrane of the target bacteria, Listeria spp., via metal-thiol self-assembly. The aptamer biosensor was validated by taking measurements to detect foodborne pathogen, Listeria monocytogenes, in an off-the-shelf food product, i.e. vegetable broth at bacteria concentrations ranging from 10 to 10^7 CFU/mL. The sensitivity value was calculated to be 186.51 Ω/log(CFU/mL)] with the detection limit of 4.82 ± 0.01 CFU/mL within 12 min, which is one of the lowest detection limits reported to date. The combination of biosensor miniaturization, aptamer functionalization of electrodes, electrochemical impedance spectroscopy and dielectrophoresis techniques for selective detection of Listeria spp. bacteria enhanced response time, limit of detection, range of bacteria concentration, sensitivity and selectivity over other published biosensors. The developed aptasensor could be easily employed for the detection of other foodborne pathogenic bacteria to ensure food safety and public health

    Stem Cell Therapy for Spinal Cord Injuries

    Get PDF
    Stem cell-based therapies are an emerging branch of medicine with the purpose of restoring tissue function for patients with serious injuries, such as a spinal cord injury. As a result, scientists and engineers are increasing research efforts in the field of regenerative medicine. Due to the delicate nature of stem cells, producing the large quantity required for a successful therapy has proved challenging. In recent years, research has shown the potential of stem cell-based therapies, and thus there is a need for the commercialization of these treatments. The proposed facility targets the demand for spinal cord injury treatments and can support production for both clinical trials and a commercial release. Bioreactors designed specifically for the culture and growth of stem cells have flexibility in their ability to support different stem cell lines for various therapies. Small reactors in parallel can easily adapt to changes in production size. This process also takes advantage of the best options currently available for purification and preservation to maximize the product yield. Due to the strict regulations set in place by the FDA and lack of adequate funding, there is an untapped market for stem cell therapies for spinal cord injuries. Approximately 250,000 people in the United States suffer from spinal cord injuries, varying in severity, and this patient base increases at a rate of 12,000 new injuries every year (“Spinal Cord Injury Facts and Figures”, 2009). Future markets include expansion into Europe and Asia. There are two steps to this proposal: the upstream process and the downstream process. The upstream process includes the scale-up, differentiation, and purification of human embryonic stem cells; the downstream process consists of the scale-up of neurons for injection. The upstream process will be built initially and yield enough cells for clinical trials, without incurring the capital costs of building the entire plant. Upon success of the clinical trials, the downstream process will be built for maximum production. The profitability of this proposal is based on running 26 batches a year at 1.02x1010 cells per batch or 2.66x1011 cells per year. By targeting 5,000 patients, two percent of the current market, and charging 45,000perdose,aprofitableprofilecanbecreated.Assuming5045,000 per dose, a profitable profile can be created. Assuming 50% production capacity the first year and a ten-year plant life, the ROI, NPV, and IRR of the proposal are 226.09%, 961,892,600, and 242.81% respectively. Using a 50% production capacity allows for higher profit margins upon expansion. The proposed plan will meet the need of this growing market
    • …
    corecore