Evaluation of Pulsed Xenon UV Lamp on Inactivation of Listeria monocytogenes on Stainless- Steel Surfaces
Notice bibliographique
Résumé
Foodborne diseases remain a major global public health concern, with Listeria monocytogenes posing a significant risk, particularly for immunocompromised individuals. Ensuring food safety and minimizing contamination has become a top priority for food production facilities. \nUV-C disinfection has emerged as a safe and effective method for inactivating various microorganisms. With the phase-out of traditional mercury UV-C lamps due to the Minamata Convention on Mercury, pulsed xenon UV lamps (PX-UV) have gained popularity as a mercury-free alternative. PX-UV lamps offer high-intensity UV-C irradiation in a short time and a wider range of wavelengths, making them environmentally friendly and versatile. \nTo better understand the factors affecting the disinfection efficacy of PX-UV lamps, an investigation of operational parameters was conducted. The study focused on the impact of exposure time, frequency, UV fluence (dose), angle of irradiance, and shielding effects due to the presence of soiling agents on the reduction of Listeria monocytogenes on stainless steel surfaces. \nRadiometry analysis revealed that pulse frequency, in the range of 1 Hz to 25 Hz, influenced the fluence delivered per pulse, with higher frequencies resulting in lower UV fluence per pulse. However, regardless of pulse frequency, angle, or exposure time, the total UV fluence received was the main determinant of the log reduction. Notably, a 5.59-log reduction was achieved with 30 seconds of exposure to UV light at 25 Hz, corresponding to a fluence of 151.2 mJ/cm2. \nExperimental studies conducted in the presence of soiling agents have demonstrated the significance of the type of soiling material. It not only could affect the growth of bacteria but also could play a role in shielding the bacteria from UV radiation. The composition of the soiling material has implications for both the susceptibility of bacteria to UV radiation and their ability to proliferate. The thesis focuses on three categories of soiling agents: proteins, carbohydrates, and lipids. Among these groups, it was observed that protein soils had the most significant impact on promoting bacterial growth, while the log reduction value remained unchanged. Carbohydrates also had an effect on bacterial growth, although to a lesser extent compared to proteins. On the other hand, lipids exhibited a shielding effect, leading to a reduction in the log reduction value of L. monocytogenes. These findings highlight the varying effects of different soiling agents on bacterial growth and the subsequent log reduction achieved during disinfection. \nThis research highlights the significance of UV-C fluence as the primary consideration when using PX-UV lamps for no-touch disinfection, emphasizing the importance of selecting appropriate operational parameters to achieve the desired fluence. However, further research in this field can enhance our understanding of this technology. Some potential areas of future study include investigating the efficacy of UV disinfection on different types of surfaces, exploring the disinfection of fresh food products, and examining a wider range of soiling agents to better comprehend the impact of material structure on UV efficacy. These studies would contribute to expanding our knowledge and improving the effectiveness of UV-based disinfection methods in various applications and particularly food industries.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».