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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Estratégia para redução de contaminação visível de carcaças de frango / Strategy to reduce visible contamination of broiler carcasses

Juliana Montesino de Freitas Nascimento 10 October 2012 (has links)
Essa pesquisa objetiva avaliar a eficácia de uma estratégia educacional aplicada junto a funcionários do setor de evisceração de um abatedouro de frango com vistas à diminuição de contaminação gastrointestinal de carcaças. A estratégia classifica-se como treinamento para exercer a função, externo ao serviço, específico e individual. Foi utilizado o método de aula expositiva-dialogada e motivacional. O conteúdo do treinamento procurou explicitar a relação entre as inadequações técnicas e comportamentais no setor de evisceração que resultam em ruptura do trato gastrointestinal, contaminação visível das carcaças e possibilidade de multiplicação de microrganismos patogênicos. Enfocou a gravidade das doenças para os consumidores bem como a corresponsabilidade e agravantes para a empresa e funcionários. Depois do treinamento (DT), os dados referentes à ocorrência e à persistência de contaminação não apresentaram, em termos de mediana, diferença significativa quando comparados ao período antes do treinamento (AT). Com relação à variância, houve diminuição significativa para a ocorrência de contaminação fecal (? = 1%) e fecal e biliar (? = 4%) quando comparada ao período AT. No período DT, a variância do percentual de persistência de contaminação diminuiu significativamente para todos os tipos de contaminação (? = 1% para contaminações fecal e biliar e 2% para gástrica) quando comparada à fase AT. Os picos (dias com persistência de contaminação maior ou igual a 1%) foram reduzidos de 38% para 4% (fecal), de 45% para 26% (biliar) e de 41% para 35% (gástrica). Embora existam fatores influentes do pré-abate, os funcionários do setor de evisceração são os principais responsáveis pela geração de contaminação visível, devido ao corte ou ruptura do trato gastrointestinal e não retirada da contaminação. Assim, diante da dificuldade em conter a maioria dos fatores que ocasionam a contaminação visível no abatedouro e da evidência do baixo nível de conscientização e instrução dos funcionários para as questões pertinentes à segurança do alimento, o investimento em um adequado programa de treinamento pode ser a ação com a melhor relação custo-benefício a fim de diminuir a persistência de contaminação visível em carcaças, os prejuízos decorrentes da sua alta ocorrência e proporcionar um alimento seguro ao consumidor e a sobrevivência da empresa no mercado global. / This research aims to evaluate the effectiveness of an educational strategy applied to employees from evisceration area of a broiler slaughterhouse, in order to decrease gastrointestinal contamination of carcasses. The strategy is classified as training to perform the function, outside the service, specific and individual. The methodology used was the exposition and dialogue lecture and motivational. The content of the training aimed explain the relationship between the technical and behavioral inadequacies in the sector of evisceration that result in rupture of the gastrointestinal tract, visible contamination of carcasses and possible growth of pathogens. It was focused on the severity of foodborne illness to consumers as well as the joint responsibility and losses for the company and employees. After training (AT), the data regarding the occurrence and persistence of contamination did not present a significant difference in terms of median, when compared to before training (BT) period. Regarding the variance, a significant decrease was observed for the occurrence of fecal contamination (? = 1%) and fecal and bile (? = 4%) when compared to BT. In the after training period, the variance of persistence contamination percentage was significantly reduced for all kinds of contamination (? = 1% bile and fecal contamination, and 2% to gastric) when compared to BT period. The persistence of contamination peaks were reduced from 38% to 4% (fecal), 45% to 26% (bile) and from 41% to 35% (gastric). Although there are factors influencing the pre-slaughter, the evisceration sector employees are the major responsible for the generation of visible contamination, due to cuts or rupture of the gastrointestinal tract and non removel of contamination. Thus, given the difficulty in containing most of the factors that cause visible contamination at the slaughterhouse, and evidence of low level of awareness and training of employees on issues related to the food safety, investment in an appropriate training program can be the action with the most costeffective to decrease the persistence of visible contamination of carcasses, the negative effects of high occurrence and provide a safe food to consumers and the company\'s survival in the global market.
302

Caracterização genotípica de Arcobacter spp. isolados de carnes de aves comercializadas no Município de São Paulo - SP / Genotypic characterization of Arcobacter spp. isolated from poultry meat sold in the city of São Paulo - SP

Oliveira, Maria Gabriela Xavier de 13 January 2016 (has links)
Arcobacter spp. é um micro-organismo Gram negativo que provoca diarreia aquosa e sepse em seres humanos. A. butzleri, A. cryaerophilus e A. skirrowii são espécies patogênicas para humanos. O objetivo deste estudo foi detectar a presença de Arcobacter spp. na carne de aves comercializadas em açougues na cidade de São Paulo, verificando os genes de virulência e o perfil genotípico. Um total de 300 cortes de carne de frango foram submetidos ao cultivo e isolamento sob condições aeróbicas, a 30°C por 72 horas. Colônias suspeitas de Arcobacter spp. foram selecionadas para a detecção molecular pela reacção em cadeia da polimerase (PCR), a fim de determinar as espécies e os genes de virulência. Os resultados revelaram a presença de Arcobacter spp. em 18.3% (55/300) de amostras de carne de aves, sendo identificado como A. butzleri 63,6% (35/55) e A. cryaerophilus 36,3% (20/55). Os genes de virulência pesquisados demonstraram positividade de 100% (55/55) para o ciaB e mviN, seguidos de cj1349 98,1% (54/55), pldA 94,4% (52/55), cadF 72,7% (40/55), tlyA 92,7% (51/55), hecA 49% (27/55), irgA 47,2% (26/55) e hecB 34,5% (19/55). Estas cepas foram submetidas ao AFLP gerando dois dendogramas. Foram identificados 19 perfis genotípicos para A. butzleri e 17 para A. cryaerophilus. Os resultados desta pesquisa apontam a presença de A. butzleri e A. cryaerophilus na fase final da distribuição de carne de frangos nos açougues. A falta de inocuidade dos alimentos de origem animal, bem como a presença de estirpes virulentas representam riscos de Saúde Pública, com especial atenção para a possibilidade de contaminação cruzada gerados por alimentos crus e utensílios de cozinha / Arcobacter spp. is a Gram negative microorganism that causes watery diarrhea and septicemia in humans. A. butzleri, A. cryaerophilus and A. skirrowii are pathogenic for humans. The aim of this study was to detect the presence of Arcobacter spp. in poultry meat from butcher shops in the city of São Paulo, checking the virulence genes and profile genotypic. A total of 300 chicken cuts were used for cultivation and isolation in broth and JM agar, under aerobic conditions, at 30 °C for 72 hours. Arcobacter colonies were selected and submitted to molecular detection by polymerase chain reaction (PCR), in order to determine species and virulence genes. Results show the presence of Arcobacter spp. in 18.3% (55/300) of poultry meat samples, identified as A. butzleri 63.6% (35/55) and A. cryaerophilus 36.3% (20/55) in chicken isolates. The virulence genes on Arcobacter spp. researched demonstrated positive these 100% (55/55) for ciaB and mviN, followed by cj134998,1% (54/55), pldA 94,4% (52/55), cadF 72.7% (40/55), tlyA 92,7% (51/55), hecA 49% (27/55), irgA 47,2% (26/55) and hecB 34,5% (19/55). These strains were submitted to AFLP generating two dendogramas. Nineteen profiles genotypins were obtained for A. butzleri and seventeen for A. cryaerophilus. The results of this research point to the presence of Arcobacter butzleri and A. cryaerophilus in the final stage of distribution of poultry meat to butcher shops. The lack of safety of food of animal origin, as well as the presence of virulent strains pose risks to Public Health, with special focus on cross contamination risks generated by uncooked food and utensils
303

Towards a hybrid conceptual operational management model of canazo supply chain: A research on the sugar-cane spirit from Peru

Imberti, Arturo, Ramos, Edgar, Provost, Kelsey, Basu, Anshuman Neil 01 January 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The present research seeks to show the importance of applying process management techniques and food safety norms in the operational processes of the supply chain to know the meaning and the need for an integrated hybrid model. The article reviews the sugarcane distillery sector of Peru and its main operational problems. Based on the literature reviewed and discussed with academics who have knowledge of the food supply chain, an integrated hybrid model was developed to help any distillery with lower levels of competitiveness than its competitors in other sectors, such as pisco, applying techniques of process management and food safety to increase the efficiency of liquor distilleries. The findings confirm that distilleries can increase their efficiency, thanks to the higher performance of their operations after their alignment with the integrated model. / Revisión por pares
304

Enzymatic Digestion Improved Bacteria Separation from Leafy Green Vegetables

Wang, Danhui 13 July 2016 (has links)
An effective and rapid method for the separation of bacteria from food matrix remains a bottleneck for rapid bacteria detection for food safety. Bacteria can strongly attach to the food surface or internalize within the matrix which makes their isolation extremely difficult. Traditional methods of separating bacteria from foods routinely involve stomaching, blending and shaking, however these methods may not be efficient at removing all the bacteria from complex matrices. Here, we investigate the benefits of using enzyme digestion followed by immunomagnetic separation to isolate Salmonella from spinach and lettuce. Enzymatic digestion using pectinase and cellulase was able to break down the structure of the leafy green vegetables resulting in the detachment and release of Salmonella from the leaves. Immunomagnetic separation of Salmonella from the liquefied sample allowed an additional separation step to achieve a more pure sample without leaves debris that may benefit additional downstream applications. We have investigated the optimal combination of pectinase and cellulase for the digestion of spinach and lettuce to improve sample detection yields. The concentrations of enzymes used to digest the leaves were confirmed to have no significant effect on the viability of the inoculated Salmonella. Results reported that the recovery of the Salmonella from the produce after enzyme digestion of the leaves was significantly higher (P
305

Characterizing the Impact of Stress Exposure on Survival of Foodborne Pathogens

Shah, Manoj Kumar January 2019 (has links)
Bacterial pathogens transmitted by the fecal-oral route endure several stresses during survival/growth in host and non-host environments. For foodborne pathogens, understanding the range of phenotypic responses to stressors and the environmental factors that impact survival can provide insights for the development of control measures. For example, the gastrointestinal system presents acidic, osmotic, and cell-envelope stresses and low oxygen levels, but Listeria monocytogenes can withstand these stresses, causing illnesses in humans. Survival/growth characteristics may differ among L. monocytogenes strains under these stressors due to their genetic diversities. Our knowledge of such phenotypic characteristics under bile and salt stresses are inadequate. In this dissertation, variation in growth characteristics was observed among L. monocytogenes strains under bile and osmotic stresses with no evidence of cross-protection, but rather an antagonistic effect was observed with the formation of filaments when pre-exposed to 1% bile and treated with 6% NaCl. This shows that variation in stress adaptability exists among L. monocytogenes strains with the ability to form filaments under these conditions. Similarly, Salmonella survival in soil is dependent on several factors, such as soil, amendment types, moisture, irrigation, and desiccation stress. In this study, the use of HTPP (heat-treated poultry pellets) was investigated as a soil amendment in the survival/growth of Salmonella in soil extracts mimicking runoff events, and in soil cultivated with spinach plants to assess its safety for use for an organic fertilizer. The presence of HTPP in soil increased S. Newport survival with a greater likelihood of its transfer to and survival on spinach plants. Increased microbial loads and rpoS mutant showed decreased growth/survival in soil extracts, however, rpoS was not important for survival in soil under the tested conditions showing possible lack of desiccation stress. These results show that HTPP provided nutrients to the Salmonella for increased growth and survival in soil extracts and soil, respectively, which show that the use of treated BSAAO to soils may still require appropriate mitigation to minimize Salmonella Newport contamination of leafy greens in the pre-harvest environment. Overall, the results in this study increased our understanding of L. monocytogenes and Salmonella phenotypic adaptation to stressful environments.
306

Zhodnocení míry kontaminace ryb netuberkulózními mykobakteriemi / Evaluation of the level of contamination in fish by non-tuberculous mycobacteria

Trávníčková, Jiřina January 2012 (has links)
The aim of a presented diploma thesis was to evaluate the level of contamination in fish by nontuberculous mycobacteria (NTM). Methods of molecular biology were used to monitor the incidence and distribution of NTM in tissues of freshwater fish (gills, pharyngeal teeth, muscles, intestine etc.). NTM frequently occur in aquacultures for commercial use. With this in mind the occurrence of NTM was monitored in fish meat (Ctenopharyngodon idella, Cyprinus carpio, Tinca tinca, Sander lucioperca, Oreochromis niloticus etc.) from the market, because processing and consumption of insufficiently heat treated meat contaminated with NTM may pose health risk to humans. The theoretical part deals with the description of mycobacteria, their clinical significance and responsibilities in food safety. There are summarised methods for detection and identification of individual mycobacterial species. The experimental part is devoted to the description of used methods followed by evaluation of experimentally obtained data. The plasmid DNA was prepared as positive controls for PCR reaction. Furthermore, the analytical sensitivity of PCR reaction and efficiency of isolation of mycobacterial DNA isolation from fish meat were determined. Lastly, the level of NTM contamination in fish was evaluated.
307

Subjective norms in food safety: An evaluation of classroom and popular web-based Key Influencers' impact on consumer food safety

Tressie E Barrett (8796878) 08 May 2020 (has links)
<p>High-school-aged youths have limited food safety knowledge and lack safe food-handling skills. However, these youths will prepare food for themselves and are frequently employed in the food service industry, where their food-handling practices can directly impact public health. Youths’ beliefs about safe food-handling behaviors are affected by Key Influencers in their lives such as peers, classroom instructors, parents, and celebrities including popular web-content authors or video hosts. Societal changes have prompted the elimination of Family and Consumer Science courses from many schools and the reduction of food-handler role models at home, while increasing access to unregulated sources of food-handling information such as information published on web-based platforms. These societal changes largely remove peers, classroom instructors, and parents from influencing youths’ food-handling behaviors. </p> <p>The purpose of this study was to (1) evaluate the effectiveness of a researcher-developed food safety educational intervention at changing students’ food-handling behaviors specifically focusing on the role of subjective norms in generating behavior change and (2) conduct an exploratory content analysis of food safety messages delivered by blog authors and video hosts of popular web-content. </p> <p>The researcher-developed curriculum was evaluated for adherence to academic standards and overall usability in the classroom using the Delphi Technique by a panel of secondary educators who were considered experts in the education field. The curriculum was evaluated for effectiveness at changing high school students’ food-handling behaviors through self-reported surveys and observation using GoPro head mounted and stationary cameras. Finally, content analysis was performed on food safety messages disseminated by authors and video hosts of popular blogs and YouTube videos, respectively. </p> Findings from the study demonstrated that youths’ food-handling behaviors are affected by Key Influencers including their peers and classroom instructor. However, post-intervention, a role-reversal was observed and reported as students became influencers who sought to improve their Key Influencers’ food-handling behaviors. Differences in influencing power within these relationships could impact the sustainability of youths’ safe food-handling behaviors. In particular, imbalances in influencing power of celebrities in the absence of other Key Influencers could leave students vulnerable to adopting unsafe food-handling practices.
308

Microbiological contamination of fresh retail ground pork and beef products in Central Ohio

Kovacs, Amy January 2021 (has links)
No description available.
309

Untersuchungen zur mikrobiologischen Sicherheit von marinierten, vorverpackten Schweinefleischzubereitungen

Schönheit, Clien 25 October 2011 (has links)
Gegenwärtig erlangen marinierte, vorverpackte Schweinefleischzubereitungen als typisches Convenience-Produkt eine zunehmende Marktbedeutung. Dem stehen allerdings wenig repräsentative Daten zur mikrobiologischen Sicherheit und Haltbarkeit dieser Produkte gegenüber. Ziel dieser Arbeit war es daher, im Interesse eines hohen Verbraucherschutzniveaus fundierte Daten über das Vorkommen und die Überlebensfähigkeit pathogener und toxinogener Mikroorganismen in vorverpackten marinierten Schweinefleischzubereitungen zu gewinnen. Darauf basierend sollten Empfehlungen für produktspezifische mikrobiologische Kriterien und Mindesthaltbarkeitsfristen abgeleitet werden. Während der Grillsaison der Jahre 2008 und 2009 wurden hierfür zwei Marktstudien über marinierte, vorverpackte Schweinenackensteaks (jeweils n=150) aus dem lokalen SB-Handel durchgeführt. Dabei erfolgte aufgrund der großen Produktvielfalt eine Einteilung der Produkte in Nackensteaks mit Senf-/Biermarinaden, Paprikamarinaden und Kräutermarinaden. Bei der Untersuchung wurden der pH-Wert, der mikrobiologische Status und das Vorkommen von verschiedenen pathogenen Keimen jeweils zum Zeitpunkt des Erwerbs und am Ende des MHD erfasst. Zudem wurden je Produktgruppe 10 für die industrielle Herstellung dieser Fleischzubereitungen verwendeten Flüssigmarinaden (n=30) mikrobiologisch auf die gleichen Parameter untersucht sowie pH- und aW-Werte in den Marinaden bestimmt. Auf Grundlage der Ergebnisse der Marktstudien wurde darüber hinaus die Überlebensfähigkeit von Salmonella spp. und Listeria monocytogenes in artifiziell kontaminierten Flüssigmarinaden jeder Kategorie während einer Lagerung für 42 Tage bei 4 und 22 °C überprüft. Die Gesamtkeimzahlen in den marinierten Schweinfleischsteaks lagen in einem Bereich von 2,8 x 103 bis 9,7 x 108 KbE/g, die Anzahl der Milchsäurebakterien zwischen 10 und 9,5 x 108 KbE/g und die der Enterobacteriaceae zwischen < 10 und 3,6 x 108 KbE/g. Bis zum Ende des MHD fand ein Anstieg der Gesamtkeimzahl und der Milchsäurebakterien bei gleichzeitigem pH-Wert-Abfall statt. Vermehrungsfähige Salmonellen wurden in 6 von 300 Proben (2,0 %) und Shigatoxin bildende Escherichia coli in 7 von 300 Proben (2,3 %) nachgewiesen. In 5 Proben (1,7 %) wurde Listeria monocytogenes mit bis zu 95 KbE/g und in 25 Proben (8,3 %) Staphylococcus aureus mit Keimzahlen bis 340 KbE/g detektiert. Bacillus cereus wurde in 64 Handelsproben (21,3 %) mit Keimzahlen bis zu 450 KbE/g und sulfitreduzierende Clostridien in 73 marinierten Schweinenackensteaks (24,3 %) mit Werten bis 500 KbE/g gefunden. Die Untersuchung der Flüssigmarinaden der drei Kategorien (n=30) erbrachte Gesamtkeimzahlen von 1,3 x 102 bis 4,2 x 105. Enterobacteriaceae und Milchsäurebakterien wurden jeweils nur in zwei Marinadenproben mit bis zu 180 bzw. 750 KbE/g nachgewiesen. Keine der Marinaden enthielt Salmonellen, Shigatoxin bildende Escherichia coli, Listeria monocytogenes oder Staphylococcus aureus. Positive Befunde wurden nur für Bacillus cereus und sulfitreduzierende Clostridien erhoben: 16 Proben (53,3 %) enthielten Bacillus cereus mit Keimzahlen von bis zu 230 KbE/g und 14 Proben (46,7 %) sulfitreduzierende Clostridien mit maximalen Keimzahlen von 120 KbE/g. Die aW-Werte der Marinaden variierten zwischen 0,2 und 0,94, die pH-Werte zwischen 3,57 und 6,53. Bei den Tenazitätsstudien in Marinaden wurde eine kontinuierliche Keimreduktion für beide Pathogene festgestellt: Sowohl L. monocytogenes als auch Salmonella spp. zeigten in Senfmarinaden sowie bei 22 °C Lagerungstemperatur eine deutlichere Absterbekinetik als in Paprika- bzw. Kräutermarinaden und bei 4 °C Lagerungstemperatur. Basierend auf den Ergebnissen dieser Arbeit können vorverpackte, marinierte Schweinenackensteaks auch nach MHD-Fristen von 18 Tagen als lebensmittelhygienisch sicher beurteilt werden. Allerdings können Lebensmittelinfektionserreger in den Produkten vorkommen und zum Teil bis zum Ende des MHD überleben. Im Hinblick auf den vorbeugenden Verbraucherschutz können folgende Empfehlungen für mikrobiologische Richtwerte von marinierten Schweinenackensteaks abgeleitet werden: Salmonellen: nicht nachweisbar in 25 g STEC: nicht nachweisbar in 25 g L. monocytogenes: < 102 KbE/g St. aureus: 1,0 x 102 KbE/g B. cereus: 1,0 x 104 KbE/g Sulfitreduzierende Clostridien: 1,0 x 104 KbE/g Aufgrund von teils starken Zunahmen der Gesamtkeimzahl und der Keimzahlen von Milchsäurebakterien und Enterobacteriaceae sollte die MHD-Frist auf maximal 7-10 Tage beschränkt werden, um eine mikrobiologisch annehmbare Qualität für den Verbraucher garantieren zu können. Bei der Zubereitung sollte auf eine Vermeidung von Kreuzkontaminationen und vor dem Verzehr auf eine vollständige Durcherhitzung geachtet werden.
310

ECONOMIC ANALYSIS ON PRODUCTION CHANGES, MARKET INTEGRATION AND EXPORT CHALLENGES OF COFFEE SECTOR IN INDONESIA / インドネシアコーヒー産業の構造変化、市場統合と輸出競争に関する経済分析

Agus, Nugroho 23 May 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19902号 / 農博第2185号 / 新制||農||1044(附属図書館) / 学位論文||H28||N5006(農学部図書室) / 32979 / 京都大学大学院農学研究科生物資源経済学専攻 / (主査)教授 福井 清一, 教授 伊藤 順一, 准教授 沈 金虎 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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