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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.
281

DESENVOLVIMENTO DE EMBUTIDO CURADO FERMENTADO DE CARNE DE EMA (Rhea americana) ASSOCIADA À DE SUÍNO / DEVELOPMENT OF THE CURED FERMENTED SAUSAGE OF GREATER RHEA MEAT (Rhea americana) ASSOCIETED TO THE PORK

Toneto, Edsom Roberto Lorenci 16 February 2007 (has links)
The wild fauna represent an option of protein source to Brazil and others countries of Latina America, Europe and Asia. In this context, the greater rhea and others ratites are very valorized in the market, because of the healthy read meat that is introduced what is similar to others sorts of slaughter. This work had the objective to develop and to characterize a cured fermented sausage with rhea meat (Rhea Americana) and the pork meat in the Brazilian market. In the formulations of the cured fermented sausage used five meat combinations (90% rhea, 67,5% rhea / 22,5% pork, 45% rhea / 45% pork, 22,5% rhea / 67,5% pork, 90% pork). The products elaborated were appraised for analysis physicochemical, microbiologics, and sensorials. The results of phisicochemical analyzes sowed that the proctucts elaboreteds were in the vigor law to the salami, therefore water activity varieted from 0,88 to 0,90 (maximum 0,92), umided varieted from 35,93% to 41,07% (maximum 40%), fat varieted from 29,89 from 31,03 (maximum 35%) and protein variated from 29,89% to 31,03% (minimum 20%). The results indicated that all products developed showed secure to the microbiologic seen. The sensorial analyze revealed bigger preference to the cured sausages that contains elevated percentage of the pork meat in relation to the rhea meat, therefore the cured sausages that contains 22,5% of rhea meat and 67,5% of pork meat obtained the best valuation of the colour, smell, texture and savour. The products developed with more proportion of rhea meat in relation to the pork obtained the minor preference for the provers panel, moreover the formulated cured sausages with 90% of rhea meat received undervaluation. Is follow that, in the present work, the cured fermented sausages that have a formulation of 22,5% of rhea meat and 67,5% of pork meat reunited characteristics to be framed into the vigor law of salami and are the most appropriate to be into the Brazilian market as a alternative font of proteins to the human consumption. / A fauna silvestre representa uma opção de fonte protéica para o Brasil e outros países da América Latina, Europa e Ásia. Nesse contexto, a ema e outras ratitas, são muito valorizadas no mercado pela carne vermelha saudável que apresentam, que é similar a outras espécies de abate. Este trabalho teve como objetivo desenvolver e caracterizar um embutido curado fermentado contendo carne de ema (Rhea americana) e carne de suíno, no mercado brasileiro. Nas formulações dos embutidos, utilizou-se cinco combinações cárneas (90% ema, 67,5% ema / 22,5% suíno, 45% ema / 45% suíno, 22,5% ema / 67,5% suíno, 90% suíno). Os produtos elaborados foram avaliados por análise físico-químicas, microbiológicas e sensoriais. Os resultados das análises físico-químicas mostraram que os produtos elaborados estavam dentro da legislação vigente para salame, sendo que a atividade de água variou de 0,88 a 0,90 (máximo 0,92), umidade variou de 35,93% a 41,07% (máximo 40%), gordura variou de 19,67% a 23,53% (máximo 35%) e proteína variou de 29,89% a 31,03% (mínimo 20%). Os produtos desenvolvidos apresentaram-se seguros sob o ponto de vista microbiológico. A análise sensorial revelou maior preferência pelos embutidos contendo percentagem mais elevada de carne de suíno em relação à carne de ema, sendo que os embutidos contendo 22,5% de carne de ema e 67,5% de carne de suíno obtiveram as melhores avaliações da cor, odor, textura e sabor. Os produtos desenvolvidos com maior proporção de carne de ema em relação ao suíno tiveram a menor preferência pelo painel de avaliadores, sendo que os embutidos formulados com 90% de carne de ema receberam as menores avaliações. Conclui-se que no presente trabalho, os embutidos curados fermentados que possuem uma formulação de 22,5% de carne de ema e 67,5% de carne de suíno reuniram características para serem enquadrados na legislação vigente de salame e são os mais adequados para serem lançados no mercado brasileiro como uma fonte alternativa de proteínas para o consumo humano.
282

Isolamento, quantificação e perfil de resistência de sorovares de Salmonella isolados de lingüiça frescal suína em Lages/SC / Isolation, quantification and resistance profile in Salmonella serovars strains isolated from fresh pork savage in Lages, Santa Catarina State

Spricigo, Denis Augusto 05 February 2007 (has links)
Made available in DSpace on 2016-12-08T16:24:14Z (GMT). No. of bitstreams: 1 PGCV07MA019.pdf: 374475 bytes, checksum: 5b7cf7f2d6a9a5ca65d84dd86e71af73 (MD5) Previous issue date: 2007-02-05 / Salmonella is one of the main causes of food poisoning. In the last years, the main focus has been on meat and swine products both because of public health concerns and also because of its commercialization/exportation. Two studies were conducted in order to: 1) verify the prevalence of Salmonella serovars in fresh pork sausages commercialized in Lages, Santa Catarina and analyze its level of contamination, and 2) determine the profile of antimicrobial resistance in samples of Salmonella sp. isolated in fresh pork sausages. For this purpose, 200 samples of nine brands were collected in different commercial stores. At laboratory 25 grs of the collected material was weighed aseptically. Each sample was submitted to a pre-enrichment in buffered water peptone (37oC/24 h) followed by selective enrichment in Tetrationate Muller- Kauffmann and Rappaport-Vassiliadis (42oC/24h) and isolated in Xylose Lysine Tergitol-4 agar and Brilliant-Phenolred-bile-Lactose-Saccharose agar with Novobiocine. Suspected colonies were cofirmed by biochemical and serological tests. Among the samples analyzed, Salmonella sp. was isolated from 27% (54). Serovar Typhimurium (20%) accounted for the highest percentage of isolates in a total of 15 serovars. Only one sausage sample had a quantity of Salmonella capable of causing diseases in human beings (>1.100 MPN/g). In the second study, the 60 strains were tested against 14 antimicrobials by the agar diffusion method. 56,67% of the analyzed isolates showed resistance to at least one antimicrobial agent, and 20% showed multi-resistance. The highest rate of resistance was detected against sulfonamide (45%) and tetracycline (41%). No sample was resistant to amoxicillin/clavulanic acid, ceflacor, gentamicin, neomycin and tobramycin. The sample that showed resistance against the highest number of antimicrobial agents (7/14) belonged to serovar Schwarzengrund, although serovar Typhimurium presented the highest number of multiresistent isolates (5/12 41,67%). Although most products were positive for Salmonella sp., in amounts below the infection dosis, their prevalence may be a risk for the consumer. The high number of isolated agents found in the study stresses that future monitoring of the use of antimicrobial agents is necessary to control the risk of selection and transmission of resistant families through the food chain / A Salmonella sp. é uma das principais causas mundiais de toxinfecção alimentar. Nos últimos anos, as preocupações têm se voltado para a carne e produtos suínos tanto no aspecto de saúde pública como de comercialização/exportação. Dois estudos foram conduzidos com o objetivo de: 1) verificar a prevalência de sorovares de Salmonella sp. em lingüiças tipo frescal de matéria-prima suína comercializadas em Lages/SC, bem como seu nível de contaminação; e, 2) verificar o perfil de resistência aos antimicrobianos em linhagens de Salmonella isoladas de lingüiças frescal suína. Para tanto, na primeira fase do trabalho, foram coletadas 200 amostras de nove marcas em diferentes estabelecimentos comerciais. No laboratório, foram pesados assepticamente 25 g de cada material coletado. Cada amostra foi submetida a pré-enriquecimento em água peptonada tamponada (37oC/24h), seguido de enriquecimento seletivo em Tetrationato Muller-Kauffmann e Rappaport-Vassiliadis (42oC/24h) e isolamento em agar seletivo Xilose Lisina Tergitol-4 e Verde Brilhante Lactose Sacarose acrescido de Novobiocina. Colônias suspeitas foram identificadas através de perfil bioquímico e sorologia. Das amostras analisadas, foram isoladas Salmonella sp. em 27% (54), sendo o sorovar Typhimurium o mais encontrado (20%) num total de 15 sorovares. Em apenas seis amostras foi isolado mais de um sorovar. Apenas uma apresentou uma quantidade de microrganismos capaz de causar enfermidade no homem (>1.100 NMP/g). Na segunda fase, os 60 isolados foram submetidos ao teste de susceptibilidade in vitro frente a 14 antimicrobianos através do método de difusão em agar Mueller-Hinton. Das amostras analisadas, 56,67% apresentaram resistência a pelo menos um dos antimicrobianos testados e o perfil de multi-resistência foi encontrado em 20% das amostras testadas. Os maiores índices de resistência foram apresentados contra sulfonamida (45%) e tetraciclina (41,67%). Nenhuma amostra foi resistente a amoxicilina/ácido clavulânico, cefaclor, gentamicina, neomicina e tobramicina. A amostra com maior índice de resistência (50%) foi do sorovar Schwarzengrund, porém o sorovar Typhimurium foi o que apresentou maior número de isolados multiresistentes (5/12 41,67%). Apesar da maioria dos produtos positivos para Salmonella sp. conter uma quantidade de microrganismo abaixo da dose infectante, sua prevalência elevada pode representar um risco ao consumidor. Além disso, o alto número de isolados resistentes encontrado no presente estudo indica a necessidade de futuro monitoramento do uso de antimicrobianos na granja, para controlar o risco de seleção e transmissão de cepas resistentes através da cadeia alimentar
283

Influência do manejo pré-abate na qualidade da carne de suínos

Jacinto, Jessika Soares 11 September 2017 (has links)
O objetivo desse trabalho foi avaliar a qualidade do produto final relacionado ao manejo pré-abate de suínos, que permitiu analisar os procedimentos e o cumprimento das normas de bem-estar animal. O manejo pré-abate é definido como o conjunto de práticas com os animais desde a propriedade até o frigorífico. Os procedimentos pré-abate estão diretamente relacionados a perdas relacionadas à qualidade da carne e perdas econômicas em todo o sistema produtivo. Foram avaliados 144 animais, em um período de seis dias de abate com relação à capacidade de retenção de água, pH inicial e final e coloração. Posteriormente, os resultados foram analisados com relação os defeitos tecnológicos como PSE e DFD. Conclui-se que o manejo inadequado influenciou na qualidade dos produtos. / The objective of this work was to evaluate the quality of the final product related to the pre-slaughtering of pigs, which allowed the analysis of procedures and compliance with animal welfare standards. Pre-slaughter management is defined as the set of practices with the animals from the property to the slaughterhouse. Pre- slaughter procedures are directly related to losses related to meat quality and economic losses throughout the production system. A total of 144 animals were evaluated over a six day slaughter period in relation to water retention capacity, initial and final pH, and staining. Subsequently, the results were analyzed with regard to technological defects such as PSE and DFD. It was concluded that improper handling influenced the quality of the products.
284

Influência do manejo pré-abate na qualidade da carne de suínos

Jacinto, Jessika Soares 11 September 2017 (has links)
O objetivo desse trabalho foi avaliar a qualidade do produto final relacionado ao manejo pré-abate de suínos, que permitiu analisar os procedimentos e o cumprimento das normas de bem-estar animal. O manejo pré-abate é definido como o conjunto de práticas com os animais desde a propriedade até o frigorífico. Os procedimentos pré-abate estão diretamente relacionados a perdas relacionadas à qualidade da carne e perdas econômicas em todo o sistema produtivo. Foram avaliados 144 animais, em um período de seis dias de abate com relação à capacidade de retenção de água, pH inicial e final e coloração. Posteriormente, os resultados foram analisados com relação os defeitos tecnológicos como PSE e DFD. Conclui-se que o manejo inadequado influenciou na qualidade dos produtos. / The objective of this work was to evaluate the quality of the final product related to the pre-slaughtering of pigs, which allowed the analysis of procedures and compliance with animal welfare standards. Pre-slaughter management is defined as the set of practices with the animals from the property to the slaughterhouse. Pre- slaughter procedures are directly related to losses related to meat quality and economic losses throughout the production system. A total of 144 animals were evaluated over a six day slaughter period in relation to water retention capacity, initial and final pH, and staining. Subsequently, the results were analyzed with regard to technological defects such as PSE and DFD. It was concluded that improper handling influenced the quality of the products.
285

Estimativa da transferência de Salmonella typhimurium DT 177 entre faca de aço inoxidável e carne suína artificialmente contaminada

Navarrete Rivas, Cláudia Andrea January 2017 (has links)
A contaminação cruzada por Salmonella spp. durante o processo de abate de suínos contribui para o aumento da prevalência de carcaças positivas no pré-resfriamento. Um dos fatores que pode contribuir para a contaminação cruzada é a execução de cortes e palpação de carcaças durante o processo de inspeção. O presente estudo teve como objetivo estimar, por meio de ensaios laboratoriais, a transferência de Salmonella Typhimurium DT 177 entre faca e carne suína, para subsidiar análises futuras aplicadas ao processo de abate. Foram conduzidas observações independentes e aleatórias da transferência de uma cepa de S. Typhimurium resistente a Ampicilina (AmpR), entre faca e carne suína, as quais formaram quatro coleções de dados: Coleção de dados A: transferência de S. Typhimurium AmpR de faca contaminada para porção de carne suína cortada uma vez (n=20); Coleção de dados B: transferência de S. Typhimurium AmpR de faca contaminada para porção de carne suína cortada cinco vezes no mesmo lugar (n=20); Coleção de dados C: Transferência de S. Typhimurium AmpR de porção de carne suína contaminada para faca após execução de um corte (n=20); Coleção de dados D: Transferência de S. Typhimurium AmpR de porção de carne suína contaminada para faca após execução de cinco cortes no mesmo lugar (n=20). As bactérias transferidas foram quantificadas na lâmina da faca e na superfície da carne, a porcentagem de transferência foi calculada em todas as coleções de dados. As porcentagens de transferência entre as coleções de dados foram comparadas por meio de teste t para amostras independentes usando o programa R Core Team. As percentagens médias de transferência na coleção de dados A e B foram de 6,26% (4,7% – 7,7%) e 8,32% (6,4% - 10,2%). Nas coleções de dados C e D, as percentagens médias de transferência foram, respectivamente, 0,42% (0,3% - 0,5%) e 0,3% (0,2% - 0,4%). Não houve diferença significativa entre as percentagens de transferência após um e cinco cortes consecutivos. A partir disso, conclui-se que há transferência de S. Typhimurium da faca para a carne suína, bem como da carne suína para a faca. A porcentagem de transferência da carne suína contaminada para a faca é baixa, ao passo que a faca contaminada transfere alta percentagem do total de células de S. Typhimurium que carreia, durante a realização dos cortes. / Cross-contamination by Salmonella spp. during the pig slaughtering process contributes to increase the prevalence of positive carcasses in pre-chilling. One of the factors that may contribute to cross-contamination is the implementation of cuts and palpation of carcasses during the inspection process. The present study aimed to estimate, through laboratory tests, the transfer of Salmonella Typhimurium between knife and swine meat, to support future analyzes applied to the slaughter process. Independent and random observations of the transfer of a strain of S. Typhimurium Ampicillin-resistant (AmpR) between knife and swine meat were conducted, which formed four collections of data: Data collection A: Transfer of S. Typhimurium AmpR from contaminated knife to one portion of swine meat cut once (n = 20); Data collection B: Transfer of S. Typhimurium AmpR from contaminated knife to swine meat portion cut five times in the same place (n=20); Data collection C: Transfer of S. Typhimurium AmpR from portion of contaminated meat swine to knife after a cut (n=20); Data collection D: Transfer of S. Typhimurium AmpR from swine meat portion contaminated to knife after five cuts in the same place (n=20). The transfer percentages between the data collection were compared by t-test for independent samples using the R Core Team software. The mean transfer percentages in the data collection A and B were 6,26% (4,7% - 7,7%) and 8,32% (6,4% - 10,2%). In the C and D data collections, mean transfer rates were, respectively, 0.42% (0.3% - 0.5%) and 0.3% (0.2% - 0.4%). There was not significant difference between transfer rates after one and five consecutive cuts. From this, it is concluded that there is transfer of S. Typhimurium from the knife to the swine meat as well as from the swine meat to the knife. The percentage of transfer of contaminated pork to the knife is low, while the contaminated knife transfers at high percentage of the total number of S. Typhimurium cells it carries during cuts.
286

Controle de Listeria monocytogenes em lingüiça frescal refrigerada através do uso de óleo essencial de orégano e nisina / Control of Listeria monocytogenes in fresh pork sausage due to use of oregano essential oil and nisin

Monika Francisca Kruger 30 June 2006 (has links)
Listeria monocytogenes é conhecida como um importante patógeno causador de doenças transmitidas por alimentos na última década. Apesar do número de casos por ano ser relativamente baixo, a infecção pode ser grave, com mortalidades acima de 30%. Pesquisas realizadas no Brasil relataram uma incidência de 32% em amostras de produtos cárneos, e o microrganismo foi encontrado em 80% das amostras lingüiças frescal de carne suína. Apesar dos recentes avanços nas tecnologias de controle de patógenos em alimentos, os consumidores têm procurado alimentos \"naturais\", isto é, submetidos a tratamentos menos agressivos e isentos de conservadores químicos. Antimicrobianos naturais são uma opção interessante, mas sua aplicação requer uma melhor compreensão de sua funcionalidade nos alimentos. Os óleos essenciais e seus compostos fenólicos estão se tornando agentes antimicrobianos naturais bastante populares, assim como a nisina, uma bacteriocina produzida por Lactococcus lactis subsp. lactis. Esta pesquisa foi desenvolvida para avaliar o efeito de óleo essencial de orégano (O.E.O.) e de nisina, individualmente ou em combinação, na inibição da multiplicação de Listeria monocytogenes Scott A in vitro (meio de cultura) e in situ -(lingüiça frescal suína). A atividade inibitória foi testada pela metodologia de difusão em poços, e os halos de inibição foram medidos 24 horas após a incubação à 37ºC. Foram testadas as concentrações 0,05%, 0,1%, 0,2%, 0,3%, 0,4% e 0,5% (v/v) de O.E.O. e 0, 100, 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800 e 2000 ppm de nisina. Quando o óleo essencial foi usado em combinação com a nisina foi observado um efeito sinérgico na inibição de L. monocytogenes. As concentrações que apresentaram o maior efeito contra o patógeno nos testes in vitro, ou seja 0,5% (v/v) O.E.O. com 200 ppm de nisina, foram utilizadas nos experimentos com três formulações diferentes lingüiça frescal, contendo pernil de porco, sal (2%), nitrito (0,015%), condimentos, emulsificantes e antioxidantes, experimentalmente contaminadas com L. monocytogenes Scott A (106 UFC/g). A multiplicação do patógeno foi monitorada no produto refrigerado a 5oC por até 10 dias, através da contagem em placas. Controles sem antimicrobianos também foram estudados. Os resultados indicaram que o O.E.O., usado isoladamente, não conferiu proteção ao alimento. A nisina causou uma redução de 2 log imediatamente após o contato com o microrganismo, mas durante o armazenamento, as células sobreviventes apresentaram a mesma taxa de multiplicação que na lingüiça controle (??0,05), mantendo as contagens 2 log inferiores as do controle por até 9 dias. Quando os dois antimicrobianos foram usados em combinação, a redução imediata após o contato foi de 4 log, e, quando comparado ao controle, a taxa de multiplicação durante o armazenamento a 5oC foi significativamente mais altas que no controle (??0,05). Entretanto, as amostras de lingüiça contendo esses antimicrobianos nas concentrações testadas não foram aprovadas nos testes sensoriais de aceitação (??0,05). Esses resultados indicam que a combinação desses antimicrobianos pode ser utilizada como uma barreira adicional para a multiplicação de L.monocytogenes em lingüiça frescal suína, mas os atributos sensoriais que conferem ao produto podem limitar sua aplicação. / Listeria monocytogenes has been recognized as an important foodborne pathogen for the past decade. Although the number of cases per annum is relatively low, the infections can be acute, with mortality up to 30%. In Brazil, some works reported that 32% of dairy meat products were contaminated with L. monocytogenes, and this organism was found in 80% of fresh pork sausage. In spite of modern improvements in food production techniques, the consumers are seeking for \"natural\" food products, i.e., not submitted to aggressive treatments or added of chemical preservatives. Natural antimicrobials are a promising option, but their application requires a better understanding of their functionality in foods. Naturally occurring antimicrobial agents, such as essential oils and their phenolic components, are becoming increasingly popular as preservation agents. Other compound with increased application in foods is nisin, a bacteriocin produced by Lactococcus lactis subsp. lactis. This study aimed to evaluate the antimicrobial effect of oregano essential oil (O.E.O.) and nisin, individually or in combination, on the inhibition of growth of Listeria monocytogenes Scott A in vitro (agar culture medium) and in situ (fresh pork sausage). The inhibitory activity was tested by the well diffusion method, measuring the inhibition halos after 24hours incubation at 37ºC. The concentrations tested were 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% (v/v) for OEO and 0, 100, 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800 and 2000 ppm for nisin. When the essential oil was used in combination with nisin, a synergistic effect was observed for L. monocytogenes, i.e., the oil enhanced the activity of the bacteriocin. The combination 0.5% (v/v) O.E.O. with 200 ppm nisin presented the best results and was used to test the functionality in fresh pork sausage prepared with three different formulations, containing deboned minced pork meat, 2% salt and 0.015% nitrite, plus spices, emulsifier and antioxidant, and experimentally contaminated with L. monocytogenes Scott A (106 CFU/g). The growth of the pathogen was monitored in the refrigerated product (5oC) up to 10 days, by means of plate counting. Controls without antimicrobials were included in the experiments. Results indicated that O.E.O., used alone, was not effective. Nisin alone caused a 2-log reduction immediately after contact, but during storage the surviving cells presented the same multiplication rate as in the control (? ? 0.5), keeping the counts 2 log lower up to 9 days. When used in combination, the two antimicrobials caused a 4-log count reduction immediately after addition and, when compared to the control, the multiplication rate of the surviving cells during storage under refrigeration up to 10 days was significantly higher (? ? 0.5). However, samples containing these antimicrobials in the tested concentrations failed the sensorial acceptance tests (? ? 0.5). These results indicate that the combination of these antimicrobials can be an additional hurdle for the control of L. monocytogenes in fresh pork sausages, but the final sensorial attributes of the product may hamper their application.
287

Détection et caractérisation génétique de Listeria monocytogenes dans une usine d’abattage/découpe de porcs au Québec

Larivière-Gauthier, Guillaume 12 1900 (has links)
No description available.
288

Role státu v regionálním rozvoji: aplikace současných teorií regionálního rozvoje na případ vybraných podpůrných programů / The role of the state in regional development: application of contemporary regional development theories in the case of selected support programs

Hána, David January 2014 (has links)
The state plays a prominent role in the process of regional development. State interventions might bring radical influences into the entire socioeconomic system, to which the other actors of regional development have to adapt. Importantly, the state administrates a large amount of funds, creates large numbers of jobs, and it is led by "elites" which might influence the other people's opinions. The need for studying of the role of the state and the expenditure side of its budget for an understanding of the mechanisms of regional development is recognized by many authors. However, deep discussions of the function of the state could be hardly found in regional development theories. The aim of this dissertation thesis is to contribute to understanding of the role of the state as one of major actors in regional development via investigation of the regional impacts of public support programs. To provide concrete scrutiny, parliamentary grants (so-called "pork barrel") were depicted through which deputies annually sent large sums of money from the state budget during its approval process in the Chamber of Deputies on projects with local impact. The topic of parliamentary grants is a traditional topic for international studies within the concept of the so-called pork barrel politics, which includes all activities...
289

Évaluation et gestion du risque associé à la présence de Salmonella spp. chez le porc à l'abattoir

Rheault, Nancy January 2005 (has links)
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.
290

Inaktivierung von Salmonella Typhimurium und Yersinia enterocolitica auf Schwarte und Schweinelachs mittels gepulsten Lichts

Koch, Franziska 27 November 2020 (has links)
Einleitung: Salmonellen und Yersinien haben als zweit- und dritthäufigste Verursacher bakterieller Gastroenteritiden in Deutschland und Europa im Jahr 2017 eine große Bedeutung als Lebensmittelinfektionserreger. Übertragen werden sie hauptsächlich durch den Verzehr roher, unzureichend gekühlter oder ungenügend erhitzter Schweinefleischerzeugnisse (Schweinemett, Hackepeter, kurz gereifte Rohwürste). Der Eintrag in die Lebensmittelkette erfolgt über symptomlose Trägertiere, die am Schlachthof in der Lebendund Fleischuntersuchung nicht als solche identifizierbar sind. Durch Kreuzkontaminationen kann es zur Verschleppung der Erreger auf die Schlachttierkörperoberflächen eigentlich gesunder Tiere kommen. Die vorherrschenden Hygienemaßnahmen am Schlachthof haben bisher nicht zu einer Verringerung des Auftretens dieser Bakterien geführt. Alternativ könnte gepulstes Licht (GL) als zusätzliches Dekontaminationsverfahren zum Einsatz kommen. Dessen antimikrobielle Wirksamkeit wurde bereits in zahlreichen Studien nachgewiesen. In der Literatur fehlten jedoch bislang Daten zur Inaktivierung von Salmonella ssp. auf Schwarte und Schweinelachs. Bezüglich Yersinia ssp. lagen noch gar keine Studien vor. Ziel der Untersuchungen: Ziel dieser Arbeit war es, die Inaktivierung beider Erreger auf oben genannten Matrices zu testen und, unter Berücksichtigung chemischer und sensorischer Attribute der Produkte sowie die Eignung des Verfahrens für die Praxis abzuschätzen. Material und Methoden: Für die Untersuchungen mit künstlich inokulierten Schwarte- und Schweinefleischproben wurden die humanpathogenen Bakterien S. Typhimurium und Y. enterocolitica (Biotyp 4) verwendet. Die antimikrobielle Wirkung von GL wurde bei Fluences zwischen 0,52 und 19,11 J/cm² geprüft. Farb- bzw. Temperaturveränderungen auf der Probenoberfläche wurden mit Hilfe eines Spektrophotometers (CM 600 d, Konica Minolta) respektive eines Infrarotthermometers (104 IR, Testo) ermittelt. Zur Beurteilung der Lipidoxidation wurde die TBARS-Methode angewandt und die Proben maximal 10 Tage bei 4° C gelagert. Veränderungen bezüglich des Geruchs wurden bei Fluences von 0.52, 4.96 und 12.81 J/cm² mittels eines Konsensprofils beurteilt. Ergebnisse: Auf Schwarte konnten innerhalb von Sekunden Reduktionen von 1,73-3,16 log (S.) und von 1,48-4,37 log (Y.), auf Schweinelachs hingegen 1,7 log-Stufen für beide Mikroorganismen erreicht werden. Moderate bis starke Behandlungsregime (≥7,36 J/cm²) führten zu einer deutlich wahrnehmbaren Farbveränderung (E*ab ≥ 3) von Schwarte, ab 9,66 J/cm² zu einem signifikanten Verlust des roten Farbanteils von Schweinelachs. Zur Bewertung einer forcierten Fettoxidation wurde Malondialdehyd (MDA) in den Proben quantitativ bestimmt. Keine der getesteten Einstellungen hatte eine Überschreitung des Grenzwertes von 0,5 μg/g, ab dem Testpersonen die Produkte als ranzig wahrnehmen, zur Folge. Eine Überprüfung des Geruches erfolgte anhand von drei getesteten Fluences, die eine niedrige (0,52 J/cm²), moderate (4,96 J/cm²) und starke (12,81 J/cm²) Behandlung repräsentieren sollten. Mit 0,52 J/cm² bestrahlte Schwarte wurde von den Panel-Mitgliedern als weniger nach Schwein und weniger fettig riechend bewertet und somit als angenehm empfunden, ansonsten wurden chemische Gerüche wahrgenommen. Schlussfolgerungen: Aus den erzielten Daten geht hervor, dass sich gepulstes Licht in niedrigen Dosen (≤0,52 J/cm²) zur Dekontamination von Schwarte eignet. Praktisch umsetzbar wäre dies am Schlachthof als geschlossene Behandlungskammer, unmittelbar nach der Eviszeration. Somit könnte der noch nicht geteilte Schlachtkörper oberflächlich behandelt werden, ohne das unter der Haut befindliche Fleisch zu erreichen und die oben genannten Veränderungen hervorzurufen. Notwendig ist hierbei die Gewährleistung des Arbeitsschutzes. In diesem Zusammenhang muss entstehendes Ozon unschädlich beseitigt werden und das Tragen einer UV-Schutzbrille in der unmittelbaren Umgebung des Gerätes angeordnet werden. Abschließend ist hervorzuheben, dass das GL als zusätzliche, unterstützende Maßnahme zur Bekämpfung von Lebensmittelinfektionserregern zu sehen ist und keine bestehenden Hygienemaßnahmen (gute Hygienepraxis) ersetzen darf. Aufgrund der geringeren Wirksamkeit auf Schweinelachs und den damit verbundenen geruchlichen Veränderungen ist eine Applikation auf Schweinefleisch ohne weiterführende Untersuchungen nicht zielführend.:Inhaltsverzeichnis ABKÜRZUNGSVERZEICHNIS ..............................................................................................III 1 EINLEITUNG ........................................................................................................... 1 2 LITERATURÜBERSICHT ........................................................................................ 3 2.1 Gepulstes Licht und gesetzliche Rahmenbedingungen ............................................. 3 2.2 Wirk- und Reparaturmechanismen, Resistenzbildung und Inaktivierungskinetik ....... 7 2.2.1 Photochemischer Effekt ................................................................................... 7 2.2.2 Photoreaktivierung ........................................................................................... 8 2.2.3 Photothermischer Effekt ................................................................................... 8 2.2.4 Physikalischer Effekt ........................................................................................ 9 2.2.5 Resistenzbildung .............................................................................................. 9 2.2.6 Inaktivierungskinetik ......................................................................................... 9 2.3 Einflussparameter ................................................................................................... 10 2.3.1 Mikroorganismus .............................................................................................10 2.3.2 Zeitpunkt der Bestrahlung ...............................................................................12 2.3.3 Matrix ..............................................................................................................12 2.4 Gepulstes Licht zur Inaktivierung von lebensmittelassoziierten Erregern in Fleischwaren .......................................................................................................... 13 2.5 Zielstellung dieser Arbeit ......................................................................................... 17 3 VERÖFFENTLICHUNG ..........................................................................................18 3.1 Eigenanteil zur Veröffentlichung ............................................................................. 18 3.2 Publikation .............................................................................................................. 18 4 ÜBERGREIFENDE DISKUSSION ..........................................................................46 4.1 Eignung des Verfahrens „Gepulstes Licht“ zur Dekontamination von Schwarte und Schweinelachs ................................................................................................. 46 4.2 Vergleich von GL mit anderen Dekontaminationsverfahren .................................... 49 4.2.1 Chemische Dekontamination ...........................................................................49 4.2.2 Physikalische Dekontamination .......................................................................49 4.2.3 Biologische Dekontamination ..........................................................................50 4.3 Alternativer Einsatz von GL..................................................................................... 51 4.4 Schlussfolgerungen ................................................................................................ 51 5 ZUSAMMENFASSUNG ..........................................................................................53 6 SUMMARY .............................................................................................................55 7 LITERATURVERZEICHNIS ....................................................................................57 ANHANG ..............................................................................................................................66 DANKSAGUNG ....................................................................................................................72 / Introduction: Since Salmonella ssp. and pathogenic Yersinia ssp. were the second and third most frequent causes for bacterial gastroenteritis in Germany and throughout Europe in 2017 they are of high significance as foodborne infectious agents. They are mainly transmitted by consumption of raw, inadequately cooled or insufficiently heated pork meat products (ground pork, minced pork, shortly ripened raw sausages). Subclinically infected pigs, so-called “carriers”, cannot be detected during ante- and post-mortem inspection in the slaughterhouse. Cross-contamination can lead to bacterial dissemination onto actually S.- or Y.-free carcasses. Prevailing hygienic measures could not reduce bacterial prevalence in the abattoir so far. Thus, pulsed light (PL) may be used as an additional decontamination procedure. Its antimicrobial potential was proven in numerous studies. However, there are no data in the scientific literature about inactivation of Salmonella ssp. on pork skin and loin. Moreover, no experiments with Yersinia in connection with pulsed light have been performed until now. Aim of this study: Hence, the aim of this work was to investigate the inactivation of both microorganisms on above-mentioned matrices and to assess the suitability of the PL treatment for implementation in a slaughterhouse considering chemical and sensory alterations of the products. Materials and Methods: For experiments with artificially inoculated pork skin and loin samples human-pathogenic bacteria S. Typhimurium and Y. enterocolitica (Biotype 4) were used. The antimicrobial effect of PL was tested at fluences between 0.52 and 19.11 J/cm². Color and temperature changes on the sample surface were determined by means of a spectrophotometer (CM 600 d, Konica Minolta) or an infrared thermometer (104 IR, Testo). The TBARS method was used to assess lipid per-oxidation and the samples were stored at 4° C for a maximum of 10 days. Odor changes were appraised at fluences of 0.52, 4.96 and 12.81 J/cm² using consensus profiling. Results: On pork skin reductions of 1.73-3.16 log (S.) and of 1.48-4.37 log (Y.) were achieved within seconds. In contrast, on pork loin only 1.7 log of both microorganisms were maximally inactivated. Moderate to strong treatments (≥7.36 J/cm²) led to distinct color changes (E*ab ≥ 3) in pork skin, fluences above 9.66 J/cm² to a significant loss of red color in pork loin. For evaluation of possible accelerated lipid peroxidation malondialdehyde (MDA) was analyzed quantitatively in samples. None of the tested parameter combinations resulted in threshold value exceedance of 0.5 μg MDA/g which is the point where panel members start to perceive products as rancid. Odor appraisal was carried out using three fluences representing a mild (0.52 J/cm²), moderate (4.96 J/cm²) and strong (12.81 J/cm²) treatment. Pork skin treated with 0.52 J/cm² was assessed as less porky, less fatty and, thus, pleasant by panel members, apart from that chemical odors were perceived. Conclusions: From the available data it appears that pulsed light could be used in mild doses (≤0.52 J/cm²) for pork skin decontamination. Practically, a PL-unit could be designed as a closed chamber, implemented directly after the evisceration in the abattoir. This way, the not yet separated carcass could be treated superficially without reaching the meat surface preventing the above-mentioned alterations. Guarantee of safety at work also plays an important role. Emerging ozone must be evacuated safely and UV-protection glasses should be worn in direct proximity to the PL-system. Finally, one needs to consider, that PL should be regarded as an additional, supportive measure to control foodborne pathogens and not as a replacement for existing hygiene standards (good hygiene practice). An application on pork meat does not seem to be conducive because of its lower effect on pork loin and the associated odor changes.:Inhaltsverzeichnis ABKÜRZUNGSVERZEICHNIS ..............................................................................................III 1 EINLEITUNG ........................................................................................................... 1 2 LITERATURÜBERSICHT ........................................................................................ 3 2.1 Gepulstes Licht und gesetzliche Rahmenbedingungen ............................................. 3 2.2 Wirk- und Reparaturmechanismen, Resistenzbildung und Inaktivierungskinetik ....... 7 2.2.1 Photochemischer Effekt ................................................................................... 7 2.2.2 Photoreaktivierung ........................................................................................... 8 2.2.3 Photothermischer Effekt ................................................................................... 8 2.2.4 Physikalischer Effekt ........................................................................................ 9 2.2.5 Resistenzbildung .............................................................................................. 9 2.2.6 Inaktivierungskinetik ......................................................................................... 9 2.3 Einflussparameter ................................................................................................... 10 2.3.1 Mikroorganismus .............................................................................................10 2.3.2 Zeitpunkt der Bestrahlung ...............................................................................12 2.3.3 Matrix ..............................................................................................................12 2.4 Gepulstes Licht zur Inaktivierung von lebensmittelassoziierten Erregern in Fleischwaren .......................................................................................................... 13 2.5 Zielstellung dieser Arbeit ......................................................................................... 17 3 VERÖFFENTLICHUNG ..........................................................................................18 3.1 Eigenanteil zur Veröffentlichung ............................................................................. 18 3.2 Publikation .............................................................................................................. 18 4 ÜBERGREIFENDE DISKUSSION ..........................................................................46 4.1 Eignung des Verfahrens „Gepulstes Licht“ zur Dekontamination von Schwarte und Schweinelachs ................................................................................................. 46 4.2 Vergleich von GL mit anderen Dekontaminationsverfahren .................................... 49 4.2.1 Chemische Dekontamination ...........................................................................49 4.2.2 Physikalische Dekontamination .......................................................................49 4.2.3 Biologische Dekontamination ..........................................................................50 4.3 Alternativer Einsatz von GL..................................................................................... 51 4.4 Schlussfolgerungen ................................................................................................ 51 5 ZUSAMMENFASSUNG ..........................................................................................53 6 SUMMARY .............................................................................................................55 7 LITERATURVERZEICHNIS ....................................................................................57 ANHANG ..............................................................................................................................66 DANKSAGUNG ....................................................................................................................72

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