Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-21T10:39:19Z No. of bitstreams: 2 Dissertação - Kassia Kiss Firmino Dourado Costa - 2015.pdf: 7188942 bytes, checksum: b55493d7db5e9c3c01e8079a3512028b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-21T10:41:30Z (GMT) No. of bitstreams: 2 Dissertação - Kassia Kiss Firmino Dourado Costa - 2015.pdf: 7188942 bytes, checksum: b55493d7db5e9c3c01e8079a3512028b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-21T10:41:30Z (GMT). No. of bitstreams: 2 Dissertação - Kassia Kiss Firmino Dourado Costa - 2015.pdf: 7188942 bytes, checksum: b55493d7db5e9c3c01e8079a3512028b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-05-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The market has been seeking new alternatives to replace food products derived from milk, due to health problems. In this context arise plant foods having similar characteristics to those of animal origin, mainly related to texture, and also add functional characteristics. The objective was to verify the influence of waxy maize starch (WMS) in the physical, chemical, microbiological, sensory and functional quality of fermented rice extracts (FRE) made with bran and broken rice grains (8:92 ), fermented mixture (FME) of soy and rice byproducts (70:30), and fermented soybeans (FSE), all inoculated with probiotic bacteria. A completely randomized design with five treatments (5 WMS concentrations for each extract) and four replications was appliedand evaluatedfor total acidity, total soluble solids, total soluble sugars, syneresis and texture.Only for FRE, images by scanning electron microscopy were obtained and analyzed for the rheology (results were adjusted to the Newton, Bingham, Casson, Herschel-Bulkley and Ostwald Waele Models, and then hysteresis calculation was performed). Fermented extracts were selected based on the results of texture (similar to the Greek yogurt analysed) and syneresis to which were added flavor and strawberry syrup(FREF, FMEF and FSEF, respectively). The latter were evaluated for the chemical properties, antioxidant activity, microbiological risk and sensory acceptance. The physical and chemical changes, microbiological, sensory and cell viability during storage of FREF and FMEF were evaluated to determine the viable time for product consumption, and also to check the resistance of the probiotic microorganisms in the gastrointestinal tract conditions. Amongst all samples, FRE with12g.100g-1 WMShad greater reduction in syneresis, 89% greater than the sample without WMS. The FRE with 4g.100g-1 WMS, FME with 5g.100g-1 WMS and the FSE with 5g.100g-1WMS presented similar texture values as to the Greek yogurt analyzed. The scavenging electronic microscopy showed that the gradual addition of WMS completely changed the microscopic structure of the FRE. The rheology showed that the FRE had rheological behavior similar to traditional yogurts. The FREF with 4g.100g-1 of WMS presented antioxidant capacity of 27,40μmolTrolox g-1 (ABTS). The FSEF presented content of total phenolic compounds of 177,96mgEAG 100g-1. The FMEF presented 71,14g.100g-1 of humidity, 10,64g.100g-1 of protein, 4,25g.100g-1 of fat and 0,49g.100g-1 of ash. Potassium was the mineral in higher concentration, 572,14mg.100g-1. All flavored fermented extracts presented to be microbiologically safe and were well sensory accepted. During cold storage of FREF and FMEF the changes of the parameters analyzed did not compromise their quality up to 28 days and the FMEF presented probiotic effect until 14 days of storage. Probiotics have shown resistance in the tested conditions. The products are presented as excellent alternatives regarding the chemical composition, antioxidant capacity and sensory acceptance. The AMC showed favorable effect on the texture and significantly reduced syneresis. / O mercado tem buscado novas alternativas alimentares que substituam os produtos derivados do leite, devido aproblemas de saúde. Nesse contexto surgem os alimentos vegetais que possuem características semelhantes aos de origem animal, principalmente relacionado à textura, e ainda, agreguem características funcionais.O objetivo deste trabalho foi verificar a influência do amido de milho ceroso (AMC) sob a qualidade física, química, microbiológica, sensorial e funcional de extratosde arroz fermentado (EAF) elaborados com farelo e grãos quebrados de arroz (8:92), misto fermentado (EMF) de soja e de coprodutos de arroz (70:30), e desoja fermentado (ESF), todos inoculados com bactérias probióticas.Para todos os extratos fermentados utilizou-se delineamento inteiramente casualizado, com cinco tratamentos (5 concentrações de AMC para cada extrato) e quatro repetições, e avaliaram-se à acidez total, os sólidos solúveis totais, os açúcares solúveis totais, a sinérese e a textura. Somente para o EAF, obteve-se imagens por microscopia eletrônica de varredura e analisou-se quanto à reologia (ajustando os resultados aos modelos de Newton, Bingham, Casson, Herschel‑Bulkley e Ostwald de Waele, e efetuando-se o cálculo da histerese). Saborizou-se com aroma e calda de morango os extratos fermentados selecionados (EAFS, EMFS e ESFS, respectivamente) baseado nos resultados de textura (semelhante ao iogurte grego analisado) e sinérese,e avaliaram-seos mesmos quanto às características químicas, atividade antioxidante, risco microbiológico e aceitação sensorial. Avaliaram-se as alterações físico-químicas, microbiológicas, sensoriais e a viabilidade celular durante o armazenamento refrigerado doEAFS e do EMFS, visando determinar o tempo viável para o consumo do produto, verificando também a resistência dos micro-organismos probióticos em condições do trato gastrointestinal. Entre todos, o EAF com 12g 100g-1 de AMCobteve maior redução da sinérese, 89%, em relação a amostra sem AMC. O EAF com 4g 100g-1 de AMC, o EMFcom 5g 100g-1 de AMC e o ESF com 5g 100g-1 de AMC apresentaram textura semelhante à do iogurte grego analisado. A microscopia eletrônica de varredura mostrou que a adição gradativa do AMC mudou completamente a estrutura microscópica dos EAF. A reologia mostrou que os EAF apresentaram comportamento reológico semelhante aos iogurtes tradicionais. O EAFS com 4g 100g-1 de AMC obteve capacidade antioxidante de 27,40μmolTrolox g-1 (ABTS). O ESFS apresentou teor de compostos fenólicos totais de 177,96mgEAG 100g-1.O EMFS apresentou 71,14g 100g-1 de umidade, 10,64g 100g-1 de proteína, 4,25g 100g-1 de lipídios e 0,49g 100g-1 de cinzas e o mineral em maior concentração foi o potássio, com 572,14mg 100g-1. Todos os extratos fermentadossaborizados apresentaram-se microbiologicamente seguros e foram bem aceitos sensorialmente. Durante o armazenamento refrigerado dos EAFS e EMFSas alterações dos parâmetros analisados não comprometeram a qualidade dos mesmosaté os 28 dias sendo queo EMFSapresentou efeito probiótico até 14 dias de armazenamento. Os probióticos mostraram resistências nas condições testadas.Os produtos se apresentaram como excelentes alternativas em relação à composição química, capacidade antioxidante e aceitação sensorial. O AMC apresentou efeito favorávelna textura e reduziu consideravelmente asinérese.

Orientador: Helena Maria André Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T23:54:10Z (GMT). No. of bitstreams: 1 Esmerino_ErickAlmeida_M.pdf: 1065128 bytes, checksum: ee13a76c96576bb03b96eb2c44313d5a (MD5) Previous issue date: 2012 / Resumo: Cada vez mais micro-organismos probióticos estão sendo incorporados aos alimentos, porém pouco se sabe sobre a influência da matriz alimentícia e da formulação dos produtos sobre a viabilidade das bactérias. A introdução de probióticos na produção de queijos surge como alternativa ao problema de sobrevivência destes micro-organismos. Diante da prevalência de obesidade, medidas como a adição de edulcorantes deve ser avaliada, e estudos sensoriais conduzidos. Este trabalho teve por objetivo avaliar o perfil sensorial de queijos petit-suisse probióticos sabor morango, adoçados com os edulcorantes Sucralose, Estévia, Aspartame e Neotame, além de amostras comerciais convencionais, e através de Análise Descritiva Quantitativa (ADQ) e testes de aceitação, verificar os diferentes parâmetros que influenciam a aceitabilidade das diferentes amostras. Os resultados obtidos foram analisados estatisticamente com auxílio dos programas SAS e XLSTAT. Foram aplicados Análise de variância (ANOVA) e Teste de Média de Tukey sobre os dados obtidos. O método ADQ foi capaz de diferenciar as amostras, principalmente, através da cor lilás e rosa, brilho, e acidez, além dos gostos amargo e doçura residual. Através do teste de aceitação, verificou-se que as amostras comerciais convencionais, apresentaram maior aceitação. A amostra probiótica com sacarose não diferiu estatisticamente de duas amostras comerciais, demonstrando a possibilidade de incorporação de culturas probióticas. Por outro lado, a amostra probiótica contendo estévia foi menos aceita. Apresentaram melhor aceitação amostras com maior intensidade dos atributos cor lilás, aroma adocicado, sabor de morango natural e lácteo, sendo esses atributos considerados direcionadores de preferência. Enquanto as menos aceitas apresentaram, principalmente, maior intensidade do gosto amargo e doçura residual. Em conclusão, os testes sensoriais foram importantes para caracterização das amostras de queijo petit-suisse, evidenciando a possibilidade da adição de culturas probióticas. Entretanto, para a adição de compostos edulcorantes, fazem-se necessários mais estudos sensoriais, que busquem compostos que apresentem perfil sensorial semelhante à sacarose, sem prejuízo à sua aceitação / Abstract: Increasingly, probiotic are being incorporated into food, but little is known about the influence of food matrix and formulation of the products on the viability of the cultures. The introduction of probiotics in cheese appears as an alternative to the problem of survival of theses microorganisms. Given the prevalence of obesity, addition of sweeteners in food should be evaluated, and sensory studies conducted. This work aimed to evaluate the sensory profile of probiotic petitsuisse cheeses strawberry-flavored with the sweeteners Sucralose, Stevia, Aspartame and Neotame, in addition to conventional commercial samples, and through Quantitativa Descripetive Analysis (QDA) and acceptance testing, check the different parameters that influence the acceptability of differente samples. The results were statistically analyzed with the aid of statistical program SAS and XLSTAT. It was applied analysis of variance (ANOVA) and Tukey test. The QDA method was able to differentiate the samples, mainly through the purple and pink color, glitter, acidity, bitter and sweet aftertaste. Through the acceptance test, it was found that commercial samples, with no probiotic cultures, showed greater acceptance. The probiotic sample with sucrose did not differ statistically from two commercial samples, demonstrating the potential for incorporating probiotic cultures in these kind of cheese. On the other hand, probiotic sample containing Stevia was less accepted. Samples showed greater acceptance when more intensely the attributes purple color, sweet aroma, natural strawberry flavor and milk flavor were found, being considered the drivers of liking. While, the samples less accepted showed, mainly, higher bitterness and sweet aftertaste. In conclusion, the sensory testes were important for the characterization of the petitsuisse cheese samples, indicating the possibility of adding probiotic cultures in this kind of food. However, the addition of sweetening compounds needs more studies, which search compounds with similar sensory profile to sucrose, without prejudice to its acceptance / Mestrado / Consumo e Qualidade de Alimentos / Mestre em Alimentos e Nutrição

Orientadores: José de Assis Fonseca Faria, Adriano Gomes da Cruz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-20T10:29:44Z (GMT). No. of bitstreams: 1 Castro_WellingtondeFreitas_D.pdf: 1296410 bytes, checksum: 49d526e153c196243566d33d07ce840d (MD5) Previous issue date: 2012 / Resumo: A demanda por alimentos probióticos tem impulsionado o desenvolvimento de novos produtos formulados. Aproveitando tal cenário, as indústrias de alimentos vêm se dedicando basicamente aos lácteos, que se mostram ser ótimos carreadores de micro-organismos probióticos. O grande volume de soro proveniente das indústrias de queijos permite a elaboração de bebidas lácteas, visando o aproveitamento de subprodutos para a alimentação humana, devido ao seu elevado potencial nutricional. Este trabalho teve por objetivo avaliar o efeito dos níveis de soro de queijo nos parâmetros de qualidade e aceitação sensorial de bebidas lácteas probióticas, em comparação a produtos comerciais não probióticos. Modelos matemáticos como Análise de Sobrevida, Mínima Diferença Significativa e Aceitação Global Média foram utilizados para ajustar os níveis de soro de queijo mais aceitáveis em formulações de bebidas lácteas. Métodos sensoriais, como Mapa Projetivo, Análise Descritiva Quantitativa e Perfil Livre foram aplicados na avaliação das bebidas formuladas. A elaboração de bebidas lácteas probióticas provou ser uma boa alternativa para as indústrias de laticínios no aproveitamento do soro proveniente da fabricação de queijos, possibilitando assim redução dos custos de produção, além de propiciar novos produtos carreadores de micro-organismos benéficos à saúde / Abstract: The demand for probiotic foods has driven the development of new formulations. Taking advantage of such scenario, the food industry has been largely devoted to dairy, which proved to be excellent vehicles for probiotic microorganisms. The large volume of whey from the cheese industry has enabled the development of dairy drinks, considering the use of products for human food with high nutritional potential. This study evaluated the effect of whey levels in the quality parameters and sensory acceptability of probiotic milk drinks, as compared to commercial non probiotic products. Mathematical models as Survival Analysis, Minimal Significant Difference, and Mean Global Acceptance were used to adjust the whey levels in the most acceptable formulated dairy beverages. Sensory methods as Projective Mapping, Quantitative Descriptive Analysis, and Free Choice were applied in the evaluation of dairy beverages. The development of probiotic dairy drinks proved to be a good alternative for the dairy industry to take advantage of the whey from the cheese-making, by reducing production costs and providing probiotic foods with recognized human health benefits / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos

Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2018-05-21T19:09:25Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_Leticia_Cunha.pdf: 1240005 bytes, checksum: 5fc9bc631519a87ecdaef8c7aac12b8e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-05-21T20:15:03Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_Leticia_Cunha.pdf: 1240005 bytes, checksum: 5fc9bc631519a87ecdaef8c7aac12b8e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-05-21T20:15:14Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_Leticia_Cunha.pdf: 1240005 bytes, checksum: 5fc9bc631519a87ecdaef8c7aac12b8e (MD5) / Made available in DSpace on 2018-05-21T20:15:14Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_Leticia_Cunha.pdf: 1240005 bytes, checksum: 5fc9bc631519a87ecdaef8c7aac12b8e (MD5) Previous issue date: 2016-12-23 / Sem bolsa / Atualmente observa-se em diversos estudos o potencial dos probióticos de modular o sistema imune do hospedeiro e reduzir o estresse oxidativo. O antineoplásico ciclofosfamida (CF) tem como efeitos colaterais, o comprometimento da função de células do sistema imune, a indução do aumento de marcadores de estresse oxidativo e a ocorrência de danos renais e hepáticos. A levedura Pichia pastoris é atualmente utilizada como sistema de expressão de proteínas recombinantes para a produção dos mais diferentes tipos de proteínas heterólogas. No entanto, alguns estudos vêm demonstrado que essa levedura possui propriedades probióticas. O presente estudo teve como objetivo avaliar a segurança da utilização da levedura P. pastoris (P.p.) em camundongos imunossuprimidos, bem como seu efeito sobre parâmetros imunológicos, histopatológicos e de estresse oxidativo em um modelo de imunossupressão induzida por ciclofosfamida (CF). Foram utilizados 20 camundongos Swiss machos, divididos em quatro grupos: controle, controle CF (tratados com 250 mg.kg-1 de CF), controle P. p (suplementados com 109 UFC.mL-1) e CF + P.p. Foram realizados leucograma, análise histopatológica, pesagem dos animais e ensaio de TBARS. Foi observado que a CF reduziu os níveis de leucócitos, neutrófilos e linfócitos e P. pastoris foi capaz de aumentar o número de leucócitos e neutrófilos dos animais imunossuprimidos. Além disso, P. pastoris mostrou-se segura também em animais imunossuprimidos, não causando mortes. As análises histopatológicas demonstraram que a CF causou lesões renais e hepáticas e P. pastoris foi capaz de reduzir as lesões hepáticas causadas pelo quimioterápico. Quando avaliado o estresse oxidativo, foi observado que P. pastoris reduziu os níveis de espécies reativas ao TBA no rim e cérebro dos animais tratados com CF e no fígado e cérebro de animais saudáveis. Dessa forma, a levedura P. pastoris demonstra um efeito protetor aos danos causados pela CF. / Actually the potential of probiotics to modulate the host immune system and to reduce oxidative stress is being observed in several studies. Antineoplastic cyclophosphamide (CF) has the effect of compromising the immune system's cell function, inducing increased markers of oxidative stress, and causing renal and hepatic damage. Pichia pastoris yeast is currently used as a recombinant protein expression system for the production of the most different types of heterologous proteins. However, some studies have shown that this yeast possesses probiotic properties. The present study aimed to evaluate the safety of the use of the P. pastoris yeast, as well as its effect on immunological, histopathological and oxidative stress parameters in an immunosuppressive model. Twenty male Swiss mice were divided into four groups: control, CF control (250 mg.kg-1), P. p control(109 CFU.mL-1) and CF + P. p. Leukogram, histopathological analysis, animal weighing and TBARS assay were performed. It was observed that CF reduced the levels of leukocytes, neutrophils and lymphocytes, and P. pastoris was able to increase the number of leukocytes and neutrophils of immunosuppressed animals. In addition, P. pastoris was also safe in immunosuppressed animals, not causing deaths. Histopathological analyzes demonstrated that CF caused renal and hepatics lesions and P. pastoris was able to reduce the hepatics lesions caused by chemotherapy. When oxidative stress was evaluated, it was observed that P. pastoris reduced the levels of TBA reactive species in the kidney and brain of animals treated with CF, and in the liver and brain of healthy animals. Therefore, P. pastoris yeast demonstrates a protective effect to CF damage.

Made available in DSpace on 2014-08-20T14:38:01Z (GMT). No. of bitstreams: 1 tese_tiago_gallina.pdf: 1322298 bytes, checksum: d7d70ae5994737372bb40269fd74a742 (MD5) Previous issue date: 2011-02-28 / The gastrointestinal parasitic infections caused by nematodes is one of most detrimental causes that impaired the sheep production, whereas the Haemonchus contortus have a role due to its pathogeny and prevalence. The methods of control are based on the use of anthelmintics, which can lead the resistence of nematodes. The objectives of these studies were to evaluate the effect of Bacillus cereus var. Toyoi (Bc), Saccharomyces boulardii (Sb) and S. cerevisiae (Sc) probiotics in lambs infected with gastrointestinal nematodes. In the Experiment 1; thirty two Texel breed lambs, aging 4 to 5 months, were randomized allocated into 4 experimental groups; Group 1 (n=8) that received Bc, 2) Group 2 (n=8), that received Sb, Group 3 (n=8); that received Sc. All groups treated with probiotics received the concentration of 1x106 CFU gr-1. The Group 4 did not receive any treatment. The animals were fed with probiotics individually once a Day during 56 days. Seven days after the beginning of the experiment, the animals were infected with H. contortus. Blood samples were collected weekly in order to evaluate hematological, biochemical and immunological parameters. The gene expression of pro-inflammatory cytokines were evaluated by RT PCR. On Day 49, after the infection, all animals were killed in order to recover the parasites and to evaluate histologically The abomasum. In Experiment 2, twenty Ideal breed lambs, with 4 to 5 months old, were fed with 1x106 UFC gr-1 of Sc and kept in two paddocks naturally contaminated with nematodes during one year. The worm burden, packed cell volume, gain of weigh and body condition score were measured. In the Experiment 1 the Sc group differ from the others groups (P < 0.05) on the worm burden and eosinophil counting on the abomasal mucosa. The levels of IL-4 showed an increase of 15 times in the animals treated with Sc and Sb. In the experiment 2, there was a significant reduction on the number of H. contortus recovered from abomasum (P < 0.01) compared with the control group. These results suggest that the treatment with Saccharomyces cerevisiae probiotic interferes with the immune response and reduces the worm burden of nematodes, being an alternative to improve the methods of control of nematodes. / A nematodiose gastrintestinal é um dos principais fatores limitantes a produção de ovinos, destacando-se por sua patogenia e prevalência o Haemonchus contortus. As medidas de controle baseiam-se no uso de anti-helmínticos, aos quais os nematódeos apresentam graves problemas de resistência. Com o objetivo de avaliar o efeito dos probióticos Bacillus cereus var. Toyoi (Bc), Saccharomyces boulardii (Sb) e S. cerevisiae (Sc) em ovinos infectados por nematódeos gastrintestinais, dois experimentos foram delineados. Experimento I- utilizaram-se quatro grupos de oito ovinos machos, da raça Texel, de quatro a cinco meses de idade. O grupo 1 recebeu Bc, o grupo 2 Sb, o grupo 3 Sc, todos na concentração de 1x106 UFC gr-1 por dia e o grupo 4 Controle C, sem probiótico. Os probióticos foram administrados individualmente, por via oral, uma vez ao dia, durante 56 dias do experimento. Sete dias após o início da administração dos probióticos, os animais foram infectados por via oral com H. contortus. Amostras de sangue foram colhidas semanalmente, para avaliações hematológicas, bioquímica e imunológica. Os níveis de expressão gênica através das citocinas pró-inflamatórias foram verificados por RT-PCR. No 49º dia após a infecção todos os animais foram eutanasiados para recuperação dos parasitos e avaliação histológica do abomaso. O Experimento II- foi composto por dois grupos de 20 cordeiros machos, da raça Ideal, de quatro a cinco meses de idade; grupo I os cordeiros receberam 1x106 UFC gr-1 de Sc e o grupo controle somente ração. Os grupos foram mantidos individualizados em piquetes naturalmente contaminados por nematódeos gastrintestinais, durante um ano. Foram medidos os aspectos referentes à carga parasitária, volume globular, ganho de peso e condição corporal. Dentre os resultados obtidos no Experimento I, demonstrou-se que a carga parasitária e contagem de eosinófilos na mucosa abomasal mostraram diferenças significativas entre o grupo Sc e demais grupos (p<0,05). Os níveis de expressão da citocina IL-4 tiveram um aumento superior a 15x nos animais suplementados com Sc e Sb em relação ao grupo controle. No experimento II, houve redução significativa do número de H. contortus recuperados, semelhante ao experimento I (p<0,01). Os resultados demonstram que o probiótico a base de S. cerevisiae interfere na resposta imune e reduz a carga parasitária em ovinos, constituindo uma alternativa para ser associada a outros métodos de controle dos nematódeos, nesta espécie animal.

Des études récentes ont montré que le microbiote participe à l’homéostasie intestinale en contribuant au développement morphologique, à l’éducation du système immunitaire, aux mécanismes de défense de l’hôte et à la régulation du métabolisme. Une dysbiose de ce microbiote ainsi qu’une réduction de la diversité bactérienne a été observé dans diverses pathologies chroniques telles que les maladies inflammatoires chroniques (MICI) et l’obésité. Le microbiote constitue donc une cible thérapeutique de choix dans la prise en charge de ces maladies chroniques. Les probiotiques, microorganismes bénéfiques pour l’hôte représentent une alternative intéressante, mais dont les critères de sélection nécessitent d’être améliorés.Dans une première étude, nous avons pu mettre en évidence les propriétés bénéfiques d’un mélange de deux probiotiques comprenant un bifide et un lactobacille dans un modèle murin d’obésité résultant d’une alimentation riche en graisses (Alard et al, 2016). Ce mélange probiotique a réduit significativement la prise de poids, amélioré les paramètres inflammatoires et métaboliques dont l’insulino-résistance, et augmenté l’expression intestinale des récepteurs aux acides gras à chaine courte (AGCC). Il a également favorisé dans un système d’intestin artificiel la production de butyrate et propionate ; principaux AGCCs. Les effets protecteurs ont été associés à l’amélioration de la dysbiose du microbiote, notamment la restauration de l’abondance d’Akkermansia muciniphila.L’objectif principal de cette thèse a été ensuite de sélectionner au sein d’une collection de 23 souches bactériennes provenant de la société PiLèJe, une ou plusieurs souche(s) probiotique(s) possédant des propriétés protectrices contre les MICI et l’obésité. Les propriétés immuno-modulatrices des souches ainsi que leur capacité à renforcer la barrière intestinale ont été étudiées in vitro à l’aide cellules mononuclées sanguines humaines, puis dans un modèle in vitro de perméabilité membranaire, induite par la sensibilisation d’une monocouche de cellules Caco-2 par de l’eau oxygénée. Six souches ont été sélectionnées, cinq souches induisant de forts niveaux de la cytokine anti-inflammatoire IL-10 et capables de restaurer la barrière intestinale et une souche capable de renforcer fortement cette barrière. Ces souches ont été ensuite évaluées en modèles in vivo de colite chronique et aigüe induite par du TNBS (2,4,6 trinitrobenzene sulfonic acid). De façon intéressante les souches protégeant en colite aigüe ne protègent pas aussi efficacement en colite chronique et inversement.Nous avons poursuivi la sélection de souches ou mélanges de souches dans le contexte de l’obésité et des maladies métaboliques associées. Nous avons utilisé les mêmes critères que précédemment (capacités anti-inflammatoires et à restaurer la barrière intestinale) complétés par l’étude de la capacité des souches à limiter l’accumulation des lipides dans un modèle in vitro de différenciation adipocytaire basé sur l’utilisation de la lignée 3T3-L1 et à induire la sécrétion de peptides entéro-endocrines impliqués notamment dans la satiété par l’utilisation de la lignée murine de cellules entéro-endocrine STC-1. Trois mélanges de souches et une souche seule ont été sélectionnées et évaluées dans un modèle murin d’obésité induite par un régime hyperlipidique à 45% de gras. Nous avons pu mettre en évidence des capacités positives d’un mélange de deux souches et d’une souche seule à réduire la prise de poids, ainsi que l’inflammation dans le tissu adipeux.Ces résultats indiquent que des criblages in vitro basés sur l’étude des propriétés immunomodulatrices, des capacités à restaurer la barrière, à diminuer l’accumulation des lipides et à induire des peptides de satiété, permettent une pré-sélection de souches ou mélanges de souches ayant un effet protecteur et démontrent à nouveau que les capacités bénéfiques des probiotiques sont souche-dépendantes et spécifiques des modèles ciblés. / Recent studies have reported that the microbiota is involved in intestinal homeostasis by contributing to the morphological development, the education of the immune system, the mechanisms of defense, and to metabolic regulation. Dysbiosis of this microbiota as well as reduction in bacterial diversity has been observed in various chronic pathologies such as chronic inflammatory diseases (IBD) and obesity. The microbiota thus constitutes a therapeutic target of choice in the management of these chronic diseases. Probiotics, which are beneficial microorganisms for the host represent therefore an interesting alternative, however their selection criteria need to be improved.In a first study, we were able to highlight the beneficial properties of a mixture of two probiotics comprising a bifidobacteria and a lactobacilli, in a murine model of high fat diet (HFD)-induced obesity (Alard et al., 2016). This probiotic mixture significantly reduced weight gain, improved inflammatory and metabolic parameters including insulin resistance, and increased intestinal expression of receptors involved in short-chain fatty acid (AGCC) recognition. It also promoted in an artificial intestinal system the production of butyrate and propionate, the two main AGCCs. The protective effects were associated with the improvement of microbiota dysbiosis, in particular the restoration of the abundance of Akkermansia muciniphila.The main objective of this thesis was then to select within a collection of 23 bacterial strains provided by PiLèJe, one or more probiotic strain (s) possessing protective properties against IBD and obesity. Immunomodulatory properties of the strains and their ability to strengthen the intestinal barrier were studied in vitro using human mononuclear blood cells and an in vitro model of epithelial permeability induced by the sensitization of a Caco-2 cells monolayer with hydrogen peroxide. Six strains were selected, five strains inducing high levels of the anti-inflammatory cytokine IL-10 and capable of restoring the intestinal barrier and a strain capable of strongly reinforcing this barrier. These strains were then evaluated in in vivo models of TNBS (2,4,6 trinitrobenzene sulfonic acid)-induced chronic and acute colitis. Interestingly, strains able to rescue mice from acute colitis did not protect as efficiently in chronic colitis and vice versa.The selection of strains or mixtures was then pursued in the context of obesity and associated metabolic diseases. We used the same criteria as previously (anti-inflammatory capacities and to restore the intestinal barrier) in addition with the capacity of the strains to limit the accumulation of lipids in an in vitro model of adipocyte differentiation based on the use of the 3T3-L1 cell line and to induce the secretion of entero-endocrine peptides, notably involved in satiety, by the use of the murine STC-1 entero-endocrine cell line. Three mixtures and one single strain were selected and evaluated in a mouse model of obesity induced by 45% HFD diet. We demonstrated the positive capacities of a mixture composed of two strains and the single strain to reduce weight gain, as well as adipose tissue inflammation.These results indicate that in vitro screenings based on the immunomodulatory properties, the capacity to restore the gut barrier, to decrease lipid accumulation and to induce gut peptides allow pre-selection of strains or mixtures exhibiting protective effects and demonstrate that the beneficial capacities of probiotics are strain-dependent and specific to the targeted models.

Among the wide range of products naturally fermented by lactic acid bacteria (LAB), there are the homemade cheeses. These bacteria are inherent to the raw milk and the fermentation process for producing compounds responsible for the flavor and texture of the products. Its use is one of the oldest food preservation techniques, since they are able to produce substances with antagonistic action against spoilage and pathogenic microorganisms, particularly Listeria monocytogenes, commonly found in refrigerated dairy products. In addition, many lactic acid bacteria have probiotic potential, thus becoming the most attractive one for its use. In North West Frontier region of Rio Grande do Sul a typical cheese is produced, popularly called colonial cheese, which its knowledge of fabrication techniques have been transferred verbally through generations. For being manufactured, in most cases, with raw milk without the addition of starter cultures and under poor conditions of hygiene, it has a diverse unwanted microbial population. This aspect is characterized as a danger to consumers, as well as spoilage organisms that can also serve as a carrier of pathogenic microorganisms. The objective of this study is to isolate and identify lactic acid bacteria with probiotic characteristics and bacteriocinogenic from milk and artisan cheeses produced in this region. Thus initially the BAL were isolated and tested for antagonist ability against pathogens, and then checked the ability to produce antimicrobial substances of proteinaceous nature (bacteriocins), as well as resistance to biological barriers, as a criteria for the selection of isolated with probiotic potential. Molecular identification was performed by obtaining and sequencing of 16S rDNA or the ITS region. Subsequently, the isolated were evaluated for antimicrobial resistance of clinical use and the production of the enzyme β-hemolysin as virulence factors. The selected isolated were used as inoculum in cheese produced at a pilot level, with monitoring of physical-chemical and microbiological, over twenty-eight days of maturation under refrigeration. Of total lactic acid bacteria isolated twentyone (34.43%) showed antagonistic potential against pathogenic microorganisms reference. Of these, seven (33.33%) were able to produce antimicrobial substances of nature protein, being classified as possibly bacteriocinogenic and five (23.81%) isolated were shown to possess probiotic potential. The molecular identification of these proved to treat Enterococcus durans, Enterococcus faecium and Lactobacillus plantarum. The isolated F9 and U5 were selected and added as bacteriocin and probiotic culture, respectively, as a pilot project in cheese artificially contaminated with Listeria monocytogenes. No isolated was able to remove this pathogenic organism in the cheese, and the cultivation of bacteriocinogenic shown to be capable of maintaining viable cells of the microorganism stable during the maturation period. The probiotic proved to be able to withstand during the ripening of the cheese, while maintaining a viable cell number in the order of 107 - 108UFC.g-1 cheese, which allows its use with probiotic purpose. / Dentre a variada gama de produtos fermentados naturalmente por bactérias ácido láticas (BAL) encontram-se os queijos artesanais. Estas bactérias são inerentes da matéria-prima leite e durante o processo fermentativo produzem compostos responsáveis pelo flavor e textura dos produtos. Sua utilização constituise em uma das técnicas mais antigas de conservação de alimentos, já que são capazes de produzir substâncias com caráter antagônico frente a micro-organismos deteriorantes e patogênicos, com destaque a Listeria monocytogenes, comumente encontrada em produtos lácteos refrigerados. Além disso, muitas bactérias ácido láticas possuem potencial probiótico, constituindo-se em um atrativo a mais para sua utilização. Na região Fronteira Noroeste do Estado do Rio Grande do Sul é produzido um queijo típico, popularmente denominado queijo colonial, cujo conhecimento das técnicas de fabricação tem sido transferido verbalmente ao longo das gerações. Por ser fabricado, na grande maioria dos casos, com leite cru, sem a adição de culturas iniciadoras e sob condições deficientes de higiene, possui uma diversificada população microbiana indesejada. Este aspecto se caracteriza como um perigo aos consumidores, já que além de micro-organismos deteriorantes pode também servir como veículo de micro-organismos patogênicos. Assim, o objetivo do presente estudo foi isolar e identificar bactérias ácido láticas com características bacteriocinogênicas e probióticas, de leite e queijos artesanais desta região. Para isso, inicialmente, as BAL foram isoladas e testadas quanto a sua capacidade antagonista frente a micro-organismos patogênicos e então verificada a capacidade de produção de substâncias antimicrobianas de natureza protéica (bacteriocinas). A resistência a barreiras biológicas, como um dos critérios para seleção de isolados com potencial probiótico também foi avaliado. A identificação molecular dos isolados potencialmente bacteriocinogênicos e probióticos foi realizada por meio da obtenção e sequenciamento do rDNA 16S ou da região ITS. Posteriormente, os isolados foram avaliados quanto à resistência a antimicrobianos de uso clínico e à produção da enzima β-hemolisina, como fatores de virulência. Os isolados selecionados foram utilizados como inoculo em queijos produzidos a nível piloto, com monitoramento de parâmetros físico-químicos e microbiológicos, ao longo de vinte e oito dias de maturação, sob refrigeração. Do total de bactérias láticas isoladas, vinte e uma (34,43%) demonstraram potencial antagonista frente a micro-organismos patogênicos de referência. Destas, sete (33,33%) mostraram-se capazes de produzir substâncias antimicrobianas de natureza proteica, sendo classificadas como, possivelmente, bacteriocinogênicas e cinco (23,81%) dos isolados demonstraram possuir potencial probiótico. A identificação molecular destes revelou se tratarem de Enterococcus durans, Enterococcus faecium e Lactobacillus plantarum. Os isolados F9 e U5 foram selecionados e adicionados como cultura bacteriocinogênica e probiótica, respectivamente, em queijos a nível piloto, artificialmente contaminados com Listeria monocytogenes. Nenhum dos isolados foi capaz de eliminar este microorganismo patogênico nos queijos, porém o cultivo bacteriocinogênico se mostrou capaz de manter as contagens de células viáveis deste micro-organismo estáveis durante o período de maturação. A cultura probiótica se revelou capaz de resistir durante a maturação do queijo, mantendo um número de células viáveis na ordem de 107 - 108UFC.g-1 de queijo, o que permite sua utilização com propósito probiótico.

Our large intestine is like a large metabolic organ colonised by microorganisms. Beneficial probiotic bacteria are of interest since they might metabolise certain prebiotic carbohydrates and produce metabolites that are suggested to promote health and prevent diseases.   Strains of Weissella have proven probiotic properties since they, for example, show ability to metabolise prebiotic oligosaccharides, are resistant to a low pH (pH 2-3) and bile salt. In a previous project, six new strains of Weissella were isolated from Indian fermented food and vegetables, and four of them, including strain 92, were able to ferment xylooligosaccharides and form short chain fatty acids (SCFA), especially acetic acid. This strengthened the probiotic potential of these strains.   The aim of this project was to see if previously untested oligosaccharides (arabinooligosaccharides (AOS), laminarioligosaccharides (LOS) and chitooligosaccharides (COS)) could be metabolised by Weissella strain 92.   This study includes the following steps; cell growth in MRS (De Man, Rogosa and Sharpe) medium on different carbohydrates measured with spectrophotometer, pH measurement (analysing the difference of MRS medium (pH 6.42) pre and post cell growth, where reduced pH indicates acid production), and analysis of fermentation products (including SCFA (short chain fatty acids, e.g. acetic acid, butyric acid, propionic acid), lactic acid and ethanol) with an HPLC (high-performance liquid chromatography) instrument.   This research study has shown that Weissella strain 92 produces acetic and butyric acid as a consequence of use of AOS, LOS and COS, this indicates that the oligosaccharides are prebiotic and emphasizes the probiotic potential of Weissella strain 92.

Depuis plusieurs années, il s’avère de plus en plus clair que le microbiote digestif a un impact remarquable sur la santé humaine. Il est affecté par de nombreux facteurs dont l’alimentation. En effet, en fonction du macronutriment majoritaire d’un régime alimentaire, certaines populations et fonctions bactériennes sont stimulées ou inhibées. Plusieurs pathologies de l’intestin ou liées à des troubles nutritionnels ou métaboliques ont un lien causal avec une altération du microbiote digestif parmi lesquelles la malnutrition sévère aigue. En effet, il a été récemment montré que le microbiote digestif des enfants malnutris était différent et colonisé par des Proteobacteria, des Enterococci, des bacilles Gram-négatifs et des espèces pathogènes. Au cours de nos travaux, une dysbiose est également observée chez nos patients malnutris par métagénomique et par culturomics avec un enrichissement en bactéries aérobies, en Proteobacteria et en espèces potentiellement pathogènes telles que Streptococcus gallolyticus et une perte notable en bactéries anaérobies associée à une perte de la capacité antioxydante du tractus gastro-intestinal révélée par une absence totale de Methanobrevibacter smitii, archeae méthanogène et un des procaryotes les plus sensibles à l’oxygène du tractus gastro-intestinal ainsi que un potentiel redox fécal accru. De plus, une perte de la diversité globale, connue et inconnue, est observée. Enfin, par culturomics et métagénomique, nous avons établi un répertoire des bactéries manquantes chez les malnutris dont treize présentent un potentiel probiotique et pourront être testées comme probiotiques dans un modèle expérimental dans un futur proche. / For the last decade, it has become increasingly clear that the gut microbiota has a tremendous impact on human health. It is affected by several factors among which diet that has a big impact. In fact, according to the major macronutrient in a diet type, specific bacterial populations and functions are stimulated or inhibited. Several pathologies of the gut or linked to nutritional or metabolic disorders among which severe acute malnutrition are causally linked to an alteration of the diversity of the human gut microbiota. In fact, it has recently been shown by several studies that the gut microbiota of malnourished patients was different and colonized by Proteobacteria, Enterococci, Gram-negative bacilli and pathogenic species. The analysis of our data regarding the fecal microbiota of children afflicted with severe acute malnutrition from Niger and Senegal showed a dysbiosis observed through metagenomics and culturomics with an increase of aerobic bacteria, Proteobacteria and pathogenic species such as Streptococcus gallolyticus, and a depletion of anaerobic species associated with a loss of the antioxidant capacity of the gastro-intestinal tract exhibited by a total absence of Methanobrevibacter smithii, a methanogenic archaeon and one the most oxygen sensitive prokaryote of the gut microbiota alongside an increased fecal redox potential. Moreover, a loss of the overall diversity, known and unknown, was observed. Finally, through culturomics and metagenomics, we were able to identify a repertoire of missing microbes in malnourished children among which thirteen presented a probiotic potential and will be tested as such in an experimental model in the near future.

Os alimentos probióticos são promotores de saúde que apresentam grande interesse comercial e quotas de mercado em crescimento. Devido às suas características, os lactobacilos e bifidobactérias são considerados os melhores microrganismos para uso como probióticos em produtos cárneos, sendo mais promissor nos produtos crus fermentados, haja vista serem consumidos sem prévio aquecimento. Várias técnicas de microencapsulação têm sido empregadas com o propósito de manter a viabilidade dos probióticos durante o tempo de armazenamento. Assim, o objetivo deste trabalho foi avaliar os efeitos da incorporação dos microrganismos Lactobacillus acidophilus e Bifidobacterium lactis livre e microencapsulado sobre as características físico-químicas, microbiológicas e sensoriais do salame tipo Italiano, assim como a sensibilidade destas culturas frente a diferentes tempos de armazenamento. Para isso, foi realizado um ensaio (ensaio 1) com microrganismos na forma livre incorporados aos salames e comparados com uma amostra padrão, isenta de probióticos. A utilização dos probióticos interferiu positivamente nas avaliações físico-químicas e sensoriais, uma vez que os salames apresentaram um desempenho similar ao controle e uma alta aceitação entre os consumidores. Após a constatação que a incorporação de probióticos era positiva, um segundo ensaio foi realizado (ensaio 2), onde os salames foram divididos em cinco tratamentos: T1 (sem adição de probióticos), T2 (Lactobacillus acidophilus livre), T3 (Lactobacillus acidophilus encapsulado), T4 (Bifidobacterium lactis livre) e T5 (Bifidobacterium lactis encapsulado). Nestes ensaios foram verificados o pH, acidez, atividade de água, cor instrumental, oxidação lipídica, contagem dos probióticos, além da realização de análises microbiológicas e sensoriais nos salames com até 90 dias de armazenamento. Durante o processamento, procedeu-se a análise de perda de peso dos salames para garantir a padronização do processo. Os resultados obtidos no ensaio 2 permitem concluir que os menores valores de pH, atividade de água e perda de peso observados foram dos Lactobacillus acidophilus e Bifidobacterium lactis ambos na forma livre, além de apresentarem os maiores valores para a determinação de acidez. No entanto, nas contagens dos probióticos, a microencapsulação para as culturas de Bifidobacterium lactis foi vantajosa e assegurou que 106 UFC/g fossem mantidos no produto final. Por sua vez, nos resultados da análise sensorial concluiu-se que os salames com probióticos foram considerados agradáveis pelos provadores, pois obtiveram pontuações acima de 6,0. A maior média na intenção de compra foi do Lactobacillus acidophilus encapsulado com 64,7%, seguido do Bifidobacterium lactis livre com 62,5%. Portanto, com estes resultados há evidências de que os salames desenvolvidos neste trabalho independente da cultura probiótica utilizada e da forma apresentada, teriam um grande potencial de venda no mercado consumidor. / The probiotic foods are health promoters with great commercial interest and growing market shares. Due to its characteristics, the lactobacillus and bifidobacterium are considered the best microorganisms for use as probiotics in meat products, being the most promising raw fermented products, due to be consumed without prior heating. Various microencapsulation techniques have been employed for the purpose of maintaining the viability of probiotics during storage time. The objective of this study was to evaluate the effects of incorporation of microorganisms Lactobacillus acidophilus and Bifidobacterium lactis on free and microencapsulated physical-chemical, microbiological and sensory type of Italian salami, as well as the sensitivity of these cultures against different storage times. For this, we performed a test (test 1) in free form by microorganisms embedded in salami and compared with a standard sample, free of probiotics. The use of probiotics had a positive influence on physical-chemical evaluations and sensory, as salami showed a similar performance to the control and a high acceptance among consumers. After finding that the incorporation of probiotics was positive, a second test was performed (test 2), where the salamis were divided into five treatments: T1 (without added probiotics), T2 (Lactobacillus acidophilus free), T3 (Lactobacillus acidophilus encapsulated), T4 (Bifidobacterium lactis free) and T5 (Bifidobacterium lactis encapsulated). In these trials were checked the pH, acidity, water activity, instrumental color, lipid oxidation, count of probiotics, in addition to conducting the microbiological and sensory salami with up to 90 days of storage. During processing, we proceeded to the analysis of weight loss of salamis to ensure standardization of the process. The test results allow the conclusion that the two lower values of pH, water activity and weight loss were observed for Lactobacillus acidophilus and Bifidobacterium lactis both on their own, in addition to presenting the highest values for the determination of acidity. However, the counts of probiotic cultures for the microencapsulation of Bifidobacterium lactis was advantageous and ensured that 106 UFC/g were kept in the final product. In turn, the results of sensory analysis concluded that the salami with probiotics were considered by the judges, as had scores above 6.0. The highest mean purchase intent was encapsulated with Lactobacillus acidophilus 64.7%, followed by Bifidobacterium lactis free with 62.5%. So, with these results there is evidence that salami developed in this work regardless of the probiotic culture used and as the presented form, have a great potential for sales in the consumer market.