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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.
1

STAPHYLOCOCCUS XYLOSUS E LACTOCOCCUS LACTIS SSP LACTIS NATIVOS UTILIZADOS NA ELABORAÇÃO DE SALAME TIPO ITALIANO / NATIVE STAPHYLOCOCCUS XYLOSUS AND LACTOCOCCUS LACTIS SSP LACTIS USED IN THE ELABORATION FERMENTED ITALIAN SAUSAGE

Cirolini, Andréia 25 February 2008 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this study was to produce and to test the performance of native starters cultures in the elaboration of fermented Italian sausage in relation to the security and quality of the sausages. In the first experiment strains of Staphylococcus xylosus isolated from colonial sausages, were characterized and after identified for the Kit Api Staph (Biomérieux). In the second experiment, the microorganism Lactococcus lactis ssp lactis was fermented in pork plasma culture medium and evaluated its efficiency in relation to MRS broth, through microbiological analyses and optic density (OD). In the third experiment the isolated and multiplied cultures were added in dry fermented sausages, elaborating four treatments: T1 - addition of commercial starters (Staphylococcus xylosus and Lactococcus lactis ssp lactis); T2 - mixture of isolated Staphylococcus xylosus more commercial Lactococcus lactis ssp lactis ; T3 - mixture of isolated Lactococcus lactis ssp lactis more commercial Staphylococcus xylosus and T4 - Staphylococcus xylosus and Lactococcus lactis ssp lactis both isolated, evaluating its influence on the microbiological, physico-chemical and sensorial characteristics. About 13.3% of the colonies isolated of sausages were identified as Staphylococcus xylosus. The maximum growth of Lactococcus lactis ssp lactis, in pork plasma culture medium was 8.58 Log UFC.mL-1 in 27 hours, and the OD 0.88. In the MRS broth the growth reached the maximum peak (8.70 Log UFC.mL-1) in 6 hours, presenting OD of 0.81. All the elaborated sausages presented a significant decreased of pH and a reduction in the water activity, ensuring a microbiological security to the products. In relation the lipid oxidation, the treatment that contained isolated strains of Staphylococcus xylosus presented significantly lower values than the other treatments. The sausages elaborated with both strains isolated presented better sensorial results than the sausages elaborated with commercial starters cultures. Therefore, this study indicated that would be promising to extend the availability of microorganisms for industrial use from the selection of native cultures, that the pork plasma culture medium becomes an alternative for the multiplication of lactic acid bacteria, because it presented a similar fermentation performance to the commercial culture medium and that the addition of natives starters cultures can be used in the elaboration of fermented Italian sausages, providing safety products and with differentiated flavor. / Este trabalho teve por objetivo produzir e testar o desempenho de culturas starters nativas na fabricação de salame tipo Italiano quanto à segurança e qualidade dos salames. No primeiro experimento, cepas de Staphylococcus xylosus foram isoladas de salames coloniais, caracterizadas e após identificadas pelo Kit Api Staph (Biomérieux). No segundo experimento, o microrganismo Lactococcus lactis ssp lactis foi fermentado em meio de cultura de plasma suíno e avaliado sua eficiência em relação ao caldo MRS, através de análises microbiológicas e densidade óptica (DO). No terceiro experimento, as culturas isoladas e multiplicadas foram adicionadas em salame, elaborando-se quatro tratamentos: T1 - adição de starters comerciais (Staphylococcus xylosus e Lactococcus lactis ssp lactis); T2 - mistura de Staphylococcus xylosus isolado mais Lactococcus lactis ssp lactis comercial; T3 - mistura de Lactococcus lactis ssp lactis isolado mais Staphylococcus xylosus comercial e T4 - Staphylococcus xylosus e Lactococcus lactis ssp lactis ambos isolados, avaliando sua influência nas características microbiológicas, físico-químicas e sensoriais. Foram identificadas 13,3% das colônias isoladas de salames coloniais como Staphylococcus xylosus. O crescimento máximo de Lactococcus lactis ssp lactis, em meio de cultura de plasma suíno, foi de 8,58 Log UFC.mL-1 no tempo de 27 horas e DO de 0,88. Em caldo MRS, o crescimento atingiu pico máximo (8,70 Log UFC.mL-1) em 6 horas, apresentando uma DO de 0,81. Todos os salames elaborados apresentaram uma queda de pH significativa e também uma redução na atividade de água, garantindo uma segurança microbiológica aos produtos. Em relação a oxidação lipídica, os tratamentos que continham cepas de Staphylococcus xylosus isolados apresentaram valores significativamente menores que os outros tratamentos. Os salames elaborados com as duas cepas isoladas (T4) apresentaram melhores resultados sensoriais quando comparados com salames elaborados com culturas starters comerciais. Portanto, este estudo indicou que seria promissor ampliar a disponibilidade de linhagens para uso industrial proveniente da seleção de culturas nativas, que o meio de cultura de plasma suíno torna-se uma alternativa para a multiplicação de bactérias ácido lácticas, pois apresentou um desempenho semelhante à fermentação do meio de cultura comercial e que a adição de culturas starters nativas pode ser utilizada na elaboração de salames, proporcionando produtos seguros e com flavor diferenciado.
2

Identifikace bakterií mléčného kvašení v tvrdých sýrech s využitím amplifikačních metod / Identification of lactic acid bacteria in hard cheeses using amplification methods

Herzogová, Jitka January 2008 (has links)
Diploma thesis was focused on identification of lactic acid bacteria of species Lactococcus lactis and subspecies Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris using species and subspecies specific polymerace chain reaction (PCR). PCR method was used for identification of bacteria of species Lactococcus lactis in 10 samples of hard cheeses. The method of sample preparation was evaluated for hard cheeses with the aim to receive sufficient amount of cells for the preparation of crude cell lysates. Whole DNA in quality suitable for PCR was separated using magnetic microspheres P(HEMA-co-GMA) in the presence of polyethylenglycol (PEG 6000) and sodium chloride. DNA isolated by phenol extraction was used as control of DNA isolation. PCR was used to the analysis of 7 strains of Lactococcus lactis from Collection of dairy microorganisms Laktofora (CCDM). Altogether 5 or 2 strains were identified into subspecies Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris, respectively.
3

Avaliação de queijo de coalho produzido com bactérias láticas endógenas

Viana, Arão Cardoso 17 February 2009 (has links)
Submitted by Glauber Assunção Moreira (glauber.a.moreira@gmail.com) on 2018-08-20T17:48:24Z No. of bitstreams: 2 versão 8 arão.pdf: 389258 bytes, checksum: a2429e8f15ea08ff3f880538dc4b37d0 (MD5) Errata Arão Cardoso Viana.pdf: 4889 bytes, checksum: 909aee0b82dd5ac49d90de1c7ce75506 (MD5) / Approved for entry into archive by Setor de Periódicos (per_macedocosta@ufba.br) on 2018-08-21T14:59:01Z (GMT) No. of bitstreams: 2 versão 8 arão.pdf: 389258 bytes, checksum: a2429e8f15ea08ff3f880538dc4b37d0 (MD5) Errata Arão Cardoso Viana.pdf: 4889 bytes, checksum: 909aee0b82dd5ac49d90de1c7ce75506 (MD5) / Made available in DSpace on 2018-08-21T14:59:01Z (GMT). No. of bitstreams: 2 versão 8 arão.pdf: 389258 bytes, checksum: a2429e8f15ea08ff3f880538dc4b37d0 (MD5) Errata Arão Cardoso Viana.pdf: 4889 bytes, checksum: 909aee0b82dd5ac49d90de1c7ce75506 (MD5) / RESUMO A utilização de leite pasteurizado, para processamento de queijo coalho, garante a qualidade do produto sob o aspecto microbiológico. Neste caso, é necessária a adição de culturas láticas, que irão conferir ao produto características sensoriais diferenciadas. Este trabalho teve como objetivo avaliar a qualidade de queijo de coalho produzido com adição de diferentes culturas láticas endógenas utilizando a Análise Descritiva Quantitativa (ADQ), teste de aceitabilidade e análise de alguns parâmetros físico-químicos. Foram utilizadas três culturas láticas: LA-02 (Lactobacillus acidofilus); RE-02 (Lactococcus ssp) e Blend (Lactococcus ssp + Lactobacillus acidofilus). A equipe da ADQ foi composta por 11 julgadores treinados. No teste de aceitabilidade utilizou-se 50 consumidores previamente selecionados por questionário. Os parâmetros físico-químicos avaliados foram: umidade, cinzas, gordura em base seca, proteínas, pH, acidez e cloretos. A aceitabilidade dos queijos produzidos pelo LA-02 e Blend foram maiores para os atributos sabor, 7.38 e 6.92 e, respectivamente. Pela ADQ foram levantados 13 termos descritores para queijo coalho. A amostra Blend foi caracterizada pela cor amarela, firmeza, aroma típico de queijo de coalho, sabor típico de queijo de coalho, elasticidade e mastigabilidade. O queijo produzido com LA-02 foi caracterizado pelo sabor ácido, homogeneidade e maciez. As três amostras avaliadas apresentaram valores de umidade e gordura dentro das especificações exigidas pela legislação vigente. As culturas LA-02 e Blend foram as que melhor desenvolveram as características típicas de queijo coalho. / Abstract The utilization of pasteurized Milk to coalho cheese process guarantees the product quality on the microbiological aspect. In this case, it needs the addition of lactic culture and so that, the product comes out with differing sensorial characteristics. The objective of this work was to evaluate the coalho cheese quality, produced by adding lactic culture endogen using coalho cheese. The objective of this work was to evaluate the coalho cheese quality produced by adding endogen lactic culture utilizing the Quantities Descriptive Analysis (QDA), test of acceptability and analysis of some physical-chemical parameters. It was utilized three lactic cultures: LA-02 (Lactobacillus acidophilus); RE-02 (Lactococcus ssp) and Blend (Lactococcus ssp + Lactobacillus acidophilus). The team of QDA was with eleven people to judge it. The acceptability utilized fifty consumers previously selected by a questionnaire. The physical-chemical parameters evaluated were: humidity, ashes, base dried fat, proteins, ph, acidity and cloret. The cheese acceptability produced by LA-02 and Blend presented the highest results to the attributes flavor, 7.38 and 6.92, respectively. By the QDA were considered 13 describing terms to coalho cheese. The display of Blend was characterized by its yellow color, hardness, typical coalho cheese smell, typical coalho cheese flavor, consistency and chewing. The cheese produced by LA-02 was characterized by its acid flavor, homogeneity and softness. The three displays evaluated presented values of humidity and fat according to the legislation exigency. The LA-02 and Blend cultures were the ones which better developed the coalho cheese characteristics.

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