The purpose of this study was to identify antimutagens in yogurt active against the experimental colon carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Our initial experiments showed that acetone extracts of yogurt, or milk fermented by various lactic acid bacteria were antimutagenic against MNNG and 3,2'-dimethyl-4-aminobiphenyl (DMAB) in the Ames test (Salmonella typhimurium TA 100). Further experiments carried out with milk fermented by Lactobacillus delbrueckii ssp. bulgaricus 191R showed that the putative compounds were more soluble in DMSO than in water, and that extractability of activity against MNNG and DMAB varied with pH, suggesting the presence of ionizable groups. Subsequent experiments demonstrated the antimutagenicity of yogurt. An acetone extract of yogurt was found to be active against a range of mutagens and promutagens in the Ames test. Simulation of fermentation by addition of lactic acid, lactic acid bacteria, or both to milk did not increase antimutagenicity, suggesting that compounds responsible for the activity may be formed during fermentation. Conjugated linoleic acid (CLA), a known dairy anticarcinogen, did not inhibit MNNG or DMAB indicating that other antimutagens may be present in yogurt. Fractionation of the acetone extract by HPLC showed that anti- MNNG and anti-DMAB activities did not co-elute, indicating that different compounds were responsible for the two activities. Using the Ames test to direct purification, isolation of an anti-MNNG active compound was accomplished using silica gel, Sephadex LH-20 and C18 reversed phase medium pressure chromatographies. The antimutagen was identified as palmitic acid by: a) co-elution with authentic palmitic acid on GC and HPLC columns, and b) by comparison of mass and ¹³C-NMR spectra. Minor components of milk fat such as iso methyl branched fatty acids (isopalmitic acid, isomargaric acid, isomyrsitic acid, and isostearic acid) were found to be more active than their straight chain counterparts. Isopalmitic acid also inhibited 4-nitroquinoline-N-oxide (4NQO) and the P450-mediated activation of 7,12-dimethylbenz[a]anthracene (DMBA). The mechanism of antimutagenesis against MNNG has not been established. / Graduation date: 1996

Bacterial research has been flourishing ever since 17th century. Bacteria play an important role in clinical microbiology, food microbiology and environmental microbiology. Therefore, the rising need to detect bacteria in clinical, food and environmental samples is emerging onto a craving research frenzy. There are some established methods to study bacteria, such as genetic techniques like PCR, culturing and RNA based analysis, but these require time, resources and labor. This thesis concentrates on highlighting the importance of MALDI-MS in rapid, direct, and simple detection of bacteria from food and clinical samples. The method is to enable detection of bacteria in real samples. First attempts were made to detect bacteria from yogurt sample, because as already known commercial yogurt samples contain bacteria. And yogurts were used in this study to demonstrate the capability of MALDI-MS technique to detect the bacteria directly by culture-free methods. Since the bacterial signals were quenched because of the strong milk peaks, we had to employ nanoparticles and ionic solution for affinity capture of the bacteria for bacterial detection. The results showed that addition of ionic solution and Ag nanoparticles lead to enhanced bacterial detection. The deterioration of the yogurt bacteria on improper storage ( at room temperature) and after extended storage in refrigerator beyond expiry date was studied using MALDI-MS. The day by day deterioration in the microbiological quality of the yogurt was also detected. A special selective media for growth of the yogurt bacteria, DifcoTM Lactobacilli MRS Broth (Agar) was used to quantify the bacteria in various experiments. MALDI-MS results were useful in understanding the shelf life and quality control on extended storage. The second part of this thesis concentrates on the use of MALDI-MS in clinical analysis. The major goal in this work was to use MALDI-MS to detect bacteria in mousy blood and urine. Phase I of this study involved detection of the bacteria by direct MALDI-MS in blood and urine samples spiked with bacteria. We call these experiments as in vitro experiments. Analysis using MALDI was a challenge since the blood peaks interfered with the bacterial peaks and subdued them. Ionic liquid is a pretty excellent extraction solvent when combined with SDME (Single-drop Microextraction). Just one drop of 1-butyl-3methylimidazolium hexafluorophosphate can extract bacteria from spiked samples. What¡¦s more, the LOD can be lower to ~105 cfu / mL using SDME with ionic liquid. It¡¦s definitely showing that 1-butyl-3methylimidazolium hexafluorophosphate, that is to say, the ionic liquid has good ability to trap pathogenic bacteria. This bacterium is injected into mouse and the growth kinetics of bacteria in vivo was studied as a function of time. Samples taken at specific time points were simultaneously analyzed using standard plate count method as well as MALDI-MS. Analysis using MALDI was a challenge since the blood peaks interfered with the bacterial peaks and subdued them. Therefore, we employ the use of silver and zinc oxide nanoparticles and ionic liquid.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 116-131). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 116-131). Also available on the Internet.

Orientador: Elizeu Antonio Rossi / Banca: João Bosco Faria / Banca: Daniela Cardoso Umbelino Cavallini / Banca: Izildinha Moreno / Banca: Valéria Monteiro da Silva Eleutério Pulitano / Resumo: Esse estudo teve por objetivo o desenvolvimento de amostras de sorvete de "iogurte" simbiótico à base de extratos aquoso de soja e de yacon (Smallanthus sonchifolius) fermentado com Lactobacillus acidophilus CRL 1014. O L. acidophilus CRL 1014 foi caracterizado quanto à resistência ao pH e à sais biliares. Foram processadas formulações com diferentes proporções do extrato aquoso de yacon em substituição parcial ao extrato de soja, as quais foram submetidas à avaliações sensoriais para a definição da melhor combinação entre os extratos analisados. Também foi realizada a contagem de células viáveis do microrganismo em estudo na formulação selecionada. No processamento das amostras de "iogurte" foi verificado que quanto maior a quantidade de yacon presente nas diferentes formulações maior o tempo necessário para se atingir o pH estabelecido de 4,3, embora esse tempo tenha variado somente de 7,5 a 9,5 horas, exceto, para a formulação constituída somente por extrato de yacon, que ultrapassou o período de 10,5 horas sem ter o seu pH reduzido. A partir dos resultados obtidos nos testes sensoriais foi constatado que a formulação de "iogurte" contendo 100% de extrato de soja (sem extrato de yacon) obteve as maiores médias em termos absolutos para todos os atributos avaliados não diferindo da formulação com 75% de extrato de soja e 25% de extrato de yacon, sendo esta a selecionada para a etapa subseqüente deste estudo, uma vez que a formulação 1 não se caracteriza como sendo um produto simbiótico. A formulação 4 (iogurte com 25% de extrato de soja e 75% de extrato de yacon) foi a amostra que apresentou as menores médias em termos absolutos para todos os atributos avaliados. A contagem de células viáveis L. acidophilus CRL 1014 obtida para o "iogurte" simbiótico... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to develop samples of symbiotic frozen yogurt with soybean and yacon (Smallanthus sonchifolius) fermented with Lactobacillus acidophilus CRL 1014. The L. acidophilus CRL 1014 was characterized for resistance to pH and bile salts. Formulations were processed with different proportion soybean water extract by adding yacon water extract, which were subjected to sensory evaluation to determine the best combination of the extract analyzed. The viable cells were counted in the formulation selected. In the processing of samples of yogurt was found that the higher concentration of yacon extract present in the different formulations increased the time required for the samples to reach the preset pH, although this time has varied only from 7.5 to 9.5 hours, except for the formulation consists of only yacon extract, which exceeded the period of 10.5 hours without having its pH reduced. From the results obtained in the sensory tests it was showed that the formulation of yogurt containing 100% of soy extract (no yacon extract) had the highest average in absolute terms for all sensory attributes and there was no significant difference between the formulation with 75% soy extract and 25% of yacon extract, this being selected as a basis for this study, since the formulation 1 is not characterized as a synbiotic product. Formulation 4 (yogurt with 25% of soy extract and 75% of yacon extract was a sample showing the lowest means in absolute terms for all attributes. The viability of L. acidophilus CRL 1014 obtained for the synbiotic yogurt 1.8 x 109 were above the recommended level from 106 to 107 CFU / mL, thus satisfying the criteria established for probiotic foods. From the tests of resistance to acidic conditions and to bile salts, it was found that L. acidophilus CRL 1014, despite having a time delay, was able to grow... (Complete abstract click electronic access below) / Doutor

The objectives of this research were to establish a semi-descriptive sensory language that describes the attributes of calamondin fruit and develop yogurt products flavored with calamondin and test consumers’ acceptance of the products. A total of 89 sensory terms were established by trained panelists to describe calamondins. Yogurt products were developed with 0%, 5%, 10%, and 15% calamondin pulp. Results demonstrated that no significant difference (P>0.05) occurred for consumers’ acceptance of yogurt appearance and texture, and significant differences (P<0.05) occurred for consumers’ acceptance of yogurt flavor and overall liking. Generally, the yogurt with 10% honey and the yogurt with 10% honey and 5% calamondin pulp were well accepted by consumers. The consumers were grouped into 6 clusters based on their prefences. The majority (60%) of the consumers liked moderately yogurts with 10% honey, and 0% and 5% calamondin pulp respectively.

En el presente estudio de prefactibilidad se muestra la viabilidad técnica, económica y financiera de implementar una empresa productora y comercializadora de yogurt en Lima Metropolitana. En el primer capítulo, Estudio Estratégico, se realiza el análisis del macro y micro entorno, en el cual se concluyó que más del 30% de la población peruana se concentra en Lima Metropolitana y que se presenta una tendencia creciente en el consumo de productos naturales y nutritivos. Así mismo se define la visión, misión y objetivos de la empresa. Además, se desarrolla la estrategia de diferenciación del negocio luego de realizar la matriz FODA. En el Estudio de Mercado se da a conocer el sector de lácteos especialmente la categoría de yogurt regular. Luego se definen los segmentos en los cual se divide el yogurt regular, de los cuales se escoge el segmento Entero debido a que representa el 77% de la división regular. Posterior a ello, se selecciona el mercado objetivo a través del análisis de variables geo demográficas, psicográficas y conductuales. Así mismo se estudia fuentes primarias y secundarias que reflejan el crecimiento de la demanda de yogurt. Para determinar la oferta, se estudian las empresas con mayor representación en el mercado, así como su crecimiento para los próximos años. Al culminar el capítulo se determina la demanda insatisfecha y la demanda para el proyecto en un horizonte de cinco años complementando con el plan de marketing para nuestro producto. En el tercer capítulo, Estudio técnico, se determina la localización óptima de la planta de producción y oficina de la empresa. Luego, se establece el proceso productivo y los requerimientos de materia prima, mano de obra y servicios para el correcto funcionamiento de la empresa. Por otro lado, se definen las características físicas del local, se realiza la distribución de planta y el dimensionamiento de las áreas. Finalmente se realiza la evaluación ambiental y social del proyecto. En el Estudio Legal y Organizacional, se define el tipo de sociedad y se detallan los impuestos y normas legales que aplican a una empresa del sector bebidas no gasificadas. Luego, se describe la estructura organizacional de la empresa, se determinan las funciones del personal. Asimismo, se definen los servicios que serán presentados por empresas terceras. / Tesis

Thesis (Ph.D.) -- University of Western Sydney, 2003. / "Thesis submitted for the degree of Doctor of Philosophy, August 2003" Includes bibliography.