Thesis (Ph. D.)--University of Pennsylvania, 1927. / 'Literature": p. 29.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 157-167.

Thesis (doctoral)--Helsinki University of Technology, 2005. / Includes bibliographical references. Also available on the World Wide Web. Myös verkkojulkaisuna.

Thesis (M.Inst.Agrar.)(Food production and processing)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Phenolic acids (principally p-coumaric and ferulic acids), which are generally esterified with tartaric acid, are natural constituents of grape must and wine, and can be released as free acids during the winemaking process by certain cinnamoyl esterase activities. Free phenolic acids can be metabolised into 4-vinyl and 4-ethyl derivatives by several microorganisms present in wine. These volatile phenols contribute to the aroma of the wine. The Bretfanomyces yeasts are well known for their ability to form volatile phenols in wine. However, these species are associated with the more unpleasant and odorous formation of the ethylphenols and the formation of high concentrations of volatile phenols. Other organisms, including some bacterial species, are responsible for the formation of volatile phenols at low concentrations, especially the 4-vinylphenols, and this enhances the organoleptic properties of the wine. The enzymes responsible for the decarboxylation of phenolic acids are called phenolic acid decarboxylases; and several bacteria and fungi have been found to contain the genes encoding these enzymes. The following genes have been characterised: PAD1 from Saccharomyces cerevisiae, fdc from Bacillus pumilus, pdc from Lactobacillus plantarum and padc from Bacillus subtilis. PadA from Pediococcus pentosaceus was also identified. S. cerevisiae contains the PAD1 (phenyl acrylic acid decarboxylase) gene, which is steadily transcribed in yeast. The activity of the PAD1-encoded enzyme is low. Phenolic acid decarboxylase from B. subtilis, as well as p-coumaric acid decarboxylase from L. plantarum displays substrate inducible decarboxylating activity with phenolic acids. Both the p-coumaric acid decarboxylase (pdc) and phenolic acid decarboxylase (padc) genes were cloned into PGK1 PT expression cassette. The PGK1 PT expression cassette consisted of the promoter (PGK1 p) and terminator (PGK1 T) sequence of the yeast phosphoglyceratekinase I gene (PGK1). Episomal and yeast integration plasmids were constructed for the PAD1 gene under the control of the PGK1 PT for overexpresion in yeast. Industrial strains with the PAD1 gene disrupted were also made. Overexpression of pcoumaric acid decarboxylase (pdc) and phenolic acid decarboxylase (padc) in S. cerevisiae showed high enzyme activity in laboratory strains. The overexpressed PAD1 gene did not show any higher enzyme activity than the control strain. Both bacterial genes, under the control of the PGK1 PT cassette, were also cloned into a yeast-integrating plasmid, with the SMR1 gene as selective marker. The cloning and transformation of pdc and padc into industrial wine yeast strains can therefore be used to detect the effect of phenolic acid decarboxylase genes in the winemaking process for the possible improvement of wine aroma. Wine was made with all three strains (the bacterial genes overexpressed and PAD1 disrupted). The effect of these genes in wine was determined through GC analysis. The results showed that the bacterial genes could effectively produce higher levels of volatile phenols in the wine. The manipulated strains also produced enzymes capable of producing large amounts of favourable monoterpenes in the wine. This study paves the way for the development of wine yeast starter culture strains for the production of optimal levels of volatile phenols, thereby improving the sensorial quality of wine. / AFRIKAANSE OPSOMMING: Die fenoliese sure (p-kumaarsuur en ferolsuur), wat as natuurlike komponente in mos en wyn voorkom, word gewoonlik as esterverbindings in wynsteensuur gevind. Seker esterase-aktiwiteite kan die fenoliese sure as vrye sure vrystel gedurende die wynmaakproses. Hierdie vrye fenoliese sure kan dan weer deur verskillende mikroorganismes na 4-viniel en 4-etiel derivate omgesit word. Hierdie derivate staan as vlugtige fenole bekend en kan tot die aroma van wyn bydra. Die Brettanomyces giste is baie bekend vir hulle vermoeë om vlugtige fenole in wyn te vorm, maar dit is gewoonlik die formasie van hoë konsentrasies van vlugtige fenole, veral die 4-etiel derivate, wat met af geure geassosieer word. Ander organismes besit egter die vermoeë om vlugtige fenole teen lae konsentrasies te vorm, veral die 4-viniel derivate, wat 'n aanvullende effek op die wyn aroma kan hê. . Die ensieme wat verantwoordelik is vir die dekarboksilasie van fenoliese sure staan as fenolsuurdekarboksilases bekend. Verskeie bakterieë en fungi bevat gene wat vir hiedie ensieme kodeer. Die volgende gene is reeds gekarakteriseer: PAD1 van Saccharomyces cerevisiae, fdc van Bacillus pumilus, pdc van Lactobacillus plantarum en padc van Bacillus subtilis. PadA van Pediococcus pentosaceus is ook reeds geïdentifiseer. S. cerevisiae bevat die PAD1- (fenielakrielsuurdekarboksilase) geen, wat teen 'n vaste tempo in gis getranskribeer word. Die aktiwiteit van hierdie ensiem is egter laag. Fenolsuurdekarboksilase van B. subtilis, sowel as p-kumaarsuurdekarboksilase van L. plantarum, vertoon "n substraat-induseerbare dekarboksilerende aktiwiteit met fenoliese sure. Beide die p-kumaarsuur dekarboksilase en die fenolsuurdekarboksilase gene is in die PGK1PT ekspressie kasset gekloneer. Episomale en gisintegreringsplasmiede is vir die PAD1-geen onder beheer van die PGK1 PT ekspressiekasset gekonstrueer vir die ooruitdrukking van hierdie geen in gis. Die PGK1 PT ekspressiekasset het bestaan uit die promotor- (PGK1 p) en termineerdersekwense (PGK1 T) van die gisfosfogliseraatkinasegeen (PGK1). Industriële gisrasse is ontwikkel waarin die PAD1-geen onderbreek is. Ooruitdrukking van p-kumaarsuurdekarboksilase (Pdc) en fenolsuurdekarboksilase (pade) in S. cerevisiae toon hoë ensiemaktiwiteit in laboratoriumgisrasse. Die ooruitdrukking van die PAD1-geen het nie hoër aktiwiteit as die kontroleras gewys nie. Albei die bakteriële gene, onder die beheer van die PGK1 PT ekspressiekasset, is ook in "n gisintegreringsplasmied met die SMR1-geen as selektiewe merker geplaas. Die klonering en transformasie van pdc en padc in industriële wyngiste kan dus gebruik word vir die bepaling van die effek van fenolsuur dekarboksilases in die wynmaakproses en die moontlike verbetering van wynaroma. Wyn is met al drie die industriële rasse (die ooruitgedrukte bakteriële gene en die ontwrigte PAD1- geen) gemaak. Die effek van die teenwoordigheid van hierdie gene in die wynmaakproses is deur gaschromatografie bepaal. Die resultate het aangedui dat die bakteriële gene op In effektiewe wyse vlugtige fenole in die wyn kan produseer. Sekere monoterpene is ook in In verhoogde mate gedurende hierdie proses gevorm. Hierdie studie baan die weg vir die ontwikkeling van reingisinentingskulture vir die produksie van optimale vlakke van vlugtige fenole om sodoende die sensoriese gehalte van die wyn te verbeter.

O chá é uma das bebidas mais consumidas em todo o mundo. Algumas funções biológicas dos chás têm sido relatadas, tais como antiinflamatória, antioxidante, antialérgica, e anti-obesidade. Estas atividades biológicas estão associadas, em parte, com a atividade antioxidante dos compostos químicos presentes nos chás, especialmente flavonoides e ácidos fenólicos. No entanto, os compostos fenólicos são primariamente responsáveis pelas propriedades benéficas do chá. Assim, a avaliação total e de quantificação individual de compostos fenólicos é essencial para correlacionar sua a atividade biológica. As amostras avaliadas foram chá verde, camomila, carqueja, boldo, branco, cidreira, preto e mate. Neste estudo os compostos fenólicos totais e flavonoides foram quantificados por espectrofotometria. A capacidade antioxidante dos extratos fenólicos foi avaliada pelos métodos DPPH e ABTS+. Compostos fenólicos foram identificados por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana foi determinada pela avaliação da concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). A análise de componentes principais (ACP) e a análise hierárquica de agrupamentos (AHA) mostraram que não foi observada uma distinção clara entre os métodos de extração. Neste estudo, a extração à frio mostrou-se mais eficiente na extração de compostos bioativos. / Tea is one of the most consumed beverages in the world. Some biological functions of tea have been reported, such as anti-inflammatory, antioxidant, anti-allergic, and anti-obesity. These biological activities are associated, in part, to the antioxidant activity of chemical compounds present in tea, especially flavonoids and phenolic acids, however, the phenolic compounds are primarily responsible for the beneficial properties of tea. Thus, the total evaluation and quantification of individual phenolic compounds is essential to correlate its biological activity. The samples were evaluated green tea, chamomile, broom, Boldo, white, lemon, black and matte. In this study, flavonoids and phenolic compounds were quantified by spectrophotometry. The antioxidant capacity of phenolic extracts was evaluated by DPPH and ABTS•+ methods. Phenolic compounds were identified by high performance liquid chromatography (HPLC). Antimicrobial activity was determined by assessing the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that it was not observed a clear distinction between the extraction methods. In this study, the cold extraction was more efficient in the extraction of bioactive compounds.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-08-20T19:39:12Z No. of bitstreams: 1 MARIA VERÔNICA LINS – DISSERTAÇÃO (PPGEP) 2018.pdf: 3739599 bytes, checksum: 98ed5746cf0966a70f4b4585e66a55ca (MD5) / Made available in DSpace on 2018-08-20T19:39:12Z (GMT). No. of bitstreams: 1 MARIA VERÔNICA LINS – DISSERTAÇÃO (PPGEP) 2018.pdf: 3739599 bytes, checksum: 98ed5746cf0966a70f4b4585e66a55ca (MD5) Previous issue date: 2018-02 / Capes / A própolis é um produto apícola de constituição química complexa produzida pelas abelhas. Elas colhem as gotas e partículas expiradas dos brotos e botões florais que se unem a outras substâncias e secreções, e transformam-se em uma rica resina com várias finalidades de uso. O objetivo geral dessa pesquisa foi avaliar a influência do armazenamento a frio dos tipos de própolis colhidas nas regiões do litoral, curimataú oriental e alto sertão, no Estado da Paraíba, sob temperatura controlada. Foram analisadas 60 amostras de própolis; sendo 20 de cada região, divididas em dois grupos A e B com 30 amostras cada um. As amostras foram submetidas ao armazenamento a frio há 10ºC, por um período de 12 meses; as amostras do grupo B foram colh idas e imediatamente submetidas às análises, em temperatura ambiente. Foi possível concluir que o valor bioativo quantificado dos teores fenóis para os extratos das própolis vermelha, verde e marrom, sendo o extrato da própolis vermelha o que apresentou os melhores níveis, garantindo assim sua excelente qualidade em função da região, a própolis marrom mostrou níveis em seus teores de fenóis inalterados ao armazenamento por um período de 12 meses em temperatura constante de 10ºC, os valores encontrados são acima da média comparando com resultados encontrados em todo o país, apresentado uma qualidade extraordinária. / Propolis is a bee product of complex chemical constitution, the be es harvest the drops and particles expired buds and flower buds, which bind to other substances and secretions become a rich resin, with various purposes of use by bees. The overall objective was to evaluate the influence of cold storage of the propolis types harvested in the litoral, curimataú oriental and alto sertão regions, in the State of Paraíba, under controlled temperature. Sixty samples of propolis were analyzed; 20 of each region, divided into two groups A and B, 30 samples from group A were submitted to cold storage at 10ºC for a period of 12 months; the samples of group B were collected and immediately submitted to the analyzes, at room temperature. It was possible to conclude that the quantified bioactive value of the phenolic contents for the e xtracts of the red, green and brown propolis, being the extract of the red propolis which presented the best levels, thus guaranteeing its excellent quality as a function of the region, the brown propolis showed levels in its contents of phenols unaltered to storage for a period of 12 months at constant temperature of 10ºC, the values found are above average compared to results found throughout the country, presented an extraordinary quality.

Orientador: Ben-Hur Mattiuz / Banca: Kelly Magalhães Marques / Banca: Teresinha de Jesus Deleo Rodrigues / Resumo: A Batata-doce é um alimento versátil, de fácil aquisição e produção, entretanto, as raízes apresentam inconvenientes como desuniformidade, descasque e rápido escurecimento após o corte, por isso, esse vegetal mostra-se um produto com características a serem superadas pelo processamento mínimo. O uso de agentes antioxidantes e/ou tratamento térmico tem apresentado efeitos satisfatórios na qualidade pós-colheita de produtos hortícolas. Os ácidos cítrico e ascórbico atuam na inativação de enzimas responsáveis pelo escurecimento, devido à redução de pH e ação antioxidante, respectivamente. O tratamento térmico moderado que age na inativação de enzimas do escurecimento sem alterar a textura do vegetal. Nesse contexto, o objetivo desse estudo foi avaliar o efeito do ácido cítrico, ascórbico e tratamento térmico em diferentes concentrações e tempos na qualidade de batata-doce minimante processadas. As raízes de casca rosada e polpa amarela, foram, higienizadas, descascadas e feitos cortes transversais ao eixo principal obtendo rodelas de 1 cm de espessura, que foram submetidas a diferentes tratamentos, à saber, imersão em soluções de ácido citrico (AC) à 0, 1, 2 e 3% por 1 min; ácido ascórbico (AA) à 0, 1, 2 e 3% por 1min e tratamento térmico (TT) à 50°C por 0, 1, 3 e 5 min. Em seguida as batatas-doce foram centrifugadas e armazenadas em bandejas de tereftalado de polietileno (PET) a temperatura de 5 °C e 85% UR por um período de 8 dias. A cada 2 dias avaliou-se a perda acumulada de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sweet potato is a versatile food, easy to acquire and produce, however, the roots present disadvantages such as unevenness, peeling and fast darkening after cutting, so this vegetable shows a product with characteristics to be overcome by the minimally processed. The use of antioxidants and / or heat treatment has shown satisfactory effects on the post-harvest quality of vegetables. The citric and ascorbic acids act in the inactivation of enzymes responsible for darkening, due to the reduction of pH and antioxidant action, respectively. The moderate heat treatment that acts in the inactivation of darkening enzymes without changing the texture of the vegetable. Therefore, this study aims to evaluate the effect of the acids citric and ascorbic combine with heat treatment at different concentrations and times in the quality of sweetened sweet potato processed. The roots with rosy peel and yellow pulp were cleaned, peeled and cut transversally around the principal axis, obtaining slices with 1 cm of thickness. The slices were submitted to different treatments, namely immersion in citric acid solutions (AC) at 0, 1, 2 and 3 % for 1 min; ascorbic acid (AA) at 0, 1, 2 and 3 % for 1min and, heat treatment (TT) at 50 °C for 0 (immersion in water at room temperature), 1, 3 and 5 min. Then, the pretreated sweet potatoes were centrifuged and stored in polyethylene terephthalate trays (pet) at 5°c and 85±5 % RH for a period of 8 days. Every 2 days the loss of accumulated fresh mass, firmn... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:27:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-28Bitstream added on 2014-06-13T20:16:38Z : No. of bitstreams: 1 bruno_m_me_jabo_prot.pdf: 2616643 bytes, checksum: 97247720aae07e408b197a60a6613f6a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho avaliou-se o desempenho de reatores anaeróbios de fluxo ascendente com manta de lodo (UASB), em dois estágios, em escala de bancada (volumes de 20 L e 10 L, respectivamente), alimentados com água residuária do beneficiamento de café por via úmida, submetidos à quatro cargas orgânicas volumétricas (COV) de 5,76; 3,62; 3,86 e 2,16 kg DQO total (m3 d)-1 no primeiro reator, R1. As concentrações médias de DQO do afluente variaram de 8626 a 23041 mg L-1, e dos efluentes dos reatores 1 e 2, 1095 a 11506 mg L-1 e de 424 a 9030 mg L-1, respectivamente. As eficiências médias de remoção de DQO total e SST variaram de 66 a 98% e de 93 a 97% respectivamente, no sistema com reatores (UASB) em dois estágios. O teor de metano no biogás variou de 69 a 89% para o reator 1 e de 52 a 73% no reator 2. A produção volumétrica máxima de metano, 0,563 m3 CH4 (m3 reator d)-1 foi obtida com COV de 3,86 kg DQO (m3 d)-1 e TDH de 124 h. Os valores médios de pH variaram na faixa de 4,7 a 7,7 e 4,9 a 8,0 nos efluentes dos reatores 1 e 2, respectivamente. A concentração de ácidos voláteis totais manteve-se estável à níveis inferiores a 200 mg L-1 nos ensaios 2, 3 e 4. As concentrações médias de fenóis totais do afluente variaram de 79,7 a 97,4 mg L-1, e as eficiências médias de remoção no conjunto de reatores UASB em dois estágios variaram de 72 a 90%. / In this work it was evaluated the performance of two stage upflow anaerobic sludge blanquet (UASB), in lab scale, treating a liquid effluent from the coffee pulping, submitted to organic load rate of 5,76; 3,62; 3,86 and 2,16 kg COD (m3 d)-1 in the first reactor. The medium values of total COD affluent varied from 15439 to 23041 mg L-1, and in the effluent from the reactors 1and 2, 1095 to 11506 mg L-1, and 424 to 9030 mg L-1, respectively. The medium values of removal efficiences of total COD and TSS varied from 66 to 98% and 93 to 97%, respectively, in the system of treating with reactors UASB, in two stages. The content of methane varied from 69 to 89% in reactor 1 and 52 to 73% in reactor 2 . The maximum volumetric methane production 0,563 m3 CH4 (m3 reactor d)-1 was obtained with OLR of 3,86 kg COD (m3 d)-1 and HDT of 124 hours. Average pH values ranged from 4,7 to 7,7 and 4,9 to 8,0 for effluents of first and second reactors. Total volatile acid concentration was kept below 200 mg L-1. The medium values of total phenols of affluent ranged from 79,9 to 97,4 mg L-1, and the average removal efficiency ranged from 72 to 90% in the two stages upflow anaerobic sludge blanket (UASB).