Na primeira etapa deste trabalho avaliou-se o desempenho fermentativo de 6 cepas de leveduras comerciais utilizadas na produção de vinhos e cerveja, em mosto de mel 30°Brix suplementado com 0,5 g/L de peptona e 1 g/L de extrato de levedura. Como resposta determinou-se o crescimento das leveduras em número de células e as concentrações de glicose, frutose e etanol por HPLC, que permitiram determinar os parâmetros rendimento, eficiência de fermentação e produtifidade em etanol, bem como a produção de sulfeto de hidrogênio. Assim, selecionou-se a cepa Saccharomyces bayanus - Pasteur Champagne - Red Star, que teve seu comportamento avaliado em mosto de mel suplementado com diferentes nutrientes. Os resultados demonstraram que a suplementação do mosto de mel com sais ou com suplemento comercial Enovit contribuiu para o bom desempenho da referida cepa. Na etapa seguinte, estudou-se a produção de hidromel em escala piloto a 18°C em reatores de polipropileno contendo 130 L de mosto sem suplementação (controle), suplementado com Enovit e suplementado com pedaços de maçãs (10% m/v). Terminada a fermentação, após 60 dias, o hidromel foi devidamente caracterizado físico-quimicamente quanto aos padrões de qualidade e identidade para hidromel estabelecidos pela Legislação Brasileira. Os resultados demonstraram que, com exceção da acidez total, todos os parâmetros avaliados se encontravam em consonância com os referidos padrões. Assim, as formulações estudadas foram adequadas para a obtenção de hidromel. Terminada a fermentação o hidromel foi submetido ao processo de envelhecimento a 20°C, por 216 dias, em tonel de carvalho (50L); galão de plástico (20 L); e frasco de vidro tipo bolha (20L), sendo neste período, caracterizado físico-químicamente, bem como quanto aos teores de compostos fenólicos totais, capacidade antioxidante, presença de aminas bioativas e compostos aromáticos derivados do tonel de carvalho. O hidromel envelhecido em galão de plástico apresentou teores de extrato seco reduzido abaixo do mínimo estabelecido nos padrões da legislação. A utilização de maçãs como suplemento do mosto de mel resultou em hidromel com maior teor de compostos fenólicos e maior capacidade antioxidante. As concentrações de aminas bioativas encontradas não comprometem a qualidade do hidromel, nem oferecem risco à saúde do consumidor. A análise de compostos fenólicos dos hidroméis envelhecidos em tonel de carvalho revelou que o processo de envelhecimento promoveu a extração de furfural, vanilina e ácido gálico, compostos que contribuem para o perfil sensorial da bebida, ficaram abaixo do limiar de percepção sensorial, fato que pode ser alterado pelo aumento do tempo de envelhecimento. Quanto a intenção de compra, os hidroméis avaliados apresentaram mais de 50% de notas variando entre 3 (tenho dúvidas se compraria) e 5 (certamente compraria), sendo os de melhor aceitação envelhecidos em recipientes de plástico e vidro. A análise sensorial revelou pouca influência do recipiente de envelhecimento sobre os atributos avaliados e a intensão de compra mostrou que os provadores preferiram os hidroméis envelhecidos em recipientes inertes (vidro e plástico). Diante do exposto, conclui-se que a produção de hidromel e seu posterior envelhecimento, por 216 dias, em recipientes inertes ou em tonéis de carvalho recondicionados, resultam em bebidas que apresentam boa aceitação, sendo uma alternativa viável para apicultores diversificarem a sua produção. / In the first stage of this work it was evaluated the fermentation performance of six commercial strains of yeast used in the of wine and beer production in honey wort 30 °Brix supplemented with 0.5 g / L peptone and 1 g / L yeast extract. In response, it was determined the yeast growth by number of cells and concentrations of glucose, fructose and ethanol by HPLC, as well as fermentation parameters as yield, efficiency and productivity in ethanol, and the production of hydrogen sulfide. Saccharomyces bayanus -Pasteur Champagne - Red Star showed better fermentation performance and it was evaluated in honey wort supplemented with different nutrients. The results showed that must supplementation with salts or commercial supplement Enovit contributes to the yeast performance. In the next step, it was studied the production of mead on a pilot scale at 18 ° C in polypropylene reactors containing 130 L of wort without supplementation (control), supplemented with Enovit and supplemented with apple pieces (10% m/v). By the end of fermentation, after 60 days, mead was properly characterized physico-chemically regarding the standards of quality and identity for mead, established by Brazilian legislation. The results showed that, with the exception of total acidity, all parameters were in accordance with the standards. After the fermentation, mead was subjected to aging process at 20 ° C by 216 days in oak barrel (50L) plastic gallon (20 L) and glass bottle (20L), and was characterized physico-chemically, as well as regarding the content of total phenolics, antioxidant capacity, presence of bioactive amines and aromatic compounds derived from the oak barrel. The results showed that the mead aged in plastic gallon presented content of \"reduced dried extract\" below the minimum patterns stated. It was also observed that the use of apples as the must supplement resulted in honey mead with a higher content of phenolic compounds and antioxidant capacity. The concentrations of bioactive amines found do not compromise the quality of mead, neither consumer health. The analysis of phenolic compounds in meads aged in oak barrel revealed that the aging process promoted the extraction of furfural, vanillin, gallic acid, compounds which contribute to the sensory profile of the beverage. Concentrations of these compounds were below the threshold of sensory perception, which can be changed by increasing aging time. Regarding purchase intent, all meads evaluated obtained more than 50% of positive scores, ranging between 3 (I doubt if buy) and 5 (definitely would buy), and meads aged in plastic and glass containers showed better acceptance. Sensory analysis showed little influence of the aging container on the attributes evaluated and the tasters preferred the meads aged in inert containers. So,it is concluded that the production of mead and its subsequent aging in inert containers or reconditioned oak casks, resulted in beverages that have good acceptance and are a viable alternative for beekeepers to diversify their products.

O benefício do consumo de compostos bioativos, como os carotenóides, tem sido amplamente demonstrado pela literatura científica. No entanto, alguns destes bioativos (como os carotenos), devido à sua hidrofobicidade, apresentam dificuldades para serem incorporados em formulações alimentícias aquosas, além de serem, dependendo da matriz alimentícia na qual estão inseridos, dificilmente absorvidos no tratogastrointestinal - ou seja, possuem limitada biodisponibilidade. Tais problemas podem ser contornados através da micro e da nanoencapsulação. O presente trabalho de Mestrado teve como objetivo utilizar a triestearina e o ácido esteárico para a encapsulação do beta-caroteno em micro e nanopartículas lipídicas sólidas, a caracterização físico-química das estruturas formadas e a avaliação da estabilidade química e microestrutural das mesmas. Nos sistemas microparticulados de ácido esteárico (AE) foi utilizado como tensoativo o polisorbato 80 e foram produzidos com 4 e 6% de lipídio, na ausência e na presença de alfa-tocoferol, e todos se mostram extremamente estáveis em relação à distribuição do tamanho médio das partículas, mas somente as partículas que continham alfa-tocoferol conseguiram preservar o beta-caroteno ao longo do período de 7 meses de armazenagem. No caso das micropartículas de triestearina também foram produzidos sistema com 4 e 6% de lipídio total, e a presença do hidrocolóide goma xantana foi essencial para evitar a floculação e permitir a estabilidade do sistema, e foram testadas formulações contendo misturas de tensoativos fosfatidilcolina de soja e polisorbato 60 e fosfatidilcolina de soja e polisorbato 20. Dentre tais sistemas, somente as micropartículas sólidas estabilizadas com polisorbato 60 se mostraram estáveis em relação ao tamanho médio das partículas, e o sistema com menor quantidade de lipídio manteve-se resistente à floculação até o 4º mês de estocagem. Sistemas nanoparticulados foram produzidos com 6% de lipídio total, testando-se uma e duas passagens no homogeneizador à alta pressão. Os dados obtidos indicaram que as nanopartículas lipídicas de AE não diferiram em relação à distribuição de tamanho, mas apresentaram aumento do diâmetro de partícula ao longo do tempo de estocagem. Por sua vez, para as nanopartículas de triestearina os sistemas (tanto com uma quanto com duas passagens no homogeneizador a alta pressão) se mostraram estáveis até cerca de dois meses de armazenagem, em termos de diâmetro médio de partícula, sendo que a distribuição de tamanho se mostrou mais homogênea para o sistema com duas passagens. A microestrutura de todos os sistemas foi avaliada por difratometria de raio-X (DRX) e calorimetria diferencial de varredura (DSC), e a quantidade de beta-caroteno preservada ao longo do tempo foi monitorada espectofometricamente e por colorimetria instrumental. De maneira geral, os sistemas microparticulados se mostraram melhores do que os nanoparticulados, tanto do ponto de vista de estabilidade da estrutura quanto da preservação do beta-caroteno. / The benefits from the consumption of bioactive compounds, like carotenoids, have been widely demonstrated for scientific literature. However, some of this compounds (like carotenes), due totheir hydrophobicity, are difficult to be incorporated in aqueous food formulations, and, depending on the food matrices where they are introduced, are hardly absorbed in the gastrointestinal tract - in order words, they present limited bioavailability. These problems can be overcome by micro and nanoencapsulation. In this context, the objective of this study was to investigate the temporal stability of beta-carotene encapsulated in solid lipid micro and nano particles produced with a mixture of stearic acid or tristearin and sunflower oil, monitoring the microstructure of the systems by X-ray diffractometry, differential scanning calorimetry, zeta potential and particle size measurements, and try to link the preservation of beta-carotene with microstructural considerations. The surfactant used for the stearic acid microparticulate systems was polysorbate 80 and formulations with 4 and 6% of total lipid were produced, in the absence and presence of alpha-tocopherol, and all systems showed high stability in terms of average particle diameter and size distribution, but only the particles containing alpha-tocopherol preserved the content of beta-carotene during the storage period of 7 months In the case of the tristearin microparticles the presence of a hydrocolloid (xanthan gum) was essential for avoid flocculation and improves the system stability, and formulations containing mixtures of surfactants (soybean phosphatidylcholine and polysorbate 60 and phosphatidylcholine and polysorbate 20) were tested. Among such systems, only the solidmicroparticles stabilized with phosphatidylcholine and polysorbate 60 showed stability in terms of average particle diameter and size distribution, and the system with less concentration of solid lipid did not show significant destabilization until the 4th month of storage. As for the nanoparticulated systems, formulations with 6% of total lipid were produced, testing one and two passages in high pressure homogenizer. Our results indicated the stearic acid solid nanoparticles did not exhibitalterations of size distribution, but average particle diameter increased along the time. On the other hand, the triestearin nanoparticles (both with one and two passage in high pressure homogeneizer) showed stability until two months of storage, in terms of average particle diameter, and the size distribution demonstrated to be more homogeneous for the systems submitted to two passages. As an overall conclusion, the microparticulated systems seemed to be more stable than the nanoparticulated ones, from the point of view of structure stability as well as in terms of beta-carotene preservation of beta-carotene.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Restricted until October 2006. Bibliography: leaves 108-134.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

In this study, novel bio-inks formulated with horseradish peroxidase, HRP, and some additives were successfully developed for piezoelectric inkjet application. The optimized bio-ink formulation had a reliable jetting performance and maintained the biofunctionality before and after printing. The bio-ink also demonstrated a good storage life for up to 40 days at 4 oC with a negligible loss of biofunctionality. However, it was observed that some additives used in the bio-ink for obtaining necessary operational characteristics had detrimental effects on the enzyme activity. Especially, it was found that various viscosity modifiers typically used in commercial inkjet inks significantly impaired HRP activity prior to printing. Sodium Carboxymethyl Cellulose was shown to be an effective viscosity modifier that had no adverse effect on the biological activity of the HRP enzyme. Using a confocal scanning fluorescent microscope, a method for characterizing the spatial distribution of the active enzyme within the cellulosic paper substrates after inkjet printing was developed. Interestingly, it was found that the active printed HRP enzyme was mostly located in the cell walls of the cellulosic fibers instead of near the pigments or fillers. In an effort to better understand the fundamental interactions between the enzyme and the immobilization substrates, HRP adsorption isotherms on various substrate surfaces were obtained using the depletion method. The substrates included not only pulp fibers with varying degree of hydrophobicity and pigment and latex (the key materials used in papermaking), but also other types of cellulosic fibers of different morphologies, crystallinities, porosities, or surface charge densities. The influence on enzyme adsorption and inactivation behaviour of these substrates was compared with that of polystyrene beads (dialysed), which has been well studied in the literature. Results from this thesis indicated that hydrophobic interactions between the enzyme and the substrate surfaces had a major impact on the HRP adsorption behavior, while electrostatic interactions played a minor role. However, strong hydrophobic interactions could lead to enzyme inactivation. Research findings from this study suggested that cellulosic pulp fibers could be tailor-made into excellent enzyme immobilization supports by using existing fiber surface modification techniques.

This thesis is an account of investigation on the natural products deriving from various marine algae and has resulted in the discovery of eleven novel bioactive metabolites. Isolation and characterization of these new molecules were carried out using different chromatographic techniques and by analyses of different spectroscopic data, respectively. Using bioassay guided fractionation (brine shrimp toxicity assay), I isolated and identified five new, biologically active compounds [2β,3α-epitaondiol, flabellinol, flabellinone, stypoaldehyde and stypohydroperoxide], together with five known compounds [2-geranylgeranyl-6-methyl-1, 4-benzoquinone, (-) epistypodiol, (-) stypoldione, fucoxanthin and iditol] from the marine brown alga Stypopodium flabelliforme, collected from Papua New Guinea. All of the new compounds were found to have cytotoxic activity (EC₅₀ ranges from 0.8-10 μg/ml) in human lung cancer (NCI-H460). 2β,3α-epitaondiol and flabellinol exhibited strong sodium channel blocking activity (EC₅₀=0.3 and 0.9 μg/ml, respectively). As a result of efforts to identify bioactive agents from marine algae, I have isolated and identified one new halogenated monoterpene [(-)-(5E,7Z)-3,4,8- trichloro-7-dichloromethyl-3-methyl-1,5,7-octatriene] in addition to another three known halogenated monoterpene compounds from the red alga Plocamium cartilagineum collected from the eastern coast of South Africa. [(-)-(5E,7Z)-3,4,8- trichloro-7-dichloromethyl-3-methyl-1,5,7-octatriene] was found to be active as a cytotoxic agent in human lung cancer (NCI-H460) and mouse neuro-2a cell lines (EC₅₀ 4 μg/ml). As part of continued search for bioactive secondary metabolites from marine sources using a bioassay guided fractionation approach (anti-trypanosome activity), I examined the organic extract of a Papua New Guinean collection of the green alga Udotea orientalis growing on a coral wall and collected in September 1998. Successive HPLC separations resulted in the isolation of three new compounds; (+) curcuepoxide A, (+) curcuepoxide B and (+)-l0α-hydroxycurcudiol. In addition I isolated four known compounds; (+)-10β- hydroxycurcudiol, (+) curcuphenol, (+) curcudiol and (+) curcudiol-10-one. A bioassay guided investigation approach (anti-Sirt2) of a Lyngbya majuscula collection from Key West Florida, led to the discovery of two novel bioactive natural products [(+)-malyngamide X and one cyclic depsipeptide, (+)-floridamide]. The new cyclic depsipeptide, (+)-floridamide contains four amino acids units beside the unique unit, 2,2-dimethyl-3-hydroxyoctanoic acid (Dhoaa). / Graduation date: 2004

In this study, novel bio-inks formulated with horseradish peroxidase, HRP, and some additives were successfully developed for piezoelectric inkjet application. The optimized bio-ink formulation had a reliable jetting performance and maintained the biofunctionality before and after printing. The bio-ink also demonstrated a good storage life for up to 40 days at 4 oC with a negligible loss of biofunctionality. However, it was observed that some additives used in the bio-ink for obtaining necessary operational characteristics had detrimental effects on the enzyme activity. Especially, it was found that various viscosity modifiers typically used in commercial inkjet inks significantly impaired HRP activity prior to printing. Sodium Carboxymethyl Cellulose was shown to be an effective viscosity modifier that had no adverse effect on the biological activity of the HRP enzyme. Using a confocal scanning fluorescent microscope, a method for characterizing the spatial distribution of the active enzyme within the cellulosic paper substrates after inkjet printing was developed. Interestingly, it was found that the active printed HRP enzyme was mostly located in the cell walls of the cellulosic fibers instead of near the pigments or fillers. In an effort to better understand the fundamental interactions between the enzyme and the immobilization substrates, HRP adsorption isotherms on various substrate surfaces were obtained using the depletion method. The substrates included not only pulp fibers with varying degree of hydrophobicity and pigment and latex (the key materials used in papermaking), but also other types of cellulosic fibers of different morphologies, crystallinities, porosities, or surface charge densities. The influence on enzyme adsorption and inactivation behaviour of these substrates was compared with that of polystyrene beads (dialysed), which has been well studied in the literature. Results from this thesis indicated that hydrophobic interactions between the enzyme and the substrate surfaces had a major impact on the HRP adsorption behavior, while electrostatic interactions played a minor role. However, strong hydrophobic interactions could lead to enzyme inactivation. Research findings from this study suggested that cellulosic pulp fibers could be tailor-made into excellent enzyme immobilization supports by using existing fiber surface modification techniques.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

A diet rich in fruit and vegetables is associated with better bone health although the reason behind this remains unclear. Mounting evidence suggests that it may be particular fruit and vegetables or a variety of fruit and vegetables that are important and it has been suggested that bioactive compounds, considered to be non-essential nutrients, may play a role. The aims of this project were to study the roles of three classes of dietary compounds on bone health: flavonoids (represented by hesperetin), anthocyanidins and carotenoids. Methods The influence of six major anthocyanidins, six major carotenoids and the citrus flavanone hesperetin were examined by three methodological approaches: (i) a cross-sectional study using outcomes of bone mineral density (BMD) and markers of bone turnover, (ii) a randomised controlled trial with bone turnover markers as the outcome measures and (iii) in vitro examinations in osteoblasts and osteoclasts. The epidemiological part of this thesis was carried out in the Aberdeen Prospective Osteoporosis Screening Study (APOSS) cohort. Women were recuited to the study between 1990 and 1994 and returned for a follow-up visit between 1997 and 1999 (n=3214, mean age 54.8 y at follow-up). Measurements of BMD at the spine and hip were taken at both visits; and urinary markers of bone resorption total deoxypyridinolines (DPD) and total pyridinolines (PYD), and a serum bone formation marker N-terminal propeptides of type 1 procollagen (P1NP), were analysed at the follow-up visit. Diet was recorded by food frequency questionnaire and dietary anthocyanidins and carotenoids were estimated using a database of food compositions developed for this purpose. Analysis was carried out to determine if anthocyanidin or carotenoid intakes were associated with BMD, change in BMD (between the 2 visits), or markers of bone resorption or formation, within the APOSS population. The effect of the carotenoid lycopene on bone turnover was assessed in a 3-month randomised controlled trial in 214 apparently healthy men and women. Participants were randomised into 3 groups: high dietary lycopene (minimum 10 mg/d); low tomato diet with lycopene capsule vi (10 mg/d) or a low tomato diet as the control. Marker of bone resorption plasma carboxyterminal collagen crosslinks (CTX) and marker of bone formation serum P1NP were analysed at baseline (after washout) and after 12 weeks of intervention. In order to study if the aglycone or glycoside compounds directly affect bone metabolism, the effects of a series of anthocyanidins on osteoblast differentiation were analysed in vitro. The effects of hesperetin on osteoblast differentiation and mineralisation and on osteoclast formation and function in vitro were also assessed. Results Regarding the epidemiological part of the project, associations between both dietary anthocyanidins and carotenoids and markers of bone health were observed in the APOSS population. Higher total dietary anthocyanidin intake was found to be associated with higher spine BMD and lower concentrations of bone resorption markers. In addition higher total dietary anthocyanidin intake was associated with less BMD loss at the spine in the period between baseline and follow-up, which was illustrated by a 13.2% difference in annual percent bone loss between the highest and lowest quartiles of anthocyanidin consumption. Individual anthocyanidins were also found to be associated with different markers of bone turnover. Total dietary carotenoid intake was found to be associated with BMD at the spine and lower concentrations of bone resorption markers. Analysis of the individual carotenoids showed that lycopene was associated with higher BMD at the hip; β-carotene was associated with less BMD loss at the spine; and β-carotene, lycopene, β-cryptoxanthin and lutein/zeaxanthin were found to be associated with lower concentrations of bone resorption markers. Each of these findings remained significant after adjusting for confounding factors. In the 3-month randomised controlled trial, lycopene supplementation did not alter bone turnover markers CTX or P1NP. These results are in contrast to those of a previous, smaller randomised controlled trial in postmenopausal women where a decrease in a marker of bone resorption (N-telopeptide of collagen cross-links (NTX)) was observed. Therefore these results suggest that the potential beneficial effect of lycopene may be specific to a population at risk of bone loss. Alternatively, lycopene may have a cumulative protective effect over the lifetime but short-term effects may only be observed in groups with high bone turnover, where there is greater potential to see measureable effects. The results of the in vitro investigations of this project showed that neither anthocyanidins nor hesperetin had an affect on osteoblasts or osteoclasts at physiologically relevant concentrations. Almost all of the anthocyanidin compounds tested had no effect on osteoblast differentiation, and none at physiological concentrations. Similarly, hesperetin had no effect on osteoblast differentiation or mineralisation although it did have an effect on both osteoclast formation and function, but only at concentrations which were not considered to be physiologically relevant. These results add weight to the suggestion that the metabolites of dietary compounds may be responsible for the action on bone metabolism rather than the dietary compounds directly or that a combination of compounds, as found in foods, may be required. Conclusions Taken together, these results support the evidence that a diet rich in fruit and vegetablederived bioactive compounds is beneficial to bone health. Future work could include: observational studies to examine the association of lifetime consumption and long-term risk of fracture; larger dietary intervention trials; and in vitro studies to examine the effects of the compound metabolites and elucidate their mechanism of action.