published_or_final_version / abstract / Mechanical Engineering / Doctoral / Doctor of Philosophy

Thirty-five volunteers were randomized and twenty-nine completed the study. Mean plasma and red blood cell (RBC) total DHA concentrations, which were analyzed among all participants as a measure of adherence, increased significantly in the DHA-enriched treatment compared to control oil-control flour. The plasma and RBC n-6: n-3 ratio was reduced after consumption of HOCODHA-control flour compared to control oil- control flour. The present study failed to see differences in body composition with the HOCODHA-barley flour treatment versus control oil-control flour treatment. In conclusion, significant increases in plasma EPA and DHA levels, as well as the omega-3 index, provide evidence supporting the cardioprotective effects of HOCODHA. The present study demonstrated that in the context of current Western macronutrient intakes, altering the dietary fatty acid composition and adding β-glucan had no major effect on body composition during the 28 days controlled dietary intervention. / February 2017

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

Six ã-Al2O3 supported metallic nitride and carbide catalysts were chosen for a scouting test for the production of a diesel fuel cetane enhancer from canola oil. The six catalysts chosen for study were ã-Al2O3 supported molybdenum (Mo) carbide and nitride, tungsten (W) carbide and nitride, and vanadium (V) nitride and carbide. All six catalysts were prepared by the impregnation method and characterized using various techniques. The six catalysts were screened for their affinity for oxygen removal, fatty acid conversion, alkane/olefin selectivity, hydrogen consumption, and gas-by product production from oleic acid. The scouting test was carried out at a reaction temperature of 390°C, a LHSV of 0.46 hr-1, and elevated hydrogen partial pressures of greater than 7000 kPa, in a laboratory microreactor in an upflow configuration. The scouting test revealed that the two molybdenum catalysts performed the best with oxygen removal near 100% and alkane/olefin content of greater than 30%. <p>Next, the supported molybdenum carbide and nitride catalysts were compared against one another over a wider range of operating conditions. A temperature range of 380 390°C, a LHSV range of 0.64 1.28 hr-1, and a hydrogen partial pressure of 7100 kPa were used. Both catalysts had the same metal loading of 7.4 wt% molybdenum. The two catalysts were compared on the basis of oxygen removal, alkane/olefin selectivity, diesel fuel selectivity, and hydrogen consumption, while using both triolein and canola oil as the feed. It was found that the supported molybdenum nitride was the superior choice for this process, specifically when using the more complex canola oil feed. The supported molybdenum nitride catalyst delivered oxygen removal of greater than 85%, alkane/olefin selectivity of greater than 20%, and diesel fuel selectivity of greater than 40%, for all conditions studied. <p>Finally, a preliminary catalyst and process optimization was carried out on the chosen ã-Al2O3 supported molybdenum nitride catalyst. The catalyst optimization consisted of varying the metal loading of the catalyst from 7.4 wt% to 22.7 wt%. The catalysts were examined over a temperature range of 390 410°C, a LHSV range of 0.9 1.2 hr-1, and a hydrogen partial pressure of 8300 kPa, with canola oil as the chosen feed. It was found that the increase in molybdenum loading on the catalyst delivered an average increase in the alkane/olefin selectivity of 43.2% and an average increase in the diesel fuel selectivity of 5.3 %. The process optimization studied a temperature range of 390 410°C, a LHSV range of 0.6 1.2 hr-1, and a hydrogen partial pressure range of 7800 - 8900 kPa, with canola oil as the chosen feed. Within the limits of the design, it was found that the optimum operating conditions were 395°C, 1.05 hr-1, and 8270 kPa. At these conditions the predicted yields of alkane/olefin products and diesel fuel are 47.3 and 50.5 g/100g liquid fed, respectively.

Six ã-Al2O3 supported metallic nitride and carbide catalysts were chosen for a scouting test for the production of a diesel fuel cetane enhancer from canola oil. The six catalysts chosen for study were ã-Al2O3 supported molybdenum (Mo) carbide and nitride, tungsten (W) carbide and nitride, and vanadium (V) nitride and carbide. All six catalysts were prepared by the impregnation method and characterized using various techniques. The six catalysts were screened for their affinity for oxygen removal, fatty acid conversion, alkane/olefin selectivity, hydrogen consumption, and gas-by product production from oleic acid. The scouting test was carried out at a reaction temperature of 390°C, a LHSV of 0.46 hr-1, and elevated hydrogen partial pressures of greater than 7000 kPa, in a laboratory microreactor in an upflow configuration. The scouting test revealed that the two molybdenum catalysts performed the best with oxygen removal near 100% and alkane/olefin content of greater than 30%. <p>Next, the supported molybdenum carbide and nitride catalysts were compared against one another over a wider range of operating conditions. A temperature range of 380 390°C, a LHSV range of 0.64 1.28 hr-1, and a hydrogen partial pressure of 7100 kPa were used. Both catalysts had the same metal loading of 7.4 wt% molybdenum. The two catalysts were compared on the basis of oxygen removal, alkane/olefin selectivity, diesel fuel selectivity, and hydrogen consumption, while using both triolein and canola oil as the feed. It was found that the supported molybdenum nitride was the superior choice for this process, specifically when using the more complex canola oil feed. The supported molybdenum nitride catalyst delivered oxygen removal of greater than 85%, alkane/olefin selectivity of greater than 20%, and diesel fuel selectivity of greater than 40%, for all conditions studied. <p>Finally, a preliminary catalyst and process optimization was carried out on the chosen ã-Al2O3 supported molybdenum nitride catalyst. The catalyst optimization consisted of varying the metal loading of the catalyst from 7.4 wt% to 22.7 wt%. The catalysts were examined over a temperature range of 390 410°C, a LHSV range of 0.9 1.2 hr-1, and a hydrogen partial pressure of 8300 kPa, with canola oil as the chosen feed. It was found that the increase in molybdenum loading on the catalyst delivered an average increase in the alkane/olefin selectivity of 43.2% and an average increase in the diesel fuel selectivity of 5.3 %. The process optimization studied a temperature range of 390 410°C, a LHSV range of 0.6 1.2 hr-1, and a hydrogen partial pressure range of 7800 - 8900 kPa, with canola oil as the chosen feed. Within the limits of the design, it was found that the optimum operating conditions were 395°C, 1.05 hr-1, and 8270 kPa. At these conditions the predicted yields of alkane/olefin products and diesel fuel are 47.3 and 50.5 g/100g liquid fed, respectively.

Several factors including an unidentified endogenous substance were found to stimulate microsomal diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) from a microspore-derived cell suspension culture of oilseed rape (Brassica napus L. cv Jet Neuf). Mg2+ salts were found to stimulate microsomal DGAT 14 to 23-fold. ATP and CoA were also found to stimulate the enzyme 2.4 and 12 fold respectively, although the effects were decreased in the presence of high Mg2+ concentrations. While microsomal DGAT activity was only slightly increased by the concentration of exogenous diacylglycerol in the reaction mixture it was increased substantially by the addition of exogenous phosphatidate. Other phospholipids tested were not found to have this stimulatory effect. During attempts to investigate possible covalent modification of the enzyme, the soluble fraction obtained from cell suspension homogenate was found to contain a small metastable organic molecule(s) which stimulated DGAT activity. Stimulation of microsomal DGAT by this factor was concentration dependent but not dependent on preincubation time. / xiii, 95 leaves : ill. ; 28 cm.

Brassica napus is known to contain an endogenous and soluble stearoyl-acyl carrier protein (^918:0-ACP) desaturase, but does not express a palmitic (16:0)-ACP desaturase. Levels of 16:0 are low in canola oil and are associated with enhanced cholesterol biosynthesis in humans. In an attempt to further reduce the saturated fatty acid (SFA) content of canola oil, B. Napus L. cv Westar was transformed with a cDNA encoding a ^916:0-ACP desaturase from cat's claw (Doxantha unguis-cati L.). Arabidopsis thaliana was also transformed with this cDNA. Transformation of both oilseeds resulted in increased production of palmitoleic acid (^16:1) and many other effects of fatty acid composition. Overall, the SFA content did not decrease in either oilseed and investigation to why this effect occurred was examined using transgenic B. napus. Molecular genetic testing on second generation B. napus also determined the plants contained the cDNA of interest and were transcribing the cDNA. / xxi, 155 leaves : ill. ; 29 cm.

Sinapic acid derivatives and tocopherols in refining byproducts of commercially produced expeller-pressed canola oils were characterized and isolated. Additionally, the antioxidant activities of the phenolics were examined by three systems including an in vitro non-biological related assay, a cellular assay and a deep-fat frying model. Sinapic acid (SA： 42.9 µg/g), Sinapine (SP: 199 µg/g), and Canolol (CAN: 344 µg/g) were found in different byproducts of canola oil refining, namely, soapstock, spent bleaching clay, and wash-water, respectively. Tocopherols (3.75 mg/g) and other non-identified phenolic compounds (2.7 mg /g) were found in deodistillates (DDL). CAN and DDL revealed significant protection effect (p<0.05) against hydrogen peroxide induced oxidation in two mammalian cell lines. The results of deep-fat frying studies indicated positive effects of CAN and DDL in preventing lipid oxidation. The canola oils fortified with DDL and CAN showed a considerable reduction (p < 0.05) in oxidation products of lipid after frying.

In a globalized and competitive world, logistics is receiving a lot of attention from business managers because of its importance concerning the fidelity of customers and their participation in the total costs of the company. Therefore, this paper aims to develop a model to the management of the services of physical distribution based on the six sigma strategy in an agroindustry that produces canola oil and it is located in the northwest of the state of Rio Grande do Sul, Brazil. The data were collected by using a questionnaire which refers to the level of satisfaction and the importance of the services offered by the company concerning the customers attendance; the kind of ordering, invoice service and payment; logistic of transports and the information given. In order to analyze the data it was used the descriptive statistics and the techniques of analyses Cluster hierarchic and Cluster k-means. The six customers who buy unmanufactured canola oil from this company took part on this study. The results showed that the customers are satisfied with most of the services offered by the company. It was also observed that the customers demonstrated a lot of satisfaction referring to the kind of ordering, invoice service and payment. However, the clients consider the attendance service as being the most important feature of the company. Based on these results, a model to the management of the services of physical distribution based on the six sigma strategy was proposed with the purpose of guaranteeing the quality of services offered. / Em um mercado globalizado e competitivo a logística começa a receber maior atenção por parte dos gestores empresariais, devido à sua importância quanto a fidelização de clientes e sua participação nos custos totais da empresa. Por isso, este trabalho tem por objetivo propor um modelo para o gerenciamento dos serviços de distribuição física, com base na estratégia seis sigma, em uma agroindústria produtora de óleo bruto de canola situada na região noroeste do Estado do Rio Grande do Sul. Os dados foram coletados por meio de um questionário, referentes ao grau de satisfação e importância dos serviços prestados pela empresa quanto ao atendimento; tomada de pedido, faturamento e pagamento; logística de transportes e informações prestadas. Para a análise dos dados utilizou-se a estatística descritiva e a técnica da análise de Cluster hierárquico e Cluster k-means. Fizeram parte deste estudo os seis clienteadquirem o óleo bruto de canola da empresa estudada. Os resultados mostraram que os clientes estão satisfeitos com a maioria dos serviços prestados pela empresa. Observou-se, também, que os clientes estão mais satisfeitos com os serviços referentes à tomada de pedidos, faturamento e pagamento. Porém, quanto ao grau de importância, eles consideram mais importante os serviços prestados no atendimento. Com base nestes resultados foi proposto um modelo de gerenciamento para os serviços de distribuição física baseado na estratégia seis sigma, visando garantir a qualidade dos serviços prestados.

Philosophiae Doctor - PhD / The aim of this study was to determine whether dietary fats constituting specific ω-6/ω-3 fatty acids (FA) ratio has chemopreventive modulating effects on the development of colon cancer. Western diets intake of saturated FA (SATS) and ω-6 polyunsaturated FA (PUFA) are very high relative to low ω-3 PUFA consumption. This high ω-6 and low ω-3 FA intake, resulting in a high ω-6/ω-3 FA ratio, appears to have a promoting effect on disease outcome, whilst increased ω-3 FA intake exhibiting anti-cancer effects. An animal cancer model was employed to evaluate the effects of dietary fat ratios on chemically induced carcinogenesis during cancer promotion. This was to determine whether the FA diets have a promoting or inhibitory effect on early neoplastic lesions by quantifying aberrant crypt foci (ACF) development and monitoring the crypt cells proliferative and apoptotic indices. The expressions of genes associated with changes in cells redox balance were also assessed. Common dietary fats were combined to produce the dietary fat ratios: sunflower oil (S), borage oil (B) and fish oil (F). Combinations of these oils generated the different ω-6/ω-3 FA ratios: SB (ω-6/ω-3: 38:1), SF (ω-6/ω-3: 13:1) and SBF (10:1). To represent the Western diet's high ω-6/ω-3 FA ratio profile, S (ω-6/ω-3: 501: 1) was used as a control, and canola oil and olive oil as additional reference. The dietary fats had no toxic effects on the liver and kidney based on serum clinical biochemical measurements. Diets containing borage oil (SB and SBF diets), canola and olive oil decreased (p<0.05) the crypt multiplicity of large (≥7 crypts/focus) ACF, exhibiting anti-cancer effects by decreasing (p<0.05) the proliferative activity of the rat colon crypts. Borage oil's protective effect resulted from the enhanced supply of C18:3ω-6 that has anti-inflammatory and anti-proliferative properties. The observed decrease (p<0.05) in apoptosis in the ACF was also facilitated by the up- and down-regulation of DNA repair and DNA replication associated genes, Xpa and Ercc2 by borage oil, respectively. Canola oil and olive had the largest inhibitory effect on suppressing crypt multiplicity by reducing (p<0.05) proliferation in the colon. Both oils effected the up-regulation (p<0.05) of the expression of several oxidative stress and anti-oxidant defence genes mediating the regulation of cell proliferation. The increased supply of C18:1ω-9 (canola and olive) and total polyphenolic content (olive) protected cells against oxidative stress induced apoptosis, which provided interesting interactive effects between FA and polyphenolic oil constituents that should be further elucidated. In contrast, the fish oil containing (SF diet) and the control sunflower (S diet) increased (p<0.05) the total ACF and colon crypt multiplicity (≥7 crypts/focus) when compared to the SB, SBF, olive oil and canola oil diets. An increased resistance to oxidative stress induced apoptosis appears to facilitate fish oil’s enhancing effect on crypt multiplicity despite the increased supply of LC ω-3 FA, which are prone to oxidation and leads to increased oxidative stress. This protective effect on crypt multiplicity and ACF development was mainly due to enhanced cellular antioxidant and DNA repair responses through the up-regulation (p<0.05) of Gpx4 and Nudt1, which favoured the increase (p<0.05) of crypt cells proliferation.The in vitro study demonstrated that oil ratio emulsions (S: ω-6/ω-3 = 249:1; SB: ω-6/ω-3 = 28:1; SF: ω-6/ω-3 = 12:1 and SBF: ω-6/ω-3 = 12:1) had differential effects on the survival indices of HT-29 and Caco-2 colon cancer cells. Contrary to the in vivo model, fish oil (SF and SBF emulsions) significantly (p<0.05) reduced the viability and proliferation of both cell lines, with the HT-29 cells showing greater sensitivity to the oil’s anti-proliferative effect. The HT-29 cells exposure to increased levels of C20:5ω-3 and C22:6ω-3 predisposes it to lipid peroxidation that increases the potential for cell removal via apoptosis. However, apoptotic effects were absent due to the HT-29 cells removal via necrosis as the cells energy status (ATP production) was significantly (p<0.05) depleted. Similar to the animal cancer model, borage oil (SB and SBF emulsions) had a reducing (p<0.05) effect on cell proliferation in both cell lines. However, as ATP was decreased (p<0.05), the S, SF and SBF emulsions resulted in an increased (p<0.05) apoptotic response in the Caco-2 cells in a dose dependent manner. This response resulted from the altered FA and lipid composition effected by the oil emulsions. Increased (p<0.05) incorporation of C20:5ω-3 and C22:6ω-3 in membrane phospholipid, phosphatidylethanolamine (PE), resulted in a significant decrease (p<0.05) in total SATS and MUFA content. A decrease (p<0.05) in membranes ω-6/ω-3 FA ratio was noted as well. This effect seems to selectively favour the induction of apoptosis by borage oil (SB and SBF). Similarly, an increase (p<0.05) in the PC/PE ratio by all oil emulsions, and a decrease (S and SB) and increase (SF and SBF) (p<0.05) in the chol/PL ratio appears to facilitate apoptosis too. A different threshold of the FA and lipid composition parameters elicits the inhibition of cell proliferation utilising lower oil emulsion concentrations. Therefore, the dietary supply of fats characterised by a defined low ω-6/ω-3 FA ratio can selectively modulate the growth indices of colon cancer. Specific oil ratio combinations by incorporating borage oil and fish oil hereby provide a selective strategy for chemoprevention in the colon, although underlying interactions and threshold effects of specific FA seems to prevail that should be further unravelled. / Medical Research Council (MRC) and Cancer Association of South Africa (CANSA)