The objective of this study was to improve canola protein gelation properties with the use of enzymes. Both cross-linking and limited proteolysis were explored. Enzyme treatments were performed prior to heat induced gelation. A texture analyzer, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy were used to characterize the resulting networks. Enzymatic cross-linking with transglutaminase was shown to improve the gelation of canola protein isolate (CPI). To the contrary, proteolysis with trypsin, ficin and bromelin, did not enhance the gelation properties of CPI.

Reducing consumption of fat is recommended for obese individuals; however, altering dietary fat, without reducing total fat, may modify obesity-associated consequences. The effects of dietary fat composition on obesity and insulin resistance in diet-induced obese rats were investigated. Rats were fed a high-fat lard-based diet for 12 weeks and then were randomized into one of six high-fat treatment groups (oils used: high-oleic canola, conventional canola, high-oleic/conventional canola mix, conventional canola/flax mix, safflower, or soybean) or kept on the lard diet for 8 weeks. Diets had varying effects on lipidemia and glycemia; however, insulin tolerance tests, oral glucose tolerance tests, and the skeletal muscle response to insulin were not different among groups. Muscle phospholipids showed expected differences in fatty acid (FA) composition, but polyunsaturated/saturated FA ratios were not different among groups. Overall, a consistent response to high-fat diets was observed which may be attributed to the robustness of polyunsaturated/saturated FA ratios of muscle phospholipids.

Considerable interest has focused on the influence of dietary fat quality on cardiovascular disease (CVD) risk. Increasingly, novel dietary oils rich in oleic acid and alpha-linolenic acid (ALA) are being developed and marketed with an aim to improve fatty acid intakes and reduce CVD risk. The objective of this research was to investigate the efficacy of high-oleic canola oil (HOCO) alone, or blended with flaxseed oil (FXCO), on traditional and emerging clinical biomarkers of CVD risk. An additional aim was to study the influence of dietary and genetic factors on metabolism of 13C-ALA to long-chain PUFA. Using a diet-controlled randomized crossover design, thirty-six hypercholesterolaemic subjects consumed three isoenergetic diets for 28 days each containing ~36% energy from fat, of which 70% was provided by HOCO, FXCO, or a Western dietary fat blend (WD; control). Endpoint measures revealed reductions (P<0.001) in serum lipid concentrations, including a 7.4% and 15.1% decrease in LDL-cholesterol after HOCO and FXCO diets, respectively, as compared with the WD control. Moreover, a reduction (P=0.023) in plasma E-selectin concentration was found after the FXCO diet compared with the WD control. Consumption of the dietary oils failed to alter whole-body fat oxidation or energy expenditure, nor lead to alterations in body composition. FXCO diet increased (P<0.001) plasma ALA ~5-fold, EPA ~3-fold, and DPA ~1.5-fold, but did not modulate DHA levels compared with the WD control. At 24 and 48 hours the amount of administered 13C-ALA recovered as plasma 13C-EPA and 13C-DPA was lower (P<0.001) after FXCO diet compared with HOCO and WD diets, suggesting decreased ALA conversion efficiency with very high intakes of dietary ALA. No difference in plasma 13C-DHA enrichment was observed across diets. Moreover, minor alleles of selected single nucleotide polymorphisms in the FADS1/FADS2 gene cluster were associated with reduced (P<0.05) plasma fatty acid compositions and apparent conversion of 13C-ALA. However, increased consumption of ALA in the FXCO diet compensated for lower levels of EPA in minor allele homozygotes. Taken together, substitution of dietary fats common to WD with both HOCO and FXCO represents an effective strategy to target several biomarkers for CVD risk reduction.

The objective of this study was to improve canola protein gelation properties with the use of enzymes. Both cross-linking and limited proteolysis were explored. Enzyme treatments were performed prior to heat induced gelation. A texture analyzer, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy were used to characterize the resulting networks. Enzymatic cross-linking with transglutaminase was shown to improve the gelation of canola protein isolate (CPI). To the contrary, proteolysis with trypsin, ficin and bromelin, did not enhance the gelation properties of CPI.

The fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary is capable of infecting over 400 plant species including canola (Brassica napus L.). The fungus secretes oxalic acid (OA), which plays an important role in infection and disease progression. An analysis of proteome-level changes associated with infection of susceptible canola leaves by S. sclerotiorum revealed significant changes in the abundance of 32 proteins, including proteins involved in photosynthesis and metabolism, hormone signaling, and antioxidant defense. A similar subset of 37 proteins was affected when leaves were treated with OA alone; this compound also caused a reduction in the activities of a number of antioxidant enzymes, suggesting an OA-mediated suppression of the oxidative burst. To further understand the mechanisms of pathogenesis, the role of Sssp, a predicted secreted protein from S. sclerotiorum, was targeted for analysis. Mutant strains of S. sclerotiorum were generated by disruption of the Sssp gene and characterized for virulence on canola. Based on the extent of symptom development, the virulence of the Sssp-disrupted mutants was significantly reduced relative to the wild-type, indicating that Sssp may play a role in the infection process. Finally, the development of sclerotia, long-term survival structures that serve as a primary source of inoculum for the fungus, was examined. A total of 88 proteins were found to exhibit temporal changes in abundance during sclerotium formation and maturation, including proteins involved in the regulation of melanogenesis. A total of 56 proteins were also identified in the sclerotial exudates, providing a basis for future studies. Collectively, the studies described in this dissertation represent the most comprehensive proteome-level analysis of the canola/S. sclerotiorum interaction and sclerotial development, and could contribute to the development of novel strategies for the management of S. sclerotiorum. / Plant Science

The nutritional value of biodiesel co-products were studied for swine. In Exp. 1, expeller-pressed canola meal was nutritionally characterized and validated for grower-finisher pigs. Expeller-pressed canola meal provided adequate energy and AA; ADG was reduced 3 g/d per 1% expeller-pressed canola meal inclusion in diets formulated to equal NE and SID AA, due to 5 mol/g dietary glucosinolates. In Exp. 2, cold-pressed canola cake samples from 4 different processing conditions were tested against expeller-pressed canola meal and seed in a digestibility study. Higher residual oil in the cake increased the DE and NE content. In Exp. 3, 15% of either solvent-extracted or expeller-pressed canola meal with or without 5% glycerol was tested against a soybean meal diet for weanlings. Solvent-extracted or expeller-pressed canola meal, or in combination with 5% glycerol can partially replace soybean meal in weaner diets formulated to equal NE and SID AA content without affecting growth performance. / Animal Science

Blackleg, caused by L. maculans, is of major economic importance in the canola growing areas of Australia. The aim of this research was to gain information about factors affecting the epidemiology of blackleg in south - eastern Australia. The effect of temperature on a number of aspects of the life cycle of L. maculans was studied in a controlled environment. Germination of ascospores was greater on agar and cotyledons than on leaves, on susceptible cultivars than resistant cultivars, and at 15 and 20 °C than at 5 and 10 °C. Elongation of germ tubes was greater at higher than lower temperatures and generally greater on cotyledons than on leaves of the cultivars after incubation for 24 h at 10 - 20 ° C. Temperature had a greater influence than plant organ or cultivar on ascospore germination and the elongation of germ tubes. Temperature, wetness duration, cultivar and leaf position ( leaves 1 - 3 ) influenced the incubation period of L. maculans on canola. Ascospores infected six canola cultivars over 10 - 20 ° C following leaf wetness duration of 16 - 72 h. Incubation period ( from inoculation to the appearance of first lesions ) was generally shorter at higher temperatures and following longer wetness periods. Incubation period decreased with increasing leaf age, regardless of the blackleg - resistance rating of the cultivars. Pseudothecia developed on naturally infested canola stubble incubated at 5 - 20 ° C under continuous wetness and a 12 h photoperiod. The time taken for pseudothecia to mature after harvest, ranged from 58.3 days at 5 ° C to 22.2 days at 15 ° C. Fewer pseudothecia developed on stubble incubated in darkness at 15 ° C than in light. Pseudothecia took longer to mature when wetness was interrupted than continuous. More ascospores were released at 20 ° C than 5 - 15 ° C, although peak sporulation occurred earlier at 5 - 10 ° C. Discharge of ascospores continued for 8 h at 5 - 10 ° C, for 10 h at 15 ° C, and for 12 h at 20 ° C. The effect of burial of infested canola stubble in sand and field soil ( in pots ) on pathogen survival, pathogenicity and stubble - associated fungi was studied over 13 months in ambient conditions. The isolation frequency of L. maculans from stubble decreased by 63.3 % after 13 months of burial, regardless of soil type. Although the frequency of isolation of L. maculans and Alternaria spp. from stubble decreased over time, that of Stachybotrys chartarum, Fusarium spp. and Coprinus sp. increased substantially over the sampling period. Stubble buried in field soil underwent more decay than in sand over the 13 months. Pseudothecium formation on buried stubble decreased with increasing duration of burial and ceased after 11 months in the field soil and 13 months in sand. The time required for pseudothecia to mature was 25 days for stubble retrieved after one month and 30 days when retrieved 10 months after burial, regardless of soil type. Ascospores from the stubble recovered from burial caused typical Phoma leaf spots on canola over the first 9 months of burial. Over the year, 16 genera of fungi and 12 colony types of bacteria were isolated from the field soil on peptone - rose bengal agar ( PRA ) and on crystal violet agar ( CVA ), respectively. Populations of fungi and bacteria isolated on soil - extract agar were markedly greater than those on PRA and on CVA, respectively. Growth and sporulation of L. maculans on agar media and on infested canola stubble was affected by a variety of fungi obtained from stubble buried in soil or from field soil. Antagonistic activities observed included lysis, deformation, overgrowth and inhibition of L. maculans hyphae, and reduction of pseudothecium density on stubble to one - third or less than that on controls following inoculation with F. equiseti, Gliocladium roseum, Trichoderma aureoviride, Sordaria sp. and an unknown Coelomycete. S. chartarum and Coprinus sp. reduced the mass of canola stubble in vitro. Findings will contribute to a better understanding of blackleg and to the development of more effective control measures. / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2006.

Thesis (Ph.D.)--University of Adelaide, School of Agriculture, Food and Wine, Discipline of Wine and Horticulture, 2007. / Includes Addenda (2 sheets) attached to back pages. Bibliography: leaves 170-183. Also available in print form.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Nanociência e Nanobiotecnologia, 2015. / Submitted by Ana Cristina Barbosa da Silva (annabds@hotmail.com) on 2015-05-08T20:20:31Z No. of bitstreams: 1 2015_AlessandraBarretodaSilva_Parcial.pdf: 1299772 bytes, checksum: 820dc04bb5a5fb196156e143e68a333e (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2015-05-11T18:21:01Z (GMT) No. of bitstreams: 1 2015_AlessandraBarretodaSilva_Parcial.pdf: 1299772 bytes, checksum: 820dc04bb5a5fb196156e143e68a333e (MD5) / Made available in DSpace on 2015-05-11T18:21:02Z (GMT). No. of bitstreams: 1 2015_AlessandraBarretodaSilva_Parcial.pdf: 1299772 bytes, checksum: 820dc04bb5a5fb196156e143e68a333e (MD5) / Uma das inovações da nanotecnologia na nutrição é a possibilidade de películas comestíveis formadas por biopolímeros veicularem nutrientes nanoencapsulados e consequentemente enriquecer nutricionalmente o alimento revestido. A nanoencapsulação protege um ativo sensível à elementos pró-oxidantes por constituir uma barreira fisicoquímica a este. A vitamina A é um importante nutriente a ser considerado, pois a sua deficiência _e um problema nutricional no mundo e é um nutriente sensível a tais elementos. Este estudo se propôs a sintetizar e caracterizar uma nanoemulsão de óleo de canola e nanopartículas de quitosana contendo acetato de retinol para serem incorporadas em uma película comestível elaborada pela combinação de amidos de milho e de mandioca para revestimento de maçãs. A presença de acetato de retinol foi confirmada por espectrometria de massa MALDI-TOF. Sintetizou-se nanoemulsões de óleo de canola (caNE) com diâmetro hidrodinâmico méedio de 228,83 ± 11,83 nm, com instabilidade coloidal incipiente (potencial-é de -29,3 ± 0,0 mV ) e polidispersas (PdI = 0,708 ± 0,021), com formação de gotículas oleosas com formato esférico, isoladas e sem formação de agregados. O método de síntese foi reprodutível e as nanoemulsões permaneceram estáveis por até 60 dias após sua obtenção. Estas aprisionaram 100% do acetato de retinol e a liberação deste ativo foi mínima (<20 %) em uido mimético gástrico (FMG) e relevante em fluido mimético intestinal (FMI) (>80%). As nanopartículas de quitosana (qsNP) formadas apresentaram diâmetro hidrodinÂmico médio igual _a 1398,00 ± 52,71 nm, divididas em duas subpopulações, a maior com ± 100 nm e a menor ± 1000 nm, sendo dessa forma considerado um nanossistema composto por micropartículas e nanopartículas. Estas qsNP apresentaram excelente estabilidade coloidal (potencial-_ = 54,2 ± 0,7 mV) e baixa polidispersão (PdI = 0,365 ± 0,035). O método de obtenção das qsNP foi reprodutível, propiciando nanopartículas estáveis até 21 dias após a sua obtenção. A eficiência de encapsulação das qsNP foi de 98,67% e a liberação do ativo ocorreu principalmente em FMG (>100%). Houve formação de solução lmogênica (SF) transparente, incolor e inodora. As maçãs submetidas a revestimento, independente do tratamento recebido apresentaram boa aparência geral e não sofreram alterações de brilho e cor ao longo dos dez dias de observação. O grupo de maçãs revestidas com SF, SF e caNE e caNE perderam mais massa (%) do que as do grupo tratado com água. Contudo, o grupo de maçãs tratadas com SF e qsNP e qsNP foram os com menores perdas de massa (%). Conclui-se que houve a formação de nanoestruturas por dois métodos diferentes. A otimização dos métodos possibilitou a formação de nanoestruturas capazes de aprisionar acetato de retinol com alta eficiência de encapsulação. Dentre as duas, a caNE ofereceu o perfil de liberação mais indicado para o nanoaprisionamento de acetato de retinol pois a liberação e retardada em FMG e rápida em FMI, protegendo este ativo até o local alvo da sua liberação. Ambas nanoestruturas são passíveis de serem aplicadas as maçãs pela película comestível de amidos podendo ser empregadas no enriquecimento nutricional de alimentos. / One of nanotechnology's innovations in nutrition is the possibility of edible films formed by biopolymers entrap nanocapsulated nutrients and hence, enhance the nutritional value of the coated food. The nanoencapsulation protects sensitive actives from pro-oxidant elements mainly because it constitutes a physical and chemical barrier. The vitamin A is an important nutrient to be considered to nanoentrapment, because its deficiency is a nutritional problem around the world and is a sensitive nutrient to such pro-oxidant elements. This study aimed to synthesize and characterize a nanoemulsion of canola oil and also chitosan nanoparticles containing retinol acetate to be incorporated into an edible film prepared by a combination of corn and cassava starches to coat apples. The presence of retinol acetate was confirmed by MALDI-TOF mass spectrometry. Canola oil nanoemulsions were synthesized (caNE) and reached an average hydrodynamic diameter of 228.83 ± 11.83 nm, with incipient colloidal instability (Zeta potential of -29.3 ± 0.0 mV), and polydisperse (PdI = 0.708 ± 0.021). There was the formation of oily droplets with spherical shape, isolated and without aggregates. The synthesis method was reproducible and nanoemulsions remained stable up to 60 days after formulation. These entrapped 100% of retinol acetate and the release of this active was low (<20 %) in mimetic gastric uid (MGF) and was mainly released in mimetic intestinal uid (MIF) (>80%). The nanoparticles of chitosan (qsNP) had an average hydrodynamic diameter of 1398.00 ± 52.71 nm, divided into two subpopulations, abundant with ± 100 nm and the lowest with ± 1000 nm. These qsNP showed excellent colloidal stability (Zeta potential = 54.2 ± 0.7 mV) and low polydispersity (PdI = 0.365 ± 0.035). This method was reproducible, providing stable nanoparticles within 21 days. The encapsulation eficiency of the qsNP was 98.67% and the release profile indicated that it occurs mainly in MGF (>100%). It was formed a film solution (SF) clear, colorless and odorless. The coated apples, independent of treatment, showed good general appearance and did not undergo brightness and color changes over the ten days of observation. The group of apples coated with FS, FS and caNE and caNE lost more mass (%) than the group treated with water. However, the coated apples treated with FS and qsNP and qsNP lost less mass (%). It is concluded that there was the formation of nanostructures by two different methods. The optimization of these methods allowed the formation of nanostructures able to nanoencapsulate retinol acetate with high encapsulation eficiency. Among the two nanostructures, the caNE o_ered the most appropriate release profile for retinol acetate since the release was delayed at MGF and very quick at MIF, protecting this active until it reached the target site of release. Both nanostructures are capable of being carried by starch edible film and may be used in nutritional food fortification.

Soil Water Balance (SWB) is a generic crop growth and irrigation-scheduling model. It improves on traditional methods of irrigation scheduling using evaporative demand by mechanistically and dynamically, quantitatively considering the soil–plant-atmosphere continuum. However, it needs specific crop growth parameters, which are not readily available for canola. The objective of this study was to determine crop growth parameters specific to canola and to identify the effect of water stress at different stages of growth on seed and oil yield. The study was conducted on the experimental farm of the University of Pretoria, South Africa, under a rain shelter during 2002 and in an open field during 2003. Weather data were recorded with an automatic weather station, phenological stages monitored frequently and growth analyses carried out every two weeks. Soil water content was measured with a neutron water meter weekly during 2002 and once every five days during 2003. Fractional interception of PAR was also measured with a sunfleck ceptometer. Specific crop parameters including specific leaf area, the leaf stem partitioning parameter, maximum rooting depth and thermal time requirements for crop development were generated from field measurements. These data form the backbone for accurate mechanistic simulations of the soil-water balance. The model was successfully calibrated and evaluated, proving its potential to be used as a generic crop irrigation-scheduling tool. Highest seed and oil yield was harvested from the unstressed treatment and lowest from the treatment stressed during the flowering stage. / Dissertation (MSc (Agric))--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted