No description available.

Phospholipids, such as phosphatidylserine (PS) have been shown to work synergistically with tocopherols to extend the shelf life of oil-in-water emulsions. However, the high cost of PS prevents it from being used as a food additive. This work investigated the potential use of a high PS enzyme-modified lecithin to be used along with α-tocopherol to extend the lag phase of oil-in-water emulsions stabilized using Tween 20. Phospholipase D from Streptomyces sp. and L-serine were used to modify lecithin to increase PS concentration. Enzyme activity was optimized as a function of pH and temperature using a high PC soybean lecithin. The high PS modified lecithin was examined for its ability to enhance the activity of α-tocopherol in Tween 20-stabilized oil-in-water emulsions. The modification was also performed in high PC sunflower lecithin and egg lecithin which were later analyzed for their efficiency in controlling lipid oxidation. α-Tocopherol (3.0 µmol/kg emulsion) alone increased the lag phase of hydroperoxide and hexanal lag phases by 3 and 4 days compared to the control. Authentic PS (15.0 µmol/kg emulsion) increased hydroperoxide and hexanal lag phases by 1 and 3 days, respectively, whereas high PS soy lecithin increased hydroperoxide and hexanal lag phases by 3 and 4 days, respectively. The addition of high PS sunflower and egg lecithin did not have any considerable effects on lag phases compared to the control. Authentic PS (15.0 µmol/kg emulsion) and a-tocopherol (3.0 µmol/kg emulsion) decreased lipid oxidation by increasing the hydroperoxide and hexanal lag phase to 6 and 9 days. The combination of phospholipase D modified high PS lecithins (15.0 µmol/kg emulsion) and a-tocopherol (3.0 µmol/kg emulsion) were able to synergistically increase the antioxidant activity of a-tocopherol increasing the hydroperoxide and hexanal lag phase by 6 and 9 days for soy, 5 days, and 7 days for sunflower and 4 and 6 days for egg lecithin, respectively. This resulted in synergistic antioxidant activity (interaction index > 1.0) except for a-tocopherol and high PS Egg lecithin which showed an additive effect. This research shows that the combination of enzyme-modified high PS lecithin and α-tocopherol could be an effective and commercially viable clean label antioxidant strategy to control lipid oxidation in emulsions.

No description available.

No description available.

Synthetic antioxidants have traditionally been added directly to food products in a single initial dose to protect against oxidation of lipids and generation of free radicals. Natural antioxidants have been shown to undergo loss of activity and become prooxidants at high concentrations; therefore, a need exists to develop active packaging which can gradually deliver antioxidants in a controlled manner. The objectives of this research were to (1) form and characterize cyclodextrin inclusion complexes with the natural antioxidants, alpha-tocopherol and quercetin, (2) incorporate cyclodextrin inclusion complexes of natural antioxidants into linear low density polyethylene (LLDPE), and (3) measure the release kinetics of inclusion complexes of natural antioxidants from LLDPE into a model food system. Cyclodextrin inclusion complexes of alpha-tocopherol and quercetin were formed by the coprecipitation method and characterized in the solid state by NMR, IR spectroscopy, and thermal analyses. Solid inclusion complex products of alpha-tocopherol:beta-cyclodextrin and quercetin:gamma-cyclodextrin had molar ratios of 1.7:1 as determined by UV spectrophotometry, which were equivalent to 18.1% (w/w) alpha-tocopherol and 13.0% (w/w) quercetin. Free and cyclodextrin complexed antioxidant additives were compounded with a twin-screw mixer into two LLDPE resin types followed by compression molding into films. Release of alpha-tocopherol and quercetin from LLDPE films into coconut oil at 30 °C was quantified by HPLC during 4 weeks of storage. The total release of alpha-tocopherol after 4 weeks was 70% from the free form and 8% from the complexed form averaged across both LLDPE resins. The mechanism by which alpha-tocopherol was released was modified due to its encapsulation inside the beta-cyclodextrin cavity within the LLDPE matrix as indicated by its diffusion coefficient decreasing by two orders of magnitude. Molecular encapsulation of natural antioxidants using cyclodextrins may be used as a controlled release mechanism within polymer food packaging to gradually deliver an effective antioxidant concentration to a food product, thereby, limiting oxidation, maintaining nutritional quality, and extending shelf life. / Ph. D.

Residual value is defined as the price for which a used piece of equipment can be sold in the market at a particular time. It is an important element of the owning costs of equipment and needs to be estimated by equipment managers for making investment decisions. The purpose of this study is to gain insights into the residual value of selected groups of heavy construction equipment and to develop a mathematical model for its prediction. Auction sales data were collected from two online databases. Manufacturer publications and an online source provided size parameters and manufacturers suggested retail prices matching the auction records. Macroeconomic indicator values were collected from a variety of sources, including government agencies. The data were brought into the same electronic format and were matched by model name and calendar date, respectively. Data from auctions in the U.S. and in Canada were considered for this study. Equipment from four principal manufacturers of up to 15 years of age at the time of sale was included. A total of 35,542 entries were grouped into 11 different equipment types and 28 categories by size as measured by horse power, standard operating weight, or bucket volume. Equipment types considered were track and wheel excavators, wheel and track loaders, backhoe loaders, integrated toolcarriers, rigid frame and articulated trucks, track dozers, motor graders, and wheel tractor scrapers. Multiple linear regression analyses of the 28 datasets were carried out after outliers had been deleted. Explanatory variables for the regression model were age in years, the indicator variables manufacturer, condition rating, and geographic region, and selected macroeconomic indicators. The response variable was residual value percent, defined as auction price divided by manufacturers suggested retail price. Different first, second, and third-order polynomial models and exponential and logarithmic models of age were examined. A second-order polynomial was selected from these functional forms based on the adjusted coefficient of determination. Coefficients for the 28 models and related statistics were tabulated. A spreadsheet tool incorporating the final regression model and its coefficients was developed. It allows performing the residual value prediction in an interactive and intuitive manner. / Ph. D.

The antioxidant properties of various blends of rosemary extract and tocopherols, either alone or with citric and ascorbic acid, were compared in filleted, headed and gutted, and minced rainbow trout (Oncorhynchus mykiss). The filleted and headed and gutted products were stored at -29 degrees C for twelve months, while the minced was stored at the same temperature for 24 weeks. Oxidation was measured by following changes in thiobarbituric reactive substances, conjugated diene hydroperoxides, texture, drip loss, pH, sensory evaluation, and gas chromatographic detection of aldehydes. Natural antioxidants, in particular those that contained citric and ascorbic acids, were effective at retarding the development of conjugated diene hydroperoxides and malonaldehyde (p<0.05). Furthermore, sensory evaluation indicated that treated samples were less oxidized. In subsequent studies, however, it was determined that the herbal flavor notes associated with natural antioxidants complicated the ability of the experienced panel to judge extent of oxidation. Also, using filleted samples, further consumer sensory panels indicated that after 12 months frozen storage, the treated and control samples were equally acceptable. For both the filleted and headed and gutted samples, no texture differences were noted over storage time or between control or variable treatments. When using natural antioxidant products, drip loss and pH were found unreliable predicators of oxidation or muscle degradation. / Master of Science

Das Ziel der experimentellen Arbeit war die Untersuchung der Einflussfaktoren auf den Ertrag, die Saatgutqualität unter verschiedenen Lagerungsbedingungen sowie die Effizienz der Expression vonRamtillkraut (Guizotia abbysinica Cass.). In Feldversuchen wurden folgende Varianten untersucht, Sorten ‚Fogera‘ und ‚Kuyu‘, Saatgutaufwand von 5, 10, 15 kg ha-1, ein Stickstoffaufwand von 13, 23 und 33 kg ha-1, sowie eine differenzierte Wasserversorgung an zwei Standorten (Adet und Koga). In Adet wurde der höchste Saatgut Ertrag mit 1.384,60 kg ha-1 ermittelt, Erträgen in Koga (ohne Bewässerung) mit 1.064,72 kg ha-1 und 967,00 kg ha-1 (mit Bewässerung). Der höchste Ölgehalt wurde im Saatgut aus Koga (ohne Bewässerung) mit 41,54% ermittelt, gefolgt von Koga (mit Bewässerung) 39,59% und Adet mit 38,67%. Signifikante Unterschiede wurden zwischen den N-Aufwandmengen in Koga mit Bewässerung und Saatgutmengen in Adet ermittelt. Die Unterschiede bei den Fettsäuregehalten in Adet waren nicht signifikant. Der Alpha-Tocopherol Gehalt betrug 80 mg pro 100 g bei hoher Saatdichte und hoher N-Düngung. Hinsichtlich des Verfahrens des Ölpressens, wurde ein signifikanter Unterschied zwischen Effizienz und Temperatur ermittelt. Die Dauer der Konditionierung und die Vorschubgeschwindigkeit sind negative korreliert gleichfalls mit der Effizienz der Expression. Die Temperaturen von 70°C und 80°C zeigten keinen signifikanten Einfluss auf die Ölausbeute, dagegen war der der Einfluss von 90°C statistisch signifikant. / The aim of this study was to investigate factors influencing seed yield, postharvest handling, and the oil expression efficiency for nigerseed (Guizotia abbysinica Cass.). Based on field study on two varieties, two locations, three seed rates and three fertilizer rates the highest mean nigerseed yield was 1384.6 kg ha-1 at Adet location (rain fed) followed by location Koga (rain) with 1064.7 kg ha-1 and Koga (irrigation) with 967.0 kg ha-1 showing significant difference. The oil content by location was 41.54% for Koga (rain) followed by 39.59 and 38.67% for Koga (irrigation) and Adet (rain) respectively showing significant difference whereas the Ash content showed a reverse trend of oil content. Fatty acid composition did not show significant difference in any treatment. Significant mean alpha-tocopherol of 80 mg/100 g (70 to 89 mg/100 g) was attained for increasing seed and nitrogen rates. Based on two temperatures and seven relative humidities model evaluation and monolayer moisture content estimation, Guggenheim-Anderson-de Boer (GAB) models was found to best suit both varieties as compared to Brunauer-Emmet-Teller (BET), and modified Chung &Pfost. For oil expression efficiency, 90ºC seed conditioning showed significant effect compared to 80 and 70ºC however conditioning times and feed rates did not differ significantly.

A indústria de alimentos é responsável pela produção de grandes quantidades de resíduos que podem representar altos custos quando não utilizados. Entre estes resíduos estão as sementes oriundas do processamento de uva, uma das frutas mais consumidas no mundo. Além do aproveitamento de resíduos e consequentemente novas formas de consumo, este material tem sido relatado como fonte natural rica em compostos bioativos. Neste contexto, o consumo de alimentos mais saudáveis também tem impulsionado a busca e a preferência por alimentos orgânicos. Assim, para investigar o potencial de utilização de resíduo da indústria de processamento de suco de uva (Vitis labrusca, cv. “Bordô” e “Isabel”) foi analisado o resíduo da obtenção do óleo de sementes de uvas orgânicas e convencionais quanto ao teor de carotenoides e atividade antioxidante em comparação à semente integral. Os resíduos orgânicos e convencionais apresentaram os maiores teores de carotenoides totais, pró-vitamina A e atividade antioxidante por DPPH em relação a semente integral. O resíduo convencional destacou-se pela maior atividade antioxidante por TRAP e pelos teores mais significativos de carotenoides presentes no extrato antioxidante. também foram determinados O conteúdo de compostos bioativos e a estabilidade oxidativa dos óleos obtidos da prensagem das sementes orgânicas e convencionais Bordô e Isabel. Não foi observada diferença significativa entre as amostras quanto à atividade antioxidante por TRAP, porém os óleos Bordôs apresentaram-se mais estáveis ao aquecimento, com teores mais significativos de luteína, α e β-caroteno e α-tocoferol. A fim de investigar a qualidade, estabilidade oxidativa e conteúdo de compostos bioativos nestes óleos, foi realizado o refino do óleo Bordô orgânico. Não foi observada presença de β-caroteno e zeaxantina no óleo refinado e o óleo virgem de mesmo cultivar apresentou maior estabilidade ao aquecimento. Neste contexto, os resultados sugerem o consumo de óleos virgens devido a presença e maior quantidade de compostos bioativos. Não foi observada diferença significativa entre os diferentes modos de cultivo, sugerindo que a preferência por alimentos orgânicos pode restringir-se à motivos como ausência de agrotóxicos e apelo socioambiental. Os resíduos obtidos do processamento de uva, inclusive da obtenção do óleo destacaram-se pela alta atividade antioxidante e quantidade significativa de carotenoides, o que sugere sua inserção na alimentação como fonte natural rica em compostos bioativos. / The food industry is responsible for producing large quantities of waste that may represent high costs when not used. Some of these residues are the seeds derived from the processing of grapes, one of the most consumed fruits worldwide. In addition to the reuse of waste and consequently new forms of consumption, this material has been reported to be rich natural source of bioactive compounds. In this context, the consumption of healthier foods has also driven the search and preference for organic foods. Therefore, to investigate the potential use of grape processing waste (Vitis labrusca, variety “Bordô” and “Isabel”), the residues obtained from the extraction of oil from organic and conventional grape seeds were examined to determine their content of carotenoids and antioxidant activity compared with those found in the whole seed. The organic and conventional residues exhibited higher levels of total carotenoids, provitamin A, and antioxidant activity by DPPH compared with the corresponding whole seeds. The conventional residue presented the highest antioxidant activity by TRAP and the highest levels of carotenoids in the antioxidant extract. The content of bioactive compounds and the oxidative stability of the oils obtained from the pressing of organic and conventional seeds “Bordô” and “Isabel” were also determined. No significant difference in the antioxidant activity by TRAP was observed between the samples, but the “Bordô” oils were more stable when heated and exhibited higher levels of lutein, α and β-carotene, and α-tocopherol. To investigate the quality, oxidative stability, and content of bioactive compounds in these oils, the organic “Bordô” oil was refined. The refined oil did not contain β-carotene and zeaxanthin, and the virgin oil of the same variety showed greater stability to heating. Thus, the results recommend the consumption of virgin oils due to their larger content of bioactive compounds. No significant difference was observed between the different modes of cultivation, suggesting that the preference for organic foods can be restricted to reasons such as the absence of pesticides and environmental appeal. The residues obtained from grape processing, including the residues obtained from the extraction of oil, exhibited high antioxidant activity and a high amount of carotenoids, suggesting their inclusion in foods as a natural source rich in bioactive compounds.

Trinta ovelhas, mestiças (Santa Inês X Dorper), adultas e hígidas foram selecionadas para avaliar o efeito da suplementação intramuscular com as vitaminas D e E no perfil bioquímico, metabolismo energético, metabolismo oxidativo, sensibilidade insulínica e imunidade no periparto. Após confirmação da gestação essas fêmeas foram distribuídas em três grupos de dez animais e no 108&deg; dia de gestação receberam veículo oleoso (grupo controle-GC); ou 70.000 UI/kg de P.V. de vitamina D3 (colecalciferol) (grupo tratado-GD); ou 60UI/kg de P.V. de vitamina E (-tocoferol) (grupo tratado-GE). As amostras de sangue foram coletadas previamente à aplicação da vitamina (-45), quatro (-30); e duas semanas (-15) antes do parto; até duas horas do parto (0), uma (7); duas (15); e quatro semanas após o parto (30). Foram analisadas as concentrações plasmáticas de glicose, beta hidroxibutirato (BHB), ácidos graxos não esterificados (AGNEs) e as concentrações séricas de colesterol, triglicérides, ureia, creatinina, cálcio total, cálcio iônico, proteína total, ácido úrico, aspartato amino transferase (AST), gamaglutamil transferase (GGT), e ainda a creatina quinase (CK). Foram também analisadas as concentrações de insulina e cortisol. Do metabolismo oxidativo foram determinadas as atividades da superóxido dismutase (SOD) e glutationa peroxidase (GSH-Px), a habilidade de redução férrica plasmática (HRFP), substâncias reativas ao ácido tiobarbitúrico (TBARS), bem como o status antioxidante total (TAS). Para avaliar aspectos relacionados à imunidade de monócitos e neutrófilos, por método in vitro, em 24 ovelhas (seis de cada tratamento). As amostras de sangue foram coletadas nos momentos 30; 0; e 30 e avaliadas sem estímulo (burst basal) e com estímulo por DCFH-DA, SaPI e PMA. A imunofenotipagem com anticorpos monoclonais CD8, CD4, CD14, CD16, CD45R, WC1, CD206, foi realizada aos dias -30, -15,0,7 e 30. Foram determinadas as concentrações das vitaminas D e E, nos momentos pré-determinados das coletas e no dia do teste de tolerância à glicose (TTG), realizado para avaliar a sensibilidade insulínica, e foi calculado RQUICKI e RQUICKI BHB. Todas as variáveis estudadas apresentaram efeito de tempo. Houve interação tempo*tratamento em TBARS (P=0,0217) e tendência para vitamina E (0,0811), SOD (0,0886) e GSH-Px (P=0,0643). Houve efeito de tratamento no colesterol (P=0,0088) e vitamina D (P<0,0001) e tendência para TAS (P=0,0830). No TTG, com resultados de AUC de BHB e AGNE apresentaram efeito de número de fetos gestados (P=0,0006 e 0,0005 respectivamente) e o RQUICKIBHB mostrou-se melhor indicador de sensibilidade insulínica do que o RQUICKI em ovelhas. A suplementação com vitamina D influenciou os teores plasmáticos de alfa tocoferol e a resposta imune das ovelhas. A suplementação com vitamina E reduziu a peroxidação lipídica no parto e relacionou-se positivamente com a melhora oxidativa dos monócitos sem estímulo e estimulados por PMA. / Thirty healthy adult ewes were selected to evaluate the effect of supplementation with intramuscular vitamins D and E in peripartum period on the biochemical profile, energetic metabolism, oxidative metabolism, insulin sensitivity and immunity. After pregnancy confirmation these females were distributed into three groups of ten animals treated with intramuscular injection containing oily vehicle (control-to-control group) on the 108th day of pregnancy, (CG); or 70,000 IU / kg of body weight of vitamin D3 (cholecalciferol) (treated group-GD); or 60 IU / kg of body weight of vitamin E (-tocopherol) (treated group-GE). Blood samples were collected before the application of the vitamins and vehicle (-45), four (-30); and two weeks (-15) before lambing; until 2 hours of lambing (0); one (7), two (15) and four weeks postpartum (30). Plasma concentrations of glucose, beta hydroxybutyrate (BHB), non-esterified fatty acids (NEFA) and serum concentrations of cholesterol, triglycerides, urea, creatinine, total calcium, ionic calcium, total protein, uric acid, aspartate amino transferase (AST), gammaglutamyl transferase (GGT), and creatine kinase (CK) were measured. The concentrations of insulin and cortisol, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), plasma ferric reduction ability (FRAP), thiobarbituric acid reactive substances (TBARS), as well as total antioxidant status (TAS) were determinate. Monocytes and neutrophils were assessed by in vitro method to identify aspects related to immunity in 24 ewes (six from each treatment) at -30, 0 and 30. Blood samples were evaluated without stimulus (basal burst), with DCFH-DA, SaPI and PMA stimulus. Immunophenotyping with monoclonal antibodies CD8, CD4, CD14, CD16, CD45R, WC1, CD206 were performed at -30, -15, 0, 7 and 30. The concentrations of vitamins D and E were determinate at the predetermined collection times and on the day of the Intravenous Glucose Tolerance Test (IVGTT), realized to evaluate the insulin sensitivity, as well as RQUICKI and RQUICKI BHB. All variables studied showed time effects. There were interaction time * treatment in TBARS (P = 0.0217) and tendency for vitamin E (0.0811), SOD (0.0886) and GSH-Px 16 (P = 0.0643). Treatment effect on cholesterol (P = 0.0088) and vitamin D (P &lt;0.0001) and tendency for TAS (P = 0.0830) were observed. About of IVGTT, AUC results of BHB and AGNE showed number of fetuses effect (P = 0.0006 and 0.0005 respectively). RQUICKIBHB was a better indicator of insulin sensitivity than RQUICKI in ewes. Vitamin D supplementation influenced the plasma levels of alpha tocopherol and the immune response of ewes. Vitamin E supplementation reduced lipid peroxidation at parturition and was positively related to the oxidative improvement of the monocytes without stimulation and stimulated by PMA. High doses of vitamins D or E administered 45 days before parturition on healthy ewes can be beneficial; however more studies are needed about this topic.