Thesis (M.A.)--University of Vermont, 2009. / Includes bibliographical references (leaves 93-95).

Thesis--Wisconsin. / Includes bibliographical references (leaves 87-90).

The negative health effects of trans fatty acids from hydrogenated fats on plasma lipid profile have been well documented. However, the mechanisms responsible for these changes remain to be elucidated. Hence the overall objective of the thesis was to examine the effect of consuming different forms of hydrogenated fats on cholesterol and triglyceride metabolism, specifically fractional and absolute synthesis rates of free (FSR-FC and ASR-FC) and esterified (FSR-CE, AER and ER) cholesterol, and the functioning of the ASP pathway. In addition, validation of the newer deuterium incorporation (DI) method for measurement of endogenous cholesterol biosynthesis against the cholesterol precursor assessment approach was also performed. Fourteen moderately hypercholesterolemic (LDL-C ≥ 130 mg.dl-1) postmenopausal women (65--71yrs) participated in this study. Subjects consumed, in random order, each of 6 diets for 5 week periods, separated by washout periods ranging from 2 to 4 weeks in duration. The experimental diets included a baseline (BL) diet (39% kcal fat) and 5 reduced fat diets (30% kcal) where 2/3rd of the fat was either soybean oil (SO), low trans squeeze (SQM), medium trans tub (TM), high trans stick (SM) margarines, or butter (BT). Results obtained from the series of analyses performed demonstrate that: (i) the DI method and levels of some cholesterol precursors correspond as methods for the study of in vivo cholesterol biosynthesis in humans; (ii) elevations in endogenous cholesterol synthesis (FSR-FC and ASR-FC) are not responsible for the increase in circulating cholesterol levels seen after consumption of the high trans SM, and high SFA rich BT and BL diets; (iii) suppression of cholesterol esterification rates on the SM diet may account for the decreased HDL-C levels observed on this diet and finally; (iv) dysfunction of the ASP pathway, with lower ASP and higher FFA levels could be responsible for the higher secretion of hepatic B 100 particles. In conc

Inaug.-diss.--Jena. / "Anhang" (p. 123-160) contains legislation. "Literatur-verzeichnis": p. 161-163.

Inaug.-diss.--Jena. / "Anhang" (p. 123-160) contains legislation. "Literatur-verzeichnis": p. 161-163.

Orientador: Daniel Barrera Arellano / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-25T11:28:26Z (GMT). No. of bitstreams: 1 Chaves_KamilaFerreira_M.pdf: 1834021 bytes, checksum: 17ab04d365f81e6b3faf3237da71b9f0 (MD5) Previous issue date: 2014 / Resumo: A redução do consumo de ácidos graxos saturados (AGS) na dieta, a fim de reduzir o risco de doenças cardiovasculares, tornou indispensável a busca por substitutos desse tipo de gordura, mediante novas alternativas tecnológicas, como a dos organogéis. O uso de estruturantes em sistemas lipídicos é visto como uma alternativa promissora, pois altera as propriedades físicas de óleos vegetais, sem que ocorram modificações químicas e aumento do teor de AGS, abrindo novas possibilidades para a produção de margarinas e spreads low sat e livres de ácidos graxos trans. O objetivo desse trabalho foi produzir margarinas utilizando a tecnologia de estruturação de óleos para reduzir a quantidade de AGS em comparação às margarinas comerciais convencionais. As matérias-primas, óleo de girassol alto oleico (OGAO), óleo de soja (OS), gordura interesterificada (GI), cera de candelilla (CC) e monoacilgliceróis (M), foram caracterizadas quanto a composição, qualidade e propriedades térmicas. O processo de elaboração das margarinas teste foi realizado em escala de bancada (1 kg), a fase lipídica foi fundida a 80ºC e misturada com a fase aquosa a uma temperatura de 60ºC, sob agitação de 300 rpm. O resfriamento até 30ºC ocorreu sob agitação a 37 rpm em uma sorveteira elétrica com parede de isolamento duplo, previamente resfriada em estufa B.O.D. a 5ºC. As margarinas comerciais avaliadas apresentaram composição de AGS entre 20,52 e 23,93% e teores de lipídios de 70 a 82%. A redução do teor de AGS foi calculada considerando a diferença da quantidade de AGS das margarinas teste em comparação com a média das margarinas comerciais. Foi possível notar através do planejamento experimental que quanto menores os teores de GI, CC e M nas formulações, maior a redução de AGS. As margarinas teste apresentaram melhor estabilidade da emulsão para as temperaturas avaliadas em comparação com as margarinas comerciais. Ocorreu maior exsudação de óleo nas margarinas comerciais em comparação às margarinas desenvolvidas conforme o planejamento experimental na temperatura de 35ºC por 48 horas. As margarinas testadas com OGAO e OS apresentaram menor valor na luminosidade (*L) em comparação às margarinas comerciais. A consistência e a espalhabilidade das margarinas testadas foram significativamente iguais a pelo menos 2/3 das margarinas comerciais avaliadas e a dureza foi estatisticamente igual para todas as margarinas testadas quando comparadas com as margarinas comerciais. Conclui-se que é possível produzir margarinas, mediante a tecnologia de estruturação de óleos, utilizando CC, M e GI como estruturantes, com redução do teor de AGS de 17,3 a 36,6% para as margarinas produzidas com OS e OGAO, respectivamente, em comparação com margarinas comerciais / Abstract: Reduce the consumption of saturated fatty acids (SFA) in the diet in order to reduce the risk of cardiovascular diseases, has made indispensable the search for substitutes for this kind of fat, through new technological alternatives, such as organogels. The use of structuring agents in lipid systems has been presented as a promising alternative, once that they change physical properties without any chemical modification or increase on the amount of SFA, which open new possibilities to the production of low sat and trans free margarines and spreads. The aim of this study was to produce margarines using oil structuring technology in order to reduce the amount of SFA compared to commercial margarines. Raw materials such as high oleic sunflower oil (HOSO), soybean oil (SO), interesterified fat (IF), candelilla wax (CW) and monoacylglycerols (M), were characterized due to their quality parameters, chemical composition and thermal properties. The processing of margarines were conducted in workbench scale (1kg per batch), the oil phase was melted, heating up to 80°C, and then mixed with an aqueous phase at 60°C, under controlled speed at 300 RPM. Cooling up to 30°C occurred under shear at 37 rpm using an electrical ice cream machine with a double wall isolated cube, previously cooled to 5°C. Commercial margarines with a SFA content between 20.52 and 23.93% and 70 to 82% amount of lipids were used as comparative standars. The reduction of SFA was calculated considering the amount of SFA on trial margarines and commercial comparative standards. It was possible to notice, through an experimental design, that smaller amounts of IF, CW and M on the formulations, resulted on reduction of SFA. Trial margarines presented better emulsion stability that commercial products. A higher oil exudation occurred for commercial margarines compared to the trial samples at 35°C for 48 hours. Tested margarines using HOSO and SO presents lower luminosity values (*L) when compared to commercial ones. Consistency and spreadability of trial margarines were statistically equal to, at least, 2/3 of the commercial margarines evaluated and hardness presented no statistical difference among all trial margarines when compared to commercial margarines. In conclusion, margarines produced by oil structuring technology using CW, M and IF as structuring agents, reduced the amount of SFA from 17.3 up to 36.6% in trial margarines with SO and HOSO, respectively when compared to commercial margarines / Mestrado / Tecnologia de Alimentos / Mestra em Tecnologia de Alimentos

No description available.

No description available.

Master of Science / Food Science Institute - Animal Science & Industry / Kelly J. K. Getty / Fats and oils are an important topic in the margarine and spreads industry. The selection of these ingredients can be based on many factors including flavor, functionality, cost, and health aspects. In general, fat is an important component of a healthy diet. Fat or oil provides nine calories per gram of energy, transports essential vitamins, and is necessary in cellular structure. Major shifts in consumption of fats and oils through history have been driven by consumer demand. An example is the decline in animal fat consumption due to consumers’ concern over saturated fats. Also, consumers’ concern over the obesity epidemic and coronary heart disease has driven demand for new, lower calorie, nutrient-rich spreads products. Fats and oils can be separated into many different subgroups. “Fats” generally refer to lipids that are solid at room temperature while “oils” refer to those that are liquid. Fatty acids can be either saturated or unsaturated. If they are unsaturated, they can be either mono-, di-, or poly-unsaturated. Also, unsaturated bonds can be in the cis or trans conformation. A triglyceride, which is three fatty acids esterified to a glycerol backbone, can have any combination of saturated and unsaturated fatty acids. Triglycerides are the primary components of animal and vegetable fats and oils. The ratio of saturated to unsaturated fatty acids in these fats and oils has a great impact on their functionality. Common fats and oils include butterfat, beef tallow, fish oils, soybean oil, rapeseed (canola) oil, corn oil, cottonseed oil, olive oil, sunflower oil, palm oil, palm kernel oil, coconut oil, linseed (flax) oil, and safflower oil. Typical fat and oil modification techniques include hydrogenation, interesterification, alternative hydrogenation, fractionation, blending, farm/field practices and genetic modification, and the use of fat replacers. There are many processing techniques that can be utilized in margarine and spreads production. The process can be optimized for each margarine or spreads product. There are many fats and oils in margarine and spreads formulations. Familiarity with commonly used fats and oils in regards to availability, cost, nutrition, chemistry, and functionality are important when creating a cost-effective, functional margarine or spreads product.

Introdução-- Os fitosteróis (FS) são esteróis de origem vegetal, reconhecidos como componentes funcionais devido ao seu papel hipocolesterolêmico. A recomendação de ingestão diária desses compostos é de 1,6 a 2 g/dia, no entanto há poucos estudos que avaliem os teores desses compostos em alimentos, sendo necessária sua quantificação. Objetivo - O objetivo deste projeto foi desenvolver uma metodologia e determinar os teores de FS em alguns alimentos usualmente consumidos e comercializados em São Paulo. Metodologia Foram avaliadas amostras de creme vegetal sem sal (in natura, e aquecidas a 100o C e 140o C), dos farináceos: farinha de trigo, farinha de milho, farinha de mandioca, amido de milho, café em pó (torras: tradicional, forte e extraforte, descafeinado e gourmet), café solúvel instantâneo, cappuccino e da bebida coada. As amostras, em triplicata, foram submetidas ao processo de saponificação a frio e a matéria insaponificável extraída foi derivatizada e posteriormente injetada em cromatógrafo gasoso. Resultados Os principais FS encontrados foram: -Sitosterol, campesterol e estigmasterol. As maiores médias de teores de FS foram encontradas nos cremes vegetais (186,2 ± 21,7 mg /100g) e nos pós de café moído (92,24 ± 3,95 mg /100g). As farinhas apresentaram teores intermediários, 42,27 ± 7,09 mg /100g; 35,10 ± 10,49 mg /100g; 22,02 ± 1,22 mg /100g; 14,33 ± 3,07 mg /100g para farinha de rosca, milho, trigo e mandioca, respectivamente. As amostras cappuccino (5,73 ± 0,78 mg /100g), café solúvel (4,03 ± 0,84 mg /100g) e amido de milho (3,55 ± 0,8 mg /100g) foram as apresentaram menores teores de FS. Nas amostras de creme vegetal, o processamento térmico reduziu os teores totais de FS das amostras in natura em 10 por cento e 53,7 por cento , para os aquecimentos até 100o C e 140o C, respectivamente. . Não houve influencia do grau de torra e do processo de descafeinização nos teores totais de FS encontrados nas amostras de pó de café moído. Conclusão: De acordo com os resultados obtidos os alimentos com maior teor de fitosteróis são a creme vegetal e o pó de café. Pode-se considerar que o creme vegetal, mesmo sem adição de FS é boa fonte desse nutriente. Nas amostras de café o processamento térmico pouco influenciou nos teores de FS, o mesmo não aconteceu com as amostras de creme vegetal. As mais baixas concentrações de FS foram observadas nas amostras de farinhas, amidos, cappuccino e café em pó solúvel. / Introduction: Phytosterols (PS) are plant sterols, known as functional components due to its hypocholesterolemic role. The recommendation for daily intake of these compounds is 1.6-2 g/day, however there are few studies that evaluate the content of these compounds in foods, requiring its quantification. Objective: the objective of this project was to develop a methodology and determine the content of PS in some foods usually consumed and traded in Sao Paulo. Methodology: Were evaluated samples of: unsalted vegetable cream (in natura, and heated to 100oC and 140oC), farinaceous: wheat, corn and cassava flour, breadcrumbs and cornstarch, powdered coffee (roasts: traditional, strong and extra strong, decaffeinated and gourmet), instant coffee, cappuccino and strained drink coffee. Samples in triplicate were subjected to cold saponification process and unsaponificable matter was extracted, derivatized and subsequently injected into the gas chromatograph. Results: The main PS founded in the samples were: -sitosterol, campesterol and stigmasterol. The highest average levels of PS were found in vegetable creams (186.2 ± 21.7 mg / 100g) and powdered coffee (92.24 ± 3.95 mg / 100g). Farinaceous had intermediate levels, 42.27 ± 7.09 mg / 100g; 35.10 ± 10.49 mg / 100g; 22.02 ± 1.22 mg / 100g; 14.33 ± 3.07 mg / 100g for breadcrumbs, corn, and wheat and cassava flour, respectively. Cappuccino samples (5.73 ± 0.78 mg / 100g), soluble coffee (4.03 ± 0.84 mg / 100g) and corn starch (3.55 ± 0.8 mg / 100g) showed lower levels of PS. In samples of vegetable cream, thermal processing reduced in 10 per cent and 53.7 per cent , for heating up to 100°C and 140°C, the total content of PS comparing with in natura samples. There was no influence of the degree of roasting and decaffeination process in the total levels of PS founded in samples of ground coffee powder. Conclusions: According to the results, in the samples evaluated, foods with the highest content of phytosterols are vegetable cream and powder coffee. Margarine can be considered good source of PS even without it industry addition. The heat treatment did not affected the PS content in the coffee samples, however, the same didn\'t happen with samples of vegetable cream. The lowest concentrations of PS were observed in samples of farinaceous, cappuccino and soluble coffee.