No description available.

No description available.

M.S.

It is thought that the peanut (Arachis hypogaea) originated in South America as peanuts have been found in the ancient burial graves in Peru. From South America they were carried to Arica and then to the United States with the slaves who came from Africa. It has been stated that when peanuts were placed in the hold of an old ship with the slaves, the slaves were in excellent physical condition on arrival for there was no beriberi. The peanut is perhaps the most important oil-bearing seed that is grown and its value as a source of oil has long been recognized. The Dutch buy peanuts from many countries and bring them to Rotterdam, where they crush the, into oil and meal, and barter these products to other countries. Much of their oil was formerly imported into the United States for here the peanut as a source of oil was not realized. Until a few years ago less than 8 percent of the crop was crushed for oil. However, 40 percent of the crop was used for oil in 1940. The “cake” or meal which is left after the oil has been expressed makes an excellent feed for cattle and is used as such to a great extent, particularly in Germany. During the first World War there was a great demand for peanut oil and today the need is felt again. It is stated in the Peanut Journal and Nut World (21) that peanut oil imports from foreign countries in the first six months of the 1940-1941 season decreased about 17 percent from the total reached during the same period of the previous years. Today the Secretary of Agriculture has called upon the peanut farmers of the nation to greatly expand their peanut acreage for the production of oil during the coming year. The goal for 1942 is 3,400,000 acres for peanut oil and 1,600,000 acres for edible use. In 1940 only one fourth of the crop of 200,000 tons of peanuts was used for oil. From each ton of peanuts approximately 600 pounds of oil can be obtained. Peanut oil is used in the United States mainly as an adulterant of or as a substitute for olive oil. It is so excellent in quality that most people cannot detect the difference. Peanut oil is mixed with nearly all the olive oil that comes from the United States. Peanut oil can replace, in part at least, the approximate 10,000,000 pounds of coconut oil that until now has been imported into the country for roasting peanuts, making soap and other uses. Since peanut production has been greatly increased for edible oil, and since so little research has been done on the culinary properties of the oil, a study of these properties seemed advisable. The primary purpose of this experiment was to study the palatability of potato chips, shoestring potatoes and French friend potatoes when fried in peanut oil as compared with those friend in cottonseed oil. The absorption of the oil by the products fried in peanut oil was compared with those fried in cottonseed oil. The changes in the two oils during repeated fryings was compared. These changes were measured by the smoking point, free acidity, and rancidity changes of the oils. Since the oils for this experiment could not be produced under experimental conditions, certain constants were measured in order to know about the qualities of the oils. These included the iodine number, saponification number, free acidity, smoking point and the resistance of the oils to rancidity changes. / Master of Science

Deep-fat fried foods have unique characteristics that attract consumers but their high fat contents must be reduced in order to provide healthy foods along with high quality. In the first part of this study, effects of frying temperature and frying pressure on the quality of partially fried breaded cheese sticks were determined. In the second part, far infrared finish cooking methods were compared to traditional deep-fat frying in terms of product quality. Increasing frying temperature significantly (P<0.05) reduced fat and moisture contents of the samples and increased crispness and exterior hardness. Pressure did not affect crust fat content of the samples significantly (P>0.05). However, increasing frying pressure resulted in the samples having higher moisture contents. Crispness and exterior hardness of pressure-fried cheese sticks were lower than traditional deep-fat fried samples. Increasing frying temperature and pressure resulted in darker sample color. Par-fried far-infrared finish cooked cheese sticks had lower fat contents than deep-fat fried cheese sticks had. Moisture contents of far-infrared finish-cooked samples were higher than those of deep-fat fried samples. Far-infrared finish cooking significantly (P<0.05) reduced crispness and exterior hardness of breaded cheese sticks. / Master of Science

Orientador: Yoon Kil Chang / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-17T11:10:29Z (GMT). No. of bitstreams: 1 VernazaLeoro_MariaGabriela_D.pdf: 8287795 bytes, checksum: a64048a016fa41109e78ee329b64b6fb (MD5) Previous issue date: 2011 / Resumo: A demanda por produtos com melhor qualidade nutricional e funcional tem aumentado nos últimos anos. O mercado de alimentos funcionais está aumentando no Brasil apresentando um crescimento superior a 50 % desde 2002. A soja e seus derivados apresentam grande potencial no mercado de alimentos funcionais, especialmente devido à presença das isoflavonas e ao alto teor protéico. Por outro lado, o amido resistente, considerado como um componente da fibra alimentar, não é digerido pelas enzimas presentes no sistema digestóriio dos seres humanos, mas pode ser fermentado pelas bactérias presentes no cólon, produzindo ácidos graxos de cadeia curta, trazendo benefociios á saúde das pessoas. O mercado mundial de macarrão instantâneo vem crescendo a taxas relativamente altas, maior do que o índice apresentado por sua própria categoria (massas alimentícias). O macarrão instantâneo, por ser um produto frito, contém uma alta porcentagem de óleo. Atualmente existe uma grande preocupação relacionada à saúde e ao consumo de alimentos com alto teor de gordura. Por isso, existe a necessidade de desenvolver produtos com melhor valor nutricional e a importância na utilização de novas tecnologias. A fritura a vácuo é uma forma alternativa de cozimento, a qual aumenta a qualidade dos alimentos desidratados. O objetivo geral deste trabalho visou o desenvolvimento de macarrão instantâneo funcional pela adição de amido resistente e isolado protéico de soja obtidos pelos processos de fritura convencional e a vácuo. Para alcançar o objetivo geral, o trabalho foi realizado em 3 etapas: i) Estudo da adição de sal (0-3 %) e de goma guar (0-1,5 %) na produção de macarrão instantâneo obtido pelo processo de fritura convencional, otimizando-se a formulação através da Metodologia de Superfície de Resposta, para obter um produto com características tecnológicas adequadas (baixo teor de gordura e boa firmeza); ii) Estudo da adição de 10 % de três amidos resistentes comerciais diferentes (Hi Maize 260, Promitor e farinha de banana verde) para estudar as propriedades reológicas e escolher a melhor formulação para obtenção de macarrão instantâneo funcional obtido pelos processos de fritura convencional e a vácuo, visando-se a obtenção de um produto com baixo teor de gordura, boa textura e alto teor final de amido resistente, e por ótimo; iii) Estudo da adição de amido resistente tipo 3 (AR3) (0-16 %) e de isolado protéico de soja (0-16 %) na produção de macarrão instantâneo obtido pelos processos de fritura convencional e a vácuo, visando-se a otimização da formulação através da Metodologia de Superfície de Resposta, com intuito de obter um produto com melhores características tecnológicas (baixo teor de gordura e boa firmeza), funcionais e nutricionais (alto teor de fibra e de proteína). Na primeira etapa, os resultados mostraram que a adição de goma guar e sal à formulação de macarrão instantâneo alteraram as propriedades da massa e a qualidade do produto final. Os maiores valores de absorção de gordura e os menores valores de firmeza foram obtidos quando utilizados valores médios das duas variáveis, enquanto que os menores valores foram alcançados ao utilizar os níveis extremos, ou seja, altos níveis de uma variável e baixos da outra, ou vice versa. Analisando os resultados obtidos no delineamento central composto rotacional (DCCR) foi possível escolher uma formulação adequada para dar continuidade ao estudo. Portanto, foi escolhido como ponto ótimo uma formulação com 0,22 % de goma guar e 2 % de sal para obter macarrões instantâneos de boa qualidade, com um teor de gordura moderadamente mais baixo e uma firmeza intermediária. Na segunda etapa, as misturas de farinha de trigo com 10 % de Hi Maize (HM10) (AR2) e Promitor (Prom10) (AR3) n? afetaram significativamente as propriedades reológicas da massa, quando comparados com a mistura com 10 % de farinha de banana verde (Ban10) que alterou significativamente a estabilidade da massa e o indice de tolerância à mistura. Os macarrões instantâneos Prom10 apresentaram as melhores propriedades tecnológicas, sendo que foram obtidos os menores valores de absorção de gordura e os maiores valores de firmeza, quando comparados com os macarrões instantâneos HM10 e Ban10. De uma forma geral, as amostras obtidas pelo processo de fritura a vácuo apresentaram menor teor de gordura, quando comparados aos macarrões obtidos pelo processo de fritura convencional. Concluindo, foi possível obter macarrões instantâneos funcionais com as três formulações diferentes estudadas, pois as amostras apresentaram um teor de amido resistente maior que 3 %, podendo ser declarados como fonte de fibra pela legislação brasileira. Na terceira etapa, as superfícies de resposta mostraram que a adição de amido resistente AR3 e de isolado protéico de soja diminuiu a absorção de gordura quando utilizados os dois processos de fritura (convencional e vácuo). No entanto, os macarrões instantâneos obtidos pelo processo de fritura convencional apresentaram teores de gordura maiores (18,28 - 25,09 %) do que os obtidos pelo processo de fritura a vácuo (18,08 e 22,26 %). Em ambos os processos foi possível obter macarrões instantâneos com um teor de amido resistente significativo (acima de 3 % para todos os ensaios). Na analise de textura, os macarrões obtidos pelo processo de fritura convencional apresentaram uma firmeza maior do que os obtidos pelo processo de fritura a vácuo. As superfícies de resposta mostraram que a adição de amido resistente e de isolado protéico de soja afetaram a firmeza dos macarrões devido à diluição das proteínas do glúten, apresentando macarrões menos firmes. Finalmente, independente do processo de fritura utilizado, ao adicionar 12 % de AR3 e 8 % de IPS foi possível desenvolver um produto funcional com alto teor de fibras, alto teor de proteínas, presença de isoflavonas e com um perfil de aminoácidos melhorado / Abstract: A higher demand for products with better quality has increased the use of new ingredients and new technologies. Therefore, nowadays, there is a greater demand for functional foods. The functional food market is growing in Brazil, showing a 50 % increase since 2002. Soybean and its derivatives present good potential in the functional food market, especially due to the presence of isoflavones and the quality of its protein and polypeptides. On the other hand, resistant starch, considered as a food fiber component, is poorly digested by the enzymes present in the human digestive system, but can be fermented by bacteria present in the colon, producing short chain fatty acids that provide health benefits to the consumer. The world instant noodle market has been growing at relatively high rates, higher than the rate presented by the category as a whole. Since they are fried products, instant noodles contain high levels of residual oil. Currently, there is a considerable concern about health with respect to the consumption of high fat foods. Therefore, there is a need to develop products with enhanced nutritional value and the use of new technologies. The vacuum frying process is an alternative way of cooking, which increases the quality of dehydrated foods when compared to the conventional deep-frying process. The objective of the present work was to develop instant noodles with functional properties, using both conventional and vacuum frying processes to reduce oil absorption and hence caloric content, by the partial substitution of wheat flour with soy protein isolate and resistant starch. To achieve the overall objective, the work was divided into three stages: i) Study of the addition of salt (0-3 %) and guar gum (0-1.5 %) in the production of instant noodles optimizing the formulation by Response Surface Methodology to obtain a product with appropriate technological characteristics (low in fat and good texture); ii) Study of the addition of 10 % of three different commercial resistant starches, such as Hi Maize (HM) (RS2), Promitor (Prom) (RS3) and green banana flour (GBF) to analyze the rheological properties to produce the best formulation of functional instant noodles obtained by both conventional and vacuum frying, in order to obtain a product with adequate technological properties (low in fat, good texture and high content of resistant starch), and finally, iii) Study of the addition of type 3 resistant starch (RS3) (0-16 %) and soy protein isolate (0-16 %) in the production of instant noodles obtained by conventional and vacuum frying, in order to optimize the formulation by Response Surface Methodology with the objective of obtaining a product with adequate technological properties (low fat and good texture) and high nutritional value (high fiber and protein). In the first stage, the results showed that the addition of guar gum and salt to instant noodles formulation changed the properties of the dough and the final product quality. The highest values of fat absorption and the lowest values of firmness were obtained when intermediate levels of the two variables were used, whereas the lowest values were achieved when using the extreme levels, i.e. high levels of one variable and low of the another, or vice versa. Analyzing the results obtained from the central composite rotational design (CCRD) it was possible to choose a suitable formulation to continue the next stages. Therefore, the instant noodles considered optimum in this stage contained 0.22 % guar gum and 2 % salt, resulting in a product of good quality, with significant lower fat content and intermediate firmness. In the second stage, mixtures of wheat flour with 10 % Hi Miaze 260 (HM10) (RS2) and Promitor (Prom10) (RS3) did not significantly affect dough¿s rheological properties when compared to the mixture with 10 % green banana flour (Ban10), that changed drastically the dough stability and the mixing tolerance index. Prom10 noodles presented the best technological properties, obtaining the lowest values of fat absorption and the highest values of firmness. In general, samples obtained by the vacuum frying process had lower fat content, compared to the samples obtained by the conventional frying process. Using the three different formulations, it was possible to obtain functional instant noodles because all samples presented a resistant starch content higher than 3 %, being possible to be claimed as source of fiber according to the Brazilian Legislation. In the third stage, the response surfaces showed that the addition of both resistant starch and soy protein isolate decreased fat absorption when using both frying processes (conventional and vacuum). However, instant noodles obtained by the conventional frying process presented higher levels of fat than those obtained by vacuum frying. In both cases there was a decrease in resistant starch content. In the texture analysis, noodles obtained by the conventional frying process presented higher firmness values than those obtained with the vacuum frying process. The response surfaces showed that resistant starch and soy protein isolate addition affected the firmness of noodles because of the dilution of gluten proteins, showing noodles with lower firmness. In conclusion, regardless of the frying process used in this study, when added 12 % of RS3 and 8 % of soy protein isolate, it was possible to develop a functional product with high fiber content (close to 8 %), high protein content (close to 11 %), isoflavones and with an improved amino acid profile / Doutorado / Doutor em Tecnologia de Alimentos

Made available in DSpace on 2015-04-17T14:49:16Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1626606 bytes, checksum: a9be7e6bd60626dd0adc197b46b4c922 (MD5) Previous issue date: 2007-12-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work deals with the quality of vegetable oils. Thus, refined oils from soybean (Glycine max L), both conventional and transgenic, and the crude and refined oils of nhandiroba (Fevillea trilobata L) were investigated. All the oil samples were studied before, during and after the frying process. The oxidative process of these oils was also quantified. With this purpose, the vegetable oils were submitted to the temperature (180 ± 50 oC) in recipients of glass, aluminum, iron and stainless steel. The oil samples were collected in aliquots of 10 ml each, at time intervals of 0, 8, 24, 48 and 72 hours. The analyses of acid value, iodine value, peroxide value, panisidine content and color were carried out. The quantification of the iron and aluminum ions was undertaken by atomic absorption. The quantification of a- tocopherol in crude nhandiroba oil was determined by HPLC. The thermal stability of the oils was assessed using the thermogravimetric curves and the chromatograms of the studied oil samples. The toxicological properties were evaluated; as well organoleptic tests were performed. In vivo laboratorial tests studied the icthyotoxicity in Poecilia reticulata L. alevins and the cytotoxicity in Artemia saline L. larvae. In the sensorial analysis hedonic tests were applied and the following attributes were appraised: aspect, flavor, scent and texture of chicken and fish croquettes. The croquettes were fried in recipients of glass, utilizing refined conventional soybean and nhandiroba oils. The results showed that all the oils investigated during the 72 hours of frying, in the four types of recipients, displayed increasing figures of peroxide value, p-anisidine content and color. The acid value varied, whereas the iodine value decreased. The vegetable oil made from conventional soybean presented important oxidative alterations, when submitted to a heating time of 72 consecutive hours in the four different types of frying recipients. In the recipients of iron and stainless steel, such differences were larger than in the aluminum and glass recipients. The results of the transgenic soybean oil, crude and refined nhandiroba oils showed mild oxidative modifications in all the four types of recipients tested. In the frying process, the physico-chemical properties of the vegetable oils influenced the sensorial profile of the victuals. It was observed for the sensorial property aspect that there was no meaningful difference between the two oil types, in other words, the aspects of the fried croquettes in the two oils were considered to be the same. In the evaluation of the attributes scent, texture and flavor, it was noticed, for the chicken croquettes, a difference between the two oil types. The conventional soybean oil was better accepted, obtaining the best notes. In the frying of the fish croquette, the nhandiroba oil displayed the best sensorial characteristics. Therefore, in the frying process the cooking recipients of glass, aluminum, iron and stainless steal exert a deleterious influence on soybean oils, as well as on nhandiroba oils. The iron recipient is the one that provokes the largest oxidative effect and the glass recipient the one with the smallest oxidation damage. These alterations, which took place in the investigated oils, influence their quality. / Nesta pesquisa foi analisada a qualidade dos óleos refinados de soja (Glycine max L.) convencional e transgênico (MSOY 8866RR) e do óleo bruto e refinado de nhandiroba (Fevillea trilobata L.) antes, durante e após os processos de frituras e também foram quantificados seus processos oxidativos. Os óleos foram submetidos à temperatura (180 ± 50C) em recipientes de vidro, alumínio, ferro e inox. As amostras de óleos foram coletadas em volumes de 10 mL cada, nos intervalos de tempo de 0, 8, 24, 48 e 72 horas. Nas amostras dos óleos foram realizadas análises de índice de acidez (IA), índice de Iodo (II), índice de peróxido (IP), valor de panisidina (VA) e cor. A quantificação dos íons ferro e alumínio foi realizada através de absorção atômica. A quantificação de a-tocoferol foi realizada no óleo de nhandiroba bruto por HPLC. O estudo da estabilidade térmica foi verificado através das curvas termogravimétricas e dos perfis cromatográficos dos óleos. Ainda, foram realizados estudos das propriedades toxicológicas e avaliações organolépticas dos óleos. Os testes laboratoriais in vivo de ictiotoxicidade sobre alevinos Poecília reticulata L. e citotoxicidade sobre larvas de Artemia salina L. foram realizados nos óleos. Na análise sensorial foram aplicados testes hedônicos para os atributos: aspecto, sabor, odor e textura em croquete de frango e de peixe, em recipiente de vidro nos óleos refinados de soja convencional e de nhandiroba. As análises dos resultados mostraram que, os óleos pesquisados durante as 72 horas de fritura nos quatro tipos de recipientes utilizados apresentaram taxas de IP, VA e cor crescentes, variação no IA e valores decrescentes de II. No óleo de soja convencional foram ocorridas alterações oxidativas relevantes, quando submetido ao tempo de aquecimento de 72 horas consecutivas nos quatro diferentes tipos de recipientes de fritura, sendo que em recipiente de ferro e inox essas alterações foram maiores do que em recipientes de alumínio e vidro. Nas análises dos óleos de soja transgênico, nhandiroba bruto e refinado foram verificadas modificações oxidativas brandas nos quatro tipos de recipientes testados. No processo de fritura, também, foi observado para a propriedade sensorial aspecto, que não houve diferença entre os croquetes de frango e peixe. Na avaliação dos atributos odor, textura e sabor, foi constatado que na fritura do croquete de frango foi registrado diferença entre os tratamentos, o óleo de soja convencional foi mais aceito, obtendo as melhores notas. O croquete de peixe frito no óleo de nhandiroba apresentou as melhores características sensoriais. Portanto, no processo de fritura os recipientes de vidro, alumínio, ferro e inox exercem diferentes efeitos deletérios nos óleos de soja e nhandiroba, sendo o recipiente de ferro o que provoca maior efeito oxidativo no óleo e o de vidro, o menor dano de oxidação. Estas alterações ocorridas nos óleos pesquisados influenciam na sua qualidade.

Master of Science / Department of Food Science / Delores Chambers / Research has shown that trans fat consumption increases the levels of low-density lipoprotein (LDL) and has a direct correlation to the incidence of heart disease. It is now widely believed that trans fat intake adversely affects the health of consumers. A Food and Drug Administration (FDA) ruling, effective January 1, 2006, required declaration of trans fat content on all Nutrition Facts labels of food products. Around the same time local governments, such as the city of New York, and some restaurants followed suit by eliminating trans fats from their menus. The food industry’s initial concern with trans fat elimination/reduction was the loss of some functionality such as shelf life, stability, and creaming ability with trans-free fats and oils. Researchers are working to develop new trans-free fats and oils that do not have negative sensory properties and maintain the functionality of traditionally hydrogenated oils when used in baked and fried goods. This is an overview of the chemistry, health risks, and research that has been performed to either reduce or eliminate trans fats in food products.

O objetivo do estudo foi avaliar o efeito da utilização de película de metilcelulose e das atmosferas de acondicionamento com ar atmosférico, vácuo e argônio sobre a conservação de batatas minimamente processadas (MP) e também sobre sua qualidade após fritura. Tubérculos foram selecionados, lavados, sanificados, cortados na forma de palitos e tratados com ácido cítrico. As batatas foram imersas em solução filmogênica contendo metilcelulose (1%) e sorbitol (0,75%) como plastificante, com posterior secagem, acondicionadas sob ar atmosférico, e modificada com argônio (20seg. e 230mmHg), além de vácuo (15seg. e 54mmHg). O produto MP armazenado a 8°C durante 12 dias foi avaliado em intervalos de 3 dias mediante análises microbiológicas, fisiológicas, físicoquímicas e físicas. A cada 3 dias as batatas MP foram também fritas e avaliadas quanto à perda de umidade, absorção de óleo, textura instrumental e avaliação sensorial. O acondicionamento sob ar atmosférico foi efetivo em reduzir a perda de massa das batatas MP. As embalagens sob vácuo foram mais efetivas para o produto MP sem película, pois mantiveram o pH, acidez titulável, teor de amido e de açúcares mais próximos do dia do início do experimento, como também mantiveram baixo o índice de escurecimento. O acondicionamento sob vácuo, entretanto, não seria indicado quando a finalidade fosse a fritura, pois foi o tratamento que apresentou maiores perdas de umidade e maior absorção de óleo. O acondicionamento sob atmosfera de argônio também foi mais efetivo nas batatas MP sem película, sendo fator determinante em reduzir os teores de CO2 no interior da embalagem, apresentou menor taxa respiratória, menor índice de escurecimento tanto antes como após a fritura, reduziu a perda de umidade durante a fritura, manteve mais a firmeza do produto frito e também minimizou a absorção de óleo a partir do 3° dia de armazename nto. A utilização de película foi efetiva em reduzir a respiração do produto MP até o 6° dia. Já no produto frito, foi fator determinante na retenção de umidade das batatas, como também na redução, ao longo do armazenamento, da absorção de óleo / The aim of this study was to evaluate the effect of methylcellulose as edible coating and packaging atmospheres with atmospheric air, vacuum and argon on the conservation of minimally processed (MP) potatoes as well as on their quality after frying. Tubers were selected, washed, sanitized, cut in the shape of sticks and treated with citric acid. Potatoes were immersed in a filmogenic solution of methylcellulose (1%) with sorbitol (0,75%) as a plasticizer, dehydrated, and then packaged under atmospheric air, and modified with argon (20seg. e 230mmHg), and vacuum (15seg. e 54mmHg). Stored MP product at 8°C for 12 days was assessed at intervals of 3 days by microbiological, physiological, physicochemical and physical analyses. Every 3 days the MP potatoes were fried and evaluated for moisture loss, oil absorption, instrumental texture and sensory evaluation. Packaging under atmospheric air was effective in reducing the mass loss of MP potatoes. The vacuum packaging was more effective for the MP product without edible coating, because they kept the pH, acidity, starch and sugar level more similar to the first day experiment, as well as low browning rate. The vacuum packaging, however, would not be appropriate when the purpose is frying, because this treatment showed the greatest loss of moisture and increased oil absorption. Packaging under argon atmosphere was also more effective for the MP product without edible coating, and it was an important factor to reduce CO2 levels inside the package, showed lower respiratory rate, lower browning index both before and after frying, reduced moisture loss during frying, kept fried product firmness better and also minimized oil absorption from the 3rd day of storage. The use of edible coating was effective in reducing the respiration of MP product until the 6rd day. For the fried product, the use of coating was a determining factor for moisture retention during frying of potatoes, and also to decrease oil absorption along the potato storage.

Os óleos vegetais constituem-se uma das fontes mais acessíveis da vitamina E pela população, sendo que o Brasil ocupa posição de destaque na América Latina como produtor e consumidor de óleos vegetais. Atualmente, dentre os óleos de maior consumo estão soja, palma, canola e girassol. As isoformas de vitamina E compreendem uma classe de oito compostos distintos denominados tocoferóis e tocotrienóis, sendo o &alpha;-tocoferol a isoforma de maior notoriedade, por sua conhecida ação antioxidante em sistemas biológicos e também como antioxidante natural na indústria de alimentos. A eficiência nutricional de um composto pode estar relacionada com a bioacessibilidade. Bioacessibilidade é a fração do nutriente que é liberada da matriz alimentar para a região gastrointestinal e está passível de absorção, podendo ser afetada por diversos fatores relacionados à própria matriz alimentar. Dessa forma, o objetivo desse estudo foi inicialmente quantificar as isoformas de vitamina E em quatro óleos refinados (girassol, canola, palma e milho) e avaliar a bioacessibilidade da vitamina E nesses óleos antes e após tratamento térmico. O tratamento térmico utilizado foi a fritura contínua em batatas (1 h a 180°C). Foi realizada a caracterização físico-química dos óleos vegetais refinados, antes e após o processo de fritura e verificado parâmetros de qualidade dos óleos. Para isso foram realizadas as análises de umidade da batata, teor de ácidos graxos livres, índice de peróxidos, composição em ácidos graxos e estabilidade oxidativa. A quantificação das isoformas de vitamina E foi realizada por CLAE acoplada ao detector de fluorescência, e para a determinação da bioacessibilidade da vitamina E, foi utilizado um modelo in vitro com cultivo de células Caco-2. O óleo de palma apresentou bioacessibilidade superior aos demais óleos estudados, seguido do óleo de milho, canola e girassol. A fritura contínua por 1 hora reduziu significativamente os teores totais de tocoferóis e tocotrienóis, e influenciou positivamente sobre a vitamina E na fração bioacessível. / The vegetable oils are one of the most acessible sources of vitamin E by the population, and Brazil occupies the leading position in Latin America as a producer and consumer of vegetable oils. Currently, soybean, palm, canola and sunflower oils are among the most consumed oils. The vitamin E isomers comprise the class of eight distinct components called tocopherols and tocotrienols, with &alpha;-tocopherol being the most notorious isomer, due to its known antioxidant action in biological systems and also as a natural antioxidant in the food industry. The nutritional efficiency of compounds may be related to bioaccessibility. Bioaccessibility is the fraction of the nutrient that is released from the food matrix into the gastrointestinal region and is passible toabsortion, which can be affected by several factors related to the food matrix. Thus the objective of this study was to quantify vitamin E isomers in four refined oils (sunflower, canola, palm and corn) and to evaluate the its bioaccessibility in these oils before and after heat treatment. The heat treatment used was the continuous frying of potatoes (1 h at 180 °C). The physico-chemical characterization of refined vegetable oils before and after the frying process was carried out, and the quality parameters of the oils were verified. For this, the potato moisture and the content of free fatty acids, peroxide index, fatty acid profile of the oils were carried out. Quantification of vitamin E isomers was performed by HPLC coupled to a fluorescence detector, and an in vitro model of Caco-2 cell culture was used to determine the bioacessibility of vitamin E. Palm oil had higher bioaccessibility than corn, canola and sunflower oil. Continuous frying for 1 hour significantly reduced the total contents of tocopherols and tocotrienols, and positively influenced by the vitamin E in the bioaccessible fraction.