Orientador: Eduardo Augusto Caldas Batista / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-12T23:16:20Z (GMT). No. of bitstreams: 1 Dalmolin_IredeAngelaLucini_M.pdf: 1335976 bytes, checksum: d9b7b355cbf37e6ff34460cbdc41bfd5 (MD5) Previous issue date: 2009 / Resumo: A extração do óleo do farelo agrega valor à produção de arroz. Este óleo possui propriedades nutricionais e nutracêuticas, portanto, o interesse de indústrias em seu uso. A desacidificação do óleo pode ser realizada por extração líquido¿líquido com baixas perdas de óleo neutro, principalmente no caso de óleo com alto conteúdo de ácidos graxos livres. Nestes processos, um solvente parcialmente miscível, como etanol ou etanol hidratado, é utilizado para extrair os ácidos graxos livres do óleo bruto. Por outro lado, questões ambientais e energéticas têm voltado à atenção para o uso de óleos vegetais na produção de biodiesel por reação de transesterificação. O conhecimento do equilíbrio líquido¿líquido como de sistemas graxos é uma importante etapa na otimização da produção de óleo comestível por extração líquido¿líquido ou de produção de biodiesel por reação de transesterificação. Deste modo, este trabalho teve por objetivo determinar experimentalmente dados de equilíbrio líquido-líquido de sistemas compostos por óleo de farelo de arroz refinado / etanol anidro / água / hexano a (25 e 40) ºC e ajustar os parâmetros do modelo NRTL aos dados experimentais. A técnica de espectroscopia no infravermelho próximo (NIR) foi utilizada para quantificar os componentes nas fases. Para evitar a separação de fases na amostragem dos sistemas a 40 ºC, a diluição com tetrahidrofurano das amostras das fases foi investigada. Todos os sistemas estudados neste trabalho apresentaram desvios de balanço de massa global menores que 0,5 %, e desvios na correlação pelo modelo NRTL menores que 1,0 %. Estes resultados indicam a boa qualidade dos dados experimentais e que a técnica de espectroscopia no NIR fornece bons resultados mesmo quando os componentes estão em pequeno conteúdo na mistura / Abstract: The extraction of oil from rice bran aggregates value to the rice production. This oil has nutritional and nutraceutical properties, therefore, the interest of the industries in its use. The oil deacidification can be carried out by liquid¿liquid extraction with lower loss of neutral oil, mainly in the case of oil with high content of free fatty acid. In this process, a partially miscible solvent, such as ethanol or hydrated ethanol, is used to extract the free fatty acids from crude oils. Moreover, environmental and energy issues have focused attention to the use of vegetable oils in biodiesel production by transesterification reaction. The knowledge of the liquid¿liquid equilibrium of such fatty systems is an important stage in the optimization of the production of edible oil by liquid¿liquid extraction or the production of biodiesel by transesterification reaction. Thus, this work aims to determine experimental data from liquid-liquid equilibrium of systems containing refined rice bran oil / anhydrous ethanol / water / hexane at (298.15 and 313.15) K and to adjust the parameters of NRTL model to the experimental data. The technique of near infrared spectroscopy (NIR) was use to quantify the components in the phases. To avoid phase separation in sampling for system at 313.15 K, the dilution of the phases with tetrahydrofuran was investigate. All systems studied in this work presented overall mass balance deviations lower than 0.5 % and deviations in correlation by NRTL model lower than 1.0 %. These results indicate the good quality of the experimental data and that the NIR gives good results even when the components are in low content in the mixture / Mestrado / Mestre em Engenharia de Alimentos

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-10-30T20:37:57Z No. of bitstreams: 2 Dissertação - Lairy Silva Coutinho - 2013.pdf: 3072078 bytes, checksum: 9e9c2f3a2bf45cb601d6984d4246199d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-31T09:29:39Z (GMT) No. of bitstreams: 2 Dissertação - Lairy Silva Coutinho - 2013.pdf: 3072078 bytes, checksum: 9e9c2f3a2bf45cb601d6984d4246199d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-31T09:29:39Z (GMT). No. of bitstreams: 2 Dissertação - Lairy Silva Coutinho - 2013.pdf: 3072078 bytes, checksum: 9e9c2f3a2bf45cb601d6984d4246199d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-07-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The rice processing industries currently designed its most byproducts generated during processing, such as rice bran and broken rice grains for animal feed. However, they are nutritionally rich and interesting human consumption. Therefore, it becomes interesting to use these for the development of new products. The soy industry also uses okara (residue coming from the aqueous extract of soy) more for animal feed. For human consumption is less used, although it has high content of protein, lipids and is a source of energy. Thus, this study aimed to formulate snacks and pre-gelatinized flour with coproducts broken grains and rice bran and soybean okara black and study the effect of extrusion variables (temperature and humidity) on the physical, chemical and technological characteristics of products, processed under various humidity (12 to 20 g.100 g-1) and extrusion temperatures (60 to 110 °C). For these analyzes was used official methodologies. Was performed desirability of snacks considering expansion index, specific volume and color parameter chroma a *. The snack of higher desirability was prepared at moisture condition in the mixture of 12 g.100 g-1 and at temperature of 85 ° C. As for the pre-gelatinized flour, moisture conditions for extrusion of mixtures influenced the viscoamilograficos aspects and texture, and milder temperatures employed were obtained with higher values of initial viscosity (above 4000 cP), final viscosity (above 5500 cP) and setback (above 4500 cP). The absorption and solubility in water and oil absorption are also affected, and the higher results in higher extrusion temperatures and lower humidities. The pre-gelatinized flour byproducts of rice and soybeans can be an alternative to the industry by adding value to them, which after processing will enable the development of an ingredient in many products for human consumption. / As indústrias de beneficiamento de arroz atualmente destinam a maior parte dos coprodutos gerados, tais como farelo de arroz e grãos quebrados de arroz para as indústrias de ração animal. Porém, esses são ricos nutricionalmente e interessantes ao consumo humano. Portanto, torna-se interessante o seu aproveitamento para desenvolvimento de novos produtos. A indústria de soja também utiliza o okara (resíduo oriundo do processamento do extrato aquoso da soja) mais para ração animal. Para alimentação humana é menos utilizado, embora possua alto teor de proteína, lipídeos e seja fonte de energia. Assim, este trabalho objetivou formular snacks e farinhas pré-gelatinizadas com os coprodutos grãos quebrados e farelo de arroz e okara da soja preta e estudar o efeito das variáveis de extrusão (umidade e temperatura) sobre as características físicas, químicas e tecnológicas desses produtos, processados sob diferentes umidades (12 a 20 g.100 g-1) e temperaturas de extrusão (60 a 110 °C). Para estas análises utilizaram-se metodologias oficiais. Foi realizado desejabilidade dos snacks considerando índice de expansão, volume específico e parâmetro de cor croma a*. O snack de maior desejabilidade foi elaborado na condição de umidade da mistura de 12 g.100 g-1 e temperatura de 85 °C. Quanto à farinha pré-gelatinizada, as condições de umidade das misturas para extrusão influenciaram nos aspectos viscoamilográficos e de textura, sendo que nas temperaturas empregadas mais brandas se obtiveram valores mais elevados de viscosidade inicial (acima de 4000 cP), viscosidade final (acima de 5500 cP) e tendência a retrogradação (acima de 4500 cP). A absorção e solubilidade em água e absorção de óleo também foram influenciadas, sendo os maiores resultados obtidos sob temperaturas de extrusão mais elevadas e umidades mais baixas. A farinha pré-gelatinizada dos coprodutos de arroz e soja pode ser uma alternativa para a indústria, por agregar valor a estes, que depois de processados poderão possibilitar o desenvolvimento de ingredientes para diversos produtos para alimentação humana.

Orientador: Eduardo Augusto Caldas Batista / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T16:41:52Z (GMT). No. of bitstreams: 1 Ansolin_Marina_M.pdf: 2006299 bytes, checksum: 85ab382490105e2f51c9502c620b007a (MD5) Previous issue date: 2012 / Resumo: Os óleos vegetais, em sua grande maioria, quando destinados ao consumo humano necessitam passar pelas etapas de refino, visando à retirada de substâncias indesejáveis. Das etapas do refino, a desacidificação ou retirada de ácidos graxos livres é a mais importante e normalmente é realizada pelo método químico ou físico. Uma alternativa para a desacidificação é a extração líquido-líquido ou refino com solvente. Nesse processo ocorrem reduções significativas de perda de óleo neutro, além de ser conduzida à temperatura ambiente e pressão atmosférica, reduzindo custos energéticos. O óleo vegetal resultante apresenta teores aceitáveis de ácidos graxos livres, sabor e odor brando e redução das perdas de compostos minoritários desejáveis como os tocoferóis e tocotrienóis (tocóis), que são antioxidantes naturais presentes nos óleos vegetais. Com base no exposto, o objetivo desse trabalho é a determinação de dados experimentais de equilíbrio líquido-líquido de sistemas graxos, com ênfase na distribuição de tocoferóis e tocotrienóis. Os sistemas graxos estudados foram óleo de soja degomado + ácido linoléico comercial + etanol anidro, óleo de soja degomado + ácido linoléico comercial + etanol + água, óleo de farelo de arroz + ácido oléico comercial + etanol anidro e óleo de farelo de arroz refinado + ácido oléico comercial + etanol + água. Os experimentos foram realizados nas temperaturas de 298,15 K, 313,15 K e 323,15 K. A partir dos resultados obtidos, verificou-se que a solubilidade mútua do óleo vegetal + solvente (etanol anidro ou etanol + água) e o coeficiente de distribuição dos tocóis foram afetados pela temperatura, concentração de ácidos graxos livres e presença de água. Quanto maior a temperatura e teor de ácidos graxos livres, maior o coeficiente de distribuição dos tocóis devido ao aumento da solubilidade entre os componentes do sistema. Em contrapartida, quando adicionado água ao etanol, o coeficiente de distribuição dos tocóis diminui, fazendo com que eles fiquem mais retidos na fase oleosa / Abstract: Vegetable oils, mostly, when for human consumption, need to be refined, with the objective of removal of undesirable substances. Deacidification or free fatty acid removal is the most important step and it is usually performed by physical or chemical method. An alternative to deacidification is the liquid-liquid extraction or solvent refining. In this process, significant reductions of loss of neutral oil occur, and it is conducted at room temperature and atmospheric pressure, reducing energy cost. The resulting vegetable oil has acceptable levels of free fatty acids, mild taste and odor and reduction in the losses of desirable minor compounds, such as tocopherols and tocotrienols (tocols), which are natural antioxidants present in vegetable oils. Based on the exposed, the objective of this study is the determination of experimental data for liquid-liquid equilibrium of fatty systems, with emphasis on the distribution of tocopherols and tocotrienols. The fatty systems studied were composed by degummed soybean oil + commercial linoleic acid + anhydrous ethanol, degummed soybean oil + commercial linoleic acid + ethanol + water, refined rice bran oil + commercial oleic acid + anhydrous ethanol and refined rice bran oil + commercial oleic acid + ethanol + water. The experiments were performed at temperatures of 298.15 K, 313.15 K and 323.15 K. From the results obtained, it was found that the mutual solubility between vegetable oil and solvent (ethanol or ethanol + water) and the distribution coefficients of the tocols were affected by temperature, concentration of free fatty acids and the water presence. The higher the temperature and free fatty acid content, higher the distribution coefficients of tocols, due to the increase of solubility among the components of the systems. In contrast, the distribution coefficients of tocols decrease when water is added to ethanol, which represents the increase in retention of tocols in the oil phase / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos

Made available in DSpace on 2014-08-20T14:38:44Z (GMT). No. of bitstreams: 1 Dissertacao_Juliana_Girardon.pdf: 735964 bytes, checksum: 63e3eac19eea956ffade85e6e6de5e54 (MD5) Previous issue date: 2011-03-25 / This study aimed to investigate four forced-moulting methods on productive performance and egg quality of brown-egg layers. A total of 448 100 week-old laying hens were fed experimental diets during 148 days (from August to December of 2009). The experimental design was a completely randomized block design, with 16 replicates per treatment. Treatments consisted of: 1) fasting during 14 days; 2) soybean hulls based diet; 3) wheat bran based diet and 4) High tannin sorghum based diet. A post-moulting corn-soybean meal basal diet, formulated to fulfill nutrient requirement of birds was fed to the animals. Hens fed alternative ingredient based diets showed better performance. Productive performance, viability and decrease in egg production were similar between hens fed the soybean hulls based diet and those exposed to fasting. Birds fed high tannin showed lower mortality, but showed a lower egg production. Birds fed alternative ingredients showed 12% egg production at 6 days after the beginning of the experiment. These results indicate that hens fed alternative ingredient sources showed better performance than those exposed to fasting at the end of the first productive cycle. / Objetivou-se avaliar e verificar o desempenho produtivo, a eficiência da muda forçada e a qualidade dos ovos de poedeiras comerciais semipesadas de linhagem comercial, com 100 semanas de idade inicial, submetidas a quatro métodos nutricionais de muda forçada. O experimento foi realizado entre agosto de 2009 em dezembro de 2009, compreendendo 142 dias experimentais, utilizando-se 448 aves. O delineamento experimental utilizado foi completamente casualizado, com quatro tratamentos distribuídos por sorteio dentro das baterias, compostos por: 1) jejum de 14 dias; 2) ração à base de casca de soja; 3) ração à base de farelo de trigo e 4) ração à base de sorgo alto tanino, sendo cada tratamento com 16 repetições. As aves foram distribuídas em 64 gaiolas com sete aves em cada. A dieta basal do pós muda foi formulada à base de milho e farelo de soja, com níveis nutricionais estabelecidos pelo manual da linhagem de acordo com a fase produtiva. Foi observado melhor desempenho durante a muda, nas aves que receberam dietas alternativas. Para as variáveis produtivas analisadas, viabilidade do lote e queda de postura, as aves que receberam alimentação à base de casca de soja tiveram desempenho semelhante ao das aves em jejum, quando comparadas aos animais que receberam os demais alimentos. O uso de sorgo com alto tanino reduziu de forma notável a mortalidade entre as aves, entretanto não tem o efeito desejado sobre a redução na taxa de postura. Com níveis de postura considerados de 12%, as aves submetidas aos protocolos alternativos atingiram este nível em aproximadamente seis dias após o início da muda forçada. Assim, é possível substituir o método convencional de muda (jejum prolongado), por métodos alternativos que não são tão degradantes fisiologicamente e nem no bem estar animal para as poedeiras comerciais no fim do primeiro ciclo produtivo.

Cette étude a fait l'objet de deux parties. L'une porte sur l'effet de différents types d'activation (chimique, thermique, mécanique) de kaolins (géo-matériaux riches en kaolinite) sur leurs propriétés de décoloration vis-à-vis de l'huile de riz. L'autre traite de l'effet de la taille et de la morphologie de kaolinites de synthèse sur leurs propriétés d'adsorption.Cette étude a montré que lorsque le kaolin était chauffé à plus de 100°C avant de subir une activation acide en milieu sulfurique, citrique ou oxalique, la capacité de décoloration vis-à-vis de l'huile de riz était fortement réduite. Cet effet a été directement mis en relation avec la destruction partielle ou totale de la structure de la kaolinite, associée à une forte lixiviation de l'aluminium de l'échantillon et à la précipitation de silice amorphe. Il s'est donc avéré que la préservation des sites aluminols présents sur les surfaces externes des particules de kaolinites semblait être un critère primordial à conserver en vue d'obtenir de bonne capacité de décoloration. Dans ce contexte, les meilleures capacités de décoloration (82% environ) ont été obtenues en utilisant conjointement un traitement thermique modéré (<100°C), un broyage mécanique de l'échantillon avant l'étape d'activation acide, une concentration en acide de l'ordre de 0.3 à 0.5 mol/L et un rapport (argile)/(solution acide) de l'ordre de 1/50. Notons que les plus fortes valeurs de surfaces spécifiques n'ont pas forcément été associées aux échantillons présentant les meilleures capacités de décoloration en raison de la présence de silice amorphe et de la non-préservation des sites aluminols de la kaolinite ; sites responsables de l'adsorption des pigments de molécules de chlorophylle-a.Par ailleurs, aucune étude à notre connaissance ne reliait directement les morphologies de particules de phyllosilicates à leurs propriétés d'adsorption vis-à-vis de deux cations inorganiques. Dans le cas des kaolinites naturelles, une charge permanente souvent significative et attribuable à des impuretés minéralogiques empêche toute tentative de relier directement la forme des particules à un coefficient de sélectivité entre deux cations pour des sites latéraux donnés. Des kaolinites ont donc été synthétisées par voie hydrothermale en considérant différentes conditions physico-chimiques, afin d'obtenir des morphologies variées (hexagones plus ou moins anisotropes). Pour ces échantillons synthétiques pour lesquels aucune impureté minéralogique et charge permanente n'a été détectée, des isothermes expérimentales d'adsorption entre Na+ et H+ ont été mesurées. Ces cations ont été choisis étant donné leur présence ubiquiste dans les eaux naturelles et leur fort pouvoir compétiteur par rapport aux cations traces métalliques. Grâce aux surfaces spécifiques des sites latéraux et des densités de site issues de la cristallographie des différentes faces présentes dans nos échantillons ((010), (110), (1-10)), un coefficient de sélectivité entre Na+ et H+ sur l'ensemble des sites latéraux d'une morphologie donnée a pu être estimé à l'aide d'un modèle de complexation de surface. Les résultats ont montré que le coefficient de sélectivité Na+/H+ dépendait très fortement de la morphologie de la particule, et que par conséquent les propriétés d'adsorption des kaolinites ne pouvaient pas être obtenues avec précision sans une connaissance fine de la morphologie des particules. / The dissertation consists of two main parts; the first part is devoted to the effect of physical/thermal and chemical activation of kaolin on bleaching of rice bran oil. In this study, samples were prepared from natural Ranong kaolin. This study focused on the effects of both thermal treatment (from 100 to 900°C) and chemical activation (sulfuric acid, hydrochloric acid, citric acid and oxalic acid using different acid concentrations or different clay/acid ratio) on the capacity of kaolins to bleach rice bran oil. When kaolin was treated with high temperature (>100°C) prior to reflux and with a high acid concentration during reflux, the kaolinite structure was partially or completely destroyed associated to a dramatic leaching of alumina, and amorphous silica dominated the samples. The measured maximum bleaching capacity obtained was not consistent with the highest specific surface area and pore volume; rather, it depended on the alumina contents in the samples. Thus, the partial preservation of the kaolinite structure is crucial to obtain an appropriate bleaching capacity of kaolin. This is directly related to the preservation of the aluminol sites present at the kaolinite surface. XRF analysis showed that the alumina contents of 28-34% were values to reach in order to obtain optimum bleaching capacities of kaolin, independently of the different acid used. Finally, optimum bleaching of ~83%, ~82% and ~81% were achieved by grinding the kaolin prior to reflux with low acid concentration of hydrochloric acid (0.5 M), sulfuric acid (0.3 M) and citric acid (0.5 M), respectively with clay/acid ratio of 1:50.The second part of the thesis aims to elucidate the influence of morphology of kaolinites on their sorption properties. For that, Na+/H+ sorption isotherms in water saturated conditions of synthetic kaolinites and natural well crystallized kaolinite, called KGa--1b commercialized by the Clay Mineral Society, were performed and interpreted. Kaolinites used in this study were hydrothermally synthesized from partially crystallized kaolinite as a function of different final pH (pHF) ranging from 0.8 to 8.3. Results obtained for KGa--1b were compared with data obtained in literature for this mineral, in order to fully validate this approach. This study found that cation exchange capacity, due to both isomorphic substitutions in the crystals (permanent charge), and silanol and aluminol edge sites were highly variable. Typically, CEC at pH=9 varied from ~0.8 cmolc/kg for well crystallized kaolinite (pHF 0.8) to ~33 cmolc/kg for disordered lath-shaped kaolinite (pHF 8.3). Na+/H+ sorption isotherms were obtained for all synthetic kaolinites as a function of pH ranging from pH 3 to 11. Results showed that sorption of Na+ increases dramatically with pH. Typically for all kaolinite samples except for the one synthesized at pHF=8.3, Na+ sorption is rigorously equal to zero when pH<7, indicating no permanent charge in the samples (in contrast to natural KGa--1b kaolinite), and increases when pH>7 due to sorption on edge sites. The amount of dissolved silica measured during Na+/H+ isotherm is higher for experiments performed with kaolinites synthesized in basic conditions (for pHF 7.4 and pHF 8.3) than for kaolinites synthesized in acid conditions (for pHF 0.8 and pHF 3.3). These latter results lead to conclude that sorption site density can be considered constant when pH is between 4 and 10, independently of the morphologies of particles. In this context, a thermodynamic modeling procedure using a complexation model was applied to interpret the data obtained with hexagonal- and lath-shaped particles. During this procedure, selectivity coefficient between Na+ and H+ cations were obtained considering the total edge site densities calculated from lateral specific surfaces estimated for synthetic kaolinites and crystallography data.

In this study a multiresidue method for the determination of 24 pesticides in wheat, flour, bran and bread using GC-MS (NCI-SIM) mode was developed and validated. The objective of this study was to evaluate the pesticides destination during the processing of wheat as well as during the process of milling for attainment of white flour and the bran. The degradation of these pesticides was evaluated during the bread baking process. QuEChERS method, developed originally for samples of fruits and vegetables, was modified and optimized for the extraction of different pesticides. For the extraction procedure acetonitrile containing 1% acetic acid, sodium acetate, sodium citrate and magnesium sulphate was used. The clean up using dispersive solid phase extraction was carried out with C18 and magnesium sulphate. The method was validated evaluating the following parameters: linearity (seven different levels of concentration), limit of detention (LOD), limit of quantification (LOQ), matrix effect as well as precision and accuracy, evaluating the percentage of recovery using four different spike levels. The linear range used in the analytical curves was from 1.0 to 100 μg L-1 for wheat and bread and 2.0 to 200 μg L-1 for flour and bran both with values of r2 > 0.99. Recoveries presenting values between 70 and 120% with RSD <20% were considered satisfactory for most compounds. It was observed that there was a greater concentration of pesticides in the external part of the wheat grain, and that the sample of bran presented higher concentrations than those of flour. During the baking, degradation of compounds was observed in the range of 50 to 70%. The method proved to be adequate for the multiresidue analysis of pesticides in the matrices studied and the GC-MS (NCI-SIM) technique proved to be sensitive and highly selective. / Um método multirresíduo para a determinação de 24 pesticidas em trigo, farinha, farelo e pão empregando GC-MS (NCI-SIM) foi desenvolvido e validado neste estudo. O objetivo deste trabalho foi também avaliar o destino de pesticidas durante o processamento do trigo, ou seja, durante o processo de moagem para obtenção da farinha branca e do farelo. Avaliou-se a degradação destes compostos durante o cozimento para obtenção do pão a partir da farinha branca, que foi preparado em panificadora doméstica, com tempo total de preparo de 1 h. O método QuEChERS modificado, desenvolvido originalmente para amostras de frutas e vegetais, foi otimizado para a extração de pesticidas de diferentes classes. Para a etapa de extração, utilizou-se acetonitrila contendo 1% de ácido acético, acetato de sódio, citrato de sódio e sulfato de magnésio, a etapa de clean up por extração em fase sólida dispersiva foi realizada pelo emprego de C18 e sulfato de magnésio. O método foi validado avaliando-se os seguintes parâmetros: linearidade (sete níveis de concentração), limite de detecção (LOD), limite de quantificação (LOQ), efeito matriz, bem como precisão e exatidão, avaliando-se o percentual de recuperação empregando-se para isto quatro níveis de fortificação. A faixa linear das curvas analíticas situou-se entre 1,0 a 100 μg L-1 para trigo e pão, 2,0 a 200 μg L-1 para farinha e farelo, ambas apresentando valores de r2 >0,99. As recuperações foram consideradas satisfatórias, ou seja, entre 70 e 120% com valores de RSD% < 20% para a grande maioria dos compostos. Observou-se que os pesticidas se concentraram mais na parte externa do grão de trigo, apresentando maiores concentrações nas amostras de farelo do que nas amostras de farinha. Durante o cozimento, observou-se a degradação dos compostos na faixa de 50 a 70%. O método mostrou-se adequado para a análise multirresíduo de pesticidas nas matrizes estudadas, e a técnica de GC-MS (NCI-SIM) altamente sensível e seletiva.

La fermentation en milieu solide est un bioprocédé pouvant éventuellement être utilisé comme technologie de rupture pour diminuer le coût des biocatalyseurs utilisés dans la conversion de biomasse lignocellulosique comme le son de blé. La première partie de ces travaux de recherche a donc étudié le potentiel de cette technologie par rapport à celle de fermentation en milieu submergé lors d'une comparaison en application. Plusieurs tests de saccharification ont ainsi été réalisés sur différentes matières premières (cellulose, son de blé) et ont permis de montrer l'avantage différentiateur des biocatalyseurs produits par fermentation en milieu solide. Ensuite, la deuxième partie de ces travaux de recherche a porté sur l'étude des facteurs de la récalcitrance du son de blé à l'hydrolyse enzymatique. Deux principaux facteurs ont ainsi pu être démontrés : un facteur physique, lié à l'accessibilité des biocatalyseurs aux polysaccharides, et un facteur biochimique, lié à l'absence ou à la faible présence de certaines activités enzymatiques (féruloyl estérase,…) dans le complexe enzymatique de Trichoderma reesei Rut-C30. Cette étude a également permis d'identifier l'origine des différentes fractions glucidiques hydrolysées et de déterminer le potentiel glucidique actuellement hydrolysable à partir de cette biomasse. Enfin, la dernière partie de ces travaux de recherche a été consacrée à l'étude pratique d'un concept innovant de procédé permettant de favoriser la conversion des polysaccharides contenus dans le son de blé. Une levée de la barrière physique au transfert de masse et par conséquent une validation de ce concept a finalement pu être réalisée. / Solid-state fermentation is a bioprocess that can optionally be used as disruptive technology to reduce the cost of biocatalysts used in the lignocellulosic biomass conversion like wheat bran. The first part of this research has explored the potential of this technology compared to submerged fermentation in an application comparison. Several saccharification tests have thus been carried on different feedstocks (cellulose, wheat bran) and have shown the differentiator advantage of biocatalysts produced by solid state fermentation. Then, the second part of this research has investigated the recalcitrance factors of wheat bran to enzymatic hydrolysis. Two main factors have thus been demonstrated: a physical factor, related to the accessibility of biocatalysts to the polysaccharides, and a biochemical factor, related to the absence or the low presence of some enzymatic activities (feruloyl esterase, ...) in the enzymatic complex of Trichoderma reesei Rut-C30. This study has also identified the origin of the various carbohydrate moieties hydrolyzed and has determined the carbohydrate potential currently releasable from this biomass. Finally, the last part of this research has been devoted to the practical study of an innovative concept of process to promote the conversion of polysaccharides in wheat bran. A removal of the physical barrier to mass transfer and therefore a validation of this concept has finally been achieved.

Foram analisadas amostras de farelo de arroz fornecidas pela EMBRAPA e Agroindústrias, provenientes de sistemas de terras altas e irrigado, submetidas a diferentes técnicas de estabilização. A avaliação da variação dos teores de nutrientes, relacionados a composição centesimal, minerais, ácidos graxos e amilose, teve como objetivo contribuir com dados que permitam a caracterização da qualidade do produto e por conseqüência o melhor aproveitamento do farelo de arroz para o consumo humano. Os resultados obtidos mostraram que a origem e as diferentes técnicas de estabilização influem na composição das amostras, sendo que o farelo obtido do arroz de terras altas apresentou maiores teores de lipídeos, proteínas e ácidos graxos, enquanto aquele do arroz irrigado mostrou-se com os maiores teores de minerais e fibras. Os métodos de estabilização empregados foram os definidos como caseiros (torração em forno de microondas e fogão) e os tratamentos industriais de estabilização direta (extrusão termoplástica) ou indireta (proveniente do beneficiamento do arroz, após a parboilização). Entre as técnicas de estabilização, a realizada em fogão mostrou-se a mais adequada, enquanto a parboilização permitiu a valorização da composição nutricional. / Samples of rice bran from low land and upland systems, provided by EMBRAPA and several rice industries, and submitted to different stabilization techniques, were analyzed. The evaluations of variations in nutrient contents related to the centesimal composition, minerals, fatty acids and amylose had the objective of contributing to data that allow a better characterisation of the product quality and consequently a better utilization of rice bran for human consumption. The obtained results show that the origin and different stabilization techniques influence the composition of the samples. Production system for upland rice released a rice bran with higher contents of lipids, proteins and fatty acids, while irrigated rice bran contained more minerals and dietary fibres. The employed stabilization methods were those defined as homemade (toasted in a microwave oven or cooker) and industrial treatments such as direct (thermoplastic extrusion) or indirect stabilization (based on rice milling after parboiling). Within the stabilization methods, the toasting with a cooker was the most adequate, while parboilization allowed a valorization of the nutritional composition of rice bran.

No description available.

Enzymes and subcritical water can be used for the extraction of hemicelluloses from cereal by-products, making the processes eco-friendly. The polysaccharides extracted from cereal by-products can be used as matrices for development of materials for various applications. This includes bio-based materials such as films and hydrogels, which offer alternatives to existing materials produced from petrochemicals. The polymeric structure of cereal hemicelluloses contains functional groups which enable the modification of their structure by cross-linking, resulting in the formation of hydrogels. This project aims to use subcritical water extraction (SWE) to extract arabinoxylans (AXs) from corn and rye bran meanwhile the enzymatic treatment is done for purifying the samples during both pre- and post-treatment. AXs were further crosslinked by enzyme (laccase) for hydrogel preparation. During the whole project, the characterization included moisture and yield determination, starch and protein content which were tested using a spectrophotometer, monosaccharide content was analyzed by high performance anion exchange chromatography followed by pulsed amperometric detection (HPAEC-PAD) and phenolic acid content was quantified by high performance liquid chromatography (HPLC). The pretreatment for destarching and SWE process was successful. The result showed that arabinoxylans form corn bran were having higher content of arabino substituents, arabino toxylans ratio and ferulic acid content than rye samples. The enzymatic crosslinking could form strong gels in the condition that the AXs had high ferulic acid content. In terms of forming strong hydrogels or to improving the properties of AXs gel, the pre- and post-treatment should be optimized to increase the purity of the extracted feruloylated AX content. / Enzymer och subkritiskt vatten kan användas för extraktion av hemicellulosa från spannmålsbiprodukter, vilket gör extraktionen miljövänlig. Polysackariderna extraherade från spannmålsprodukter kan användas som matriser för utveckling av material för diverse applikationer. Detta inkluderar biobaserade material som filmer och hydrogeler, där petrokemikalier kan ersättas som råvara. Den polymera strukturen hos spannmålshemicelluloser innehåller funktionella grupper som möjliggör formation av tvärbindningar vilket resulterar i bildandet av hydrogeler. Syftet med detta projekt är extraktion av arbinoxylaner (AXs) från majs och rågkli genom att använda subkritiskt vatten-extraktion (SWE) där rening under för- och efterbehandling utförs enzymatiskt. AX modifierades därefter enzymatiskt (laccas) med tvärbindningar för hydrogelframställning. Under hela projektet karakteriserades hydrogelen utifrån fuktinnehåll, bestämmelse av utbyte, stärkelse och proteininnehåll som testades med en spektrofotometer, monosackaridhalten analyserades med högpresterande anjonsutbyteskromatografi följt avpuls-amperometrisk detektion (HPAEC-PAD), samt kvantifierades fenolsyrahalten med högupplöst vätskekromatografi (HPLC). Resultatet visade att arabinoxylaner från majskli hade högre innehåll av arabinosubstituenter, där förhållandet mellan arabino och xylans, samt arabino och ferulsyra innehållet var högre än för rågproverna. Den enzymatiska tvärbindningen kunde bilda starka geler i det tillståndet där AX hade en hög ferulsyrahalt. När det gäller att bilda starka hydrogeler eller att förbättra egenskaperna hos AXs-gel, bör för-och efterbehandlingen optimeras för att öka renheten fördet extraherade feruloylerade AX-innehållet.