<p dir="ltr">This study aims to develop Long Short-Term Memory (LSTM), Gated Recurrent Units (GRU), and Transformer-based Informer models and evaluate the performance of these models using data from one, two, three, and four weeks in advance to predict the progression of rice leaf blast disease; and assess the generalizability of these models across various climatic regions in Taiwan. This research utilized multi-location rice leaf blast diseased leaf percentage data collected between 2015 and 2021 in Taiwan, along with weather data from the Taiwanese meteorological observation network to predict rice blast disease one week in advance, serving as a benchmark for comparing with predictions made two, three, and four weeks in advance.</p>

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Tesis por compendio / [ES] El arroz, es uno de los cereales más consumidos a nivel mundial y debido a su alto valor nutricional, forma parte de la dieta básica de la población en general. Su elevado contenido de almidón, sin modificar o tras su modificación, lo convierte en un alimento atractivo para la industria alimentaria. No obstante, este mismo componente favorece el desarrollo del Bacillus cereus después de su cocción. Este microorganismo forma esporas resistentes al calor, lo que supone un riesgo para el consumidor, especialmente si el arroz cocinado no se almacena a temperatura adecuada. En la presente tesis doctoral, se han propuesto algunas estrategias tecnológicas para mejorar el procesado y garantizar la inocuidad alimentaria del arroz y sus derivados. Estas estrategias consisten en la aplicación de plasma frío y en el uso de quitosano de insecto (Tenebrio molitor) como antimicrobiano. Desde el punto de vista tecnológico, se ha visto que la tecnología de plasma es capaz de modificar determinadas propiedades tecnológicas del almidón que dependen de la variedad del arroz. Estos resultados abren la puerta a un uso más amplio de este componente en la industria alimentaria y en la formulación de alimentos a la carta. En cuanto a la inocuidad del arroz, el plasma frío reduce los niveles de células vegetativas y de esporas de B. cereus, convirtiéndolo en una tecnología alternativa de desinfección de materias primas como el arroz, antes de su procesado posterior. El nivel de inactivación tanto de células vegetativas como de esporas, estuvo determinado por el tiempo y potencia de tratamiento, así como la matriz que lo contenía en el caso de las esporas. El quitosano de insectos redujo la termorresistencia del B. cereus y resultó ser bacteriostático o bactericida en función de la concentración y la temperatura de almacenamiento. Estos efectos lo convierten en una buena estrategia de control de dicho microorganismo en arroz y sus derivados. A través de un modelo de evaluación a la exposición se ha podido corroborar los resultados sobre el efecto del quitosano en el B. cereus, a la vez que se pone de manifiesto la importancia que tienen cambios accidentales en las condiciones de procesado sobre el nivel final de microorganismos en el alimento y del número inicial de microorganismos sobre el porcentaje de unidades infectas después del tratamiento. Los resultados de la presente tesis ponen de manifiesto estrategias más sostenibles que son capaces de mejorar el procesado y la inocuidad del arroz y productos derivados del mismo. / [CA] L'arròs és un dels cereals més consumits a nivell mundial i, a causa del seu alt valor nutricional, forma part de la dieta bàsica de la població en general. El seu alt contingut d'almidó, sense modificar o després de la seva modificació, el converteix en un aliment atractiu per a la indústria alimentària. No obstant això, aquest mateix component afavoreix el desenvolupament del Bacillus cereus després de la seva cocció. Aquest microorganisme forma espores resistents al calor, la qual cosa suposa un risc per al consumidor, especialment si l'arròs cuinat no es conserva a una temperatura adequada. En la present tesi doctoral, s'han proposat algunes estratègies tecnològiques per millorar el processament i garantir la innocuïtat alimentària de l'arròs i els seus derivats. Aquestes estratègies consisteixen en l'aplicació de plasma fred i en l'ús de quitosà d'insecte (Tenebrio molitor) com a antimicrobià. Des del punt de vista tecnològic, s'ha vist que la tecnologia de plasma és capaç de modificar certes propietats tecnològiques de l'almidó que depenen de la varietat de l'arròs. Aquests resultats obren la porta a un ús més ampli d'aquest component en la indústria alimentària i en la formulació d'aliments a la carta. Quant a la innocuïtat de l'arròs, el plasma fred redueix els nivells de cèl·lules vegetatives i d'espores de B. cereus, convertint-lo en una tecnologia alternativa de desinfecció de matèries primeres com l'arròs, abans del seu processament posterior. El nivell d'inactivació tant de cèl·lules vegetatives com d'espores va estar determinat pel temps i potència de tractament, així com la matriu que les contenia en el cas de les espores. El quitosà d'insectes va reduir la termoresistència del B. cereus i va resultar ser bacteriostàtic o bactericida en funció de la concentració i la temperatura d'emmagatzematge. Aquests efectes el converteixen en una bona estratègia de control d'aquest microorganisme en l'arròs i els seus derivats. A través d'un model d'avaluació a l'exposició s'ha pogut corroborar els resultats sobre l'efecte del quitosà en el B. cereus, alhora que es posa de manifest la importància que tenen accidentals canvis en les condicions de processat sobre el nivell final de microorganismes en l'aliment i del nombre inicial de microorganismes sobre el percentatge d'unitats infectades després del tractament. Els resultats de la present tesi posen de manifest estratègies més sostenibles que són capaces de millorar el processament i la innocuïtat de l'arròs i productes derivats del mateix. / [EN] Rice is one of the most widely consumed cereals worldwide, due to its high nutritional value, it is part of the population basic diet. Its high starch content, unmodified or modified, makes it an attractive ingredient for the food industry. However, this same component promotes the development of Bacillus cereus after cooking. This microorganism forms heat-resistant spores, which poses a risk to consumers, especially if the cooked rice is not stored at the correct temperature. In this doctoral thesis, some technological strategies have been proposed to improve the processing and ensure the food safety of rice and its derivatives. These strategies include the application of cold plasma and the use of insect chitosan from Tenebrio molitor as an antimicrobial. From a technological perspective, plasma technology has demonstrated its ability to modify technological properties of starch, which vary based on the type of rice. These results open the door to a broader use of this component in the food industry and in customized food formulation. Regarding the safety of rice, cold plasma reduces the levels of vegetative cells and spores of B. cereus, making it an alternative technology for disinfecting raw materials such as rice before further processing. The level of inactivation of both vegetative cells and spores was determined by the time and power of the treatment, as well as the matrix containing them in the case of the spores. Insect chitosan reduced the thermo-resistance of B. cereus and was found to be bacteriostatic or bactericidal depending on the concentration and storage temperature. These effects make it a good control strategy for this microorganism in rice and its derivatives. Through an exposure assessment model, the results on the effect of chitosan on B. cereus have been corroborated, while also highlighting the importance of accidental changes in processing conditions on the final level of microorganisms in the food and the initial number of microorganisms on the percentage of infected units after treatment. The results of this thesis demonstrate more sustainable strategies that are capable of improving the processing and safety of rice and its derivatives. / La presente tesis doctoral se enmarca dentro del Programa de Doctorado Ciencia, Tecnología y Gestión Alimentaria de la Universidad Politécnica de Valencia. Para el desarrollo de la presente tesis doctoral, María Inés Valdez Narváez, ha disfrutado de una beca concedida por la Generalitat Valenciana para la contratación de personal investigador predoctoral (ACIF/2021/424) llevada a cabo en el Instituto de Agroquímica y Tecnología de Alimentos de Valencia, Centro de Excelencia Severo Ochoa, así como una beca BEFPI concedida por la Generalitat Valenciana para Estancias de contratados predoctorales en centros de investigación fuera de la comunidad Valenciana (CIBEFP/2022/56) desarrollada en The Agriculture and Food Development Authority- TEAGASC (Dublin-Irlanda). Este trabajo ha sido cofinanciado además por los proyectos: fondos del Ministerio de Ciencia e Innovación Ref. PID2020- 116318RB-C31 y proyecto TRACE-RICE Ref. AMD-1934-1 / Valdez Narváez, MI. (2024). Estrategias tecnológicas para mejorar la desinfeccion y procesado de derivados de arroz [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/210721 / Compendio

The flavour or fragrance of Basmati rice is associated with the presence of 2-acetyl-1- pyrroline. This work shows that a gene with homology to betaine aldehyde dehydrogenase (BAD) has significant polymorphisms in the coding region of fragrant genotypes relative to non fragrant genotypes. Accumulation of 2-acetyl-1-pyrroline in fragrant rice genotypes may be explained by the presence of mutations resulting in loss of function of the fgr gene product. The fgr gene corresponds to the gene encoding BAD2 in rice while BAD1 is encoded by a gene on chromosome 4. Development of an allele specific amplification (ASA) based around the deletion in the gene encoding BAD2 allows, perfect, simple and low cost discrimination between fragrant and non-fragrant rice varieties and identifies homozygous fragrant, homozygous non-fragrant and heterozygous non-fragrant individuals in a population segregating for fragrance. The cDNAs transcribed from rice chromosomes 4 and 8, each encoding an enzyme with homology to betaine aldehyde dehydrogenase were cloned and expressed in E. coli. The enzyme responsible for fragrance, encoded from chromosome 8, had optimum activity at pH 10, showed low affinity towards betaine aldehyde (bet-ald) with Km value of approximately 63ìM but a higher affinity towards -aminobutyraldehyde (GABald) with a Km value of approximately 9ìM. The enzyme encoded from chromosome 4 had optimum activity at pH 9.5 and showed generally lower affinity towards most substrates compared to the enzyme encoded from chromosome 8, substrate specificities suggest that the enzymes have higher specificity to aminoaldehydes and as such both should be renamed as an aminoaldehyde dehydrogenase (AAD). The inactivation of AAD2 (BAD2) in fragrant rice varieties likely leads to accumulation of its main substrate GABald which then cyclises to 1-pyrroline the immediate precursor of 2AP.

Architecture is a dilemma of transforming complex desires into compelling forms. It stands to reason, then, that to better understand the desires of a user might produce a more compelling form. This is an investigation into the process of design, wherein narratives are constructed as a productive tool for innovation. These narratives are the synthesis of both the desires of the client and the discriminations of the designer. Eschewing the conception of the architect as a mystic, this thesis begins with an investigation into how we represent complex Architectural ideas to a client. It begins a process, or framework, through which a project can be conceived. It both demands that the client shed preconceived, and potentially erroneous, associations between desires and design, to get to a more pure understanding of the needs of a client. The hope is that by rendering Architectural intention less opaque, we might come to a better understanding of the desires of a client, and thus create a new way of practicing; wherein neither client nor architect rely on a pre-defined set of formal solutions for a constantly evolving problem. The single-family home is the programmatic basis for this investigation. Few other programs illicit as robust and divergent desires than the home. It's not that architecture is in the pursuit of creating narratives. But rather, it's that the process of design is one wherein the creation of a compelling narrative has the potential to produce innovative work. And important to the construction of that narrative is the productive engagement of the client.

In dieser Arbeit wurden Ergebnisse einer Analyse der elektronischen Struktur in Sr2CuO2Cl2 mittels winkelaufgelöster Photoemission dargelegt. Sie betreffen i) Sr2CuO2Cl2 als Untersuchungsgegenstand für die Grundlagenforschung an Hochtemperatursupraleitern (HTSL), ii) winkelaufgelöste Photoemission als Untersuchungsmethode zur Messung der elektronischen Struktur von HTSL und deren Muttersubstanzen, iii) Eigenschaften der elektronische Anregungen in Sr2CuO2Cl2 in unmittelbarer Nähe des chemischen Potenzials, sowie iv) das durch Korrelationen stark beeinflusste Dotierungsverhalten der Kuprate. 1. Sr2CuO2Cl2 eignet sich Dank seiner exakten Stöchiometrie und der strukturell perfekten Kupfer-Sauerstoff Ebenen hervorragend als Untersuchungssubstanz für die isolierende Phase der HTSL. 2. Mittels winkelaufgelöster Photoemission ist es möglich, die k-Raum- und Energieverteilung (Dispersion) von Anregungen nahe des chemischen Potenzials in Sr2CuO2Cl2 auszumessen. Dabei wurde eine starke Abhängigkeit der Intensität des Photoemissionssignales in Abhängigkeit von der Photonenenergie beobachtet. Es konnte nachgewiesen werden, dass sich diese Intensitätsoszillationen mit hoher Wahrscheinlichkeit durch eine Bragg-Interferenz der Photoelektronenewelle an der Schichtstruktur von Sr2CuO2Cl2 erklären und weiterhin, dass die gemessenen Dispersionskurven, von einer willkürlichen Normierung der Intensität abgesehen, unabhängig von der verwendeten Photoenenenergie sind. 3. Die Photoemissionsspektren von Sr2CuO2Cl2 zeigen die für Ladungstransfer-Isolatoren charakteristische Aufteilung des spektralen Gewichts (der besetzten Elektronenstruktur) in ein unteres Hubbardband, bindende und nichtbindende Sauerstoffbänder und der ZR-Singlet Struktur. Dabei konnte das untere Hubbardband identifiziert werden durch seine durch Resonanz hervorgerufene Intensitätsverstärkung (und dem daraus resultierenden d8-Charakter dieser Struktur), die Sauerstoffbänder und die ZR-Singlet Struktur durch eine Analyse ihres Symmetrieverhaltens unter Berücksichtigung der Polarisationsabhängigkeit des Photoemissionssignales. Das ZR-Singlet besitzt eine a1g-Symmetrie was sowohl die Konstruktion des ZR-Singlets nach Zhang und Rice als auch die Ergebnisse der Diagonalisierung der isolierten, mit zwei Löchern besetzten Plakette bestätigt. 4. Die Dispersion des ZR-Singlets ist parabolisch entlang Gamma-(Pi,Pi) mit einem absoluten Bindungsenergieminimum bei (0.5Pi,0.5Pi) und parabolisch entlang Gamma-(Pi,0) mit einem lokalen Bindungsenergieminimum bei (0.7Pi,0). Die Bandbreite entlang dieser beiden Richtungen beträgt etwa 300 meV beziehungsweise 200 meV, der Abstand der beiden minimalen Bindungsenergien entlang dieser Richtungen ist 72 meV. Das Spektralgewicht des ZR-Singlets ist keilförmig verteilt mit einem Maximum bei (0.5Pi,0.5Pi) und (0.7Pi,0), also jeweils in unmittelbarer Nähe der minimalen Bindungsenergien dieser Struktur. Es verschwindet bei Gamma und (Pi,Pi), hat jedoch einen endlichen Wert bei (Pi,0). Der Vergleich dieser Resultate favorisiert das erweiterte t-J-Modell zur Beschreibung der Dynamik des ZR-Singlets. Insbesondere i) die parabolische Dispersion des ZR-Singlets entlang Gamma-(Pi,Pi), ii) der geringe aber endliche energetische Abstand der Bindungsenergie-Minima entlang Gamma-(Pi,Pi) und Gamma-(Pi,0) und iii) die keilförmige Verteilung des Spektralen Gewichts entlang Gamma-(Pi,0) sind die experimentellen Indizien dafür. / A detailed ARPES study of the low binding-energy occupied electronic structure of Sr2CuO2Cl2 has been done. It corresponds to an investigation of the first electron-removal states of an undoped CuO2-plane: 1. The photoemission signal of the first electron-removal states at both (0.5Pi,0.5Pi) and (0.7Pi,0) exhibits a marked photon-energy dependence. The intensity profile shows strong oscillations with maxima near 16, 25, 35 and 49 eV, corresponding to final state crystal momenta kperp=0.82, 1.63, 2.40 and 3.12 A-1. 2. Along the high-symmetry directions Gamma-(Pi,Pi) and Gamma-(Pi,0) the first electron-removal states shows a strong polarization dependence. This can be linked to the strongly polarization-dependent matrix element, which in turn allows the determination of the symmetry of the first electron-removal state itself. For both high-symmetry directions we observe a polarization dependence in keeping with that expected for a Zhang-Rice singlet state in the framework of either a three-band or one-band model Hamiltonian. 3. Our data show that the dispersion of the first electron-removal states along both high symmetry directions (Gamma-(Pi,Pi) and Gamma-(Pi,0)) is parabolic-like and independent of the excitation energy. This, and the rather large difference in lowest binding energy of the first electron-removal state along these directions, shows the validity of the extended t-J model for describing the disperion relation of a single hole in an antiferromagnetic CuO2 plane. Thus, the inclusion of second (t2) and third (t3) neighbor hopping terms with realistic values of t2=-0.08 and t3=0.15 in units of the next neighbor hopping t=t1 are required. 4. Upon application of a simple fit procedure, we infer the momentum distribution of the spectral weight of the coherent and incoherent part of the first electron-removal state to have its maximum along Gamma-(Pi,Pi) at (0.5Pi,0.5Pi), being symmetrically suppressed away from this point. Along Gamma-(Pi,0) the spectral weights of both parts reach their maximum at (0.7Pi,0) and then drop fast. The ratio between the coherent and incoherent spectral weight is strongly photon-energy dependent, which, at first sight would appear to violate the physics of the spectral function: (i) the necessity for a more sophisticated framework in which to analyse the weight of the coherent and incoherent contributions to the spectral weight (ii) significant (hn-dependent) intensity due to extrinsic processes (iii) intensity in this energy region due to intrinsic electronic states other than the Zhang-Rice singlet.

The flavour or fragrance of Basmati rice is associated with the presence of 2-acetyl-1- pyrroline. This work shows that a gene with homology to betaine aldehyde dehydrogenase (BAD) has significant polymorphisms in the coding region of fragrant genotypes relative to non fragrant genotypes. Accumulation of 2-acetyl-1-pyrroline in fragrant rice genotypes may be explained by the presence of mutations resulting in loss of function of the fgr gene product. The fgr gene corresponds to the gene encoding BAD2 in rice while BAD1 is encoded by a gene on chromosome 4. Development of an allele specific amplification (ASA) based around the deletion in the gene encoding BAD2 allows, perfect, simple and low cost discrimination between fragrant and non-fragrant rice varieties and identifies homozygous fragrant, homozygous non-fragrant and heterozygous non-fragrant individuals in a population segregating for fragrance. The cDNAs transcribed from rice chromosomes 4 and 8, each encoding an enzyme with homology to betaine aldehyde dehydrogenase were cloned and expressed in E. coli. The enzyme responsible for fragrance, encoded from chromosome 8, had optimum activity at pH 10, showed low affinity towards betaine aldehyde (bet-ald) with Km value of approximately 63ìM but a higher affinity towards -aminobutyraldehyde (GABald) with a Km value of approximately 9ìM. The enzyme encoded from chromosome 4 had optimum activity at pH 9.5 and showed generally lower affinity towards most substrates compared to the enzyme encoded from chromosome 8, substrate specificities suggest that the enzymes have higher specificity to aminoaldehydes and as such both should be renamed as an aminoaldehyde dehydrogenase (AAD). The inactivation of AAD2 (BAD2) in fragrant rice varieties likely leads to accumulation of its main substrate GABald which then cyclises to 1-pyrroline the immediate precursor of 2AP.

The rice is one of the cereals most consumed in world, consumption carried out mostly in the form of grains whose processing generates by-products such a rice bran, from which is obtained the rice bran oil. Due the presence of phospholipids, gums, waxes, this oil has a darker color and higher viscosity as compared to other vegetable oils. Also contains γ-orizanol, composed absent in other oils, which have been assigned antioxidants and hypocholesterolemics effects; but to become fit for consumed, the rice bran oil needs to be refined. The refining method modifies the oil composition; the chemical refining cause significant losses or changes in composition of rice bran oil; in the physical refining loss of these components is minimized, however the rice bran oil must have a phosphorus content below to 10 mg.kg-1 before to desodorization step, for to perform the physical refining. Thus, the aim of this study was to conduct studies on the degumming in order to make it fit the physical refining; and on the clarification, so that besides fit the physical refining, this is attractive to the consumer. Clarifying activity tests were performed two clarifiers lands: Tonsil ® Supreme 180 FF Tonsil ® and Actisil FF 280 added in different proportions (1.0, 1.5 and 2.0); degumming with water (0.6 and 5%) and phosphoric acid (0.2%), citric (0.5%); and clarification tests using the land and proportions that showed the best clarifying activity. There was the physicochemical characterization of crude, degummed oil and clarified oil with 2% of the earth Tonsil ® Supreme 180 FF and profile of fatty acids, γ-oryzanol content, tocopherols and tocotrienols content. The clarifier earth Tonsil ® Supreme 180 FF was the one with the best clarifying activity in the proportion of 2%, and when added at the rate of 1.5% showed the same activity clarifying that the earth Tonsil ® Actisil 280 FF added at a ratio of 2 0%; which was verified both in the clarifier activity tests, for the clarification test. The degumming with 5% water caused a reduction of the phosphorus content to less than 10 mg.kg-1. Thus, the degumming with 5% water, followed by clarification test using citric acid (50%) in the proportion of 0.5% to 2.0% addition of the clarifier earth Tonsil ® Supreme 180 FF, to provide a suitable oil physical refining, and the physical and chemical characteristics similar to crude oil and within the requirements specified by law. / O arroz é um dos cereais mais consumidos no mundo, principalmente na forma de grãos. O beneficiamento gera subprodutos, como o farelo de arroz, de onde se obtém o óleo bruto de arroz. Devido a presença de fosfolipídios, gomas, ceras este óleo apresenta uma coloração escura e maior viscosidade, quando comparado a outros óleos vegetais. Além disso, contem 1-2% de γ-orizanol, composto ausente em outros óleos, ao qual têm-se atribuído efeitos antioxidantes e hipocolesterolêmicos. Para tornar-se apto ao consumo, o óleo bruto necessita ser refinado. O método de refino modifica a composição do óleo; no refino químico, há perdas significativas de componentes durante o processo; no refino físico a perda desses componentes é minimizada, porém é necessário que o óleo chegue na etapa de desodorização com um teor de fósforo inferior a 10 mg.kg-1, para que seja possível realizar o refino físico. Portanto,o objetivo deste trabalho foi realizar estudos sobre a degomagem, a fim de torná-lo apto ao refino físico, e sobre a clarificação, para que este seja atraente para o consumidor. Foram realizados testes de atividade clarificante utilizando duas terras clarificantes: Tonsil ® Supreme 180 FF e Tonsil ® Actisil 280 FF adicionadas em diferentes proporções (1,0; 1,5; e 2,0%); de degomagem com água (0,6 e 5%) e ácidos fósforico (0,2%) e cítrico (0,5%); e testes de clarificação utilizando as terras e proporções que apresentaram a melhor atividade clarificante. Realizou-se a caracterização físico-química do óleo bruto, óleo degomado e óleo clarificado com 2% da terra Tonsil ® Supreme 180 FF, bem como perfil de ácidos graxos, teor de γ-orizanol, teor de tocoferóis e tocotrienóis. A terra clarificante Tonsil ® Supreme 180 FF foi a que apresentou a melhor atividade clarificante na proporção de 2%, e quando adicionada na proporção de 1,5% apresentou a mesma atividade clarificante que a terra Tonsil ® Actisil 280 FF adicionada na proporção de 2,0%; o que foi verificado tanto nos testes de atividade clarificante, quanto no teste de clarificação. A degomagem com 5% de água promoveu a redução do conteúdo de fósforo para valores menores que 10 mg.kg-1. Assim, a degomagem com 5% de água, seguida da clarificação utilizando ácido cítrico (50%) na proporção de 0,5% e adição de 2,0 % da terra clarificante Tonsil ® Supreme 180 FF, forneceram um óleo apto ao refino físico e com as características físico-químicas semelhantes ao óleo bruto e dentro dos requisitos especificados pela legislação.

Rice culture is an activity that has currently been gaining more importance due to its use in human feeding, allowing enough food and acceptable quality to the population. There is a great concern regarding the intensive use of pesticides, the main strategy employed in the countryside to combat and prevent plagues, as well as the residues resulting from such practice. This paper has been developed and validated on an analytical procedure, using the QuEChERS modified extraction approach and gas chromatography with electron-capture detection (GC-ECD) for the determination of residual insecticides lambda-cyhalothrin and bifenthrin and azoxystrobin fungicides and trifloxystrobin in rice plants. The QuEChERS modified method was applied in an initial stage of extraction using 3.0 g of rice plants in which was added 15 mL of acetonitrile containing 1% (v/v) acetic acid, followed by a partition step after the addition of a mixture of anhydrous salts (3 g of magnesium sulphate and 1.7 grams of sodium acetate). Next, the clean-up stage was carried out 4 mL extract using 200 mg of activated charcoal and 600 mg of magnesium sulfate and the analysed by GC-ECD using an apolar DB-5 column. During method validation, LOD; LOQ; linearity; precision (repeatability and intermediate precision); and accuracy, evaluated in terms of recovery, were determined. Using this method, LOQ quantities were 1 mg kg-1 for azoxystrobin and 0.05 mg kg-1 for lambdacyhalothrin, bifenthrin and trifloxystrobin. The analytical curves presented linearity between 0.01 and 1.0 mg L-1, with coefficient of determination greater than 0.993. The method had shown good precision, with RSD values smaller than 19.0%, and accuracy, with recoveries between 71.2 and 103.6%. The method was considered adequate to the analysis of pesticides in rice plants, considering that all validation parameters meet the levels required for validation of chromatographic methods. After being validated, the method was applied to the study of the residual concentration of pesticides in rice plants, from rice crops irrigated with an experiment carried through at the UFSM Campus; where the pesticides azoxystrobin, bifenthrin, lambda-cyhalothrin, and trifloxystrobin were individually applied in 2007/2008 harvest. All pesticides in this study were detected up to approximately twenty (20) days after being applied. / A cultura do arroz é uma atividade de importância cada vez maior pela sua utilização na alimentação humana, garantindo alimento suficiente e de qualidade para a população. A grande preocupação é o uso intensivo de pesticidas; principal estratégia no campo para o combate e a prevenção de pragas, e os resíduos decorrentes desta prática. Neste trabalho, desenvolveu-se e validou-se um procedimento analítico, utilizando o método de extração QuEChERS modificado e Cromatografia Gasosa com Detecção por Captura de Elétrons (GC-ECD) para a determinação residual dos inseticidas bifentrina e lambda-cialotrina e dos fungicidas azoxistrobina e trifloxistrobina em plantas de arroz. O método QuEChERS modificado consistiu em uma etapa de extração inicial utilizando 3,0 g de plantas de arroz na qual foi adicionado 15 mL de acetonitrila contendo 1% (v/v) de ácido acético, seguida por uma etapa de partição após a adição de uma mistura de sais anidros (3 g de sulfato de magnésio e 1,7 g de acetato de sódio). Na seqüência foi realizada a etapa de clean-up de 4 mL de extrato com 20 mg de carvão ativado vegetal e 600 mg de sulfato de magnésio e a análise por GCECD utilizando-se coluna apolar DB-5. Na validação do método determinou-se LOD, LOQ, linearidade, precisão (repetitividade e precisão intermediária) e exatidão, avaliada pela recuperação. Os valores de LOQ do método foram 1,0 mg kg-1 para azoxistrobina e 0,05 mg kg-1 para lambda-cialotrina, bifentrina e trifloxistrobina. As curvas analíticas apresentaram linearidade entre 0,01 e 1,0 mg L-1, com valores de coeficiente de determinação maiores que 0,993. O método apresentou boa precisão, com valores de RSD inferiores a 19,0%, e boa exatidão, com recuperações entre 71,2 e 103,6%. O método foi considerado adequado à análise dos pesticidas em plantas de arroz, visto que todos os parâmetros de validação atendem os limites sugeridos para validação de métodos cromatográficos. Após ser validado, o método foi aplicado em um estudo da concentração residual dos pesticidas em plantas de arroz, oriundas de lavoura de arroz irrigado de um experimento realizado no Campus da UFSM, onde foram aplicados separadamente os pesticidas azoxistrobina, bifentrina, lambda-cialotrina e trifloxistrobina, na safra 2007/2008. Todos os pesticidas em estudo foram detectados até aproximadamente 20 dias após a sua aplicação.

Instituto Federal de Educação, Ciência e Tecnologia Farroupilha / Rice (Oryza sativa) stands out as an important food, considering production and consumption. Although the rice usually cultivated in most countries is the one with light-brown pericarp color, there are other grains with red and black pericarp color, used for food in some regions of the world. The consumption of these grains is mainly related to their organoleptic characteristics, but some researches demonstrate that they can also present nutritional differences compared to light-brown color rice grains. So, the present research aimed at evaluating the chemical composition, the antioxidant characteristics and the physiological effect on rats, of rice grains with light-brown, red and black pericarp color, from recommended genotypes and weedy rice, for their utilization in the diet. The grains were obtained in the 2006/07 growing season, under equal conditions, in the experimental area of Universidade Federal de Santa Maria, RS. For the evaluation of the chemical composition the contents of total carbohydrates, amylose, fiber, protein, lipids, mineral matter and minerals were determined in brown rice grains. The antioxidant characteristics were determined from the concentration of total soluble phenolic compounds (TSPC) and the antioxidant activity (AOA), evaluated in grains with different processing (brown, polished, parboiled brown and parboiled polished; raw and cooked). By a bioassay, with healthy Wistar male rats fed diets containing brown rice grains with light-brown, red or black pericarp color, or a control diet, the effect of the consumption of these grains was evaluated. Body weight gain, feed consumption, epididymal fat pad, blood concentration of glucose, triglycerides, total cholesterol and HDL cholesterol, activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase in the liver, and lipid peroxidation in the blood and liver were determined. The results showed significant difference in the chemical composition among grains with light-brown, red and black pericarp, mainly in the content of fiber and minerals, and some genotypes with red and black pericarp stood out with higher concentration of some of the components evaluated, like protein and minerals. In the antioxidant characterization, significant difference was observed in the concentration of TSPC and AOA among genotypes, with the higher values for grains with red and black pericarp color, with positive and significant correlation between these parameters. Parboiling reduced the concentration of TSPC in the grains, with reduction in the AOA. In a similar way, cooking of the grains also reduced the concentration of TSFC, especially in brown and polished grains. In the bioassay, no significant effect of the diets containing rice grains was observed for most of the evaluated parameters, with effect only on the weight of the epididymal fat pad and on the activity of SOD in the liver, but with no difference among rice types. The increase in the activity of SOD may indicate possible reduction in the oxidative stress of the organism, but more research is necessary. / O arroz (Oryza sativa) destaca-se como um dos principais alimentos, tanto em produção como consumo. Embora o arroz normalmente cultivado na maioria dos países seja aquele com pericarpo marrom-claro, também existem grãos com pericarpo vermelho e preto, utilizados na alimentação em algumas regiões do mundo. O consumo desses grãos está relacionado principalmente as suas características sensoriais, mas algumas pesquisas demonstram que eles também podem apresentar diferenças nutricionais em relação ao arroz com pericarpo marrom-claro. Dessa forma, este trabalho foi conduzido com os objetivos de avaliar a composição química, as características antioxidantes e o efeito fisiológico em ratos, de grãos de arroz com pericarpo marrom-claro, vermelho e preto, tanto de genótipos recomendados para cultivo como aqueles considerados daninhos, com vista a sua utilização na alimentação. Os grãos avaliados foram cultivados em ensaio de campo na safra 2006/07, sob iguais condições, em área de várzea da Universidade Federal de Santa Maria, RS. Para a avaliação da composição química foram determinados os teores de carboidratos totais, amilose, fibra alimentar, proteína, lipídios, matéria mineral e minerais, de grãos integrais. As características antioxidantes foram determinadas a partir da concentração de compostos fenólicos solúveis totais (CFST) e da atividade antioxidante (AAO), sendo avaliados grãos submetidos a diferentes processamentos (integral, polido, parboilizado integral e parboilizado polido; cru e cozido). Através de ensaio biológico, com ratos machos Wistar sadios alimentados com rações contendo grãos integrais de arroz com pericarpo marrom-claro, vermelho ou preto, ou ração controle, foi avaliado o efeito do consumo desses grãos. Foram avaliados o ganho de peso, consumo de ração, gordura epididimal, concentração sangüínea de glicose, triglicerídeos, colesterol total e HDL, atividade das enzimas superóxido dismutase (SOD) e glutationa peroxidase no fígado, e peroxidação lipídica no sangue e no fígado. Os resultados mostraram diferença significativa na composição química entre grãos com pericarpo marrom-claro, vermelho e preto, principalmente no teor de fibra e minerais, sendo que alguns genótipos com pericarpo vermelho e preto se destacaram por possuírem maior concentração de certos componentes avaliados, como proteína e minerais. Na caracterização antioxidante, foi observada diferença significativa na concentração de CFST e na AAO entre genótipos, sendo os maiores valores encontrados nos grãos com pericarpo vermelho e preto, com correlação positiva e significativa entre estes parâmetros. A parboilização reduziu a concentração de CFST nos grãos, com conseqüente redução da AAO. De forma semelhante, o cozimento dos grãos também reduziu a concentração de CFST, principalmente nos grãos integrais e polidos. No ensaio biológico não foi observado efeito significativo das rações contendo grãos de arroz para a maioria dos parâmetros avaliados, observandose efeito somente para o peso da gordura epididimal e a atividade da enzima SOD no fígado, mas sem diferença entre os tipos de arroz. O aumento na atividade da enzima SOD pode indicar possível redução no estresse oxidativo do organismo, entretanto maiores estudos são necessários.