Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-03-29T12:47:48Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Laury Francis Costa tese doutorado 2016.pdf: 1371853 bytes, checksum: b52b62a7c70253ba774a4a1f09aa6adb (MD5) / Made available in DSpace on 2017-03-29T12:47:48Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Laury Francis Costa tese doutorado 2016.pdf: 1371853 bytes, checksum: b52b62a7c70253ba774a4a1f09aa6adb (MD5) Previous issue date: 2016-07-22 / CAPES / A irradiação de alimentos utiliza doses de radiação gama previamente estabelecidas, para manter as características nutricionais e físico-químicas dos alimentos e evitar contaminação por micro-organismos. O mix de cereais ou farelos é uma farinha composta por uma mistura de ingredientes, incluindo linhaça, gergelim e aveia. O fungo filamentoso Aspergillus flavus pode contaminar esse tipo de alimento e produzir aflatoxina. O objetivo deste estudo foi analisar amostras de mix de cereais, irradiadas ou não, para verificar se a radiação gama consegue inibir a contaminação por fungos aflatoxigênicos, além de manter as características nutricionais do alimento; além de analisar a rotulagem das amostras embaladas. Foram analisadas 9 amostras diferentes de mix de cereal (M1 a M9), em embalagem plástica ou metalizada, comercializado a granel e industrializado. Também foram analisados grãos e farinha de linhaça, gergelim e aveia. Foram feitas análises micológicas (fungos totais e aflatoxigênicos), testes físico-químicos (cinzas, umidade, proteínas, lipídios, carboidratos, Aw) e análise de rotulagem. A menor dose de radiação gama (2,5kGy) foi suficiente pra inibir os fungos aflatoxigênicos na maioria da amostras, e a dose considerada ótima foi de 5kGy. A amostra com maior contaminação fúngica foi a granel M3 (1,2x104UFC/g), mas a M8 teve maior variedade de fungos. Foi observado que 75% das amostras a granel e 80% das amostras industrializadas de mix de cereais foram positivos pra fungos aflatoxigênicos. A amostra M2 foi a mais irregular na rotulagem, infringindo a RDC nº360/2003 e RDC nº259/2002. Os testes estatísticos comprovaram que a composição nutricional e a germinação dos grãos não foram afetadas pela radiação. Gergelim só teve contaminação na amostra controle; aveia e linhaça tinham pouca ou nenhuma contaminação. O MALDITOF confirmou o Aspergillus flavus. A sugestão é padronizar a lista de ingredientes do mix de cereais, regularizar a rotulagem junto às empresas, e orientar os consumidores a comprar mix de cereais apenas em embalagem lacrada, pois a venda a granel facilita a contaminação por fungos aflatoxigênicos devido à manipulação e má conservação. / Food irradiation uses gamma radiation dose previously established for maintaining the nutritional and physicochemical characteristics of the food and prevent contamination by micro-organisms. The cereal mix is made of bran or flour of a mixture of ingredients, including linseed, sesame and oats. The filamentous fungus Aspergillus flavus can infect this type of food and produce aflatoxin. The objective of this study was to analyze samples mix of cereals, irradiated or not, to check whether the gamma radiation can inhibit contamination by aflatoxigenic fungi as well as maintaining the nutritional characteristics of the food; besides analyzing the labeling of packaged samples. We analyzed 9 different samples of cereal mix (M1 to M9) in plastic or metallic packaging, sold in bulk and industrialized. They were also analyzed grains and flaxseed meal, sesame and oats. Mycological analyzes were performed (total and aflatoxigenic fungi), physical-chemical (ash, moisture, protein, lipids, carbohydrates, Aw) and analysis of labeling. The lowest dose of gamma radiation (2,5kGy) was sufficient to inhibit the majority of aflatoxigenic fungi in samples and the optimum dose was considered 5kGy. The sample with higher fungal contamination was bulk M3 (1,2x104UFC / g), but the M8 had a greater variety of fungi. It was observed that 75% of bulk samples and 80% of the industrialized mix samples of grain were positive for aflatoxigenic fungi. The sample M2 was the most irregular in the labeling, breaking the RDC 360/2003 and RDC 259/2002. Statistical tests have shown that the nutritional composition and grain germination was not affected by radiation. Sesame only had contamination in the control sample; flax and oats had little or no contamination. The MALDITOF confirmed Aspergillus flavus. The suggestion is to standardize the list of ingredients in the mix of cereals, regulate the labeling from the companies, and guide consumers to buy mix of cereals only in sealed packaging, because sale in bulk facilitates contamination by aflatoxigenic fungi due to handling and poor conservation.

Um estudo crítico foi realizado utilizando quatro métodos clássicos de extração de lipídios em aveia em flocos e peito de frango. Foram comparados os rendimentos, o tempo de extração, a repetibilidade de cada método e a qualidade oxidativa da fração lipídica obtida. As metodologias utilizadas foram as de Soxhlet, com n-hexano como solvente, nos períodos de quatro e oito horas de extração; Folch et al., com clorofórmio e metanol na proporção de 2:1 (v/v); Bligh & Dyer, com clorofórmio, metanol e água na proporção de 1:2:0,8 (v/v) e Hara & Radin, com n-hexano e isopropanol, na proporção de 3:2 (v/v). Os resultados obtidos indicaram que para a aveia em flocos, os métodos de Soxhlet e Bligh & Dyer apresentaram um rendimento superior (7,71 % e 7,66 %, respectivamente) em relação ao método de Hara & Radin e Folch et al. (6,61 % e 6,93 %, respectivamente). No estudo do peito de frango, os métodos de Soxhlet, Folch et al. e Bligh & Dyer apresentaram um rendimento satisfatório de lipídios totais, sendo, respectivamente, de 1,56 %, 1,56 % e 1,65 %. Apesar do bom rendimento em lipídios totais, o método de Soxhlet afetou a qualidade da fração lipídica em ambas amostras, demonstrada pela presença de peróxidos (4,39 e 4,19 meq O2/kg no peito de frango; 3,71 e 3,70 meq O2/kg na aveia em flocos) e pela acidez oléica (2,58 % de ácidos graxos livres (AGL) no peito de frango; 2,25 e 2,24 % AGL na aveia em flocos), em ambos os períodos de tempo da extração. Com base nos resultados deste trabalho, indica-se a metodologia de Bligh & Dyer para os casos em que haja interesse em uso posterior das frações lipídicas, em detrimento da de Soxhlet, não recomendável para o fim mencionado. / A critical study was carried through with four clasical methods of extraction of lipids from chicken breast and oat flakes. The yield, the extraction time, the repeatability of each method and the oxidative quality of the lipid fraction were evaluated and compared. The methodologies evaluated were Soxhlet, with n-hexane as the solvent, in periods of four and eight hours of extraction; Folch et al., with chloroform and methanol in the ratio of 2:1 (v/v); Bligh & Dyer, with chloroform, water and methanol, in the ratio of 1:2:0.8 (v/v), and Hara & Radin, with n-hexane and isopropanol, in the ratio of 3:2 (v/v). The results indicated that for oat flakes, the methods Soxhlet and Bligh & Dyer presented higher yields in total lipids (7.71 % and 7.66 %, respectively) than the methods Hara & Radin and Folch et al. (6.61 % and 6.93 %, respectively). In the study with chicken breast, the methods Soxhlet, Folch et al. and Bligh & Dyer presented the highest yields, being respectively 1.56 %, 1.56 % and 1.65 %.Despite the good yields in total lipids, the Soxhlet method affected the quality of the lipid fraction in both samples, demonstrated by the presence of peroxides (4.39 and 4.19 meq O2/kg in chicken breast; 3.71 and 3.70 meq O2/kg in oat flakes) and by the acid values (2.58 % FFA [free fatty acids] in chicken breast for both extractions; 2.25 and 2.24 % FFA in oat flakes,) for both periods of time evaluated. Based on the results obtained in this research, the authors recommend Bligh & Dyer methodology whenever there is interest in further use of the lipid fraction and strongly disencourage Soxhlet method for the purpose mentioned.

Orientador: Caroline Joy Steel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-21T01:27:39Z (GMT). No. of bitstreams: 1 Ishida_PatriciaMelloGarrido_M.pdf: 10468557 bytes, checksum: e14750e5c86d022d5e7540a7e8e04a2f (MD5) Previous issue date: 2012 / Resumo: O uso de fibras brancas se mostra como uma alternativa de enriquecimento de fibras ao pão diminuindo os efeitos sensoriais negativos das fibras comuns, como coloração mais escura em relação aos pães sem fibras. Dentre as fibras brancas disponíveis temos as fibra de trigo-TR e aveia-AV (insolúveis) e a goma acácia-GA (solúvel). O objetivo deste trabalho foi verificar os efeitos de fibras brancas aplicadas em pães de forma, avaliando possíveis alterações na qualidade tecnológica e a aceitação sensorial dos pães. Este trabalho foi dividido em duas etapas: 1 - Estudo das características físico-químicas e sensoriais de pães de forma comerciais (brancos e integrais) do mercado brasileiro e; 2 - Estudo do efeito de fibras brancas na qualidade de pão de forma. Na Etapa 1, foram adquiridas 12 amostras de pães brancos e integrais consumidos no Brasil. Foram obtidos volumes específicos entre 3,88 e 5,37 mL/g para pães brancos e integrais. Os miolos no primeiro dia apresentaram: umidade 37,03 e 41,23%, aw 0,954 e 0,966, firmeza 267,8 e 276,3 gf; e média de cor: L* 74,73 e 64,45, a* 0,37 e 3,85 e b* 15,51 e 18,98 para pães brancos e integrais respectivamente. No período analisado, todos mostraram aumento da firmeza, diminuição de umidade e aw e a cor praticamente não foi alterada. Na análise sensorial (6 pães n=121), 67,8% eram mulheres e 72,7% consumiam pão de forma de 2 a 7 vezes semanalmente. Os três fatores mais importantes no ato da compra foram sabor (19,6%), maciez (16,8%) e validade (14,3%). 67,8% disseram preferir pão com fibras, 82,6% disseram que provavelmente ou certamente comprariam um pão branco com fibras. No teste de aceitação, apenas em relação à textura os pães brancos foram mais aceitos do que os integrais. O Mapa de Preferência Interno mostrou que um pão branco foi o mais aceito. Na Etapa 2, foram produzidos pães, utilizando um planejamento completo central 23, tendo como variáveis independentes TR (0 a 10%), AV (0 a 10%) e GA (0 a 5%). Foram obtidos volumes específicos de 3,30-4,97 mL/g para os ensaios e 5,00 mL/g para o controle (FC). Os miolos no primeiro dia apresentaram: umidade 36,98-42,58%, aw 0,948-0,965, firmeza 193,9-404,4 gf e para FC: 37,53%, 0,954, 227,5 gf. A cor dos miolos no primeiro dia foi de: L* 73,46-78,08, a* 0,36-1,10 e b* 15,95-18,93 e FC: L* 79,08, a* 0,35, b* 14,90. O valor de ?E variou de 1,69 a 6,62 neste dia. As fibras de trigo e aveia aumentaram: absorbância (Abs) e tempos de chegada (TC), desenvolvimento (TD) e saída (TS), umidade, aw e firmeza e; diminuíram a extensibilidade (E). A goma acácia aumentou E, diminuiu Abs, TC, TD, TS. As três fibras diminuíram o volume específico e L* e aumentaram a* e b*. As três formulações da validação dos modelos foram: FF (2,5% GA); FR1 (6% AV e 2,5% GA) e FR2 (2% TR, 4% AV e 2,5% GA). Abs, umidade, aw, L* e b* apresentaram alta correlação entre valores preditos e experimentais. No teste de aceitação (n=121) não foram encontradas diferenças significativas para aparência, aroma, sabor, textura e impressão global. FR2 apresentou a maior redução nos índices de hidrólise (-24,9%) e glicêmico (-14,4%), 6,7% de fibras totais e boa aceitação pelos consumidores / Abstract: The use of white fibers is shown as an alternative enrichment fiber bread minimize their negative sensory fibers common as darker compared to bread without fiber. Among the white fibers available have the fiber wheat-TR and oats-AV (insoluble) and gum acacia-GA (soluble). The objective of this study was to assess the effects of white fibers applied to pan bread, assessing possible changes in the technological quality and sensory acceptance of the loaves. This work was divided into two steps: 1 - Study the physical-chemical characteristics and sensory analysis of commercial pan bread (white and whole grain) and; 2 - Study the effect of white fibers on the quality of bread. In Step 1, 12 samples were acquired white and whole breads consumed in Brazil. Specific volumes were obtained between 3.88 and 5.37 mL/g for white and whole grain breads. The brains were on the first day: moisture 37.03 and 41.23%, aw 0.954 and 0.966, firmness 267.8 and 276.3 gf and color average: L* 74.73 and 64.45, a* 0.37 and 3.85 and b* 15.51 and 18.98 for white bread and whole bread respectively. In the period analyzed, all showed increased strength, reduced moisture and aw and the color was practically not changed. In the sensory analysis (6 breads, n = 121), 67.8% were women and 72.7% ate bread 2-7 times a week. The three most important factors in the purchase were flavor (19.6%), tenderness (16.8%) and validity (14.3%). 67.8% said they preferred bread with fiber, 82.6% said they probably or definitely buy a white bread with fiber. In acceptance testing, only in relation to the texture white breads were more acceptable than the whole. The internal preference mapping showed that a white bread was more accepted. In Step 2, buns were produced using a central composite 23, having as independent variables TR (0-10%), AV (0-10%) and GA (0-5%). We obtained specific volumes from 3.30 to 4.97 mL/g for the trials and 5.00 mL/g for the control (FC). The brains were on the first day: moisture 36.98-42.58%, aw 0.948-0.965, firmness 193.9-404.4 gf and FC: 37.53%, 0.954, 227.5 gf. The color of the brains on te first day was: L* 73.46-78.08, a* 0.36-1.10 and b* 15.95-18.93 and FC: L* 79.08, a* 0.35, b* 14.90.The value of ?E ranged from 1.69 to 6.62 on this day. The wheat and oat fibers have increased: Absorbance (Abs), arival (TC), development (TD), output (TS) times, moisture, firmness and aw, and decreased extensibility (E). Acacia gum increased E and decreased Abs, TC, TD, TS. The three fibers decreased the specific volume and L* and increased a* and b*. The three formulations of the validation of the models were: FF (GA 2.5%), FR1 (AV 6% and GA 2.5%) and FR2 (TR 2%, AV 4% and GA 2.5%). Abs, moisture, aw, L* and b* values showed a high correlation between predicted and experimental values. In the acceptance test (n = 121) were not significant differences for appearance, aroma, flavor, texture and overall impression. FR2 showed the greatest reduction in hydrolysis index (-24.9%) and glycemic index (-14.4%), 6.7% of total fiber and good consumer acceptance / Mestrado / Tecnologia de Alimentos / Mestra em Tecnologia de Alimentos

No description available.

In the forest products industry the opportunity exists to extract currently under-utilised compounds from the process or waste streams and thereby derive more value from the wood entering the process. A big portion of the hemicellulose content of wood does not form part of the final product. Extracting the hemicelluloses from the waste streams or other locations in the process would allow them to be used more effectively. The predominant hardwood hemicellulose, xylan, is polymeric xylose. Xylose is an important platform sugar in bioconversion strategies and can be converted to fuels and other valuable chemicals. The xylan polymer can be hydrolysed to its xylose monomers by a number of conversion strategies; the most widely known being chemical and enzymatic digestion. Chemical conversion is usually done using acid at elevated temperatures, but high yields are often offset by degradation of the product. On the other hand, enzymatic hydrolysis can be better regulated to prevent unwanted degradation of the monomeric sugar products. Enzymatic hydrolysis has been pronounced the environmentally friendly choice of technology, although it is hampered by low conversions and high cost of enzymes. To date commercial enzymes for biomass conversion are not readily available most of which are still in development. In understanding how to best utilise a xylan, recovered from the pulping process, the potential to convert hardwood xylan to xylose with enzymes currently available on the market was studied. A hardwood xylan extracted from fully bleached Eucalyptus pulp with a chelating agent, Nitren, was used as substrate to evaluate the ability of some commercial enzymes to degrade the extracted xylan to xylose monomers. The enzymes used in this study were not dedicated biomass conversion enzymes, but rather chosen for their xylan degrading potential, i.e. xylanase content. By means of hydrolysis profiles on commercial Birchwood and Oat Spelts xylan as substrates and enzyme characterisation, Multifect xylanase was identified as most promising enzyme for xylan conversion. Multifect contained high levels of xylanase and xylosidase activity in the enzyme preparation. Commercial Birchwood xylan and the extracted Eucalyptus xylan were found to be chemically similar, both composed predominantly of xylose. The hydrolysis profiles obtained on Birchwood xylan could therefore serve as a benchmark against which the hy-drolysis of Eucaluptus xylan could be compared. Full conversion of the Eucalyptus xylan with Multifect could not be achieved, although Multifect completely degraded the Birchwood xylan. The maximum xylose yield that could be obtained on Eucalyptus xylan was 80 % and it was concluded that the remaining 20% was unhydrolysable by the enzyme, most likely due to the limitations in the employed extraction method. It was however noted that up to the point of 80 % conversion higher hydrolysis rates were observed on Eucalyptus xylan than Birchwood xylan with equal charges of Multifect. The differences in hydrolysis rates may have indicated that the Eucalyptus xylan is more accessible to enzyme attack than the Birchwood xylan, likely as a result of the extraction methods used to prepare the xylans. A simple economic evaluation illustrated the weight of various costs in process profitability. The most economic operation of a continuous steady state reactor is at a low enzyme charge, 17 IU/ℓ, and a long retention period, five days, due to the high cost of the enzyme compared to other factors. For a reduced retention time, an investigation into enzyme immobilisation and the use of a packed-bed type reactor is recommended. / Dissertation (MEng)--University of Pretoria, 2009. / Chemical Engineering / unrestricted

This paper examines the process of Operations Acceptance Management, whose main task is to control Operations Acceptance Tests (OAT). In the first part the author focuses on the theoretical ground for the problem in the context of ITSM best practices framework ITIL. Benefits, process pitfalls and possibilities for automation are discussed in this part. The second part contains a case study of DHL IT Services (Prague), where a solution optimizing the overall workflow was implemented using simple web applications. The author of this paper was personally involved in the described project.

El proyecto de tesis tiene como fin desarrollar y caracterizar productos fermentados a partir de licuados vegetales con una excelente calidad nutricional y sensorial. Para conseguir el propósito mencionado se eligieron licuados de almendra, avellana y avena, cuyas propiedades fisicoquímicas y nutricionales son aptas para el proceso de fermentación. Para ello, se estudió el efecto de los tratamientos térmicos y de homogenización sobre las cualidades fisicoquímicas y de estabilidad de los diferentes licuados, para elegir en base a los resultados obtenidos, las condiciones idóneas de su obtención. Por otra parte, se seleccionaron dos cepas probióticas comerciales (L. rhamnosus GG y L. reuteri ATCC 55730) con el fin de obtener productos fermentados a partir de los licuados elegidos y, de este modo, ofrecer nuevas posibilidades y beneficios al consumidor dentro del sector de productos no-lácteos. Por otra parte, con la adición de microorganismos probióticos se pretende satisfacer la demanda actual de productos funcionales; es decir, ofrecer productos que, además del aporte de nutrientes, tengan un efecto beneficioso para la salud. / Bernat Pérez, N. (2013). Desarrollo, caracterización y optimización de productos fermentados a base de licuados vegetales como alternativa a los yogures convencionales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/33748 / TESIS

The goal of this model is to create and to implement qualitative model of the signal track of olfactory sensory neuron, including the feedback with a focus on diffusion of substances that allows to conduct more simulations for the better understanding of dynamics of the signal track. This model is expected to be used for the simulation of influencing during the activation of two receptors in firstly defined distance. Model was created and therefore implemented in a programming language Python with the use of library STEPS. Then I have conducted sensitivity analysis by a method Morris OAT on the model, together with an optimization with the usage of change of individual parameters with a great importance on the output of the model. Model is conducting good and biologically comparable results when there are from 10 to 100 active receptors at the beginning of the track. Unfortunately with a lower numbers, the results are not valid and therefore not to be used for the simulation of influencing of two activated receptors. Despite this is a main benefit of the work the model of signal transduction for the whole signal track with an included feedback and emphasis on diffusion. Another benefit is a set of scripts for the sensitivity analysis by a method Morris OAT and optimization.

A series of dioxidomolybdenum(VI) complexes, [MoVIO2L1–6] (1–6) and [MoVIO2L1–6(solv)] (1a–6a) {where solv (solvent) = DMSO (1a, 3a, 5a and 6a) and H2O (2a and 4a)} have been synthesized using thiosemicarbazone ligands, H2L1–6. Furthermore, six monooxidomolybdenum(IV) complexes [MoIVOL1–6(N-N)] (7–12) {where co-ligand (N-N) = 2,2′-bipyridine (bipy) (7, 10 and 11) and 1,10-phenanthroline (phen) (8, 9 and 12)} have also been synthesized from the corresponding Mo(VI) precursors, [MoVIO2L1–6] (1–6) by oxygen atom transfer (OAT) reaction. Complexes have been characterized by conventional methods, including X-ray crystallography, and DFT (density functional theory) calculations. OAT reactivity of Mo(VI) and Mo(IV) complexes have been successfully established through the formation of OPPh3 and Me2S. These OAT products have been characterized by 31P NMR (OPPh3), UV–Vis spectroscopy and GC–MS (Me2S) and DFT simulations supported this finding through the prediction of ΔGtotsol for the reaction of oxygen atom transfer. DFT methods suggested that the oxygen atom transfer from [MoVIO2L] species to PPh3 to give [MoIVOL(bipy)] and from DMSO to [MoIVOL(bipy)] to yield [MoVIO2L] is strongly favored, whereas the formation of μ-oxido dimer [MoV2O3L2], is much less probable.

Streambank erosion is a major problem and a major known source of sediment in impaired streams. Stream deterioration is mainly due to the excess sediment in the United States. Many models have been developed to predict streambank erosion and sediment transport in the streams. Determining the most sensitive soil-specific parameters of the CONCEPTS Model for Goodwin Creek, MS was the focus of the study. The Latin Hypercube Oneactor-At-a-Time (LH-OAT) method was used to complete the sensitivity analysis on soil-specific parameters in CONCEPTS. Overall results demonstrate that erodibility and critical shear stress parameters should be determined very carefully and realistic to determine streambank erosion and sediment transport rate more accurately. This sensitivity analysis also shows the minimum effects of suction angle and cohesion on results. In this case, making an assumption in a literal range, or safely ignoring them should not cause a big variation on CONCEPTS results.