To understand the function of the cardiovascular system, the propagation of waves in arteries has to be investigated, since they carry information which can be used for the prevention and diagnosis of cardiovascular diseases. The main goal of this thesis is to improve the understanding of wave propagation in central and peripheral arteries studying the local hemodynamics of the ascending aorta, the carotid artery and the femoral artery by analysing human, animal and in vitro data. Also, another aim is to introduce a technique for non-invasive determination of the local arterial distensibility, the wave speed, and wave intensities. Arterial hemodynamics is here studied using wave intensity analysis, a time domain technique based on pressure and velocity measurements that is derived from the 1D theory of wave propagation in elastic tubes. Also, variations of this technique were used, such as (i) the non-invasive wave intensity analysis that relies on diameter and velocity measurements and (ii) the reservoir-wave approach in which pressure is considered the sum of a pressure due to the elastic properties of the arteries and a pressure due to the travelling wave. To identify the correct analysis to describe the wave propagation in the ascending aorta using pressure and velocity measurements, the hemodynamics of the canine ascending aorta was studied invasively using the traditional wave intensity (or waveonly) analysis and the reservoir-wave approach in both control condition and during total aorta occlusions in order to provide clear reflection sites. The models produced a remarkably similar wave intensity curves, although the intensity magnitudes were different. The reservoir-wave model always yielded lower values for all hemodynamic parameters studied. Both models led to the conclusion that distal occlusions have little or no effect on hemodynamics in the ascending aorta. Since the ascending aorta is not an accessible vessel its examination in clinical routine is challenging. More superficial arteries, such as carotid, radial, brachial and femoral arteries, might be easier to examine, in particular using ultrasound equipment that is normally available in the clinic. These considerations led to the second study of this thesis that is the introduction of a new technique for the non-invasive determination of arterial distensibility, local wave speed and wave intensities to study arterial hemodynamics in humans. The technique relies only on diameter and velocity measurements that can be obtained using ultrasound. In particular, the technique was used for the first time to study the hemodynamic of the carotid and femoral arteries in a large population of healthy humans to investigate the changes with age and gender. The carotid artery was more affected by the aging process than the femoral artery, even in healthy subjects. Local wave speed, distensibility and hemodynamic wave intensity parameters (except the reflection index) had strong correlations with age at the carotid artery. The mechanical properties and hemodynamic parameters of the femoral artery were not significantly age-dependent, but local wave speed, distensibility and forward wave intensity were significantly gender-dependent. The findings of the first and second studies contributed to the design of the third study. The carotid artery is an elastic artery relatively close to the heart and thus the hemodynamics of this vessel is related to left ventricular function. For this reason, the carotid hemodynamics of the same healthy population was investigated for the first time using the reservoir-wave approach. Pressure and velocity measurements were separated into their reservoir and excess components and the effects of age and gender on these parameters were studied. It was found that in the carotid artery reservoir and excess components are strongly affected by the ageing process. From the above studies some questions about the hemodynamics of central arteries remained unsolved. For this reason it was decided to carry out in vitro experiments in a mock circulatory system to investigate the effects of variation of compliance and stroke volume on the reservoir and excess pressure components of the ascending aorta. This allows for the study of different physiological and pathological conditions, such as age, hypertension, atherosclerosis and ventricular dysfunction in relation to vascular compliance and stroke volume. The reservoir and excess components of the measured pressure wave were both significantly related to aortic compliance and stroke volume, but the reservoir pressure had a stronger relationship with aortic compliance compared with the excess pressure and its magnitude increased more significantly when the aorta became stiffer. Wave speeds, calculated using measured and excess pressures, followed the same pattern, but the one calculated using excess pressure was smaller than the other. Wave speed was strongly related to aortic compliance, but not to the change of stroke volume. In conclusion, the use of the wave-only and the reservoir-wave models led to different values of wave speed and intensities that can be explained considering the anatomy of the arterial system. Notably, elastic and muscular arteries are differently affected by age and gender. The hemodynamics of the carotid artery are strongly related to age also in healthy subjects. Pressure and flow velocity in the carotid artery can be separated into their reservoir and excess components. The new non-invasive technique based on diameter and velocity measurements could be relevant in clinical practice as a screening tool.

Efficient function of the left ventricle (LV) is achieved by coherent behaviour of its circumferential and longitudinal myocardial components. Little was known about the direct association between the long and minor axis velocities and the overall haemodynamics generated by ventricular systolic function such as aortic waves. The forward running expansion wave (FEW) during late systole contains important information about the condition of the LV and its interaction with the arterial system. The aim of this thesis was to underpin the mechanics and timing of the LV wall velocities, which are associated with the deceleration of flow. Both invasive and noninvasive data have been analysed in canines and humans and the following conclusions can be drawn. LV long axis peak shortening velocity lags consistently behind the minor axis, representing a degree of normal asynchrony. The FEW is seen to have a slow onset before a rapid increase in energy. The slow onset corresponds with the time that the long axis reaches its peak velocity of shortening. After both axes reach their respective maximum shortening velocity they continue to contract, although at a slow steady velocity until late ejection when there is a sudden simultaneous change of shortening velocity of both axes. This time corresponds with peak aortic pressure and the rapid increase in energy of the FEW. The time that the minor axis reaches its maximum velocity of shortening interestingly coincides with the arrival of the reflected wave at the LV during mid-systole. During canine aortic manipulation through the introduction of total occlusions along the aorta, the sequence of events observed in control conditions remains unchanged. In humans both LV wall movement and carotid wave intensity can be measured successfully using non-invasive methods. The FEW is generated when the last long axis segment begins to slow. The minor axis begins to slow before this time and corresponds to the time of peak aortic flow.

Wave dissipation was previously investigated intensively in the frequency domain, in which the dissipation of waves is described as attenuation of pressure pulse decay with respect to the frequency or harmonics. In this thesis, wave dissipation, including decay of pressure pulse, peak of wave intensity and wave energy, is investigated in the time domain using wave intensity analysis (WIA). Wave intensity analysis benefits to this research in several aspects including: 1) WIA allows for wave dissipation investigated in the time domain; 2) WIA does not make any assumptions about the tube's wall non-linearity and the analysis takes into account the effects of the vessel's wall viscoelastic properties, convective, frictional effects and fluid viscosity; 3) WIA offers a technique (separation) to study wave dissipation in one direction whilst taking into account the effect of reflections from the opposite direction; 4) The physical meaning of wave intensity provides a convenient method to study the dissipation of energy carried by the waves along flexible tubes. In this research, it is found that the degree of dissipation in flexible tube were not only affected by the mechanical properties of the wall property and viscosity of liquid but also by the other factors including initial pressure and pumping speed of piston as well as direction of wave in relation to direction of flow. Also an new technique to separate waves into forward and backward directions only using diameter and velocity might potentially be used to separate the waves in both directions non-invasively based on the non-invasive measurement of diameter (wall movement) available.

The wall properties of the arteries play an important role in cardiovascular function. Stiffness of large artery is predictive of cardiovascular events. To understand the function of the cardiovascular system, special attention should be paid to the understanding of pulse wave propagation, because pulse waves carry information of the cardiovascular function, and provide information which can be useful for the prevention and diagnosis of diseases. This thesis presents a series of in vitro experimental studies of wave propagation, wave reflection and determination of mechanical properties of flexible vessels. In this thesis, several studies have been included: 1) applied and compared foot-to-foot, PU-loop and lnDU-loop methods for determination of wave speed in flexible tubes and calf aortas; 2) investigated the variation of local wave speed determined by PU-loop with proximity to the reflection site; 3) investigated using wave intensity analysis (WIA) as the analytical technique to determine the reflection coefficient; 4) developed a new technique which based on one-point simultaneous measurements of diameter and velocity to determine the mechanical properties of flexible tubes and calf aortas. In the first study, it is found wave speeds determined by PU-loop and lnDU-loop methods are very similar, and smaller than those determined by foot-to-foot method. The timing of arrival time of reflected wave based on diameter and velocity technique highly agreed with the corresponding timing based on pressure and velocity technique. The shapes of forward and backward non-invasive wave intensities based on diameter and velocity are very similar with the corresponding shapes based on pressure and velocity. Although the density term is not part of the equation, the lnDU-loop method for determining local wave speed is sensitive to the fluid density. In the second study, it is found wave speed measured by PU-loop is varied with proximity to the reflection site. The closer the measurement site to the reflection site, the greater the effect upon measured wave speed; a positive reflection caused an increase in measured wave speed; a negative reflection caused a decrease in measured wave speed. Correction iteration process was also considered to correct the affected measured wave speed. In the third study, it is found, reflection coefficient determined by pressure, square roots of wave intensity and wave energy are very close, but they are different from reflection coefficient determined by wave intensity and wave energy. Due to wave dissipation, the closer the measurement site to the reflection site, the greater is the value of the local reflection coefficient. The local reflection coefficient near the reflection site determined by wave intensity and wave energy are very close to the theoretical value of reflection coefficient. In the last study I found that distensibility determined by the new technique which utilising lnDU-loop is in agreement with that determined from the pressure and area which obtained from tensile test in flexible tubes; distensibility determined by the new technique is similar to those determined in the static and dynamic distensibility tests in calf aortas; Young’s modulus determined by the new technique are in agreement with that those determined by tensile tests in both flexible tubes and calf aortas. In conclusion, wave speed determined by PU-loop and lnDU-loop methods are very similar, the new technique lnDU-loop provides an integrated noninvasive system for studying wave propagation; wave speed determined by PU-loop is affected by the reflection, the closer the measurement site to the reflection site, the greater the change in measured wave speed; WIA could be used to determine local reflection coefficient when the measurement site is close to the reflection site; the new technique using measurements of diameter and velocity at one point for determination of mechanical properties of arterial wall could potentially be non-invasive and hence may have advantage in the clinical setting.

This thesis deals with the mechanics of the Intra-Aortic Balloon Pump (IABP), the most widely used temporary cardiac assist device, whose beneficial action is based on the principle of counterpulsation. The investigation is carried out in vitro in increasingly more realistic setups, including a mock circulatory system with physiological distribution of peripheral resistance and compliance in which IABP counterpulsation was simulated. Pressure and flow measurements show the effect of variables such as intra-luminal pressure, angle and aortic compliance on balloon hemodynamics. These data are complemented by results on the duration of balloon inflation and deflation obtained by means of high-speed camera visualisation. Furthermore, wave intensity analysis is carried out and it is identified as a possible alternative method for the assessment of IABP performance. This work includes two prototypes of intra-aortic balloons of novel shape with the balloon chamber tapering both from and toward the balloon tip. In clinical terms, with reference to the semi-recumbent position in which patients assisted with the IABP are nursed in the intensive care unit, the results presented in this thesis indicate that operating the balloon at an angle compromises the benefit of counterpulsation when assessed in vitro.

Orientador: Helena Maria Andre Bolini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-25T18:57:52Z (GMT). No. of bitstreams: 1 Gomes_CarolinaLugnani_D.pdf: 2627248 bytes, checksum: d87d40e4b6b56259e0241367e575e41a (MD5) Previous issue date: 2014 / Resumo: Dois métodos de cocção (forno e chapa) e três temperaturas internas finais (65, 71 e 77°C) foram aplicados em contrafilé bovino (m. longissimus lumborum), com o objetivo de avaliar qual dos procedimentos proporciona a obtenção de um produto com perfil sensorial descritivo superior em relação à qualidade sensorial. As amostras de contrafilé, porção compreendida da 12º costela e a 2º vértebra lombar, de meias carcaças esquerdas de bovinos da raça Angus, da mesma idade e acabamento de gordura, foram coletadas e congeladas (-20ºC). Cada peça foi cortada em seis bifes de 2.54 cm, que foram embalados a vácuo e mantidos congelados. Os bifes foram distribuídos em seis tratamentos. Para a cocção, os bifes foram descongelados a 4°C por 24 horas antes das análises. As temperaturas internas foram monitoradas por meio de termopares inseridos no centro geométrico de cada bife. Para a perda de peso por cocção, houve interação significativa do método de cocção X temperatura interna final (p=0.002). O aumento da temperatura aumentou constantemente as perdas por cocção em ambos os métodos de cocção, de 65ºC para 77ºC. A 65ºC e 71ºC as perdas por cocção foram similares entre forno e chapa, enquanto a 77ºC, as amostras assadas no forno tiveram as maiores perdas, provavelmente devido ao longo tempo de preparo. Para a força de cisalhamento, não houve interação do método de cocção X temperatura interna final (p=0.54). Os bifes preparados a 65°C e 71ºC tiveram menores valores de WBSF (p<0,05), enquanto que aqueles preparados a 77°C tiveram valores maiores (p<0,05). Na análise de aceitação, a aparência, o aroma e o sabor tiveram maior aceitação nas amostras preparadas no forno elétrico em temperaturas mais altas, entretanto a maciez e a suculência tiveram maior aceitação nas amostras preparadas em temperaturas mais baixas, independente do método de cocção. Os bifes grelhados na chapa elétrica a 65°C foram melhores, porque proporcionaram a obtenção de uma amostra com aceitação significativamente superior em relação a todas as características sensoriais analisadas. Na Análise Descritiva Quantitativa, os bifes do forno e da chapa a 65°C foram principalmente caracterizados pelos atributos de aroma e sabor de sangue, sabor metálico, suculência, maciez, suculência aparente e cor interna vermelha. Na análise tempo-intensidade, a Imáx do estímulo maciez e suculência foi significativamente maior (p<0,05) no forno elétrico em relação à chapa elétrica. E em relação às temperaturas a Imáx das amostras submetidas a 65 e 71ºC não diferiram (p>0,05), mas diferiram (p<0,05) das amostras a 77ºC. O Ttot não foi diferente (p>0,05) para as amostras nos métodos de cocção e nas temperaturas internas finais para os estímulos de maciez e suculência. Portanto sugere-se que as diferenças encontradas pelos assessores na maciez e suculência das amostras, foram percebidas somente a primeira mordida (Imáx). E durante a mastigação até a fase de deglutição (Ttot) não variaram, indicando que as amostras permaneceram igualmente homogêneas em relação aos dois atributos após a primeira mordida / Abstract: Two cooking methods (oven and griddles) and three end-point temperatures (65, 71 and 77°C) were applied in beef strip loin (m. longissimus lumborum), to assess which of the procedures provides a product with superior descriptive sensory profile in order to the sensory quality. Strip loin samples with the similar degree of fat thickness from the 12th rib to the second lumbar vertebra of the left side of the carcass of similarly age Angus steers were collected and frozen (-20ºC). Each piece was cut into six 2.54 cm thick steaks. The steaks remained vacuum packed and frozen. For cooking, the steaks were thawed at 4°C for 24 hours. The internal temperatures were monitored by thermocouples inserted in the geometric center of each steak. The interaction between cooking method and end-point temperature had a significant (P=0.002) impact on cooking loss. The increasing end-point temperature, constantly increase levels of cooking loss in both cooking methods, from 65ºC to 77ºC. At 65ºC and 71ºC the cooking loss were similar between oven and griddle, while at 77ºC the oven had the great loss, probably due to the long cooking. The interaction between cooking method and end-point temperature did not significantly impact (P=0.54) shear force. The steaks prepared at 65°C and 71ºC had lower (P<0.05) shear force values, while those prepared at 77°C had higher values (P<0.05). In acceptance analysis of appearance, aroma and flavor, samples cooked in electric oven, at higher temperatures, had the greater acceptance, however the tenderness and juiciness had greater acceptance in samples prepared at lower temperatures, regardless the method of cooking. Steaks grilled on the counter-top griddles at 65°C yielded a sample with a significantly greater acceptability in terms of all of the sensory characteristics analyzed. For Descriptive Quantitative Analysis, steaks prepared in oven and griddles at 65°C were mainly characterized by a blood aroma and flavor, a metallic flavor, juiciness, initial tenderness, apparent juiciness and internal red color. In the time-intensity analysis, the Imax values for tenderness and juiciness stimuli was higher (P<0.05) for the samples subjected to the electric oven as compared to the electric griddles. Regarding the temperatures, although the Imax for tenderness and juiciness of the samples subjected to temperatures of 65 and 71ºC were not different (P>0.05), it differed (P<0.05) from the samples at 77ºC. The Ttot value was not different (P>0.05) for both cooking methods and end-point temperatures in relation to the stimuli tenderness and juiciness. It can be suggested that the differences on tenderness and juiciness found by the assessors were noted only at first bite (Imax). Perception of tenderness and juiciness during chewing to swallowing (Ttot) did not vary, indicating that the samples remained homogeneous for both attributes after the first bite / Doutorado / Consumo e Qualidade de Alimentos / Doutora em Alimentos e Nutrição

Orientador: Helena Maria André Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-17T12:01:23Z (GMT). No. of bitstreams: 1 Morais_ElisaCarvalhode_M.pdf: 1165882 bytes, checksum: e31a11a9884ec992fc2a62dbb8c1a7e4 (MD5) Previous issue date: 2011 / Resumo: O pão e outros produtos à base de cereal se tornaram alimentos de ¿primeira necessidade¿ em todo o mundo e estão atualmente instituídos como parte integrante de diversas dietas modernas. O alto consumo deste produto no Brasil e nos mercados internacionais, e a crescente procura dos consumidores por produtos alimentícios, não somente saborosos e nutritivos, mas que também tragam benefício à saúde, estimula o estudo da adição de prebióticos e edulcorantes. Na primeira parte deste trabalho, que avaliou os efeitos da adição dos prebióticos, inulina e frutooligossacarídeos, nas concentrações de 1, 2 e 4%, nas propriedades físicas e sensoriais de pães de forma sem glúten, a adição de 2% de inulina e 2% de FOS apresentou boa aceitação e maior intenção de compra pelos consumidores. No segundo estudo seis formulações de pães sem glúten foram avaliadas por 15 assessores celíacos treinados que identificaram 15 termos descritores para aparência, aroma, sabor e textura. Foi realizado teste de aceitação com 123 consumidores, não celíacos, de pão de forma. As amostras apresentaram diferença significativa entre si (p<0,05) para todos os atributos avaliados na ADQ. Por meio da correlação dos quadrados mínimos parciais entre as amostras, em relação aos atributos da ADQ e impressão global do teste de aceitação, observou-se que as variáveis mais significativas para discriminação entre as amostras foram cor da casca, aroma de fermento, doçura e textura de borracha. No terceiro estudo objetivou-se avaliar os pães de forma sem glúten por meio de outro teste de aceitação, com 32 consumidores celíacos, assim como avaliar o comportamento tempo-intensidade para os atributos gosto doce e sabor de fermento. Análises físico-químicas também foram realizadas com o intuito de estudar a qualidade global dos pães. Os consumidores celíacos apresentaram boa intenção de compra em relação às amostras de pão de forma sem glúten, sendo que a amostra com adição de FOS apresentou maior média para este parâmetro. Os pães apresentaram boas características físico-químicas mostrando a possibilidade de desenvolvimento de pães de forma sem glúten e naturais, com propriedades funcionais e características desejáveis aos consumidores celíacos / Abstract: Bread and other cereal-based products have become ¿first necessity¿ food in the world and are now established as an integral part of many modern diets. The high consumption of this product in Brazil and international markets and the growing consumer demand for food products, which not only are tasty and nutritious, but also that bring health benefits, encourage the study of prebiotics and sweeteners addition. In the first part of this study, which evaluated the effects of prebiotics incorporation, inulin and fructooligosaccharides, in concentrations of 1%, 2% and 4%, to gluten-free breads on physical and sensorial properties, the addition of 2% inulin and 2% FOS had good acceptance and greater purchase intent by consumers. In the second study, six gluten-free bread formulations were evaluated by 15 trained celiac assessors who identified 15 descriptors terms of appearance, aroma, taste and texture. Acceptance test was conducted with 123 not celiac bread consumers. Samples presented significant differences amongst them (p<0.05) for all attributes in the QDA. By partial least squares correlation between samples, in relation to the attributes of the QDA and overall impression of the acceptance test, it was observed that the most significant variables to discriminate among the samples were color crust, yeast flavor, sweetness and rubber texture. The third study aimed at evaluating the glutenfree breads through another acceptance test, with 32 celiac consumers, as well as evaluating the time-intensity behavior for the attributes of sweetness and yeast taste. Physical-chemical analyses were also performed in order to study the breads overall quality. Celiac consumers presented good purchase intention for the gluten-free bread samples, and the sample added with FOS had a higher mean value for this parameter. Gluten-free breads presented good physical-chemical characteristics showing the potential development of gluten-free and natural breads, with functional properties and desirable characteristics for celiac consumers / Mestrado / Consumo e Qualidade de Alimentos / Mestre em Alimentos e Nutrição

Orientador: Helena Maria André Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T20:52:35Z (GMT). No. of bitstreams: 1 Paixao_JulianaAlves_M.pdf: 2838447 bytes, checksum: 4a2d26125ef98f480babaff6ba1f4f48 (MD5) Previous issue date: 2014 / Resumo: A exigência por dietas controladas têm demonstrado um crescimento exacerbado, sendo que dentre elas destacam-se as dietas com redução calórica e restrição de açúcares, com intuito de prevenir doenças como a obesidade, além da busca pelo emagrecimento e de uma estética corporal "perfeita". Em função do aumento da procura por produtos dessa natureza, além da ampla aceitação de achocolatados em pó apresentadas pelo mercado consumidor, buscou-se o desenvolvimento de um alimento que atendesse às necessidades e preferências dos consumidores. Diante disso, o presente estudo objetivou formular diferentes amostras de bebida preparada com achocolatado em pó, contendo leite em pó integral e desnatado em duas diferentes temperaturas de consumo (6ºC e 45ºC), já apresentadas em outros estudos com bebidas solúveis, contendo cinco diferentes edulcorantes (Aspartame, Neosucralose (blend neotame, sucralose e assessulfame-K), Neotame, Stévia reb A 95% e Sucralose), os quais foram utilizados como substitutos da sacarose com o intuito de se obter um produto final com uma considerável redução calórica e semelhante sensorialmente a sacarose. As concentrações ideais de chocolate e sacarose foram determinadas através do teste de escala-do-ideal. As doçuras equivalentes foram determinadas utilizando-se estimação de magnitude e o poder edulcorante foi obtido através da Lei de Stevens. Visando a caracterização dos produtos formulados, foi realizado o teste sensorial descritivo. Conduziu-se uma Análise Descritiva Quantitativa com equipe treinada composta de 12 provadores, os quais avaliaram 17 termos descritores durante sessões individuais de análise. Para o teste tempo-intensidade foram analisados os atributos considerados mais relevantes (estímulo doce e amargo) para análise de bebida preparada com achocolatado em pó em função do tempo. Para que fosse possível analisar a opinião dos consumidores em relação às características sensoriais do produto foi realizada a avaliação afetiva através de teste de aceitação com 120 consumidores potenciais da bebida, onde os produtos foram estudados nas temperaturas de 6ºC e 45ºC, os quais foram avaliados quanto à aparência, aroma, sabor, amargor, textura, impressão global e intenção de compra. Na realização do estudo tempo intensidade para o estímulo doce, as amostras que apresentaram maior intensidade e duração nesse estímulo foram as amostras contendo neosucralose e sucralose. Quanto ao tempo-intensidade para o estímulo amargo a amostra preparada com neosucralose destacou-se quanto a intensidade e duração desse estímulo, caracterizando, o gosto amargo e o gosto residual amargo. Segundo os resultados encontrados, de uma forma geral a substituição da sacarose por sucralose e aspartame seria bem sucedida. Torna-se importante a realização de estudos sensoriais, já que produtos de diferentes matrizes podem manifestar-se de formas diferentes / Abstract: The requirement for controlled diets have demonstrated an overgrowth, and among them there stand out the calorie reduction and restriction of sugars, in order to prevent diseases such as obesity and pursuit of thinness and an aesthetic body "perfect". Due to the increased demand for such products and therefore this increased market demand, we sought to develop a food that meets the needs and preferences of consumers. Therefore, this study aimed to formulate different samples of chocolate milk beverage containing whole and skimmed milk powder at two different temperatures of consumption (6 º C and 45 º C ), already presented in other studies with soluble beverages, containing five different sweeteners ( Aspartame, Neosucralose ( blend neotame , sucralose and assessulfame -K ) , neotame , Stevia reb A 95% sucralose ) , which were used as substitutes for sucrose in order to obtain a final product with a considerable calorie reduction and the like sensory sucrose. The optimal concentrations of chocolate and sucrose were determined with the Just- About- Right scale. Equivalent sweetness was determined using magnitude estimation and sweetening power was obtained by Stevens Law. Aiming the characterization of formulated products, the descriptive sensory test was performed. The Quantitative Descriptive Analysis was conducted with trained team of 12 tasters who defined 17 terms descriptors during individual sessions of analysis. To the time - intensity test were deemed most relevant attributes (sweet and bitter stimulus) for chocolate milk beverage for analysis with chocolate beverage powder as a function of time were analyzed. To make possible to analyze consumer opinion regarding sensory characteristics was performed acceptance with 120 potential consumers of the drink , the products were studied at temperatures of 6 ° C and 45 ° C test, which were evaluated appearance, odor , flavor, bitterness , texture, overall impression and purchase intent . In relation the time intensity study for sweet stimulus, samples with greater intensity and duration in this stimulus were samples containing neosucralose and sucralose. In relation the time intensity study for sweet stimulus, samples with greater intensity and duration in this stimulus were samples containing neosucralose and sucralose. Regarding the time - intensity to the bitter stimulus, samples prepared with neosucralose stood out in relation intensity and duration for this stimulus, featuring the bitter taste and residual bitter taste. According to the results, in general the substitution of sucrose by sucralose and aspartame would be successful. It is important to undertake sensory studies, since products of different matrices can manifest itself in different ways / Mestrado / Consumo e Qualidade de Alimentos / Mestra em Alimentos e Nutrição

Orientador: Helena Maria Andre Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T18:13:30Z (GMT). No. of bitstreams: 1 Mello_FabioMagalhaesde_M.pdf: 5446376 bytes, checksum: 646a197fd2813f62c13b997f312d70e4 (MD5) Previous issue date: 2005 / Mestrado / Consumo e Qualidade de Alimentos / Mestre em Alimentos e Nutrição

The objective of this study was to analyze patterns, dynamics and processes of land-use/cover changes in the transboundary Mara River Basin in East Africa. We specifically focused on deforestation and expansion of agriculture in the watershed. The intensity analysis approach was used to analyze data from satellite imagery-derived land-use/cover maps. Results indicate that swap change accounted for more than 50% of the overall change, which shows a very dynamic landscape transformation. Transition from closed forest to open forest was found to be a dominant landscape change, as opposed to a random change. Similarly, transition from open forest to small-scale agriculture was also found to be a dominant transition. This suggests a trend (pathway) of deforestation from closed forest to small-scale agriculture, with open forest as a transitional land cover. The observed deforestation may be attributed to continuous encroachment and a series of excisions of the forest reserve. Transition from rangeland to mechanized agriculture was found to be a dominant land-use change, which was attributed to change in land tenure. These findings are crucial for designing strategies and integrated watershed management policies to arrest further deforestation in the forest reserves as well as to sustainably control expansion of agriculture.