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The controversial condition of carbohydrate craving is believed by some researchers to be a defect in the regulation of food intake by an individual. This defect is believed to be responsible for the inability of some persons to control their food intake and therefore their weight. Research was conducted to test the hypothesis that, given a group of carbohydrate cravers and a group of noncravers, the cravers will experience a greater plasma insulin response (concentration and area under the curve) than will the noncravers, and that, because of this higher response, the cravers will experience equal or lower plasma glucose levels during a carbohydrate load. A second hypothesis was that, because of cephalic insulin response due to sensory stimuli, cookies would elicit a greater plasma insulin response than would a glucose solution. This higher plasma insulin response may in part explain the uncontrollable snacking that some individuals experience. The purpose of this research was to attempt to identify a biochemical distinction between persons who crave carbohydrates and persons who do not crave carbohydrates. Eleven overweight female subjects, age 30 to 40, were recruited and divided into two groups, five carbohydrate cravers and six noncravers, based on scores received on a questionnaire that was devised for this study to attempt to distinguish between the groups. A Restrained Eating questionnaire was also administered to the subjects. Both groups had similar, but high, restrained eating scores, indicating that all of the subjects were probably restrained eaters. The eating restraint, as supported by the reported frequency of dieting among the subjects, may well have influenced the subjects' responses to the carbohydrate craving questionnaire. Utilizing these two groups of subjects, two tests were administered. The oral glucose tolerance test was administered, utilizing 75 g of carbohydrate each in the forms of glucose solution and cookies, which were administered in a random order. The tests were administered during the premenstrual phase of the subjects' menstrual cycles, 0-10 days prior to the onset of menstruation. Blood was drawn and assayed for plasma glucose and insulin. The research showed that the cravers experienced a significantly greater plasma insulin concentration and area under the curve than the noncravers, particularly at the 30, 60 and 120 minute time points with the glucose treatment. For the glucose treatment, the cravers experienced plasma insulin concentrations that were 32% to 50% greater than those of the noncravers in the early portion of the test. This supports the hypothesis which states that cravers will experience a greater plasma insulin response to a carbohydrate load than will noncravers. This elevated plasma insulin level may be responsible for the carbohydrate cravings that the individuals experience. There was no significant difference in plasma glucose levels at any time point in either of the tests as compared between the cravers and noncravers, thus supporting the expectation that these levels would be similar between the groups. The hypothesis that cookies would elicit a greater plasma insulin response than would a glucose solution was not supported. Any cephalic insulin response which may have resulted from the sight and smell of the cookies, while not specifically measured, was not strong enough to override the physiological factors that control insulin release. Therefore, the glucose solution elicited a significantly greater plasma insulin concentration than did the cookies in the cravers during the first two hours of the tests, and a significantly greater area under the curve for the cravers at 60 minutes and both groups at 120 minutes. However, the cookies did have an effect on insulin release at the fasting point, causing elevated (x = 79%) plasma insulin levels in three of five subjects who were waiting while others were eating the cookies, as compared with these subjects' fasting insulin levels when they were not exposed to the cookies prior to their glucose test. Another finding was a difference between the groups in fasting plasma insulin concentrations over the 10 day premenstrual portion of their menstrual cycles. The noncravers experienced fasting plasma insulin concentrations that decreased as the onset of menstruation was approached, which would parallel the decrease in progesterone levels. However, the cravers experienced first a decrease in fasting plasma insulin levels to day 3 premenstrual, and then an increase to the level of that found 8-10 day premenstrual. This pattern is contrary to what would be expected as progesterone levels drop, and suggests an altered pattern of progesterone levels in the cravers, although progesterone was not measured in this study. To summarize, in a group of overweight women, carbohydrate cravers and non cravers, the cravers experienced a greater plasma insulin response than did the noncravers for the glucose treatment but not for the cookie treatment, and there was no significant difference between the groups for plasma glucose concentration for either treatment. / Graduation date: 1991

Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2013. / Acha starch was isolated and purified from clean and milled acha grain. Functional, thermal and physicochemical properties of acha starch were analysed using appropriate methods. Wheat starch was used as the reference standard. Acha bread from acha grain was baked and the consumer sensory acceptability was evaluated and white wheat bread was used as the reference standard. The effect of baking, boiling, steaming and microwaving on the starch and glycemic properties of the acha starch was evaluated. With regard to thermal properties, gelatinisation temperature of acha and iburu starches typifies that of waxy starch. Acha starch has similar retrogradation temperature profiles as that of wheat. There were however significant differences in some of the functional properties (pasting and turbidity) and physico-chemical properties (in vitro starch digestibility), but no significant difference in the texture profile analysis (TPA) and water binding capacity (WBC). WBC of both acha varieties was higher than that for wheat starch. Due to its high break down viscosity, white acha starch can be included in foods that are subjected to high temperature processing. This indicates that both acha starch varieties can be used for hot and cold desserts as well as for soft jelly like sweets and confectionery toppings. A prescreening exercise using carboxymethyl cellulose (CMC), Xanthan gum, yeast and acha starch as the variables was successful in concluding a recipe which rendered acha bread with the optimum specific loaf volume for both white and black acha bread. The optimum recipe consisted 8.0 % acha starch, 2.0 % xanthan gum, 2.0 % CMC and 1.0 % yeast. The majority of the consumer panellists found the crust colour, taste and aroma to be moderately desirable. This implies that most consumers find acha bread to have the potential to be marketed as wheat free bread. The different processing methods baking, boiling, microwaving and steaming, affected the black and white acha starch hydrolysis. The amount of starch hydrolysed for the different processing methods was in the following order: baking > boiling > microwaving > steaming. It can thus be concluded that different processing methods affects the micro structure and physical properties of the acha and wheat samples which thus influence their starch hydrolysis. The equilibrium percentage of starch hydrolysed after 180 min incubation was affected differently for the various starches, black acha, white acha and wheat starch by the different processing methods and times. In the case of baking black acha starch and wheat bread were affected similarly. However, this was not the case for microwaving, steaming and boiling, where both acha starch varieties and wheat starch were affected in the same way. The rate of starch hydrolysis for both acha varieties and wheat grain for the different processing methods, steaming, boiling, microwaving and baking was affected to the same degree respectively.

The economics of microalgal bioproduct commercialization would benefit from increased accumulation of energy storage compounds, such as carbohydrates and lipids, and increased biomass productivity. This thesis explores two adaptive laboratory evolution strategies for improving Scenedesmus obliquus: single UV-mutagenesis and low light cultivation at a high dilution rate to produce cultigens with greater carbohydrate content and iterative UV-mutagenesis and selection under outdoor conditions in a raceway pond at a high dilution rate to increase biomass productivity. Two cultigens were generated with the goal of increased carbohydrate content: K5 and K7. Both were mutagenized for 5 seconds and cultivated in 50-mL Klavins reactors. K5 was maintained at 95 μmol/m2-sec for 16 hours/day, and K7 was maintained at 250 μmol/m2-sec for 6 hours/day. When evaluating the two cultigens in triplicate 800-mL bubble columns against wild-type Scenedesmus obliquus, neither K5 nor K7 demonstrated an increase in carbohydrate content. To increase biomass productivity, Scenedesmus obliquus was iteratively UV-mutagenized (aliquots exposed for 5-60 seconds were combined) and cultivated in a 100-L, 0.5-m2 outdoor raceway pond fed with filtered reclaimed wastewater at a high dilution rate. Three rounds of mutagenesis and selection took place during the spring, summer, and winter months, with the MBE 509 and MBE 510 cultigens being produced after the summer and winter selection rounds, respectively. When evaluated in triplicate 800-mL bubble column reactors: MBE 509 (491 ± 42 mg/L-day, expressed as the mean of the time series ± SD) was 24% more productive than wild-type (397 ± 39 mg/L-day), and MBE 510 (443 ± 26 mg/L-day) was 13% more productive than wild-type (391 ± 9 mg/L-day). When evaluated in replicate 1,350-L, 4.5-m2 raceway ponds, MBE 509 (15.2 ± 2.2 g/m2-day) and MBE 510 (16.1 ± 1.8 g/m2-day) were 5% and 12% more productive than wild-type (14.5 ± 2.4 g/m2-day), respectively. Selection under low light and high dilution did not result in cultigens with higher carbohydrate content relative to wild-type Scenedesmus obliquus, but iterative mutagenesis and selection in an outdoor raceway pond did generate cultigens with higher biomass productivity in both indoor and outdoor environments.

A field and laboratory study was made to determine the effect of alternate year rest rotation grazin in stem bases and root crowns of crested wheatgrass. Analyses for carbohydrate reserves and total nitrogen were made for the following treatments: (1) exclosures; (2) open range; (3) agronomy cages. Both carbohydrate concentration and total nitrogen content showed differences between sampling dates but did not show differences as a result of grazing treatment on individual dates. Differences between sampling dates were associated with season and growth stage of plants. Although differences due to grazing teatment were not shown for individual dates the combined average carbohydrate concentration for plants rested or protected from grazing for one season was higher than from protected plants inside exclosures or from plants grazed during the study. Despite the short duration of this study these results indicate that alternate year rest rotation grazing as practiced on Diamond Mountain is not adversely affecting storage of food reserves in crested wheatgrass.

Syftet med rapporten är att sammanställa samt jämföra olika ätbara makroalgarter från det Rhodophyta, Phaeophyta och Chlorophyta divisionerna utifrån dess näringsinnehåll. Detta för att analysera algernas utvecklade potential som livsmedel och som substitut till animaliska proteinkällor. För att uppnå syftet kommer algarternas näringsinnehåll att sammanställas utifrån protein-, kolhydrat- och fettinnehåll genom datainsamling av tidigare forskning. Rapporten utgörs av en litteraturstudie där insamling av data sker via databasen Google Scholar och enbart originalartiklar väljs ut. Algernas näringsvärde jämförs sedan med värden för sju referensprodukter som används som proteinkällor på livsmedelsmarknaden idag. Rapporten visar att alger hos divisionen Rhodophyta har det högsta proteininnehållet, men att även alger hos övriga divisioner innehåller mer protein än ett flertal av referensprodukterna. De granskade algarterna har generellt sett goda förutsättningar att substituera många av referenslivsmedlen och därmed den näringsinnehållsmässiga potentialen för utvecklad användning inom livsmedelsindustrin. / The aim of the report is to compile and compare different edible macroalgaes from the Rhodophyta, Phaeophyta and Chlorophyta divisions by their nutritional content. This in order to analyze if the algaes have potential for expanded use on the food market and as a substitute for animal protein sources. To achieve the aim, the nutritional content of the algaes will be compiled on the basis of protein, carbohydrate and fat content through a data collection of previous research. This bachelor thesis is a study of literature, where only journal articles and scientific reports are used. The algaes nutritional values are then compared to values for seven reference products, that are used as protein sources on the food market today. The report shows that the algal species from the Rhodophyta division have the highest protein content, and that algae from the other divisions show protein contents higher than most of the reference values. The reviewed algaes generally have good qualifications to substitute many of the reference products and therefore, as regards the nutritional content, big potential for expanded use within the food industry.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-06-14T12:26:32Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) tese_carlos_davi_santos_e_silva.pdf: 1996582 bytes, checksum: f5e5507222353ab43be89856ea18958b (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-06-14T20:55:21Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) tese_carlos_davi_santos_e_silva.pdf: 1996582 bytes, checksum: f5e5507222353ab43be89856ea18958b (MD5) / Made available in DSpace on 2017-06-14T20:55:21Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) tese_carlos_davi_santos_e_silva.pdf: 1996582 bytes, checksum: f5e5507222353ab43be89856ea18958b (MD5) Previous issue date: 2015-09-25 / Sem bolsa / Devido às diferenças de altitude entre as diversas regiões de cultivo de macieira no Brasil, conhecer as respostas fisiológicas das plantas nessas diferentes condições constituem-se questões relevantes a serem estudadas, uma vez que a altitude pode influenciar a interação das plantas com diversos fatores abióticos e bióticos, afetando o crescimento e o desenvolvimento das mesmas. Este trabalho teve por objetivos caracterizar a densidade de estômatos e as trocas gasosas em folhas, a dinâmica do teor de amido e da relação C/N em ramos do tipo brindila, bem como a produção e qualidade de frutos de macieiras cultivadas em três diferentes altitudes. O experimento foi conduzido em pomares localizados nas altitudes de 1.000, 1.200 e 1.400 metros, nos ciclos 2012/2013, 2013/2014 e 2014/2015. Utilizou-se as cultivares de macieiras (Malus domestica Borkh.) Fuji Suprema e Imperial Gala, com 7-8 anos de idade, enxertadas sobre M-9 e 2.500 plantas ha-1. Durante os três ciclos produtivos foram avaliados o conteúdo de amido e a relação C/N em ramos do tipo brindila. Durante os ciclos 2013/2014 e 2014/2015 foram avaliadas as trocas gasosas em folhas de brindilas, o índice SPAD, produção e qualidade de frutos. Em dezembro de 2013 foi determinada a densidade de estômatos. Cada cultivar foi avaliada de forma independente e adotou-se o delineamento inteiramente casualizado com três tratamentos (1.000m, 1.200m e 1.400m de altitude) e sete repetições, sendo cada repetição representada por uma planta. Realizou-se a análise de variância dos dados e as médias foram comparadas pelo teste de Scott- Knott (p≤5). A cultivar Fuji Suprema apresentou densidade estomática crescente de acordo com a altitude, porém nenhuma alteração significativa foi identificada na cultivar Imperial Gala. De maneira geral, as diferenças nos parâmetros de trocas gasosas registradas entre cada altitude, dentro de cada época de avaliação, variaram principalmente em função das condições climáticas locais. A eficiência instantânea de carboxilação, no entanto, tendeu a ser maior com o aumento da altitude nas plantas de ambas as cultivares. Similar resposta foi identificada para o teor de amido nas brindilas, de ambas cultivares, porém foi observado que quanto maior a carga de frutos, menor foi o teor de amido nos ramos até a colheita. No geral o teor de amido e a relação C/N apresentaram uma relação diretamente proporcional com as variações na altitude dos pomares. A ocorrência de mancha de Glomerella na ‘Imperial Gala’ cultivada a 1.000m influenciou essas duas últimas variáveis. Os frutos de ambas as cultivares estudadas tenderam apresentar melhor qualidade nas maiores altitudes. Isso ficou evidenciado quando comparados a firmeza de polpa e o teor de sólidos solúveis totais. / Due to differences in altitude between the various apple-growing areas in Brazil it is extremely important to know the physiological responses of plants under those different conditions, because altitude can influence the interaction of plants with various biotic and abiotic factors affecting their growth and development. The objective of this work was to characterize the density of stomata, gas exchange in leaves, starch content dynamics, C/N ratio in brindila-type branches, and production and quality of apple tree fruits grown at three different altitudes. The experiment was conducted in orchards located at altitudes of 1000, 1200 and 1400 meters, 2012/2013, 2013/2014 and 2014/2015 cycles. We used apple trees (Malus domestica Borkh) Fuji Suprema and Imperial Gala cultivars that were 7-8 years old, grafted on M-19, and 2500 plants ha-1. During the three production cycles we evaluated the starch and C/N ratio in brindila-type branches. Gas exchange in brindilas leaves, SPAD index, fruits production and quality were evaluated during 2013/2014 and 2014/2015 cycles. Stomata density was determined in December 2013. Each cultivar was evaluated independently and we adopted the completely randomized design with three treatments (1000m, 1200m, and 1400m altitude) and seven repetitions, each one represented by one plant. We performed analysis of variance (ANOVA) to the data set, and means were compared by Scott-Knott test (p≤5). Fuji Suprema cultivar showed growing stomata density in accordance with altitude, but no significant change was identified in Imperial Gala cultivar. In general, differences in gas exchange parameters recorded between each altitude, in each evaluating time varied mainly depending on local weather conditions. The instantaneous carboxylation efficiency, however, tended to be higher in both plants cultivars with increasing altitude. Similar response was identified for starch content in brindilas of both cultivars, however we observed that the higher the fruit load, the lower the starch content in the branches to harvest. In general, starch content and C/N ratio showed a directly proportional relationship with variation in altitude of the orchards. The occurrence of Glomerella spot in ‘Imperial Gala’ grown at 1000m influenced those latter two variables. The fruits of both cultivars studied tended to have better quality at a higher altitude. It was evidenced when the pulp firmness and total soluble solid content were compared.

Diabetes mellitus is a frequent endocrinopathy in dogs. Exogenous insulin and nutritional management are the mainstays of therapy. High carbohydrate and fibre diets have been traditionally recommended for canine diabetes mellitus. However, recent studies in healthy and diabetic dogs have challenged the use of these traditional diabetic diets. In addition, dietary carbohydrate content was found to be the main determinant of postprandial blood glucose concentrations over 1.5 hours in healthy dogs. Increasing carbohydrate content increased blood glucose concentration. In a search of the literature, no studies in dogs were found comparing the effects on postprandial plasma glucose, insulin, triglyceride and free fatty acid concentrations of a traditionally recommended high carbohydrate and fibre diabetes diet with a moderate carbohydrate and fibre diet, or a commercially-available maintenance diet. Although fasting plasma triglyceride concentrations are commonly used for diagnosis and management of canine hyperlipidemia, a review of the literature found that in human beings, it may not to be predictive of the highest postprandial concentration. Importantly, in overweight and obese dogs with postprandial plasma triglyceride concentrations >5 mmol/L (>445 mg/dL), it was found there was a 6 fold increase in risk of laboratory evidence of exocrine pancreatic disease. However, there are limited studies on the effect of maintenance diets on postprandial plasma triglyceride concentrations in dogs, and no reference intervals determined for a triglyceride meal challenge test in healthy dogs. For the dietary studies in this thesis, animal welfare was of paramount importance, and minimally invasive peripheral venous catheterization and blood collection techniques were needed to collect 4 mL blood samples over 13 hours in conscious dogs. A search of the literature found no studies evaluating the reliability of using peripheral catheterization via the cephalic vein for the collection of larger blood volumes (for example, 4 mL). The aims of this thesis were firstly, to investigate the influence of three diets with varying carbohydrate and fibre content on postprandial plasma glucose, insulin, triglyceride and free fatty acid concentrations in healthy dogs over 12 hours; secondly, to develop a triglyceride meal challenge test and associated reference intervals; and finally, to evaluate a minimally invasive catheterization and blood collection technique for reliability in collecting the blood volumes required for these studies. For the studies in this thesis, twelve healthy dogs were fed each of three diets for three weeks in a three period cross-over design. For the meal response test at the end of each three-week period, 10 blood samples were collected over 13 hours. Reference intervals for fasting and postprandial triglyceride concentrations at single and multiple time points after eating a standard meal were determined in healthy dogs. Associations between fasting and postprandial triglyceride concentrations, and time to measure highest postprandial triglyceride concentration were also evaluated. Blood volume obtained, resistance on aspirating the blood sample, and methods used to improve blood flow during collection were recorded for the 358 samples collected. The results of the studies in this thesis demonstrated that a moderate carbohydrate diet resulted in lower peak and postprandial glucose concentrations compared with a traditional diabetic diet (CHO 55 %ME) and a maintenance diet (CHO 45 %ME). Fasting triglyceride concentrations were found not to be predictive of peak postprandial triglyceride concentrations. The highest triglyceride concentration measured at 2, 5, and 6 hours after eating had the closest agreement with peak postprandial triglyceride concentration. Glucose, insulin and triglyceride concentrations in some dogs were significantly above baseline concentrations at 12 hours after eating each of the diets. Of 358 blood samples collected, 93 % achieved the required 4 mL volume, while the remaining samples were greater than 1.5 mL, and 87 % were obtained with minimal resistance. It was concluded that the moderate carbohydrate and fibre test diet warrants evaluation in diabetic dogs. It was found that when following the same protocol, blood samples should be collected 2, 5, and 6 hours after eating to determine the highest postprandial plasma triglyceride concentration. For future nutritional studies, dogs may need to be fasted for at least 12 hours, and analytes measured over at least 12 hours after feeding to evaluate fasting and postprandial plasma analyte concentrations. Finally it was demonstrated that percutaneous catheterization of the cephalic vein using a 20-gauge catheter allows for successful collection of multiple 4 mL blood samples over 13 hours in conscious dogs. This thesis presents new information for future nutritional studies in healthy and diabetic dogs by suggesting that there may be no glycemic benefit feeding the high carbohydrate and fibre diet compared with a moderate carbohydrate and fibre diet. A triglyceride meal challenge test was developed to assist the diagnosis of canine hyperlipidemia. Finally, a minimally invasive method for obtaining serial blood samples was evaluated and described. These findings are expected to help in designing future studies in the nutritional management in healthy dogs, and dogs with diabetes mellitus and hyperlipidemia.