Thèse d'exercice : Pharmacie : Nantes : 2007. / Bibliogr.

Thesis (doctoral)--Lunds Universitet. / Description based on print version record.

Wheat is the most agronomically important crop with an annual production of approximately 680 million tonnes per year over the five year period of 2008-2012 (Shewry and Tatham 2016). Wheat typically contributes about 20% of the total calorie intake in Western Europe and between 50-70% in some countries in North Africa and in West and Central Asia. It is estimated that in order to meet the continuous growing global demand wheat production needs to increase by 50% by 2050. Wheat is most commonly consumed as bread, pasta and noodles however it is also used as a food ingredient in other types of foods such as sauces and condiments. The versatility of wheat is largely determined by the unique physiochemical properties of gluten (Bailey 1941). Gluten is one of the earliest proteins to be studied, and was first described by Beccari in 1728 (Bailey 1941) and is readily isolated from wheat flour as a viscoelastic mass. Gluten is a complex mixture of proteins which are the major seed storage proteins found in the cereal grains wheat, barley, rye and oats. Gluten accounts for 70-80% of the total protein content in wheat grains and is traditionally divided into two groups based on their solubility called gliadins and glutenins (Osborne 1907). In genetically pre-disposed patients gluten is able to elicit a non-IgE mediated T-cell response known as coeliac disease (CD). CD affects approximately 1% of the global population for which there is no cure. As no cure is available patients must adhere to a strict gluten-free diet which is often costly and socially excluding. The Codex Standard states that gluten-free foods must contain less than 20 ppm of gluten from wheat, barley, rye and oats and their crossbreeds (FAO/WHO 1983). The Codex Standard also recommends using immunobased methods (or alternative methods) that are able to achieve appropriate sensitivity and specificity for the detection and quantification of gluten with a 10 ppm limit of detection (FAO/WHO 1983). Consequently the current gold standard method for detection of gluten is enzyme linked immunosorbent assay (ELISA) utilising the R5 antibody, however this method is not without shortcomings. Proteomics by mass spectrometry has the potential to offer an alternative, complementary method to determine gluten proteins in foods but for the methodology to become fully validated and accepted it must also overcome similar challenges to immunoassay methods, such as effective extraction of samples and the identification of peptide targets with the requisite specificity. In this research a global approach is taken to aid the development of gluten detection methods using mass spectrometry. One of the major hurdles that has stunted the development of mass spectrometry methods for the detection and quantification for gluten is the lack of protein sequence databases which are required to undertake the MS data searching. In the first results chapter of the thesis a curated gluten protein sequence database was developed (GluPro), and investigated for its utility as a MS data searching tool. It was observed that utilising the GluPro database resulted in improved protein identifications. Following the development of the curated database, extensive method development was carried out to undertake the most extensive background characterisation of the gluten proteome to date using discovery proteomics. To ensure the most comprehensive profile was obtained a number of extraction protocols were investigated and two mass spectrometry platforms with intrinsic differences utilising different modes of acquisition were used. This resulted in the most comprehensive profile of the gluten proteome to date being obtained. In order to meet the continually growing global demand for wheat previous mentioned it is considered that this may be done through the use of genetically modified crops with improved traits such as pesticide resistance. Resulting in the very real possibility of GM crops being introduced into the food supply chain, however there is much widespread public concern regarding the toxicity and allergenicity of genetically modified crops. As wheat is already listed as one of the major eight allergens, it is crucial to be able to undertake safety assessments which are able to assess the toxicity and allergenicity and determine if the GM crop is substantially equivalent to the non-GM counterpart. In the third part of this thesis it is shown how the MS method developed in the previous chapters could be applied and has great potential to be used for safety assessment. Further to this, it is demonstrated how utilising the additional information gathered during the curation of the GluPro database was able to ground the results into in silico measure of toxicity. In the final part of this research all information gathered was interrogated to pick appropriate MRM target peptides, which were unique to a single gluten protein and reproducibly observed to be free from modification. The peptides were synthesised with heavy labels to develop a targeted method to replace current ELISA methods for the detection and quantification. Unexpectedly mass shifts were observed for the precursor ion corresponding to deamidation of the synthetic peptides. Further investigation was undertaken to understand the location and cause of the deamidation sites. This development leads into further recommendation for future development of MRM methods for the detection and quantification of gluten.

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro de Ciencias Fisicas e Matematicas. Programa de Pós-Graduação em Química / Made available in DSpace on 2012-10-23T22:26:23Z (GMT). No. of bitstreams: 1 252774.pdf: 6091056 bytes, checksum: ec225a3f22eb19bbb54e14fdf1e72295 (MD5) / Microesferas de glúten de trigo foram preparadas a partir da técnica de emulsificação/evaporação de solvente. Como aditivo, adicionou-se PEG à solução e como substâncias modelo foram utilizadas a rodamina B e o cloridrato de diltiazem. As propriedades físico-químicas, morfológicas e sua eficiência de encapsulação foram avaliadas. Verificou-se a obtenção de partículas esféricas com tamanhos entre 8,76 e 24,80 µm. A porosidade variou de acordo com os aditivos utilizados. A eficiência de encapsulação de rodamina foi de 23,59% e 34,21% para as microesferas de glúten de trigo e Glúten/PEG 95/05, respectivamente. Para o diltiazem, a eficiência de encapsulação foi de 72,82% e 96,67%. Os resultados obtidos por DSC e FTIR indicaram interações entre as micropartículas e os aditivos utilizados. Observou-se para os ensaios de liberação in vitro que para todos os sistemas estudados houve a ocorrência de efeito burst nas duas primeiras horas de liberação. Para elucidar o mecanismo de liberação, os sistemas foram tratados com base no modelo de Higuchi e na lei das potências, determinando-se que o mecanismo de liberação das microesferas não é controlado exclusivamente por difusão. Provavelmente, a liberação ocorre via um mecanismo que combina a difusão parcial através da matriz intumescida e poros hidrofílicos. O teste de degradação mostrou que este processo não exerce influência significativa no mecanismo de liberação das microesferas de glúten de trigo.

abstract: Background: Research has found that nearly a quarter of the American population follows a gluten-free diet in some capacity, while only about 1% of the population is diagnosed with celiac disease. Although the amount of research-based evidence supporting any health benefits of a gluten-free diet in an individual without a gluten- related disorder is limited, the number of people claiming to follow a gluten-free diet continues to rise. Also, despite an increasing belief that gluten is harmful for health, the potentially undesirable effects of gluten substitutions used in gluten-free foods are largely unknown. Due to the protein network encapsulating starch granules, gluten is thought to lengthen the amount of time needed during starch digestion, thereby reducing postprandial glycemia. Therefore, it is predicted that breads containing gluten will produce a lower glycemic response compared to gluten-free breads. Aim: The aim of this study was to investigate the glycemic response of gluten-free bread made with different types of flour compared to bread made with gluten-containing wheat flour. Methods: This study involved a 3-week, randomized, single blind crossover study in which 17 healthy individuals were asked to consume a different type of bread each week, 2 of which were gluten-free. Blood glucose was taken by finger prick at fasting as a baseline measurement, then for 2 hours after bread consumption in 30-minute increments. Results: Across the three groups, there was no significant difference in iAUC values after 120 minutes (p=0.192 ). The greatest mean was seen in the gluten-containing bread (145.3 ± 82.6), then the gluten-free bread made with rice flour (125.5 ± 62.8), and lastly the gluten-free bread made with potato and fava bean flour (112.4 ± 64.5). Conclusion: The inconsistent results of this study compared to previous, similar studies suggests that the postprandial glycemic response of gluten-free products can not be generalized as a whole, but instead is dependent on the type of product and the ingredients used to replace the gluten. Although the results did not show a significant difference, it does argue against the belief that gluten-free products are invariably better for health in the general, non-gluten sensitive population. / Dissertation/Thesis / Masters Thesis Nutrition 2019

Teff (Eragrostis tef (Zucc.)) is an annual, warm-season cereal crop most notable for its gluten-free, nutrient-packed seed. Experiments were conducted in two regions of Virginia (Blacksburg and Steeles Tavern) in 2010 and 2011 to determine the grain production potential of two teff varieties (brown and white). Additionally, commercially purchased teff flour was evaluated for its suitability in producing a satisfactory baked product. Teff varieties were planted in early June and July at a seeding rate of 6 kg PLS ha??. Nitrogen fertilizer was applied at planting in the form of urea at a rate of 56 kg ha??. The experimental design was a randomized complete block with a two-way factorial treatment structure (variety and planting date) and four replications. Grain yield and nutritive value, straw yield and quality, and plant height were evaluated for each variety and planting date at Steeles Tavern in 2010. Due to failure in crop establishment and difficulties involved in threshing and processing the harvested crop, no data is available in 2010 or 2011 for Kentland or in 2011 for Steeles Tavern. In 2010 at Steeles Tavern, grain yield was significantly higher for the brown variety (367 kg ha??) compared to the white variety (97 kg ha??) for both planting dates. There was no significant difference in straw yield between varieties or planting dates with straw yield averaging 2645 and 2475 kg DM ha?? for brown and white varieties, respectively. Precipitation accumulation at Steeles Tavern was higher in 2010 (greater than 10 cm) during June and July compared to 2011 and the historic average. This may explain why the plots in 2010 were able to successfully establish and out compete weeds. In the lab, four types of baked products were tested to determine the suitability of teff for baked goods. Cakes, cookies, biscuits and bread were tested with varying treatments of teff: control (100% wheat flour) and 10, 20, 30, 40 and 100% teff flour. Each treatment was replicated three times for each product. Generally, bread and cake volumes decreased as the percent of teff increased. Teff flour was best suited for use in cookie and biscuit products compared to cakes and breads since cookies and biscuits require less leavening. Overall, both experiments (field and laboratory) demonstrated the potential of teff as an alternative grain crop in Virginia. However, additional research is needed to overcome problems associated with establishment, harvest, threshing and processing. / Master of Science

L'extraction du gluten et de l'amidon de la farine de blé est un procédé en pleine expansion avec le renchérissement des usages non-alimentaires de ces deux produits. Ce procédé repose sur l'aptitude des protéines du blé à former un réseau au cours du malaxage de suspensions farine / eau. Une difficulté majeure auquel ce procédé est confronté est la variabilité de cette aptitude selon la farine. L'enjeu de notre étude est de faire émerger les critères de composition des farines qui déterminent leur comportement dans le procédé amidonnier et de proposer des conduites du procédé adaptées. L'étude s'appuie sur un panel de 40 farines provenant de différents génotypes de blés dont on a déterminé la composition biochimique. On utilise un mélangeur planétaire (P600) couplé à une station de contrôle de la vitesse de mélange et instrumenté en couple et température pour développer le réseau de gluten (Plastographe, Brabender). Les essais sont réalisés à 25°C, pour des vitesses variables (50-110 rpm) et des teneurs en eau contrastées (rapports eau/farine de 70 à 120 g/g). Une relation reliant la durée de développement du réseau de gluten à la puissance de mélange a d'abord été établie. Cette relation fait apparaître deux paramètres propres aux farines, la quantité d'énergie et la puissance de mélange minimale pour développer le gluten. Ces paramètres sont fortement associés au locus glu-1D et à la teneur en protéines polymériques non extractibles au SDS. Par ailleurs, l'inclusion de temps d'arrêt dans le procédé et l'étude des effets d'agents chimiques interférant avec les fonctions thiols nous permet d'affirmer que la mise en place du réseau de gluten obéit successivement à un contrôle temporel puis énergétique. Dans la mesure où la viscosité des suspensions impacte également le procédé, une équation prédictive de celle-ci a été réalisée. Elle prend en compte les teneurs en amidon endommagé et en arabinoxylanes solubles, dans des proportions variables selon la teneur en eau de la pâte. Le rendement en gluten s'est enfin révélé sensible uniquement à la teneur en protéine, pour autant que l'extraction soit réalisée à l'atteinte de l'optimum de développement du réseau. De façon à disposer d'outils prédictifs faciles à mettre en œuvre industriellement, on a évalué les performances de plusieurs tests de qualité d'usage des farines (Farinographe, Alvéographe) et d'un mélangeur récemment développé (Gluten Peak Tester, Brabender). On montre qu'il est possible d'accéder à la plupart des paramètres définis dans ce travail à l'aide de cet appareil. Cette étude fournit ainsi un ensemble de relations pour contrôler le procédé et l'adapter à la farine utilisée. / Gluten and starch extraction out of wheat flour is a developing process due to the growing use of these two products for non-alimentary uses. This process is based on wheat protein abilities to form a network when flour and water are mixed. A difficulty that this process has to face is the variability of this ability among flours. The scope of our work is to determine the flour components that determine their behaviour in the gluten/starch separation process and to propose adapted process control.This study is based on a pool of 40 flours from various wheat genotypes and known biochemical composition. A planetary mixer (P600) coupled with a station controlling mixing speed and measuring torque has been used to develop gluten network (Plastograph, Brabender). Tests were performed at 25°C for varying mixing speeds (50-110 rpm) and contrasted dough water contents (water/flour ratio varying from 70 to 120g/g). A relation predicting mixing duration for network formation according to mixing power has been established. From this relation two parameters characterising flours have been isolated, energy demand and minimum mixing power to develop gluten network. Theses parameters are strongly linked with locus glu-1D and to SDS-unextractable polymeric protein content (UPP) in the flour. Besides, the inclusion of mixing stops in the process and the study of the effects of thiol-interfering chemical reactant has demonstrated that gluten development inclusing successively a temporal and an energetic phenomenon.As dough viscosity also strongly impacts process, a predictive equation of viscosity has been determined. Viscosity is obtained from the calculated effects of damaged starch and soluble arabinoxylans contents, varying with dough water content. Finally, it was whown that gluten extraction yield depends only of flour protein content when extraction is performed out of optimally developped dough,.In order to get tools applicable industrially, the predictive performance of two devices measuring flour quality (Farinograph, Alveograph) and of a novel mixer (Gluten Peak Tester, Brabender) was evaluated. Most of the relevant parameters defined in this work could be obtained out of that novel apparatus. This study hence gives relations to control the process and adapt it to the flour.

8 pp. / With the growing popularity of the gluten-free diet, there are many misconceptions surrounding gluten, carbohydrates, celiac disease, and gluten-sensitivity. This article explains the definitions of and differences between celiac disease, gluten-sensitivity, and other gluten-related conditions. The article also addresses the risks of adopting a gluten-free diet without a medical necessity to do so. Lastly, the article provides a healthy gluten-free recipe.

Celiac disease is attributable to autoimmune diseases, where treatment is based on absolute respect for gluten-free diet. As the gluten used widely in all areas of food production, strict adherence to a gluten-free diet really can be difficult for people with celiac disease. Products suitable also for those suffering from the disease are usually expensive. Finally, patients that undergo exclusively on a gluten-free diet are robbing the important nutritional components. Therefore, interest in this type of products innovation enhance as to the nutritional, technological, as well as organoleptic properties. The aim of this final thesis was to draw up literature review of the celiac disease and gluten allergen, or his particular part of gliadin. In the experimental part, attention was focused on the first hydrolytic cleavage of starch, the substrate was sterilized wheat flour and water, where is incorporated spiral just gluten. The best ability of degrading the starch grains, the combination of enzymes and MT3K and GLUAMK concentration of 0, 1% over 4 hours of action, as indicated by a reduction in the starch content of the original amount of 72,65 % at a concentration of 29,00 %. The next item of work distribution used different proteases, to reduce the amount of gliadin to below 20 ppm per kilogram of final product. Low levels investigated allergen (10,79 ppm/kg) recorded by the enzyme combination exoprotease Flavourzyme (0,1 %) and endoprotease Neutral Protease (0,1 %) at 7 hours hydrolytic action. The conclusion of the thesis was prepared several alternatives gluten-free breads and through sensory evaluation assessed the characteristics of color, aroma and taste to predict the location of the products on the commercial market.

Gluten-related disorders (GRDs) refer to a group of conditions that are caused by the ingestion of the gluten proteins present in wheat, barley, and rye. The global prevalence of GRDs is estimated to range from 0.6% to 10.6% of the general population, making it a significant global health issue. Treatment of GRDs requires dietary gluten avoidance. In China, there is believed to be a growing number of people with GRDs associated with changing eating patterns, increasing awareness, and better detection methods of these conditions in China. However, there is a lack of research about how to help this population maintain a restrictive diet and navigate food and social environment. The main purpose of this study was to explore the feasibility and acceptability of a culturally adapted low-gluten diet intervention among young adults in southeastern China. This study was a pre-post study design to investigate whether the intervention is effective in helping participants maintain a low-gluten diet for eight weeks. Participants were 62 young adults living on campus in southeastern China. Image-based food records and questionnaires were used to assess their dietary adherence, dietary quality, satisfaction, knowledge, self-efficacy, and other related determinants of following a low-gluten diet. Results suggested good feasibility of this dietary intervention. Only 1.9% of the total items consumed during the intervention was high-gluten or likely-high-gluten items, such as processed meat, mixed dishes, and fried food, and traditional noodles, suggesting an overall good compliance to the low-gluten diet. Specifically, over 95% of participants were found to be compliant with the diet based on all adherence measures. Females had better compliance than males (p=0.005 based on frequency, p=0.039 based on grams of gluten intake). Results also suggested good acceptability of this dietary intervention. All participants found the dietary intervention to be satisfactory with group communication and reminders rated to be the most helpful components. The perceived difficulty level of maintaining the low-gluten diet was 6.34 out of 10 (10 being the most difficult). The most rated barriers were fewer food choices and change of eating habits. Participants reported having more perceived barriers at the end of study compared to the beginning of the study, mean (SD) 17.19 (5.82) vs. 16.13 (4.19) out of 32, p = 0.285. Motivation scores were significantly lower at the end of study compared to the beginning of the study, mean (SD) 11.66 (2.21) vs. 13.40 (2.37) out of 16, p < 0.001. Increased perceived barriers and decreased motivation may suggest that they experienced more challenges in maintaining the low-gluten diet at the end of this two-month intervention. During the intervention, participants had significantly lower calories, carbohydrates, and vitamin B1 (thiamin) intake compared to baseline (p <0.05). Participants’ average dietary diversity score had no significant difference compared to baseline, 7.68 (1.10) vs. 7.69 (1.35), p=0.96. Participants had increased objective knowledge (p<0.0001), subjective knowledge (p< 0.0001), and behavioral capability (p<0.0001) compared to baseline. However, univariate and multivariate regression analyses did not find significant predicting effects of any determinants on dietary adherence. Our dietary assessment method, the image-based food records, was shown to be a reasonably valid and reliable tool to estimate the dietary intake among Chinese young adults based on comparison to weighted food records with the Bland–Altman plot and inter-rater reliability test (Cohen’s kappa=0.875). These findings suggested that a culturally adapted low-gluten dietary intervention was feasible and acceptable among Chinese young adults. Improvement on long-term dietary adherence and more research on determinants is needed. This study may inform health practitioners and policy makers to provide better culturally tailored support to patients who need to follow a low-gluten diet in China.