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1
Gan, Zhilin. "The structure and functional properties of gas cells in wheat bread dough with special reference to the use of wholemeal flour". Thesis, King's College London (University of London), 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242897.
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2
Alava, Juan Manuel. "Formation and development of bread structure in high speed breadmaking". Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288681.
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3
Juwah, Charles Isitoa. "The microbiology and biochemistry of commercial pre-fermented doughs". Thesis, University of Strathclyde, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389697.
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4
Campbell, Grant M. "The aeration of bread dough during mixing". Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302951.
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5
Kindred, Daniel R. "Investigating heterosis for yield, breadmaking quality and nitrogen use efficiency in wheat". Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412168.
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6
Tyler, Adam Michael. "Manipulating Rab GTPase activity in wheat to alter gluten quality for breadmaking". Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12914/.
Testo completoAbstract (sommario):
In the developing endosperm of bread wheat (Triticum aestivum), seed storage proteins are produced on the rough endoplasmic reticulum (ER) and transported to protein bodies, specialised vacuoles for the storage of protein. The important gluten proteins of wheat are transported to the protein bodies they are stored in by two distinct routes. One route consists of vesicles that bud directly off the ER, while the other involves transport through the Golgi (Arcalis et al, 2004). In plants, the RabD clade mediates ER to Golgi vesicle transport (Batoko et al, 2000). Available sequence information for Rab GTPases in Arabidopsis, rice, Brachypodium and bread wheat was compiled and compared in phenetic trees. Partial genetic sequences were assembled using the first draft of the Chinese Spring wheat genome. A suitable candidate gene from the RabD clade (TaRabD2a) was chosen for down-regulation by RNA interference (RNAi) and an RNAi construct was used to transform wheat plants. Using real time PCR, all four available RabD genes were shown to be knocked down in the developing endosperm of transgenic wheat. The transgenic grain was found to produce flour with significantly altered processing properties when measured by farinograph and extensograph. SE-HPLC found that a smaller proportion of HMW-GS and large LMW-GS are incorporated into the glutenin macropolymer in the transgenic dough. Lower protein content but a similar protein profile on SDS-PAGE was seen in the transgenic grain
7
Thompson, Andrew. "The comparative performance of wheat cultivars and genotypes in different organic systems of production". Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294863.
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8
Stinson, Jesse. "A quantitative method to evaluate the effect of xylanases in baking". Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/19752.
Testo completoAbstract (sommario):
Master of ScienceFood Science Institute
Fadi Aramouni
β-(1,4)-endoxylanases, commonly referred to as xylanases, have become integral to the industrial breadmaking process. This enzyme is known to cause improvement in dough rheology, loaf volume, and crumb grain. Significant research has been conducted regarding the structure, function, and inhibition of xylanases, but there is currently no quick and reproducible method to evaluate their effect in baking. The goal of this research was to develop a quantitative method for this purpose and to determine why the effect of xylanases varies with different wheat flours. The currently used methods of test baking, dough stickiness, and spectrophotometric analysis for reducing sugars were evaluated, and failed to provide reproducible results. Therefore, a new method was developed to measure the Flour Water Expression Rate (FWER) with the addition of xylanases. Commercially available enzymes from Aspergillus niger and Bacillus subtilis were evaluated in this study. The FWER method measures the amount of water released by the xylanase over a set period of time. This method consistently provided statistically significant data (p<0.05), which was able to provide a comparison of xylanases from A. niger and B. subtilis in different flours. The results indicated that the xylanase from A. niger tends to release more water, have a higher FWER value, than the xylanase from B. subtilis. In one flour, A. niger xylanase resulted in an FWER of 15.18 compared to B. subtilis xylanase that resulted in an FWER of 9.57 at equivalent activities. However, inhibitors in the wheat appeared to cause an impact on the FWER, which was evaluated with an uninhibited xylanase from B. subtilis. This new method for the evaluation of xylanases in baking suggests varying levels of xylanase inhibitors in wheat may be the reason xylanases effect wheat flours differently.
9
Godfrey, David Daniel. "The impact of Nutrition on the Development, Composition and Breadmaking Quality of Wheat Grain". Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503886.
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10
Salt, Louise Jane Patricia. "The role of the aqueous phase of dough in gas-cell stabilisation during breadmaking". Thesis, University of East Anglia, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410502.
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11
Baasandorj, Tsogtbayar. "Hard Red Spring Wheat Quality Evaluation with Various Roller Mill Types and Breadmaking Methods". Diss., North Dakota State University, 2016. http://hdl.handle.net/10365/25923.
Testo completoAbstract (sommario):
Roller mill type and breadmaking methods might be a source of variation in the evaluation of the end-use quality of Hard Red Spring (HRS) wheat. In this study, various roller mill types and baking methods have been used to investigate whether they affect end-use quality evaluation of HRS wheat cultivars. In addition, a quality scoring system has been developed to determine if ranking of the HRS wheat cultivars would change when different roller mills and breadmaking methods were used. Both the roller mill type and breadmaking method had an effect on the end-use quality of HRS wheat cultivars. When using different roller mills for quality evaluation, HRS wheat samples of MN Bolles and ND Glenn from Gulf/Great Lakes (G/GL) region and ND Glenn from Casselton location had overall quality scores of 6.5 or above when averaged across mill types. When using various baking methods and conditions for quality evaluation, ND 817, MN Bolles, ND Glenn cultivars from Pacific Northwest region, and MN Bolles and ND Glenn from G/GL region received overall baking quality scores of 6.5 or above hence these cultivars were considered to have ?excellent? baking quality characteristics under different baking conditions. The results in the current research study indicate that although there are differences in the mill type and breadmaking methods on the end-use quality evaluation, the ranking of HRS wheat flours is not affected by the mill type or baking methods and conditions. In other words, cultivars considered to have ?fair? quality tend to have low end-use quality, while ?excellent? cultivars will have superior end-use quality regardless of the roller mills and/or baking method and processing conditions used. The proposed overall wheat scoring system could assist farmers and breeders in selection of wheat cultivars considering the wheat end-use quality. Development of a comprehensive scoring system will also enable a more detailed scoring system for screening new lines for suitable end-use.North Dakota Wheat Commission
12
Pickett, Melissa M. "Study of gas cell stability during breadmaking using x-ray microtomography and dough rheology". Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1674.
Testo completo
13
Therdthai, Nantawan, University of Western Sydney, of Science Technology and Environment College e of Science Food and Horticulture School. "Modelling and optimisation of an industrial bread baking oven". THESIS_CSTE_SFH_Therdthai_N.xml, 2003. http://handle.uws.edu.au:8081/1959.7/545.
Testo completoAbstract (sommario):
In bread-making, the baking process is one of the key steps to produce the final product quality attributes including texture, color and flavor, as a result of several thermal reactions such as non-enzymatic browning reaction, starch gelatinisation and protein denaturation. These thermal reactions are dominated by heat and mass transfer mechanisms inside an oven chamber as well as inside the dough pieces. In this study, an industrial baking process was divided into 4 zones. Experiments were conducted, and mathematical models were developed to account for the heat and mass contribution as well as their consequent impacts on the product qualities. Monitoring systems were developed and installed inside an industrial oven to evaluate oven performance, including temperature profile and airflow pattern. Many other tests and experiments were conducted and results given in some detail. To deal with the complexity of a continuous baking process, a three dimensional transient-state CFD model with moving grids was established to account for the effect of oven load on heat transfer in the oven chamber. The dynamic response of the travelling tin temperature profiles could be predicted in accordance with a change in the oven load. The modelled tin temperature profiles showed a good agreement with the measured tin temperature profiles from the actual industrial baking process. Finally, the three-dimensional CFD model could provide guidance in manipulating the oven condition to achieve the optimum temperature profile in the industrial travelling-tray baking oven.Doctor of Philosophy (PhD)
14
Suchy, Jerzy. "Physicochemical studies of SDS gel protein and its value for prediction of wheat breadmaking quality". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23518.pdf.
Testo completo
15
Kaur, Harkirat, e h_harkiratkaur@student rmit edu au. "Baking enzymes and microencapsulation strategies for retardation of staling". RMIT University. Applied Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081203.133339.
Testo completoAbstract (sommario):
The staling of baked products remains a significant cause of economic loss due to the loss of enjoyment seen as crumb firming occurs. The aims of the current project have been to investigate the stability of amylases in bakery formulations. In addition, the impact of partial hydrolysis products of starch on staling is investigated. Specific assays were used to measure Ñ-amylase and Ò-amylase, in the presence of the other potentially interfering activity. Ñ-Amylase activity levels appeared to gradually increase during the proofing stages and then to decline upon heating of the dough. However, the activity remaining in the final baked loaf was readily measurable indicating that not all of the enzyme had been inactivated. Free and total Ò-amylase activities were also measured and most was found to be in the free form. Ò-Amylase was unstable with only relatively low activities remaining in the final baked loaf. It appears that of the two amylolytic enzymes, Ñ-a mylase is sufficiently stable that it may exert some impact on the crumb characteristics in the freshly baked product and during subsequent storage. In order to assess the likelihood that amylolysis is of significance to crumb characteristics, HPLC was used to analyse aqueous extracts for sugars. Commercial flours were found to contain low levels of sugars with maltose being the predominant sugar present. A number of commercial breads were also analysed and the composition found to vary between the different samples. Typically maltose was present at higher levels than the other sugars. When experimental loaves were analysed, the patterns showed that other sugars declined during proofing whereas maltose remained at readily measurable levels. Upon baking and subsequent storage the amounts of maltose increased. These results are consistent with the findings that some amylolytic activity remains in the baked product. In the third phase of this study, a potential means of investigating the role of particular carb ohydrates in product textures and staling rates was examined. The approach of spray drying was used to prepare microencapsulated maltodextrin. The encapsulating agents used were based upon rice starch and guar galactomannan. When these microcapsules were incorporated into the breadmaking formulation and baked, it appeared that softer crumb characteristics were achieved. The data also indicates an effect of delay in the staling rates. In a preliminary evaluation of the potential of two X-ray scattering methods, it was found that both techniques appear useful. The differences seen for samples of bread crumb analysed at various stages of storage did not show large differences in the intensity patterns. Of the two approaches, small angle analysis (SAXS) appears to show greater potential for application in ongoing studies of staling. In conclusion, cereal grain Ñ-amylase may be more stable during breadmaking than previously thought. There appears to be an increase in the level of some low molecular weight sugars in the final, baked product. Microencapsulation may offer a useful technique for the study of the role of specific carbohydrates during baking and storage of breads.
16
Kuktaitė, Ramunė. "Protein quality in wheat : changes in protein polymer composition during grain development and dough processing /". Alnarp : Dept. of Crop Science, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a499.pdf.
Testo completo
17
Mense, Andrew Lawrence. "Effects of aging new crop wheat and whole wheat flour on breadmaking quality and glycolipid composition". Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/15076.
Testo completoAbstract (sommario):
Master of ScienceDepartment of Grain Science and Industry
Jon Faubion
Whole wheat flour has become a popular ingredient in baked goods. Consumers are seeking the added benefits of consuming healthy phytochemicals and bioactive compounds. As the demand for wholemeal flour increases it is important to understand the factors contributing to changes in whole wheat flour breadmaking quality as a function of both wheat and flour age. In wholemeal flour, the lipid composition appears to be a factor causing variable baking quality. Changes that occur in both freshly harvested wheat and milled flour can cause variations in baking quality. Bakers’ attempts to adjust formulations and processes are often unsuccessful. The objective of this study was to determine the effects of aging both new crop wheat and freshly milled flour at 2 different temperatures on baking quality and glycolipid composition. This study aged freshly harvested Overley hard red winter wheat at RT (23˚C) and FZ (-26˚C) for 8, 50, and 91 days before milling. Whole wheat flour baking and lipid extraction studies were performed incrementally over 31 days of flour storage after each milling. Glycolipid structure and amounts were measured using automated electrospray ionization-tandem mass spectrometry. The glycolipids analyzed in this study were DGDG (digalactosyldiglycerol), MGDG (monogalactosylmonoglycerol), MGMG (monogalactosylmonoglycerol), and DGMG (digalactosylmonoglycerol). Both the wheat and flour stored at -26˚C produced larger mean loaf volumes than did the 23˚C treatment for all 3 wheat ages. The FZ and RT DGDG:MGDG ratios were similar over both wheat and flour age so changes to the glycolipid fraction did not appear to be the cause of the significant difference between volumes of bread baked from samples stored at RT and FZ. There was limited change in mean volume over flour age except for an increase at the FZ 91 day point. The DGDG:MGDG ratios were generally unchanged over flour age. Loaf volumes were the same over wheat age except for an unexpected drop during the 50 day wheat study. The corresponding DGDG:MGDG ratios did not show any significant differences over wheat age. The FZ storage temperature might be inhibiting some biochemical change not affecting the glycolipids, leading to higher volumes than the RT storage treatment.
18
Stoerzinger, Karolyn M. "Effects of postmilling time and temperature on the breadmaking quality and lipids of whole wheat flour". Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1669.
Testo completo
19
Gooding, M. J. "Interactions between late-season foliar applications of urea and fungicide on foliar disease, yield and breadmaking quality of winter wheat". Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233232.
Testo completo
20
Roy, Nandita. "Improvement of Australian wheat grain functionality for breadmaking by introgression of novel high-molecular weight glutenin subunits into Australian cultivars". Thesis, Roy, Nandita (2019) Improvement of Australian wheat grain functionality for breadmaking by introgression of novel high-molecular weight glutenin subunits into Australian cultivars. PhD thesis, Murdoch University, 2019. https://researchrepository.murdoch.edu.au/id/eprint/51075/.
Testo completoAbstract (sommario):
Bread wheat (Triticum aestivum) is one of the most important cereal crops in the world. It is an important component of human diet, chiefly as the main ingredient of the many available presentations of bread and noodles around the world. Wheat flour can produce dough with visco-elasticity properties, which is essential for bread making. Glutenin, a group of grain storage proteins, confers these visco-elasticity properties of dough. From the food production point of view, it is also called functional protein since it regulates end product quality. The breadmaking quality of Australian wheat cultivars can be enhanced by improving grain glutenin protein content. In this thesis, a range of HMW glutenin protein manipulation was conducted utilising introgression lines containing various alleles of the 1Ay high-molecular-weight glutenin subunit (HMW-GS) gene - which is silenced in current Australian wheat cultivars.
Wheat lines expressing two 1Ay HMW glutenin subunit alleles, 1Ay21* and 1AyT1, sourced from Italian hexaploid wheat germplasm, were successfully introgressed into a range of commercial Australian cultivars and advanced to the BC4F4 generation before further rounds of selfing were conducted to generate nearly-isogenic lines (NILs) carrying the introgressed genes. The F1 generation was developed by reciprocal crossing of the Australian cultivars with Ay donor wheat lines. MALDI-TOF mass spectrometry and SDS-PAGE were used to confirm introgression of the target 1Ay HMW-GS at each generation. Ay introgression NILs were developed through conventional breeding process that’s why may have change some unwanted gene effects on plants growth habit, grain and protein quality. The influence of different alleles of 1Ay on relative HMW GSs composition, HMW‐ /LMW‐GSs ratio, end‐use quality and grain yield has been evaluated from plants grown in small-scale glasshouse experiments and large-scale field trials. NIR and HPLC analyses were used for protein quantification. Extensograph, farinograph, and baking tests were carried out to evaluate dough and bread quality. Because of traditional breeding, there has been a greater possibility of passing unwanted genes in advance generations. That is why, the agronomic performance on 1Ay allele introgression lines have also been examined though large-scale field trial.
Expression of the novel Ay subunits in the NILs was stable in the Australian environment, as evidenced by the analysis results of grain from two years of field trials. No significant differences were observed between the reciprocal crossing NILs in terms of agronomic traits and grain protein attributes based on small scale quality test. However, introgression of the expressed 1Ay subunit genes led to an overall increase in protein and glutenin contents and resulted in significant increases of various end-product quality parameters. The level of changes was variable between the cultivar’s background. The active 1Ay21* subunit increased the amount of total protein by up to 15.4%, gluten content by up to 10%, glutenin content by up to 5%, the HMW-to-LMW-GS ratio and hence improved the dough extensibility (21%) without affecting the expression levels of the other subunits at Bonnie Rock background. On the other hand, expressed 1Ay21* increased polymeric protein (UPP%) by up to 14.3%, and improved dough strength by up to 28% respectively in Livingston background NILs. The Lincoln-derived Ay21* NILs showed increased grain protein% by up to 9% and grain yield up to 10%, indicating that protein content and grain yield can be increased simultaneously by introgressing the expressed Ay21* gene which shows great potential to ultimately increase Australian wheat productivity and value without increasing production costs. NILs at Lincoln bacground also showed increased UPP% by up to 24%, bread volume by up to 28%. The thesis also studied the allelic effect of expressed 1Ay gene that showed the two alleles have different levels of potential in improving grain, dough and baking qualities. On the other hand 1AyT1 subunit increased total grain protein by up to 9%, dough elasticity (Rmax) increased by up to 24%, reduced dough mixing time by up to 23% and increased bread volume by up to 2.4% (rapid-dough protocol) compared to the recurrent parent Livingston.
Since this study demonstrated significant variation between two expressed 1Ay alleles (Ay21* and AyT1) allele in influencing protein and end product quality another novel expressed Ay allele (AyT2) from an Israeli wheat tetraploid line also cloned and characterised. NILs were also generated in three Australian wheat cultivars Yitpi, Kukri and Livingston by integrating this novel expressed 1Ay HMW-GS, as for the other two Ay alleles. Result showed that the open reading frame of AyT2 is 1830 bp long and encodes a 608-residue polypeptide. 1AyT2 introgression NILs showed that UPP% increased by up to 50% and seed size increased by up to 36%.
The wheat lines developed in the current study and carrying the novel Ay HMW-GS genes have the potential to become new varieties or be used as parent lines by breeding programs to improve grain protein content and composition, thus improving viscoelastic properties of dough and therefore quality of baking products. Such improvement would in turn contribute toward enhancing the marketability of Australian wheat in global markets.
21
Therdthai, Nantawan. "Modelling and optimisation of an industrial bread baking oven". Thesis, View thesis, 2003. http://handle.uws.edu.au:8081/1959.7/545.
Testo completoAbstract (sommario):
In bread-making, the baking process is one of the key steps to produce the final product quality attributes including texture, color and flavor, as a result of several thermal reactions such as non-enzymatic browning reaction, starch gelatinisation and protein denaturation. These thermal reactions are dominated by heat and mass transfer mechanisms inside an oven chamber as well as inside the dough pieces. In this study, an industrial baking process was divided into 4 zones. Experiments were conducted, and mathematical models were developed to account for the heat and mass contribution as well as their consequent impacts on the product qualities. Monitoring systems were developed and installed inside an industrial oven to evaluate oven performance, including temperature profile and airflow pattern. Many other tests and experiments were conducted and results given in some detail. To deal with the complexity of a continuous baking process, a three dimensional transient-state CFD model with moving grids was established to account for the effect of oven load on heat transfer in the oven chamber. The dynamic response of the travelling tin temperature profiles could be predicted in accordance with a change in the oven load. The modelled tin temperature profiles showed a good agreement with the measured tin temperature profiles from the actual industrial baking process. Finally, the three-dimensional CFD model could provide guidance in manipulating the oven condition to achieve the optimum temperature profile in the industrial travelling-tray baking oven.
22
Coelho, Maria do Rosário Ribeiro. "Incorporação de drêche de cerveja em produtos de panificação. Adaptação da fórmula e do processo". Master's thesis, ISA/UTL, 2013. http://hdl.handle.net/10400.5/5639.
Testo completoAbstract (sommario):
Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaThe present work aimed to study the incorporation of Draff (about 20% fibre and 25% protein)and Sodium Stearoil Lactilate (SSL) at wheat flour to produce bread supplemented with fibre and protein. An experimental design was adopted based on the Response Surface Methodology with 5 levels and two variables: addition of draff and addition of SSL; given rise to 9 formulations plus two replicates of the central point (10% draff and 0.25% SSL). Farinografic tests were previously made to define the hydration levels of the formulations as well as their mixing times and dough stability. The breadmaking experiments were conducted after a previously designed protocol, producing 4 breads for each formulation. These breads were evaluated after 24h for appearance (supported by photographs and scanning of the bread slices); colour Lch parameters (Minolta colorimeter); volume (rape seed method); aw (rotronic equipment); texture of the crust and crumb (Texturometer Tax-Tplus da Stable Microsystems, UK) and weight loss as well as texture and moisture at 48h and 72h after baking to follow bread aging. It was concluded that it is possible to add up to 10% draff using about 0.15% SSL and produce breads with good properties
23
Schopf, Marina [Verfasser], Katharina [Akademischer Betreuer] Scherf, Katharina [Gutachter] Scherf e Wilfried [Gutachter] Schwab. "Analytical and structural characterization of wheat gluten to predict its functionality in breadmaking / Marina Schopf ; Gutachter: Katharina Scherf, Wilfried Schwab ; Betreuer: Katharina Scherf". München : Universitätsbibliothek der TU München, 2021. http://d-nb.info/1236343271/34.
Testo completo
24
Junior, Roberto de Moraes Junqueira. "Estudo da interação entre lipoxigenase da soja e ácido ascórbico nas propriedades reológicas e sensoriais de pães". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-05062007-101009/.
Testo completoAbstract (sommario):
A enzima lipoxigenase através da farinha integral de soja é amplamente utilizada na panificação com objetivos de branqueamento e melhora da reologia. Com base nesse pressuposto, o objetivo inicial deste estudo foi de observar a ação oxidante dessa enzima na presença de dois outros oxidantes (ácido ascórbico e peróxido de benzoíla) nas propriedades reológicas e sensoriais de pães. Sete misturas com diferentes combinações dos três compostos foram elaboradas utilizando-se um delineamento experimental do tipo \"centroide-simplex\", sendo aplicadas à farinha de trigo para o preparo de pães. A enzima apresentou sinergia com o ácido ascórbico na elasticidade da massa, sugerindo uma inter-relação bioquímica entre os dois compostos no fortalecimento da matriz protéica do glúten. A mesma sinergia entre a lipoxigenase da soja e o acido ascórbico foi observada na redução da tonalidade amarela dos pães medida instrumentalmente. A partir desses resultados, buscou-se avaliar a ação da enzima frente a variações tanto na força da farinha como no tempo de fermentação, reproduzindo as condições reais de processamento. Desta vez, um planejamento experimental do tipo Box-Behnken com três fatores (atividade da enzima, força da farinha e tempo de fermentação) em três níveis de variação, foi aplicado no preparo das amostras. Os resultados mostraram que a lipoxigenase da soja (fração 1) é uma enzima oxidante de ação rápida e seu efeito no branqueamento dos carotenóides da farinha de trigo exibiu interação positiva tanto com a força da farinha como o tempo de fermentação. Respostas reológicas e sensoriais decorrentes da ação conjunta de diferentes oxidantes e condições de processamento em pães foram pela primeira vez descritas através de modelos polinomiais com capacidade preditiva.Soy lipoxygenase enzyme through soy flour is widely used in breadmaking for bleaching and rheological improvement. Based on this fact, the initial objective of this study was to observe the enzymes\' action in the presence of two other oxidants (ascorbic acid and benzoyl peroxide) in the rheological and sensory properties of breads. Seven mixtures with different combinations of the three compounds were prepared using a \"centroid-simplex\" design and applied to wheat flour for breadmaking. The enzyme showed synergism with ascorbic acid in the dough elasticity suggesting a biochemical interrelation between the two compounds in strengthening the gluten protein matrix. The same synergy between soy lipoxygenase and ascorbic acid was observed with the yellow hue reduction of breads measured instrumentally. From these results, the enzyme action was evaluated with wheat strength and proofing time variations reproducing real processing conditions. This time, a Box-Behnken experimental design with three factors (enzyme activity, wheat strength and proofing time), and three variation levels were applied in the sample preparation. The results showed that soy lipoxygenase (type 1) is a fast-acting oxidizing enzyme and its bleaching effect on wheat flour carotenoid exhibited a positive interaction with wheat strength and proofing time. Rheological and sensory results attributed to the combined action of the different oxidants and breadmaking conditions were for the first time described through polynomial models with predictive capacity.
25
Therdthai, Nantawan. "Modelling and optimisation of an industrial bread baking oven /". View thesis, 2003. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20040428.131506/index.html.
Testo completoAbstract (sommario):
Thesis (PhD) -- University of Western Sydney, 2003.A thesis submitted to the University of Western Sydney in partial fulfillment of the requirements for the degree of Doctor of Philosophy. Includes references pp.191 - 202, and appendices.
26
Marangoni, André Luis 1976. "Pão de forma "zero trans" : estudo do efeito de diferentes óleos e gorduras na qualidade tecnológica dos pães". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256010.
Testo completoAbstract (sommario):
Orientador: Caroline Joy SteelTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A interesterificação é uma ferramenta fundamental para o desenvolvimento de gorduras "zero trans"; entretanto, comparada ao processo de hidrogenação, esta apresenta limitações, sobretudo no desenvolvimento de gorduras para uso em panificação. De acordo com a literatura, na produção de pão de forma, a gordura exerce diversas funções, como a lubrificação e o aumento da extensibilidade da massa, e o aumento do volume e do sabor do pão. A gordura afeta a textura, mantendo os pães macios por mais tempo; isto se deve possivelmente à sua interação com o amido da farinha, retardando o processo de retrogradação e, assim, estendendo a vida de prateleira do pão. O objetivo deste trabalho foi aplicar a tecnologia de Redes Neurais Artificiais (RNA) na formulação de gorduras "zero trans" à base de óleo de soja e gorduras interesterificadas de soja para facilitar o processo de formulação por blending, específicas para produtos de panificação, e determinar a influência das mesmas na qualidade dos pães de forma e nas interações entre as gorduras e o amido da farinha. Para tanto, foram produzidos pré-misturas e pães de forma com a adição de 4% de gordura. Como padrões, foram utilizadas gorduras comerciais, hidrogenada (GHS) e low trans (GLT), além de óleo de soja (OLS). Também foram utilizados os blends de gordura formulados através da RNA (BL1, BL2, BL3 e BL4). Para efeito de controle, foi produzido um pão sem adição de gordura (C). A análise farinográfica mostrou que a absorção de água (ABS) da farinha de trigo pura (59,0%) foi em média 6,5% maior que a das pré-misturas adicionadas de gordura. O tempo de desenvolvimento (Td) foi menor para as amostras GHS, GLT e BL4. A extensografia mostrou que, dentre todas as amostras, a BL4 foi a mais resistente (980 UE) e a menos extensível (114 mm). Isto provavelmente ocorreu devido ao menor teor de óleo de soja em sua constituição (54%), o que pode ter contribuído para uma massa de maior consistência. A análise dos pães produzidos revelou que apenas os volumes específicos das amostras OLS (3,46 mL/g) e BL4 (4,07 mL/g) diferiram significativamente entre si. A análise de firmeza dos pães mostrou que ao longo da estocagem houve diferença significativa entre a firmeza dos pães com gordura e a amostra controle (1005,75 gf), sendo este valor 13% superior ao da amostra GHS - a mais firme dentre os pães com adição de gordura. A uniformidade do miolo foi maior com a utilização de gordura. Nos pães controle (C), a porosidade (26,73%) foi quase 3 vezes superior ao das amostras com a adição dos blends. Os miolos dos pães BL1, BL2, BL3 e BL4 apresentaram alvéolos pequenos e espalhados mais uniformemente, quando comparados aos pães C, GHS, GLT e OLS. Quanto à umidade, os pães com gordura apresentaram um menor teor em relação ao da amostra controle (35%), pois as suas massas absorveram menos água durante a mistura. A análise térmica através de DSC sugeriu um efeito da gordura sobre o envelhecimento dos pães, uma vez que as variações de entalpia de retrogradação foram menores para os pães com gorduras. Os blends de gordura desenvolvidos usando a RNA e aqui utilizados, além do baixo teor de ácidos graxos trans (1,18% em média), apresentaram-se viáveis para aplicação em panificação, sobretudo o BL4
Abstract: Interesterification is a fundamental tool in the development of "zero trans" fats; however, when compared to the hydrogenation process, it presents limitations, especially when developing shortenings for bakery products. According to literature, in the production of pan bread, fat has several functions, such as lubrication and an increase in dough extensibility, and an increase in bread volume and flavor. Fat affects texture, maintaining breads soft for a longer period of time; this is possibly due to its interaction with starch in flour, retarding the retrogradation process and, thus, extending bread shelf-life. The aim of this study was to apply Artificial Neural Network (ANN) technology in the formulation of "zero trans" fats based on soybean oil and soybean interesterified fats to ease the formulation process through blending, for use in bakery products, and determine their influence on the quality of pan bread and on their interaction with starch in flour. For this, pre-mixes and breads with the addition of 4% fat were produced. As standards, commercial fats (hydrogenated soybean fat ¿ GHS and low trans fat ¿ GLT) were used, as well as soybean oil (OLS). The fat blends formulated using the ANN (BL1, BL2, BL3 e BL4) were also used. As control (C), bread without fat addition was prepared. The farinographic analysis showed that water absorption (ABS) of pure wheat flour (59.0%) was in average 6.5% higher than that of the pre-mixes of flour and fats. Dough development time (Td) was lower for the samples GHS, GLT and BL4. The extensographic analysis showed that, amongst all samples, BL4 showed the highest resistance to extension (980 EU) and the lowest extensibility (114 mm). This probably occurred due to the lower soybean oil content in its constitution (54%) that could have contributed to a more consistent dough. The analysis of the breads produced revealed that only the specific volumes of the samples OLS (3.46 mL/g) and BL4 (4.07 mL/g) differed significantly. Firmness analysis of breads showed that throughout the storage period studied there was a significant difference between the firmness of the breads with fats and the control sample (1005.75 gf), being this value 13% higher than that of GHS ¿ the firmest amongst samples with fat. Crumb uniformity was greater with the use of fat. In the control breads (C), porosity (26.73%) was almost 3 times greater than that of the samples with the addition of the blends. The crumbs of breads BL1, BL2, BL3 and BL4 presented small and more uniformly distributed alveoli, when compared to breads C, GHS, GLT and OLS. As to moisture content, breads with fat presented lower values when compared to the control sample (35%), as their doughs absorbed less water during mixing. Thermal analysis through DSC suggested an effect of fat on bread staling, once retrogradation enthalpy changes were lower for breads with fats. The fat blends developed using the ANN and used in this study, as well as having a low trans fatty acid content (1.18% in average), showed feasibility for application in pan bread, especially BL4
Doutorado
Tecnologia de Alimentos
Doutor em Tecnologia de Alimentos
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Maldonado, Alvarado Pedro Gustavo. "Facteurs déterminants du pouvoir de panification de l’amidon de manioc modifié par fermentation et irradiation UV". Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20004/document.
Testo completoAbstract (sommario):
Compte tenu que la capacité de panification de l'amidon aigre, amidon de manioc modifié par fermentation et irradiation UV, n'a pas encore été complètement élucidée, l'influence du génotype et les traitements post-récolte sur le pouvoir de panification de l'amidon aigre a été l'objectif de ce travail. 13 génotypes de manioc de Colombie, cultivés à 1000 m. et 1700 m.p.n.m (3 de plaine et 10 d'altitude, respectivement) modifiés par fermentation (0 ou30 jours) et séchage (four ou soleil) ont été étudiés. Les analyses de la taille des granules, la viscosité d'empesage RVA et la viscosité intrinsèque révèlent que les traitements post-récolte ont été les facteurs prépondérants en vue de l'amélioration de la capacité de panification tandis que le facteur génotype a présenté une influence moins importante. Parmi les traitements post-récolte, la fermentation a présenté un effet plus prononcé sur la structure des granules d'amidon, que le séchage au soleil. Cependant, la combinaison de ces deux traitements a été nécessaire pour obtenir une forte capacité de panification. L'effet d'altitude de culture a été mis en évidence lors de la fermentation par des sensibilités différentes trouvées entre les granules de plaine et d'altitude (exocorrosion et endocorrosion, respectivement). Les génotypes d'altitude, donc, ont montré une bonne capacité de panification. Néanmoins, d'autres facteurs entrent en jeu, la teneur en amylose mesurée par DSC a influencé négativement l'expansion de la pâte, probablement en raison de la formation de complexes amylose-lipide. Par conséquent, la combinaison de génotypes de manioc (la teneur en amylose principalement) et les traitements post-récolte sont un élément clé de la capacité de panification de l'amidon aigre. Ces contributions peuvent aider à l'établissement de standards de qualité de l'amidon aigre vis à vis de leur potentielle utilisation dans la fabrication des produits sans-glutenThe breadmaking ability of sour cassava starch, cassava starch modified by fermentation and UV irradiation, have not been yet fully elucidated. The influence of genotype and postharvest treatments on expansion ability of sour cassava was the objective of this work. Thirteen cassava genotypes have been studied. All genotypes proceeded from Colombia. Two altitudes of origin (1000 m. and 1700 m.a.s.l. refered to respectively as lowland and highland), fermentation treatments (0 or 30 days) and drying treatments (oven or sun) were considered. Analyses of the granule size, RVA pasting behavior and intrinsic viscosity were analysed as indicators of breadmaking ability. Results showed that post-harvest treatments were prevailing factors in improving breadmaking ability while the genotype factors had a smaller influence. Among post-harvest treatments, fermentation had a greater influence than sun-drying on these indicators, in particular on starch granular structure. The combination of both treatments was needed to obtain a high capacity bread. Furthermore, the altitude of origin of cassava genotypes was observed to affect the fermentation process: different sensitivities to fermentation were found between granules of lowland and highland (exocorrosion and endocorrosion, respectively). Highland genotypes showed a better breadmaking ability. Other influencing factor related to genotype was the amylose content measured by DSC: it negatively influenced the expansion of the dough, probably due to the formation of amylose-lipid complex. As a conclusion, the combination of cassava genotypes (mainly amylose content) and post-harvest treatment is key for expansion ability of sour starch. This knowledge is a first, essential step to provide quality standards for sour starch, targeted particularly for use in gluten-free products
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Bell, Ruth Mary. "Extraction of arabinoxylan from animal feed and investigations into its functionality as an ingredient in bread dough". Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/extraction-of-arabinoxylan-from-animal-feed-and-investigations-into-its-functionality-as-an-ingredient-in-bread-dough(a234da96-130a-45ac-912f-cbafb7f69880).html.
Testo completoAbstract (sommario):
Arabinoxylans (AX’s) are the predominant non-starch polysaccharides found in the structural matrix of cell walls in wheat grains, being present in large quantities in wheat bran, accounting for up to 25% of its composition. Their physicochemical properties define their functionality which can be beneficial in cereal-based products such as bread, where their addition could enhance the gluten matrix responsible for the aerated structure and quality of bread. Bioethanol production has grown rapidly, however, to be economically viable, cereal-derived first generation biorefineries need to adopt the process integration approaches employed in petrochemical refineries, and exploit the interaction opportunities arising from multiple product streams. A potential source of AX is its extraction from the wheat bran based low value animal feed produced as an end product of the bioethanol distillation process. The benefits of extraction are twofold, to enhance feed nutritional value by reducing fibre content and produce a high value product for use as a functional ingredient in the breadmaking industry. Extraction of AX involves precipitation with ethanol, giving opportunity for integration and economic extraction in the context of a bioethanol plant. Currently no commercial supply of AX is available in sufficient quantities to conduct functionality trials; therefore the objective of the current work was to study the feasibility of extracting AX from animal feed and, by developing a scaled-up extraction process based on that of Hollmann and Lindhauer (2005) and Du et al. (2009), to produce sufficient quantities to conduct functionality trials into its effects on the breadmaking process. Two animal feeds, representative of contrasting biorefinery operations, were used for AX extraction, Distillers’ Dried Grains with Solubles (DDGS) and C*Traffordgold®, with water and alkaline AX being extracted from each. Monosaccharide analysis of the feedstocks confirmed the presence of arabinoxylans, with DDGS containing 12.5% AX and TG 13% AX, with A/X ratios of 0.55 and 0.61, respectively. The purity of AX extracted at both lab scale and on scale up was consistent, with 29.5% and 23% extracted at lab scale and 30% and 25% extracted in the scaled up process for WEAX from DDGS and TG, respectively. The purity of AEAX was lower, with 18% and 14% at lab scale and 15% and 14% for scale up for DDGS and TG, respectively. The results indicate that the same purity of crude extract can be achieved at both lab and larger scale extraction, however lower yields and absolute yields were observed at scale up and anticipated to be due to the crude nature of the process, which needs further optimisation. Addition of crude AX extracts to bread dough gave insights into its effects and potential benefits and issues. The type and origin of AX was found to affect bread dough characteristics in different ways. WEAX from both DDGS and TG exhibited effects on all stages of the breadmaking process, by improving stability and reducing softening at mixing, and slowing proving allowing the dough to retain a better aerated structure, leading to an open aerated finished loaf structure. AEAX from both types of animal feed generally caused destabilization of gas cells and coalescence, resulting in loaves with a tighter crumb structure. The AX dosage appeared to have a non-linear effect, with some positive changes at 1% addition turning to negative changes when added at 2%. This work has provided insights into the functionality of AX in bread dough, and a process has been developed to allow greater than lab scale production of arabinoxylan. The effects of AX need to be understood more clearly to retain beneficial effects, whilst supressing detrimental ones, preferably while avoiding the need for extensive purification. The work supports the possibility for AX extracts to be produced commercially as bread ingredients that could enhance bread structure and nutritional quality, and provides an elegant solution for synergy between two wheat-based industries serving both the food and non-food needs of society.
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Rogério, Walison Fábio. "El sabor de la mano en la masa del pan: artesanía, tradición y actualidad". Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/666292.
Testo completoAbstract (sommario):
Hace aproximadamente cuarenta años que algunos estudiosos pronosticaban la desaparición de las panaderías artesanas a causa de la industrialización del sector y la falta de mano de obra especializada. Sin embargo, algunas de estas panaderías han resistido y se mantienen aún vivas hasta hoy. Esta investigación, de naturaleza cualitativa, ha buscado comprender, a través de la etnografía, cómo y por qué algunas panaderías artesanas tradicionales, como el caso que nos atañe aquí de Forn Elias, han resistido manteniéndose y funcionando desde hace más de un siglo. Al mismo tiempo, se ha pretendido comprender el papel que juegan instituciones profesionales como el Gremio de Panaderos de Barcelona, en el mantenimiento, en la sociedad actual, de la artesanía y la tradición del oficio a través de la formación de nuevos panaderos que prosigan con el oficio. Por otro lado, esta tesis aporta un concepto observado y, a mi juicio, la clave más importante: la transmisión del saber y los conocimientos del oficio a través de los sentidos del cuerpo tanto en la elaboración de los productos artesanos tradicionales como en aquellos tradicionales que han sufrido innovaciones o nuevos productos, sin menoscabo de su esencia artesana, a fin de satisfacer las exigencias del consumidor en los tiempos actuales. Para ello, se desarrolló in situ la observación participante, con registros en diarios de campo, tanto en el Gremio de Panaderos como en el Forn Elias. Además, en este último se hizo uso de entrevistas semiestructuradas con panaderos y clientes a fin de buscar y comparar el concepto de artesanía y tradición de ambos que muestran por qué aún hoy en día perviven estos hornos tradicionales. Como resultado, si bien es cierto que se observó un uso frecuente auxiliado de máquinas y herramientas para ahorrar tiempo y esfuerzo físico junto a las técnicas tradicionales, es el panadero, con su sensibilidad, el que en todo momento controla el proceso de elaboración del pan.About forty years ago, some experts predicted the disappearance of artisan bakeries by industrialization of the sector and for lack of skilled labor. However, some of these bakeries have resisted and are still alive today. This research, of a qualitative nature, has been sought to understand, through ethnography, how and why some traditional artisan bakeries, as in the current case that concerns us of Forn Elias, have resisted and have been operating for more than a century. At the same time, it has been tried to understand the role played of professional institutions such as the Guild of Bakers of Barcelona, in the maintenance, in contemporary society, of the craftsmanship and tradition of the baker’s trade, through training of new bakers who will continue with the job. On the other hand, this thesis provides an observed concept and, in my opinion, the most important key: the transmission of the knowledge of the baker’s trade through the senses of the body both in the production of the traditional craft products and such as traditional products that have undergone innovations or new products, without detriment to its artisan essence, to satisfy the demands of the consumer in the current times. For that, participant observation was developed in situ, with records in field diaries, both in the Gremio de Panaderos de Barcelona and in the Forn Elias. In addition, in this latter, semi-structured interviews were used with bakers and customers to seek and compare the concept of craftsmanship and tradition of both, which show why these traditional ovens still exist today. As a result, although it is true that a frequent use of machines and tools was observed to save time and physical effort along with traditional techniques, it is the baker, with his sensitivity, who, during all the time, controls the bread-making process.
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Cappa, C. "GLUTEN-FREE BREAD: OPTIMIZATION OF FORMULATION AND PROCESS CONDITIONS". Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/169986.
Testo completoAbstract (sommario):
The aim of this PhD research project was to identify the formulations and to define the process conditions that most influence the quality and the shelf-life of gluten-free (GF) bread. Raw materials that are commonly used in GF bread production were first characterized, in particular as regards the rheological properties of different starchy gels during a short term ageing. Waxy rice flour (WRF) and rice bran (RB), at 25% and 50% substitution level, came out to be very effective in reducing gel stiffness and storage modulus (G’) of the mixtures containing corn starch (CS) or rice flour (RF). The effects of High Hydrostatic Pressure treatments on CS, RF and WRF were also investigated. A partial gelatinization of RF treated at 400MPa and 600MPa was evidenced by the viscoamylographic test and the formation of a more compact structure and a higher water retention capacity were registered for CS treated at 600MPa. The effect of Psyllium (Psy) and sugar beet (SB) fibers on dough and bread properties was also evaluated. The presence of 2.5% Psy generally determined an increase of dough height and CO2 production during leavening. Psy fiber also showed an anti-staling effect, higher than SB fiber. Taking into account all these results, a GF sourdough (SD) containing selected bacteria and yeasts (Lactobacillus sanfranciscensis and Candida humilis) was developed; then it was constantly refreshed and monitored in terms of number and type of microorganisms, capability to produce/retain CO2 and pH variations. When a stable microbial association was achieved, as well as constant SD properties, some breadmaking trials were performed. GF SD combined with compressed yeast resulted an excellent opportunity to improve GF bread quality and shelf-life.
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Kihlberg, Iwona. "Sensory Quality and Consumer Perception of Wheat Bread : Towards Sustainable Production and Consumption. Effects of Farming System, Year, Technology, Information and Values". Doctoral thesis, Uppsala University, Department of Domestic Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4529.
Testo completoAbstract (sommario):
In order to study the effect of production systems aimed at sustainability on product quality and of sensory and non-sensory factors on product acceptance – the effect of farming system, year, milling and baking techniques on the sensory qualities of wheat bread as a model product was investigated using a descriptive test, and the effect of information and values on liking of bread using consumer tests.
Whole wheat and white breads were baked with wheat grown in six lots in established conventional and organic farming systems in field trails, in two subsequent years for the white bread.
Milling technique influenced flours’ rheology and had greater impact on the sensory qualities of whole wheat bread and on the slice area than did farming system and baking technique. Bread baked with roller-milled wheat was characterized by sweetness, juiciness, compactness and smaller slice area than bread baked with stone-milled wheat, which was characterized by saltiness, deformity and roasted cereals.
The effect of year on the white bread was greater than the effect of farming system or recipe modification. Bread baked with wheat harvested in 1999 had significantly lower intensities of crumb attributes such as smoothness, juiciness and elasticity, but higher rancid flavour, springiness, compressibility, mastication resistance than bread baked with wheat harvested in 2000. Bread baked with conventional flour had significantly higher juiciness and elasticity than organic bread.
Image analysis did not show differences in slice area between bread baked with conventionally and organically grown wheat harvested in 1999 compared with 2000. Information affected liking in relation to the type of provided information. Information on organic origin enhanced most liking of bread, particularly for the less liked samples and frequent consumers of organic food. Significantly different values and different specific liking of breads were found among consumer segments. Results linked values and age with “taste”.
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Vidal, Corominas Arnau. "Mycotoxins: presence and stability during processing of cereal based food". Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/404911.
Testo completoAbstract (sommario):
Mycotoxins are toxic secondary metabolites produced by fungi that contaminate various agricultural commodities either before harvest or under post-harvest conditions. The most important producing genera are Aspergillus, Fusarium and Penicillium. Mycotoxins can be present in a wide range of products and their intake is of concern because they can produce a wide range of harmful effects to human and animal. Cereal products represent one of the main sources of exposure to mycotoxins. Several mycotoxins have been identified up to the present, but those of special interest in food and feed safety are: aflatoxins (B1, B2, G1 and G2), fumonisins (Fbs), ochratoxin A (OTA), patulin, trichothecenes (deoxynivalenol and nivalenol), and zearalenone (ZEN). However, unaltered mycotoxins might not be the only threat for health consumers, because they can be present in conjugated forms which cannot be detected in the routinary mycotoxins analysis, but they can become as dangerous as parent mycotoxins.
The objectives of this thesis were determine the presence of some mycotoxins in cereal products, study the stability of them during the food process and assess the mycotoxin exposure. To reach these aims different studies have been done. Firstly, cereals and cereal based food commercial samples have been analysed to study the presence of aflatoxins (Afs), deoxynivalenol (DON), nivalenol (NIV), ZEN, OTA and some of them conjugated mycotoxins. Bread making and pasta making processes have been deeply studied and some factors have been evaluated to observe the stability of mycotoxins. Mycotoxins exposure has been assessed through two different methods: 1) the combination of contamination data with consumption data and 2) using biomarkers.Les micotoxines són metabòlits secundaris produïts per fongs que poden contaminar diferents productes agrícoles abans o després de la collita. Els gèneres més importants de fongs productors de micotoxines són Aspergillus, Fusarium i Penicillium. Les micotoxines poden estar presents en una gran varietat de productes i la seva ingesta pot ser de gran perillositat perquè produeixen una gran varietat d’afectes perjudicials per la salut dels humans i animals. Els productes a base de cereals representen una de les principals fonts d’exposició a les micotoxines. Varies micotoxines s’han identificat fins a dia d’avui, però aquelles micotoxines amb major interès per la seguretat dels aliments i el pinso són: les aflatoxines (B1, B2, G1 i G2), les fumonisines (Fbs), la ocratoxina A (OTA), la patulina, els tricotecens (deoxinivalenol i nivalenol) i la zearalenona (ZEN). Però, les micotoxines no alterades poden no ser l’únic problema per la salut dels consumidors, perquè també poden estar presents les micotoxines conjugades. Aquestes poden no ser detectades durant els anàlisis rutinaris encara que poden arribar a tenir la mateixa perillositat que les micotoxines lliures. Els objectius d’aquesta tesis eren determinar la presència d’algunes micotoxines en els productes fets a base de cereals, estudiar l’estabilitat de les micotoxines durant el processat dels aliments i avaluar l’exposició a aquest tipus de compostos. Per aconseguir aquests objectius s’han elaborat diferents estudis. En primer lloc, s’han realitzat alguns anàlisis de cereals i aliments a base de cereals procedents del mercat per estudiar la presència de les aflatoxines (Afs), el deoxinivalenol (DON), el nivalenol (NIV), la ZEN, la OTA i alguns dels seus conjugats. A continuació s’ha estudiat en profunditat el procés d’elaboració del pa i de la pasta i alguns factors que afecten la seva estabilitat han estat avaluats. L’exposició a les micotoxines s’ha realitzat a través de dos mètodes diferents: 1) combinació de les dades de contaminació amb dades de consum i 2) utilitzant biomarcadors.
Las micotoxinas son metabolitos secundarios producidos por hongos que pueden contaminar a varios productos agrícolas antes o después de la cosecha. Los géneros más importantes de hongos productores de micotoxinas son Aspergillus, Fusarium y Penicillium. Las micotoxinas pueden estar presentes en una gran variedad de productos y su ingesta puede ser peligrosa porque producen una gran variedad de efectos dañinos para la salud de los humanos y los animales. Los productos a base de cereales representan una de las principales fuentes de exposición a las micotoxinas. Varias micotoxinas se han identificado hasta la fecha, pero las micotoxinas con interés especial para la seguridad de los alimentos y los piensos son: las aflatoxinas (B1, B2, G1 y G2), las fumonisinas (Fbs), la ocratoxina A (OTA), la patulina, los tricotecenos (deoxinivalenol y nivalenol) y la zearalenona (ZEN). Sin embargo, las micotoxinas no alteradas pueden no ser el único problema para la salud de los consumidores, debido a que también pueden estar presentes las micotoxinas conjugadas. Este tipo de compuestos pueden no ser detectados en los análisis rutinarios aunque pueden llegar a ser igual de peligrosos que las micotoxinas libres. Los objetivos de esta tesis fueron determinar la presencia de algunas micotoxinas en los productos a base de cereales, estudiar su estabilidad durante el procesado de los alimentos y evaluar la exposición a este tipo de compuestos. Para lograr estos objetivos se han elaborado distintos estudios. En primer lugar, se han realizado varios análisis de cereales y alimentos a base de cereales procedentes del mercado para estudiar la presencia de aflatoxinas (Afs), deoxinivalenol (DON), nivalenol (NIV), ZEN, OTA y algunos de sus conjugados. A continuación, se ha estudiado en profundidad el efecto del proceso de elaboración del pan y de la pasta en la concentración de las micotoxinas y también se han evaluado algunos de los factores que podrían afectar al contenido final de las micotoxinas. Para la evaluación de la exposición a los metabolitos secundarios producidos por hongos se han utilizado dos métodos distintos: 1) combinación de los datos de contaminación con los datos de consumo y 2) utilización de biomarcadores.
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Diana, Pérez Marina. "Desarrollo de un pan de masa madre rico en GABA y péptidos IECA". Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/284604.
Testo completoAbstract (sommario):
Existe una relación evidente entre el consumo de sal y el mayor riesgo de padecer hipertensión. La hipertensión es una enfermedad crónica que afecta a algo más del 40% de la población general adulta en España. El pan es uno de los alimentos básicos de la dieta humana siendo en España la principal fuente dietética de sodio en la población adulta. El uso de masa madre produce un pan con una notable mejora de las características nutricionales y sensoriales, incluyendo aroma, sabor, textura de la corteza y miga, así como un alargamiento de la vida útil del pan. En este contexto nace el proyecto de obtener una nueva formulación de pan de masa madre funcionalmente activo, contribuyendo a disponer de un alimento saludable con propiedades beneficiosas para la salud. Para ello, se ha estudiado la posibilidad de sustituir el sodio (Na) por potasio (K) en las formulaciones de pan y la inclusión de moléculas biológicamente activas con un efecto hipotensor científicamente demostrado. El Ácido γ-Amino Butírico (GABA), un amino ácido no proteico, con numerosas funciones fisiológicas entre los que se encuentra el sistema de regulación de la presión arterial. La ingesta de un alimento rico en GABA y una reducción de su contenido en sal pueden ayudar a reducir la tensión arterial. En el proyecto se reúnen por tanto, las dos condiciones básicas para la obtención de un pan, elaborado con una masa madre que realza el sabor del pan, enmascarando posibles defectos asociados a la inclusión de sal potásica y por otra parte, la posibilidad de que esta masa madre contenga además sustancias bioactivas como el GABA y los Inhibidores del Enzima Convertidor de la Angiotensina (IECA).
En el primer estudio se aislaron bacterias ácido lácticas de quesos artesanales españoles con el fin de obtener cepas altamente productoras de GABA. Las cepas fueron sometidas a ensayos cualitativos y ensayos cuantitativos para evaluar la habilidad de sintetizar GABA. Tras la selección de la mejor cepa, Lactobacillus brevis CECT 8183, ésta se usó para la producción de una masa madre optimizada para la producción de GABA. Los ensayos se llevaron a cabo a escala laboratorio y a escala piloto. En el estudio II se analizó el contenido de aminoácidos libres de los quesos artesanales con especial interés en conocer el perfil de GABA y ornitina como posibles compuestos bioactivos en los quesos y encontrar relación entre la capacidad de producción de la cepa aislada y el contenido de GABA presente en el queso. En el tercer estudio se obtuvo un pan elaborado con la masa madre rica en GABA que fue comparado con otros panes del mercado en cuanto contenido de aminoácidos, aminas biógenas y acrilamida como principales compuestos derivados del nitrógeno. Finalmente, se hizo una revisión del GABA como molécula bioactiva con gran interés aplicativo en la industria alimentaria. Estos resultados pueden contribuir a mejorar los beneficios para la salud de los panes enriquecidos en GABA y a tener en cuenta la cepa Lactobacillus brevis CECT 8183 como estárter para la producción de alimentos ricos en GABA.The use of dough containing naturally occurring lactobacilli and yeasts produces bread with a notable improvement in nutritional and sensorial characteristics, including the aroma, taste and texture of both the crust and the crumb, and also increases the useful life of the bread. From this stems the project to obtain a new bread formulation using such a dough that is functionally active and contributes to providing a healthy foodstuff with beneficial properties. To this end we studied the possibility of substituting the sodium (Na) by potassium (K) in bread formulations and the inclusion of biologically active molecules with a scientifically demonstrated hypotensive effect. γ-Aminobutyric acid (GABA) is a non-protein amino acid with numerous physiological functions including playing a role in the regulation of blood pressure. Intake of food rich in GABA and a reduction in its salt content may help reduce blood pressure. Therefore, this project brings together two basic conditions for the production of a bread made using dough containing naturally occurring lactobacilli and yeasts which heightens the taste of the bread and furthermore offers the possibility that this dough also contains bioactive substances such as GABA and angiotensin-converting-enzyme (ACE) inhibitors. In the first study lactic acid bacteria were isolated from Spanish artisanal cheeses in order to obtain strains that produce large amounts of GABA. The strains were subjected to qualitative and quantitative tests to evaluate their capacity to synthesise GABA. After selection of the best strain, Lactobacillus brevis CECT 8183, it was used to produce a dough optimised for the production of GABA. In another study a bread was produced with the experimental dough, rich in GABA, and it was compared with other commercially available breads in terms of amino acid, biogenic amine and acrylamide contents as the main nitrogen-derived compounds. These results could contribute to improving the health benefits of breads enriched in GABA and to raising awareness of the strain Lactobacillus brevis CECT 8183 as a starter ingredient for the production of foodstuffs rich in GABA.
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Wadhawan, Charanjeet Kaur. "Fundamental studies on vitality of gluten for breadmaking". 1988. http://hdl.handle.net/1993/16740.
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Fenn, Dora. "Effect of the 1BL/1RS translocation on breadmaking quality". 1992. http://hdl.handle.net/1993/18016.
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36
Fu, Bin Xiao. "Biochemical properties of wheat gluten proteins in relation to breadmaking quality". 1997. http://hdl.handle.net/1993/12273.
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37
Gao, Lei. "Physicochemical and structural studies of glutenin in relation to breadmaking quality". 1992. http://hdl.handle.net/1993/18532.
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Faraj, Abdul Kipruto. "Wheat flour protein solubility in relation to breadmaking quality of different genotypes". 1993. http://hdl.handle.net/1993/17523.
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Sodhi, Hatinder. "The stability of enzymes during breadmaking and their influence on staling characteristics". Thesis, 2003. https://vuir.vu.edu.au/18211/.
Testo completoAbstract (sommario):
Baked products continue to enjoy popularity in many parts of the world. This reflects
the appealing sensory attributes of the fresh products, including the soft textural
characteristics of the freshly baked goods. Staling remains a significant cause of
economic loss in breads due to the loss of saleability resulting from crumb firming. The
aims of the current project have been to investigate some of the factors which may
impact on staling, particularly the stability of amylolytic enzymes in bakery
formulations. In addition, the role enzymic hydrolysis of starch in producing partial
hydrolysis products and the potential of microencapsulation as a means of studying
these effects is investigated.
Recently developed assay methods which are able to specifically measure α-amylase
and ß-amylase, in the presence of the other potentially interfering activity, have been
evaluated. These have been applied to an investigation of enzyme levels at various
stages during the breadmaking process, using a cereal source of the enzyme α-amylase.
For this a rapid dough formulation and processing procedure were used. α-Amylase
activity levels appeared to gradually increase during the proofing stages and then to
decline upon heating of the dough. However, the activity remaining in the final baked
loaf was readily measurable indicating that not all of the enzyme had been inactivated.
Free and total ß-amylase activities were also measured. Most of the enzyme was found
to be in the free form although a higher proportion was bound in the dough than in the
wheat flour used for baking. ß-Amylase was heat labile with only relatively low
activities remaining in the final baked loaf. It appears that of the two amylolytic
enzymes, α-amylase is sufficiently stable that it may exert some impact on the crumb
characteristics in the freshly baked product and during subsequent storage.
In order to assess the likelihood that amylolysis is of significance in influencing crumb
characteristics, samples were also extracted and analysed for the levels of low molecular
weight carbohydrates. For this purpose high-performance liquid chromatography was
used to analyse the aqueous extracts for maltose, glucose, fructose, lactose and sucrose.
Commercial flours were found to contain low levels of sugars with maltose being the
predominant sugar present. For comparative purposes, a number of commercial breads were also analysed and the composition found to vary between the different samples.
Typically maltose was present at higher levels than the other sugars. When experimental
loaves were analysed, the patterns showed that other sugars declined during proofing
whereas maltose remained at readily measurable levels. Upon baking and subsequent
storage the amounts of maltose increased. These results are consistent with the findings
that some amylolytic activity remains in the baked product.
In the third phase of this study, a potential means of investigating the role of particular
carbohydrates in product textures and staling rates was examined. The approach of
spray drying was used to prepare microencapsulated maltodextrin. The encapsulating
agents used were based upon rice starch and guar galactomannan. When these
microcapsules were incorporated into the breadmaking formulation and baked, it
appeared that softer crumb characteristics were achieved. The data also indicates an
effect of delay in the staling rates.
From these studies it is concluded that cereal grain a-amylase may be more stable
during breadmaking than previously thought. There appears to be an increase in the
level of some low molecular weight sugars in the final, baked product.
Microencapsulation may offer a useful technique for the study of the role of specific
low molecular weight carbohydrates and dextrin fractions during baking and storage of
breads. These finding could form the basis of further research into staling of breads.
40
Wu, Yangsheng. "Wet-processing of low-protein hard winter wheat flour to improve its breadmaking potential". 1985. http://hdl.handle.net/2097/27601.
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41
Ng, Perry K. W. "Relationship between high molecular weight subunits of glutenin and breadmaking quality of Canadian grown wheats". 1987. http://hdl.handle.net/1993/9437.
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42
Stuteville, Brian. "Comparision of white and whole wheat flour brews in the liquid ferment process of breadmaking". 1987. http://hdl.handle.net/2097/22526.
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43
David, Pratiba. "Breadmaking quality of durum wheat : effects of semolina particle size, fermentation time and glutenin molecular size". 2003. http://hdl.handle.net/1993/19866.
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44
Lin, Chen-hwa. "Preparation of high total dietary fiber material from wheat mill feed, and its utilization in breadmaking". 1988. http://hdl.handle.net/2097/22533.
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45
Unger, Christopher J. H. "The impact of sulphur on the breadmaking quality of Canadian Western Red Spring wheat in western Canada". 2009. http://hdl.handle.net/1993/3729.
Testo completoAbstract (sommario):
Canada Western Red Spring (CWRS) wheat (Triticum aestivum L. cv. AC Barrie) was grownl at twelve locations, over two growing seasons across western Canada, to study the impact of S fertilization on grain yield and quality of wheat. Treatments consisted of two rates of fertilizer S (0 and 20 kg ha-l) as ammonium sulphate and two rates of fertilizer N (26 and 100 kg ha-l) as urea in a factorial design. Soil and plant tissue tests were also evaluated for their ability to predict grain S concentration, grain N:S ratio, total S accumulation in the plant, and grain quality responses to S fertilization. Analysis of grain for total S, N, and N:S ratio accurately predicted the concentration of S, N, and N:S ratio in flour. Grain S concentration and N:S ratio were weakly correlated with both absolute and relative grain yield. Grain S concentration was strongly and positively correlated with loaf height, loaf volume, and oven spring; grain N:S ratio was negatively, but more weakly, correlated with these baking parameters. The improvements in baking quality were accompanied by an increase in dough extensibility and reduction in dough strength. Grain S concentration was positively correlated with dough extensibility and negatively correlated with maximum dough resistance, mixograph peak time, and work input to peak. Grain N:S ratio was negatively correlated with dough extensibility and positively correlated with maximum dough resistance and work input to peak. The improvements in baking and dough quality were associated with changes in the protein composition of flour. Grain S concentration was positively correlated with the proportion of soluble glutenin and negatively correlated with the ratio of insoluble to soluble glutenin in flour. Grain N:S ratio was negatively correlated with the proportion of soluble glutenin and positively correlated with the ratio of insoluble to soluble glutenin in flour. Sulphur fertilization increased grain yield at two of seven sites used for breadmaking quality evaluation. Application of S fertilizer also frequently improved the breadmaking quality, dough quality, and flour protein composition of wheat at four of these seven sites. All four sites where grain quality improvements were observed contained < 40 kg SO4-S ha-l prior to fertilization, a concentration of soil S regarded as marginally sufficient for grain yield. Also, at these four marginal S sites, the S concentration and N:S ratio of plant tissue samples collected at 50 % heading was < 0.15 % S and > l7:1, respectively. Sulphur fertilization increased the concentration of S in grain and reduced the N:S ratio in grain at all marginal S sites. The improvements in grain S nutrition were accompanied by significant improvements in loaf volume at two of the four marginal S sites when S fertilizer was applied in combination with 26 or 100 kg N ha-l, and at one more site where 100 kg N ha-l was applied. Sulphur fertilization increased loaf height and oven spring at three of the four sites. Application of S fertilizer also significantly increased dough extensibility at all four marginal S sites and reduced maximum dough resistance and mixograph peak time at three of four sites. Mixograph peak time was significantly reduced at the other marginal S site only in the presence of 100 kg N ha-1. Furthermore, S fertilization reduced the viscoelastic ratio and mixograph work input to peak at all four marginal S sites. Sulphur fertilization increased the proportion of soluble glutenin in flour and reduced the ratio of insoluble to soluble glutenin in the flour at three of four marginal S sites. Sulphur fertilization in the presence of 100 kg N ha-1 only, increased the proportion of soluble glutenin in flour and reduced the ratio of insoluble to soluble glutenin in the flour at the other marginal S site. At the three sites where soil SO4-S concentrations were > 40 kg ha-l, no yield and few breadmaking quality improvements were observed in response to S fertilization. For these high S sites, S fertilization did not increase the S concentration in grain at any site and reduced the N:S ratio in grain at only one site. At all four sites where grain contained <- 0.17 % S and an N:S ratio > 17:1, quality improvements due to S fertilization were consistently observed. At all three sites where grain contained S concentrations >-0.17 % S and N:S ratios < 17:1, breadmaking quality responses to S fertllization were infrequent...
46
Lukie, Christian Andrew. "Effects of genotype and environment on the breadmaking quality of Canada Western Extra Strong Red Spring wheat cultivars". 2009. http://hdl.handle.net/1993/3767.
Testo completoAbstract (sommario):
In 1995, The Canadian Wheat Board established a collaborative working group of researchers from the Canadian Grain Commission's Grain Research Laboratory, Agriculture and Agri-Food Canada's Cereal Research Centre, and the University of Manitoba's Department of Food Science to investigate the breadmaking quality of the CWES wheat class. The specific issues this group was to investigate the uniformity of cultivars within the class in terms of breadmaking quality, and the consistency of quality for each cultivar grown in different locations. In 1995, the CWES class comprised three registered cultivars, Glenlea (first licensed in 1972 as a Utility class wheat), Bluesky and Wildcat (both registered in l987). Descriptions of these three cultivars were published by Evans et al. (L972) and Clarke et al. (1994a and 1994b, respectively). In addition, the wheat line PT754, which had undergone three years of testing in the Parkland Wheat Co-operative Trial by the prairie Registration Recommending Committee for Grain, was expected to be registered. In 1996, PT754 received a three-year interim registration, and was given the name Laser, thus bringing the total number of cultivars in the cwES class to four. Buyers of CWES wheat expressed concern that the class was no longer performing as well as when Glenlea was the only cultivar within the class for various products, e.g. bread. It was suggested that one or more of the cultivars Bluesky, Wildcat and Laser possessed weaker dough properties compared to those of the established standard CWES wheat cultivar Glenlea. Further, it was not known whether the apparent differences in quality were genetic and/or environmental in nature. This thesis project was undertaken in 1997 to comprehensively examine these questions. CWES wheats are characteristically unique in dough physical properties and protein composition. The flour can be distinguished by very long dough mixing times and relatively high contents of so-called "unextractable" glutenin protein, i.e. glutenin of relatively high average molecular size. This wheat class was founded upon the cultivar Glenlea that was developed at the U of M and was originally licensed into the Canada Western Utility wheat class. In 1993, CWES became the new name of the wheat class to better reflect the functional quality of the cultivars within this class. Commercial interest in CWES wheat increased significantly in the 1990s as its gluten attributes became more widely known and studied. These attributes relate to its use as a blending wheat in a variety of applications where there is a need for increased gluten strength in the dough (Bushuk 1980). For example, to carry weaker and less costly wheats in white pan bread production, as a vital gluten replacer in whole wheat, high-fibre and hearth breads, and in frozen doughs to mitigate the damaging effects of extended freezing and thawing. This study evaluated a sample set of 36 flours derived from six different wheat genotypes- four CWES, and two CWRS- grown in six different locations in Saskatchewan and Alberta. The CWES genotypes were Glenlea, Bluesky, Wildcat, and Laser. The CWRS genotypes were Katepwa and Laura. The three objectives of the study were as follows: * To quantify genotypic differences in dough protein composition, dough mixing properties, and bread baking potential across locations * To similarly quantify the magnitude of location effects * To establish which tests (protein composition, mixing, and/or backing) best characterize the unique properties of CWES wheat.
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Masuhara, Yasuo J. "Evaluation of breadmaking quality from common wheat quality parameters and fundamental rheological, chemical, and functional properties of wheat cultivars". Thesis, 1993. http://hdl.handle.net/2429/2025.
Testo completoAbstract (sommario):
The stress relaxation and deformability modulus of wheat doughs made from five groups of wheat cultivars of differing breadmaking ability were determined. Doughs made from poor breadmaking cultivars had greater rates of stress relaxation than doughs made from good breadmaking cultivars. Doughs made from hard wheats had a greater resistance to deformation (deformability modulus) than doughs made from soft wheats. The solubility, sulfhydryl, and disulfide content of gluten of the five groups of wheat cultivars were also determined. Gluten of poor breadmaking cultivars had greater sulfhydryl content than gluten of good breadmaking cultivars. No differences were found in the extent of stress relaxation, gluten disulfide content, and gluten solubility of the different groups of wheat cultivars. The prediction of breadmaking quality (loaf volume) by fundamental rheological, chemical, and functional properties and common wheat, flour, and dough quality tests was examined. Simple linear regression of baking tests on common wheat, flour, and dough quality tests did not result in any single test having a squared correlation coefficient greater than 0.743. General multiple regression equations predicting baking test volumes were made based on the significance of the simple linear regressions. The adjusted squared multiple correlation coefficients of these equations were as high as 0.924. A more practical prediction equation (adjusted R2=0.907) with only five independent variables (mixograph first minute slope, extensigraph extensibility to resistance ratio, sedimentaion value, thousand kernel weight, andB value) was obtained by stepwise regression analysis. The addition of the measurements of the fundamental rheological(stress relaxation, deformability modulus), chemical (sulfhydry land disulfide content), and functional (solubility) properties to the regression equations did not improve the adjusted squared multiple correlation coefficients of the equations.
Principal component analysis reduced the data set to seven components which explained 91% of the total variation. Qualitative (dough strength parameters) and quantitative (milling parameters) components were identified.
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Jarvis, Chad Kelvin. "Growing season weather impacts on breadmaking quality of Canada western red spring wheat grown in producer fields across western Canada". Thesis, 2006. http://hdl.handle.net/1993/287.
Testo completoAbstract (sommario):
A study was conducted to quantify the relationships between growing season weather conditions and end-use quality of Canada Western Red Spring (CWRS) wheat (Triticum aestivum) grown in producer fields across western Canada (Alberta, Saskatchewan and Manitoba). Grain samples received an official grade at the Canadian Grain Commission and were milled into flour using a Buhler flour. Flour samples underwent an extensive analysis of flour, dough, and breadmaking quality. Daily precipitation amounts and maximum/minimum temperatures were accumulated for each field and then compared to quality data.
In this study we also investigated the effectiveness of the Canadian grain grading system’s ability to segregate wheat samples into levels of increasing quality performance and uniformity. We found that for several flour and dough quality analysis, this was often achieved for either quality performance or uniformity, but there was not an improvement in both with an improvement in grade except in bread quality.October 2006
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Hung, Tsui-Hwa Tracy. "Determination of L-ascorbyl 6-palmitate in breadmaking using reverse-phase high-performance liquid chromatography (HPLC) with electrochemical (EC) detection". 1986. http://hdl.handle.net/2097/22083.
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