EFFECT OF ENZYMATIC TREATMENTS ON CARBOHYDRATE MATRICES TOWARDS HEALTHY GLUTEN FREE FOODS APPLICATION

Tesis por compendioStarch is the major energy reserve in plants, extensively present in many food and non-food applications, and is one of the most abundant carbohydrates in human diet. In addition to starch native form currently used as a raw material for industrial applications, modified starches have become very attractive to develop numerous products that have greatly expanded starch use and utility. Enzymatic modifications are carried out to enhance starch functionality with the aim of overcoming technological constraints and to improve final product quality. Above all starches, corn starch is widely produced and consumed, and used as main ingredient to produce gluten-free products. This Thesis focuses to the study of the individual effect of three different enzymes, fungal alpha-amylase, amyloglucosidase and cyclodextrin glycosyltransferase, on the above sub-gelatinization temperature of corn starch, in order to modify its properties and extend its applications. Different analyses have been performed to improve the understanding of functional and structural changes promoted by the enzyme action. Moreover, corn starch modified with cyclodextrin glycosyltransferase was selected to investigate the glycemic response in mice. The presence/absence of hydrolysis products released from the enzyme catalytic activity and gelatinization properties were related to glycemic index. Enzymatically modified corn starch resulted in a diversity of functional starch granules that may be used in food applications for many purposes.El almidón es la principal fuente de reserva de energía en las plantas, está ampliamente presente en diversas aplicaciones alimentarias y no alimentarias, y constituye uno de los hidratos de carbono más abundantes en la dieta humana. Además del uso frecuente y clásico del almidón nativo como materia prima en la producción de alimentos, los almidones modificados han experimentado gran expansión en el desarrollo de numerosos productos debido a su carácter versátil. Las modificaciones enzimáticas se llevan a cabo para realzar la funcionalidad del almidón con objeto de soslayar las restricciones tecnológicas y mejorar la calidad del producto final. En concreto, el almidón de maíz ampliamente producido y consumido, es apropiado como ingrediente principal en la producción de alimentos libres de gluten. Esta Tesis aborda el estudio del efecto individual de tres diferentes enzimas, alfa-amylasa fúngica, amiloglucosidasa y ciclodextrina glucosiltransferasa, sobre la temperatura de sub-gelatinización del almidón de maíz. Se realizaron diferentes análisis para ampliar el conocimiento de los cambios estructurales y funcionales asociados a la acción de la enzima. Así mismo, se seleccionó el almidón de maíz modificado con ciclodextrina glucosiltransferasa para investigar la respuesta glicémica en ratones. El índice glicémico se relacionó con la ausencia/presencia de productos de hidrólisis liberados por la acción catalítica de la enzima y las propiedades de gelatinización. Los almidones de maíz enzimáticamente modificados presentaron alteraciones funcionales en los gránulos de almidón, lo que les confiere características de interés para diversos usos alimentarios.El midó és la principal font de reserva d'energia en les plantes, està àmpliament present en diverses aplicacions alimentàries i no alimentàries, i constitueix un dels hidrats de carboni més abundants en la dieta humana. A més de l'ús freqüent i clàssic del midó natiu com a matèria primera en la producció d'aliments, els midons modificats han experimentat gran expansió en el desenvolupament de nombrosos productes a causa del seu caràcter versàtil. Les modificacions enzimàtiques es duen a terme per a realçar la funcionalitat del midó a fi d'esbiaixar les restriccions tecnològiques i millorar la qualitat del producte final. En concret, el midó de dacsa àmpliament produït i consumit, és apropiat com a ingredient principal en la producció d'aliments lliures de gluten. Aquesta Tesi aborda l'estudi de l'efecte individual de tres diferents enzims, alfa-amylasa fúngica, amiloglucosidasa i ciclodextrina glucosiltransferasa, sobre la temperatura de sub-gelatinizació del midó de dacsa. Es van realitzar diferents anàlisi per a ampliar el coneixement dels canvis estructurals i funcionals associats a l'acció de l'enzim. Així mateix, es va seleccionar el midó de dacsa modificat amb ciclodextrina glucosiltransferasa per a investigar la resposta glicémica en ratolins. L'índex glicémic es va relacionar amb l'absència/presencia de productes d'hidròlisis alliberats per l'acció catalítica de l'enzim i les propietats de gelatinización. Els midons de dacsa enzimàticament modificats van presentar alteracions funcionals en els grànuls de midó, la qual cosa els confereix característiques d'interès per a diversos usos alimentaris.Durá De Miguel, Á. (2017). EFFECT OF ENZYMATIC TREATMENTS ON CARBOHYDRATE MATRICES TOWARDS HEALTHY GLUTEN FREE FOODS APPLICATION [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79509TESISCompendi

Physico-chemical properties of corn starch modified with cyclodextrin glycosyltransferase

Cyclodextrin glycosyltransferase (CGTase) has been used to produce cyclodextrins (CDs) from starches, but their ability to modify starches has been barely explored. The effect of CGTase on corn starch at sub-gelatinization temperature (50 °C) and at different pH conditions, pH 4.0 and pH 6.0, was evaluated. Biochemical features, thermal and structural analysis, oligosaccharides and CDs content were studied. Microscopic analysis of the granules confirmed the enzymatic modification of the starches obtaining structures with irregular surface and small pinholes. The extent of the starch modification was largely dependent on the pHs, being higher at pH 6.0. This was also confirmed by the low viscosity of the resulting pastes during a heating and cooling cycle. Thermal parameters were not affected due to enzymatic treatment. Modified starches were less susceptible to undergo α-amylase hydrolysis. CDs released were higher for samples treated at pH 4.0. Therefore, CGTase modification of corn starches at sub-gelatinization temperature offers an attractive alternative for obtaining porous starches with different properties depending on the pH conditions.Financial support of the Spanish Ministry of Economy and Competitiveness (Project AGL2011-23802, AGL2014-52928-C2-1-R), the European Regional Development Fund (FEDER) and Generalitat Valenciana (Project Prometeo 2012/064). A. Dura would like to thank predoctoral fellowship from Spanish Ministry of Economy and Competitiveness.Peer reviewe

Glycemic Response to Corn Starch Modified with Cyclodextrin Glycosyltransferase and its Relationship to Physical Properties

Corn starch was modified with cyclodextrin glycosyltransferase (CGTase) below the gelatinization temperature. The porous granules with or without CGTase hydrolysis products may be used as an alternative to modified corn starches in foods applications. The amount and type of hydrolysis products were determined, containing mainly β-cyclodextrin (CD), which will influence pasting behavior and glycemic response in mice. Irregular surface and small holes were observed by microscopic analysis and differences in pasting properties were observed in the presence of hydrolysis products. Postprandial blood glucose in mice fed gelatinized enzymatically modified starch peaked earlier than their ungelatinized counterparts. However, in ungelatinized enzymatically modified starches, the presence of β- CD may inhibit the orientation of amylases slowing hydrolysis, which may help to maintain lower blood glucose levels. Significant correlations were found between glycemic curves and viscosity pattern of starches.financial support of the Spanish Ministry of Economy and Competitiveness (Project AGL2011-23802 and AGL2014-52928-C2-1-R), the European Regional Development Fund (FEDER) and GeneralitatValenciana (Project Prometeo 2012/064). A. Dura would like to thank predoctoral fellowship from Spanish Ministry of Economy and Competitiveness. This research was performed in part at the Processed Foods Research, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, United States.Peer reviewe

Modelización de la tasa respiratoria de caqui rojo brillante

Dado el importante incremento que ha experimentado la producción de caqui en los últimos años en España, más concretamente la variedad "Rojo brillante", se hace inevitable la introducción de métodos de conservación para adaptarse a la demanda del mercado actual. La temperatura ha sido identificada como el factor externo más importante capaz de influenciar la respiración. Por tanto, es muy importante conocer la influencia de la temperatura sobre la tasa respiratoria. Además, la tasa respiratoria se ve influenciada por la geometría del corte. En general, hay un aumento en la tasa respiratoria de las frutas troceadas frente a las enteras, asociado a una aceleración de su metabolismo por el estrés inducido por las heridas provocadas con el corte. En el presente estudio se ha modelizado la evolución de la tasa respiratoria de rodajas y cubos de Caqui (Diospyros kaki) de la variedad Rojo Brillante persimon. A partir de los resultados experimentales obtenidos mediante un sistema de análisis estático cerrado a diferentes temperaturas de almacenamiento (1, 5, 10 y 15 ºC), monitorizando el consumo de O2 y la producción de CO2 a lo largo del tiempo, a través del análisis del espacio de cabeza. Se han utilizado diferentes modelos predictivos basados en regresiones lineales y no lineales. Los parámetros obtenidos para todos ellos, así como la predicción obtenida sobre los datos experimentales en cada caso, han permitido comprobar el grado de predicción de cada uno de ellos. Todos los modelos desarrollados fueron validados a una temperatura de 7ºC. ABSTRACT: Given the important increase that has undergone the khaki production in the last years in Spain, more concretely the "Rojo brillante" variety, is made the introduction inevitable of conservation methods to adapt to the demand of the present market. The temperature has been identified as the more important external factor able to influence the breathing. Therefore, it is very important to know the influence of the temperature on the respiratory rate. In addition, the respiratory rate is influenced by the geometry of the cut. Generally, there is an increase in the respiratory rate of the fruits divided against the whole ones, associated to an acceleration of his metabolism by the stress induced by the wounds caused with the cut. In the present study, it has modelled the evolution of the respiratory rate of slices and buckets of Khaki (Diospyros kaki) of the "Rojo Brillante" variety persimon. From the obtained experimental results by means of a system of closed static analysis to different temperatures from storage (1, 5, 10 and 15 ºC), monitoring the consumption of O2 and the CO2 production throughout the time, through analysis of the head space. Different predictive models based on regressions linear and nonlinear have been used. The parameters obtained for all of them, as well as the prediction obtained on the experimental datas in each case, has allowed to verify the degree of prediction from each of them. All the developed models were validated to a temperature of 7ºC.Durá De Miguel, Á. (2010). Modelización de la tasa respiratoria de caqui rojo brillante. http://hdl.handle.net/10251/14455Archivo delegad

Effect of Partial Substitution of Wheat Flour by Processed (Germinated, Toasted, Cooked) Chickpea on Bread Quality

The effect of partial substitution of wheat flour with either raw and processed chickpea (germinated, toasted and cooked) flour at different levels (10 and 20%) on pasting properties of composite flours and on physical and nutritional parameters of the composite breads were studied. Composite flours of wheat and processed chickpea showed different pasting properties, decreasing the viscosity in all kinds of flour and levels, being more accentuated with the cooked flour. The least affected flour was the toasted that showed similar pasting profile than raw flour. Breads with 10% wheat flour replacement showed minor changes in their quality, but 20% replacement resulted in great detriment of the quality. Crumb hardness was greatly improved when 20% raw or toasted flour was incorporated. Overall, germinated chickpea flours were the most appropriate flour for wheat replacement pertaining bread specific volume, crumb hardness and nutritional composition (higher protein content).Financial support of Spanish National Research Council (CSIC) and the Generalitat Valenciana (Spain, Project Prometeo 2012/064). They thank the University of Abderahmane Mira for supporting predoctoral stay of Mrs Ouazib.Peer reviewe

Combination of extrusion and cyclodextrin glucanotransferase treatment to modify wheat flours functionality

This research aims to vary functional properties of native and extruded wheat flours combining cyclodextrin glucanotransferase and extrusion treatments. The level of released cyclodextrins (CD) was assessed, besides the microstructure, crystallinity, pasting properties and starch hydrolysis of the flours. Photomicrographs of enzymatically treated flours suggested the production of fragile structures that broke easily. Enzymatic hydrolysis was significantly higher in extruded flours, as confirmed the CD levels, being predominant the γ-CD followed by α-CD, whereas very low β-CD values were obtained probably due to the formation of CD–lipid complexes, as suggested X-ray diffractometry results. Both extruded and native samples showed very low viscosity and flat pasting profile consequence of the enzyme hydrolytic activity on the starch chains. Enzymatically treated flours (native and extruded) showed higher hydrolysis rates at the early hydrolysis stage, and extruded flours exhibited higher fractal exponent h in agreement with the extended crystalline structures resulting from enzymatic treatment.This study was financially supported by Junta de Castilla y León (Spain, Project VA054A12-2) and the Generalitat Valenciana (Spain, Project Prometeo 2012/064). The authors are also grateful to Molendum Ingredients and Novozymes for supplying the raw materials. MM Martínez and A Dura would like to thank predoctoral fellowship from Spanish Ministry of Education, Culture and Sport and Spanish Ministry of Economy and Competitiveness, respectively.Peer reviewe

Effects of Cyclodextrin Glycosiltranferase Modified Starch and Alfa and Beta Cyclodextrins on Plasma Glucose and Lipids Metabolism in Mice

The potential functional and nutritional benefits of granular starch treated with cyclodextrin glycosyltransferase (CGTase) and the released cyclodextrins (CDs) were explored in in vivo studies. The metabolic effects of diets in the C57BL/6J mouse containing native and enzymatically modified corn starch by CGTase with or without hydrolysis products were studied. The hydrolysis products were oligosaccharides and CDs, mainly b-CD. Blood glucose concentration at 2 hours was higher suggesting that enzymatically treated starches containing CDs slowed digestion resulting in a longer period of absorption and consequently higher blood glucose levels at the later times. The modified starch with CDs tended to increase HDL-cholesterol levels while decreasing VLDL-cholesterol levels. The CGTase modified starches lowered total and cholesterol ester values in liver and decreased fecal fat extraction. The inclusion of CGTase modified granular starches in the presence of their hydrolysis products may be useful to prevent obesity and other related metabolic diseases, offering an alternative healthy ingredient to the food industry.financial support of the Spanish Ministry of Economy and Competitiveness (Project AGL2011-23802 and AGL2014-52928-C2-1-R), the European Regional Development Fund (FEDER. A. Dura would like to thank predoctoral fellowship from Spanish Ministry of Economy and Competitiveness. This research was performed in part at the Processed Foods Research, Agricultural Research Service, U.S.Department of Agriculture, Albany, California 94710, United States.Peer reviewe

"El alma en el mar". Álbum ilustrado

[EN] The soul in the sea is an illustrated album, which integrates the knowledge and skills obtained during the process of graduate studies in Fine Arts at the Universidad Politécnica de Valencia. In the work will develop the creation of a narrative, the design of characters, the study of illustration as a means of communication, the layout and design of the work as an editorial product that contains the same aspects and helps the result general be harmonious, uniform and professional.[ES] El alma en el mar es un álbum ilustrado que integra los conocimientos y habilidades obtenidos durante el proceso de los estudios de grado en Bellas Artes en la Universidad Politécnica de Valencia. En el trabajo se desarrollará la creación de una narración, el diseño de personajes, el estudio de la ilustración como medio de comunicación, la maquetación y el diseño de la obra como un producto editorial que contenga los mismos aspectos y que ayude a que el resultado general sea armónico, uniforme y profesional.Gallego Durá, ÁM. (2018). "El alma en el mar". Álbum ilustrado. http://hdl.handle.net/10251/109127TFG

Functionality of porous starch obtained by amylase or amyloglucosidase treatments

9 pages, 4 tables, 4 figures. --Available online 12 October 2013Porous starch is attracting very much attention for its absorption and shielding ability in many food applications. The effect of two different enzymes, fungal α-amylase (AM) or amyloglucosidase (AMG), on corn starch at sub-gelatinization temperature was studied as an alternative to obtain porous starch. Biochemical features, thermal and structural analyses of treated starches were studied. Microscopic analysis of the granules confirmed the enzymatic modification of the starches obtaining porous structures with more agglomerates in the case of AMG treated starches. Several changes in thermal properties and hydrolysis kinetics were observed in enzymatically modified starches. Hydration properties were significantly affected by enzymatic modification being greater influenced by AMG activity, and the opposite trend was observed in the pasting properties. Overall, results showed that enzymatic modification at sub-gelatinization temperatures really offer an attractive alternative for obtaining porous starch granules to be used in a variety of foods applications.financial support of the Spanish Ministry of Economy and Competitiveness (Project AGL2011-23802), the European Regional Development Fund (FEDER) and Generalitat Valenciana (Project Prometeo 2012/064). A. Dura would like to thank predoctoral fellowship from Spanish Ministry of Economy and CompetitivenessPeer reviewe