<p>Савремено пекарство у нашој земљи, још увек, у највећој мери подразумева производњу хлеба и пекарских производа<em> in situ</em>. Припрема пекарских производа у кућним условима своди се, готово искључиво, на мешење према традиционалном<br />моделу. Овакво понашање пекара и потрошача делимично је последица навика, али и изузетно лоше снабдевености нашег тржишта замрзнутим пекарским производима добијеним од квасног теста, као и сировинама намењеним за<br />производњу истих.</p><p>Циљ истраживања обухваћених докторском дисертацијом усмерен је ка дефинисању и унапређењу услова производње и финализације замрзнутих пекарских производа непосредно пред употребу, у близини корисника или од стране самог корисника. Добијени резултати требало би да дају допринос бољем разумевању феномена који се дешавају у поступкузамрзавања/одмрзавања теста. Модификација постојеће, код нас примењиване технологије, у смислу примене одабраних сојева квасца, одабраног режима замрзавања/одмрзавања и дужине чувања теста у замрзнутом стању, као и примене одабраних додатака тесту, требало би да резултује пекарским производима добијеним од замрзаваног теста чије су технолошке и сензорне карактеристике побољшане.</p><p>Испитан је сировински састав теста и квалитет употребљених сировина карактеристичан за наше поднебље са аспекта њихове примене у производњи замрзаваног теста, о чему нема публикованих резултата. Доказана је могућност употребе комерцијалног пекарског квасца и комерцијалног брашна које по садржају и квалитету глутена не одговара у потпуности литературним препорукама.</p><p>Предложене су математичке релације које омогућавају предвиђање трајања операција замрзавања и одмрзавања квасног теста у дефинисаним условима који су уобичајени у пекарској производњи, о чему нема литературних података.<br />Дефинисани су оптимални услови замрзавања и одмрзавања квасног теста који омогућавају очување активности квасца у замрзаваном тесту на прихватљивом нивоу.<br />На основу активности квасца у замрзаваном тесту са хидроколоидима, матурографских и екстензограмских показатеља квалитета као и његове микроструктуре доказан је позитиван утицај додатка хидроколоида у замрзавано тесто са аспекта његовог квалитета. Јасно изражене промене микроструктуре замрзнутог теста током његовог складиштења доприносе разумевању феномена који се дешавају у тесту услед његовог замрзавања, одмрзавања и складиштења у замрзнутом стању до 28 дана, као и интеракција између конституента теста и додатих хидроколоида.</p><p>Доказано да је за припрему замрзаваног теста могуће користити сировине чији квалитет није оптималан, али да се тиме<br />значајно скраћује период складиштења у коме не долази до неприхватљиве деградације његовог квалитета са неколико седмица колико препоручује литература, на свега 7 до 14 дана. Квалитет готовог пекарског производа добијеног од замрзаваног теста које се састоји од сировина уобичајено присутних<br />на нашем тржишту, а које је припремљено уз предложене минималне модификације традиционалног начина припреме хлеба, задовољавајући је из угла конзумента.</p> / <p>Savremeno pekarstvo u našoj zemlji, još uvek, u najvećoj meri podrazumeva proizvodnju hleba i pekarskih proizvoda<em> in situ</em>. Priprema pekarskih proizvoda u kućnim uslovima svodi se, gotovo isključivo, na mešenje prema tradicionalnom<br />modelu. Ovakvo ponašanje pekara i potrošača delimično je posledica navika, ali i izuzetno loše snabdevenosti našeg tržišta zamrznutim pekarskim proizvodima dobijenim od kvasnog testa, kao i sirovinama namenjenim za<br />proizvodnju istih.</p><p>Cilj istraživanja obuhvaćenih doktorskom disertacijom usmeren je ka definisanju i unapređenju uslova proizvodnje i finalizacije zamrznutih pekarskih proizvoda neposredno pred upotrebu, u blizini korisnika ili od strane samog korisnika. Dobijeni rezultati trebalo bi da daju doprinos boljem razumevanju fenomena koji se dešavaju u postupkuzamrzavanja/odmrzavanja testa. Modifikacija postojeće, kod nas primenjivane tehnologije, u smislu primene odabranih sojeva kvasca, odabranog režima zamrzavanja/odmrzavanja i dužine čuvanja testa u zamrznutom stanju, kao i primene odabranih dodataka testu, trebalo bi da rezultuje pekarskim proizvodima dobijenim od zamrzavanog testa čije su tehnološke i senzorne karakteristike poboljšane.</p><p>Ispitan je sirovinski sastav testa i kvalitet upotrebljenih sirovina karakterističan za naše podneblje sa aspekta njihove primene u proizvodnji zamrzavanog testa, o čemu nema publikovanih rezultata. Dokazana je mogućnost upotrebe komercijalnog pekarskog kvasca i komercijalnog brašna koje po sadržaju i kvalitetu glutena ne odgovara u potpunosti literaturnim preporukama.</p><p>Predložene su matematičke relacije koje omogućavaju predviđanje trajanja operacija zamrzavanja i odmrzavanja kvasnog testa u definisanim uslovima koji su uobičajeni u pekarskoj proizvodnji, o čemu nema literaturnih podataka.<br />Definisani su optimalni uslovi zamrzavanja i odmrzavanja kvasnog testa koji omogućavaju očuvanje aktivnosti kvasca u zamrzavanom testu na prihvatljivom nivou.<br />Na osnovu aktivnosti kvasca u zamrzavanom testu sa hidrokoloidima, maturografskih i ekstenzogramskih pokazatelja kvaliteta kao i njegove mikrostrukture dokazan je pozitivan uticaj dodatka hidrokoloida u zamrzavano testo sa aspekta njegovog kvaliteta. Jasno izražene promene mikrostrukture zamrznutog testa tokom njegovog skladištenja doprinose razumevanju fenomena koji se dešavaju u testu usled njegovog zamrzavanja, odmrzavanja i skladištenja u zamrznutom stanju do 28 dana, kao i interakcija između konstituenta testa i dodatih hidrokoloida.</p><p>Dokazano da je za pripremu zamrzavanog testa moguće koristiti sirovine čiji kvalitet nije optimalan, ali da se time<br />značajno skraćuje period skladištenja u kome ne dolazi do neprihvatljive degradacije njegovog kvaliteta sa nekoliko sedmica koliko preporučuje literatura, na svega 7 do 14 dana. Kvalitet gotovog pekarskog proizvoda dobijenog od zamrzavanog testa koje se sastoji od sirovina uobičajeno prisutnih<br />na našem tržištu, a koje je pripremljeno uz predložene minimalne modifikacije tradicionalnog načina pripreme hleba, zadovoljavajući je iz ugla konzumenta.</p> / <p>Currently the baker&#39;s industry in our country is based on the production of bread and bakery products <em>in situ</em>. ln domestic conditions the preparation of bakery products is done solely using the traditional model. This is a consequence of baker and consumer habit in our country as well as the poor market supplies of frozen bakery products from yeast dough and raw material for this production.<br />The aim of research for this dissertation is based on the definition and improvement of the production conditions as well as the flnalization of frozen bakery products prior to use. The results should contribute to the understanding of phenomena that exist in the process of freezing/thawing of dough. In order to preserve the technology commonly<br />used in our country, minor modifications were made using selected yeast types, selected regime of freezing/tharving, frozen dough storage time and additives to dough. These minor changes should result in the improvement of technological and sensor characteristics for baker products obtained from frozen dough. The raw material structure in dough and the quality of used raw material were analyzed from the aspect of the frozen dough production where there is nothing published upon this subject yet. The possibility of the use of commercial baker yeast and flour was proven even though their content and quality of gluten does not correspond to the literature recommendation.<br />Mathematical relations that enable prediction of freezing/thawing of yeast dough operation durance in defined conditions were suggested and has no published results upon this subject yet. Optimal conditions of freezing/thawing yeast dough that preserves the activity of yeast in frozen dough on an accepted level were defined.<br />On the basis of the yeast activity in frozen dough with hydrocolloids, the rheological characteristics and its microstructure, the positive affect of hydrocolloid addition to frozen dough was proven from its quality aspect. Major changes in microstructure of frozen dough during its storage contribute to the understanding of the phenomena that<br />appear in dough during freezing, thawing and storage in frozen state up to 28 days, as well as the interaction between the dough constituents and added hydrocollcids.<br />The possibility of the use of raw material for the dough preparation that has not the optimal quality but shortens the storage time was proven. During this storage time the degradation of its quality does not appear as reconlmended by literature in the period of few weeks but in the period of 7 to 14 days.<br />From the consumerrs point of view the quality of finished bakery product derived from frozen dough with available raw material and with minor modifications of the traditional method of preparation was satisfactorily.</p>

<p>Osnovni cilj ovog istraživanja je utvrđivanje mogućnosti proizvodnje funkcionalnog niskoenergetskog prehrambenog namaza na bazi bra&scaron;na od semena tikve golice i hidrokoloida ugljenohidratnog porekla.<br />Utvrđivanju ove mogućnosti prethodilo je potpuno karakterisanje i definisanje sastavnih komponenti namaza. To su bra&scaron;no od semena tikve golice i prehrambeni hidrokoloidi na bazi vlakana. Bra&scaron;no od semena tikve golice analizirano je radi određivanja njegovih fizičko&ndash;hemijskih karakteristika, funkcionalnih svojstava, mikrobiolo&scaron;ke ispravnosti i mikrostrukturalne prirode. Analizama bra&scaron;na stečen je uvid u fizičke, nutritivne i mikrobiolo&scaron;ke karakteristike i u svojstva pona&scaron;anja, s ciljem utvrđivanja mogućnosti primene bra&scaron;na od semena tikve u daljem radu. Takođe, ispitane su dve vrste hidrokoloida ugljenohidratnog porekla metodom mikrostrukturalne analize, metodom određivanja raspodele veličina čestica, reolo&scaron;kim određivanjima i teksturalnim karakterisanjem sistema. Cilj ovog ispitivanja je definisanje vrste i koncentracije vlakana u gel strukturi hidrokoloida, koja ima sposobnost da ostvari ulogu nosača bra&scaron;na, odnosno kontinualne faze u namazu. Time je predviđeno i pona&scaron;anje ugljenohidratnih hidrokoloida u prehrambenom sistemu tipa namaza.<br />Nakon definisanja sastavnih komponenti, radi utvrđivanja optimalnih svojstava namaza, analizirani su namazi sa različitom vrstom i koncentacijom vlakana u gel sistemu i različitim udelom primenjenog hidrokoloida u sastavu namaza. Pri ispitivanju značajnosti uticaja promenljivih faktora na svojstva dobijenih namaza kori&scaron;ćena je metoda planiranja eksperimenta (DOE&ndash;design of experiment) u okviru koje je primenjen potpuni faktorijalni dizajn. Takođe, međusobna linearna zavisnost<br />između pojedinih promenljivih određena je metodom korelacije sa ciljem utvrđivanja povezanosti parametara senzorske analize sa instrumentalno određenim karakteristikama.<br />Cilj objedinjenja svih analiza je definisanje sastava namaza optimalnih svojstava i formulacija niskoenergetskog prehrambenog namaza na bazi bra&scaron;na od semena tikve.<br />Na osnovu prikazanih rezultata istraživanja u okviru ove doktorske disertacije izvedeni su zaključci da je bra&scaron;no od semena tikve golice nutritivno i biolo&scaron;ki vrlo vredna sirovina dobre održivost, bez patogenih mikroorganizama i da predstavlja pogodnu sirovinu za proizvodnju namaza. Takođe, hidrokoloid Vivapur MCG 611F se odlikuje<br />povoljnijim reolo&scaron;kim i teksturalnim svojstvima od hidrokoloida Vitacel WFG HS73, jer tiksotropno protiče, ima veći stepen uređenosti i povezanosti strukture sa izraženom elastičnom prirodom koja mu omogućava manju podložnost deformacijama i čini ga pogodnim za proizvodnju namaza.<br />Na osnovu analize uticaja promenljivih faktora, koji se odnose na sastav namaza, zaključeno je da posmatrani namazi predstavljaju realne reolo&scaron;ke sisteme i da sastav namaza izraženo utiče na njihove reolo&scaron;ke, teksturalne i senzorske osobine.<br />Na osnovu sprovedenih istraživanja zaključuje se da je moguća proizvodnja niskoenergetskog namaza na bazi bra&scaron;na od semena tikve golice. Pri tome namaz treba da sadrži 80% MCG zamenjivača masti (na masu namaza) koncentracije hidrokoloidnog gela 7% i 20% bra&scaron;na od semena tikve golice (na masu namaza). Namaz optimalnih svojstava je polidisperzan sistem sa uređenom strukturom u<br />kojoj su čestice primenjene količine bra&scaron;na uklopljene u kontinuiranu mrežu hidratisanih MCG vlakana i potpuno obložene dostupnom količinom zamenjivača masti. Zahvaljujući takvoj organizaciji i strukturi sistema optimalni namaz ispoljava dobre reolo&scaron;ke karakteristike, optimalnu mazivost, dobro prijanjanje na povr&scaron;inu i laku manipulaciju namazom tokom proizvodnje i tokom primene. Dobijeni namaz predstavlja nutritivno vredan proizvod koji se na osnovu sastava i zdravstvenog uticaja komponenti može svrstati u funkcionalne prehrambene proizvode.</p> / <p>The main objective of this study was to determine the possibility of production the low-fat functional food spreads based on flour of pumpkin seed and carbohydrate<br />hydrocolloids.<br />That included complete characterization of components of the spreads, the flour of hull&ndash;less pumpkin seed and fiber based food hydrocolloids. Flour of pumpkin seed was analyzed in order to determine its physico&ndash;chemical characteristics, functional characteristics, microbiological safety and microstructural nature. These analyses of flour defined the physical, nutritional and microbiological characteristics and behavior of flour, with the aim of determine the possibilities of its application in further work.<br />Also, two types of carbohydrate based hydrocolloids were examined by microstructural aspect, by particle size distribution, rheological determinations and textural characterization. The aim of these analysis was to define the type and concentration of fibers in the gel structure of hydrocolloids, which has the ability of to flour carrier and the role of continuous phase in the spread. This predicted<br />the behavior of carbohydrate based hydrocolloids in the food system such as spreads.<br />The determination of main components of the spreads was followed by determination of optimal properties of the spreads, which included analysis of spreads with different type and concentrations of fibers in the gel system and the<br />different amount of the applied hydrocolloid. To determine the significance of the influence of variable factors on the properties of the obtained spreads, the method of design of experiment (DOE) was used, with applied full factorial design. Also, correlation between certain sensory and instrumentally determined parameters was defined.<br />The aim of all analysis was to define the composition of the spread with optimal properties and to formulate the low&ndash;fat food spread based on flour of pumpkin seed<br />Based on the results obtained within this doctoral thesis, it was concluded that the flour of pumpkin seed cake is nutritionally and biologically very valuable raw material<br />with good sustainability, without pathogenic microorganisms, thus it is a suitable raw material for the production of spread. Also, Vivapur MCG 611F was characterized as hydrocolloid with better rheological and textural properties than the hydrocolloid Vitacel WFG HS73, because of its thixotropic flow properties, higher degree of<br />networking and pronounced elastic nature of structure that provides lower susceptibility to deformation and makes it suitable for the production of spread.<br />Based on the influence of variable factors, related to the composition of spreads, it was concluded that the observed spreads were real rheological systems and that the<br />composition of spreads signifficantly influenced on their rheological, textural and sensory characteristics. Obtained resultes of this research suggested that the production of low&ndash;fat food spread based on flour of pumpkin seed is possible. This spread contains 80% of MCG 611F fiber based hydrocolloid ( on the mass of the spread) with gel concentration of 7% and 20% of flour of pumpkin seed cake ( on the mass of the spread). The spread with optimal properties is poydisperse system with compact structure in which the flour particles are incorporated into continious network of hydrated MCG fibers and completly coated with avaliable amount of fat relacer. Due to this organization and structure of the system, optimal spread exhibits good properties for manipulation during production and application, such as good rheological characteristics, optimal spreadability and good adhesion to the surface. Obtained spread is nutritionaly valuable food product which can be classified into functional food product based on the composition and health inffluance.</p>

Made available in DSpace on 2017-07-21T18:53:04Z (GMT). No. of bitstreams: 1 ANDRESSA GABARDO GRANZA.pdf: 2807698 bytes, checksum: a0442acfb9a8bff732a7ec5ecaa9a286 (MD5) Previous issue date: 2015-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The development of gluten free products is becoming increasingly important as the number of celiac people have increased. Cheese breads and sour cassava starch biscuits are examples of gluten free baked products widely consumed in Brazil, however, these products have problems related to starch retrogradation, in other words, a very rapid staling in the case of baked products and the cheese breads marketed as frozen dough are susceptible to release of water (syneresis). Thus, the objective of this study was to develop a anti-staling premix able to increase freeze-thaw stability of gluten free baked products (cheese bread and sour cassava starch biscuits) without interfere negatively on the expansion property of these products. Binary and ternary mixtures were prepared using native cassava starch and oxidized cassava starch ranging the type of gum (guar, locust, xanthan and carrageenan) and the concentration used (2, 4 and 6 %). Mixtures using the acid modified cassava starch instead of oxidized cassava starch were also tested, but in this case using only guar gum at concentrations of 2, 4 and 6 %. The mixtures were evaluated for freeze-thaw stability and expansion property and the results were compared with those obtained for sour cassava starch (PA) native cassava starch (N), oxidized cassava starch (O) and acid modified cassava starch (A). The binary and ternary mixtures with better results and samples PA, N and O were evaluated for technological properties (pasting properties, swelling power and solubility and paste clarity), thermal properties (Differential Scanning Calorimetry - DSC), structural properties (Fourier Transform Infrared Spectroscopy - FTIR) and crystalline properties (X-ray diffraction); moreover, cheese breads were prepared with these samples and the staling of these products was evaluated (hardness parameter in texturometer and crumb moisture content). The mixture made with the native cassava starch, oxidized cassava starch and guar gum at a concentration of 4 % (MNO+GG 4 %) showed the best results of syneresis (loss of 4,87; 7,79 and 11 % in the 1st, 2nd and 3rd freeze-thaw cycle, respectively) compared with the other samples and the low retrogradation of this sample was confirmed by DSC analysis (enthalpy of retrogradation was non-existent) and FTIR (sample separated from others by principal component analysis - PCA). The expansion property of MNO GG+4 % sample was high (> 10 mL.g-1) and the cheese breads developed with this sample had a later staling compared with other samples, with lower hardness after 24 and 30 h of storage (23.71 and 29.59 N, respectively) and a wetter crumb (38.8 and 37.07%, respectively). These results indicate the possibility of using the premix MNO+GG 4% in gluten free baked products in place of sour cassava starch and/or native cassava starch. / O desenvolvimento de produtos livres de glúten está se tornando cada vez mais importante uma vez que o número de pessoas celíacas tem aumentado. Pães de queijo e biscoitos de polvilho são exemplos de produtos panificados livres de glúten consumidos em território brasileiro, porém, estes produtos possuem problemas relacionados com a retrogradação do amido, ou seja, um envelhecimento muito rápido no caso de produtos assados e os pães de queijo comercializados na forma de massa congelada estão susceptíveis à liberação de água (sinérese). Dessa forma, o objetivo do presente trabalho foi desenvolver uma pré-mistura capaz de retardar o envelhecimento e aumentar a estabilidade ao congelamento-descongelamento de produtos panificados livres de glúten (pães de queijo e biscoitos de polvilho), além de não interferir negativamente na propriedade de expansão dos mesmos. Misturas binárias e ternárias foram elaboradas utilizando-se o amido de mandioca nativo e o amido de mandioca oxidado variando-se o tipo de goma (guar, locusta, xantana e carragena) e a concentração utilizada (2, 4 e 6 %). Misturas utilizando o amido de mandioca ácido modificado ao invés do amido de mandioca oxidado também foram testadas, mas neste caso utilizando somente a goma guar nas concentrações de 2, 4 e 6 %. As misturas foram avaliadas quanto à estabilidade a ciclos de congelamento-descongelamento e propriedade de expansão e os resultados foram comparados com os obtidos para o polvilho azedo (PA), amido de mandioca nativo (N), amido de mandioca oxidado (O) e amido de mandioca ácido modificado (A). As misturas binárias e ternárias com melhores resultados e as amostras PA, N e O foram avaliadas quanto às propriedades tecnológicas (propriedade de pasta, poder de intumescimento e solubilidade, e claridade de pasta), térmicas (calorimetria exploratória diferencial - DSC), estruturais (Espectroscopia de infravermelho por transformada de Fourier - FTIR) e cristalinas (difração de raios X); além disso, foram elaborados pães de queijo com essas amostras e o envelhecimento dos mesmos foi avaliado (parâmetro dureza em texturômetro e teor de umidade dos miolos). A mistura feita com o amido de mandioca nativo, amido de mandioca oxidado e goma guar na concentração de 4 % (MNO+GG 4 %) apresentou os melhores resultados de sinérese (perdas de 4,87; 7,79 e 11 % no 1º, 2º e 3º ciclo de congelamento-descongelamento, respectivamente) em comparação com as demais amostras e a baixa retrogradação desta amostra foi confirmada pela análise de DSC (entalpia de retrogradação foi inexistente) e FTIR (amostra separada das demais pela análise de componentes principais – PCA). A propriedade de expansão da amostra MNO+GG 4 % foi considerada elevada (>10 mL.g-1) e os pães de queijo desenvolvidos com esta amostra tiveram um envelhecimento mais tardio em relação as demais amostras, apresentando menor dureza após 24 e 30 h de armazenamento (23,71 e 29,59 N, respectivamente) e um miolo mais úmido (38,8 e 37,07 %, respectivamente). Esses resultados indicam a possibilidade de utilização da pré-mistura MNO+GG 4 % em produtos panificados livres de glúten, em substituição do polvilho azedo e/ou amido de mandioca nativo.

The ability of the soluble fibre (1->3)(1->4)-β-D-glucan to attenuate postprandial glycemic responses depends on its viscosity which, in turn, depends on molecular weight (MW) and dose. However, the effect of altering viscosity by changing solution volume is unknown. Furthermore, β-glucan solutions may form hard gels when left to age, but the effect of these gels on glycemic responses is unknown. Therefore, the effects of varying the MW and volume of β-glucan solutions and hard gels, on glycemic responses were determined. The results showed that glycemic responses were reduced by increasing viscosity by increasing MW but not by reducing solution volume. Although β-glucan gels reduced the rate of glucose diffusion in vitro, they had no effect on glycemic responses in vivo. Thus, changing solution viscosity through changes in volume does not alter the effect of β-glucan on glycemic response, and β-glucan gels are ineffective at attenuating in vivo glycemic responses.

The ability of the soluble fibre (1->3)(1->4)-β-D-glucan to attenuate postprandial glycemic responses depends on its viscosity which, in turn, depends on molecular weight (MW) and dose. However, the effect of altering viscosity by changing solution volume is unknown. Furthermore, β-glucan solutions may form hard gels when left to age, but the effect of these gels on glycemic responses is unknown. Therefore, the effects of varying the MW and volume of β-glucan solutions and hard gels, on glycemic responses were determined. The results showed that glycemic responses were reduced by increasing viscosity by increasing MW but not by reducing solution volume. Although β-glucan gels reduced the rate of glucose diffusion in vitro, they had no effect on glycemic responses in vivo. Thus, changing solution viscosity through changes in volume does not alter the effect of β-glucan on glycemic response, and β-glucan gels are ineffective at attenuating in vivo glycemic responses.

[ES] La presente Tesis doctoral plantea distintas estrategias para el diseño y desarrollo de oleogeles estables, con un perfil lipídico de alta calidad nutricional y la posterior incorporación de los oleogeles en la formulación de distintos alimentos. Se pretende diseñar alimentos mediante el reemplazo de grasas sólidas, ricas en ácidos grasos saturados y trans por oleogeles, que, por un lado, mantengan las propiedades texturales y organolépticas, y, por otro lado, presenten un perfil lipídico mejorado. En una primera etapa, se desarrollaron oleogeles elaborados con 1% de hidroxipropilmetilcelulosa y 0,6% de goma xantana empleando dos condiciones de secado diferentes: secado convencional en estufa a 80 °C durante 10 h 30 min y secado a vacío a 60 °C durante 24 h. Los aceites estructurados fueron aceite de oliva, lino, girasol y girasol alto oleico. La microestructura permitió apreciar oleogeles bien estructurados cuando se utilizaron los aceites de oliva, girasol y girasol alto oleico. La estabilidad física y las propiedades reológicas corroboraron la formación de oleogeles de alta estabilidad física, a lo largo de 35 días de almacenamiento, y con un comportamiento de gel sólido. Se observó que tanto el grado de insaturación del aceite como las condiciones de secado afectaron a la estabilidad física y química del oleogel. De esta manera, se obtuvieron oleogeles poco estructurados y no homogéneos al utilizar aceite con un alto grado de insaturación, como el aceite de lino, por secado convencional, mientras que no fue factible desarrollar oleogeles de lino con secado a vacío. Además, el secado en estufa convencional a 80 °C durante 10 h 30 min generó oleogeles de girasol y de girasol alto oleico con mayor estabilidad estructural y física que el secado a 60 °C durante 24 h. Los oleogeles de oliva y de girasol alto oleico producidos por secado convencional y los oleogeles de oliva y de girasol producidos por secado a vacío presentaron valores de estabilidad oxidativa primaria y secundaria dentro de los límites de aceptabilidad establecidos por el Codex Alimentarius. En una segunda etapa se desarrollaron cremas de cacao untables y panes dulces. En las cremas se estudió la microestructura, textura, reología y atributos sensoriales. La reformulación de las cremas con un reemplazo total (100%) y parcial (50%) de grasa de coco por oleogeles de oliva o girasol obtenidos por secado a vacío permitió mantener sus propiedades estructurales. Concretamente, la sustitución parcial de grasa de coco por oleogel de girasol permitió obtener cremas con atributos sensoriales como "apariencia cremosa", "textura cremosa" y "sabor a cacao", por lo que podría ser una alternativa viable para reformular cremas untables con un perfil nutricional más saludable. Los oleogeles de oliva o girasol alto oleico obtenidos por secado convencional y previamente caracterizados, se emplearon en la formulación de panes dulces elaborados al horno o al vapor. La reformulación con oleogeles permitió obtener panes con unas características estructurales y apariencia similar a la de los panes elaborados con margarina. La realización de una prueba triangular mostró diferencias en la apariencia de la miga y el sabor, mientras que no se observaron diferencias para el atributo textura entre los panes elaborados con oleogeles y con margarina. No se encontraron diferencias en la cantidad de ácidos grasos liberados tras la digestión in vitro entre los panes dulces elaborados con oleogeles y con margarina. Sin embargo, la velocidad inicial de la digestibilidad lipídica fue diferente dependiendo del tipo de procesado, horneado o vaporización, empleado en la elaboración de los panes. El desarrollo de oleogeles a base de hidrocoloides además de ofrecer a la industria alimentaria una alternativa como sustituto de grasas plásticas, podría investigarse como estrategia para modular la digestión de lípidos y brindar beneficios para la salud. Todas las estrategias abordadas en el transcurso de esta Tesis permitieron comprender y ahondar en los conocimientos que conducen a cómo reformular un alimento para mejorar su perfil lipídico sin comprometer sus características sensoriales y fisicoquímicas. / [CA] La present Tesi doctoral planteja diferents estratègies per al disseny i desenvolupament d'oleogels estables, amb un perfil lipídic d'alta qualitat nutricional, i la posterior incorporación dels oleogels en diferents aliments. Es pretén dissenyar aliments mitjançant el reemplaçament de greixos sòlids, rics en àcids grassos saturats i trans per oleogels, que d'una banda, mantinguen les propietats texturals i organolèptiques, i d'altra banda, presenten un perfil lipídic millorat. En una primera etapa, es van desenvolupar oleogels elaborats amb un 1% de hidroxipropilmetilcel·lulosa i un 0,6% de goma xantana emprant dues condicions d'assecat diferents: assecat convencional en estufa a 80 °C durant 10 h 30 min i assecat a buit a 60 °C durant 24 h. Els olis estructurats van ser d'oliva, de lli, de gira-sol i de gira-sol alt oleic. La microestructura va permetre apreciar oleogels ben estructurats quan es van utilitzar els olis d'oliva, gira-sol i gira-sol alt oleic. L'estabilitat física i les propietats reològiques van corroborar la formació d'oleogels d'alta estabilitat física, al llarg de 35 dies d'emmagatzematge, i amb un comportament de gel sòlid. Tant el grau d'insaturació de l'oli com les condicions d'assecat van afectar l'estabilitat física i química del oleogel. D'aquesta manera, es van obtindre oleogels poc estructurats i no homogenis en utilitzar oli amb un alt grau d'insaturació, com l'oli de lli, per assecat convencional, mentre que no va ser factible desenvolupar oleogels de lli amb assecat a buit. A més, l'assecat en estufa convencional a 80 °C durant 10 h 30 min va generar oleogels de gira-sol i de gira-sol alt oleic amb major estabilitat estructural i física que l'assecat a 60 °C durant 24 h. Els oleogels d'oliva i gira-sol alt oleic, produïts per assecat convencional i els oleogels d'oliva i gira-sol produïts per assecat a buit van presentar valors d'estabilitat oxidativa primària i secundària dins dels límits d'acceptabilitat establits pel Codex Alimentarius. En una segona etapa, es van desenvolupar cremes de cacau untables i pans dolços. En aquest treball, es va estudiar la microestructura, textura, reologia i atributs sensorials de les cremes untables. La reformulació de cremes amb un reemplaçament total (100%) i parcial (50%) de greix de coco per oleogels d'oliva o gira-sol obtinguts per assecat a buit, va permetre mantindre les propietats estructurals de les cremes untables. Concretament, la substitució parcial de greix de coco per oleogel de gira-sol va ser descrita amb atributs sensorials com a "aparença cremosa", "textura cremosa" i "sabor de cacau", la qual cosa podria ser una alternativa viable per a reformular cremes per a untar amb un perfil nutricional més saludable. Els oleogels d'oliva o gira-sol alt oleic obtinguts per assecat convencional i prèviament caracteritzats, es van empra en la formulació de pans dolços cuinats al forn o al vapor. Es van estudiar les propietats estructurals, i la digestibilitat lipídica in vitro del producte final. La reformulació amb oleogels va permetre obtindre pans amb unes característiques estructurals i aparença similar a la dels pans elaborats amb margarina. La realització d'una prova triangular va mostrar diferències en l'aparença de la molla i el sabor, mentre que no es van observar diferències per a l'atribut textura, entre els pans elaborats amb oleogels i amb margarina. No es van trobar diferències en la quantitat d'àcids grassos alliberats després de la digestió in vitro entre els pans dolços elaborats amb oleogels i amb margarina. No obstant això, la velocitat inicial de la digestibilitat lipídica va ser diferent depenent de la mena de processament, enfornat o vaporatge, emprat en l'elaboració dels pans. El desenvolupament d’oleogels a base de hidrocol∙loides, a més d ́oferir a la indústria alimentària una alternativa com a substitut de greixos plàstics, podria investigar-se com a estratègia per modular la digestió de lípids i brindar beneficis per la salut. Totes les estratègies abordades en el transcurs d'aquesta Tesi van permetre comprendre i aprofundir en els coneixements que condueixen a com reformular un aliment per a millorar el seu perfil lipídic sense comprometre les seues característiques sensorials i fisicoquímiques. / [EN] The research of this doctoral thesis proposes different strategies for the design and development of stable oleogels, with high nutritional lipid profile and the subsequent incorporation of the oleogels in the formulation of different . It aims to design foods by replacing solid fats, rich in saturated and trans fatty acids with oleogels, which, on the one hand, maintain the textural and organoleptic properties, and on the other hand, present an improved lipid profile. In a first stage, oleogels made with 1% hydroxypropylmethylcellulose and 0.6% xanthan gum were developed using two different drying conditions: conventional drying in an oven at 80 ° C for 10 h 30 'and vacuum drying at 60 ° C for 24 h. The structured oils were olive, flaxseed, sunflower and high oleic sunflower oil. The microstructure showed the oleogels structured, when olive, sunflower or high oleic sunflower oils were used. Physical stability and rheological properties corroborated the formation of oleogels with high physical stability, over 35 days of storage, and with a solid gel behaviour. Both the degree of unsaturation of the oil and the drying conditions affected the physical and chemical stability of the oleogel. In this way, unstructured non-homogeneous oleogels were obtained by using oil with a high degree of unsaturation, such as flaxseed oil, by conventional drying, while it was not feasible to develop flaxseed oleogels with vacuum drying. Furthermore, drying in a conventional oven at 80 ° C for 10 h 30 min generated sunflower and high oleic sunflower oleogels with more structural and physical stability than drying at 60 ° C for 24 h. Olive and high oleic sunflower oleogels, produced by conventional drying, and olive and sunflower oleogels produced by vacuum drying, presented primary and secondary oxidative values within the acceptability limits established by the Codex Alimentarius. In a second stage, spreadable cocoa creams and sweet breads were developed. The microstructure, texture, rheology and sensory attributes of spreadable creams were studied. The reformulation of cocoa creams with a total (100%) and partial (50%) replacement of coconut fat by olive or sunflower oleogels obtained by vacuum drying allowed to maintain the structural properties of spreadable creams. Specifically, the partial substitution of coconut fat for sunflower oleogel gave place to creams described with sensory attributes such as "creamy appearance", "creamy texture" and "cocoa flavor"; therefore, it could be a viable alternative to reformulate spreads with a healthier nutritional profile. The olive or sunflower oleogels obtained by conventional drying and previously characterized, were used in the formulation of sweet breads made in the oven or steamed. Replacement of margarine for oleogels produced breads with similar structural characteristics and appearance that those made with margarine. A triangular discriminatory test showed differences in the appearance of the crumb and the flavor, while no differences were observed for the texture attribute, between the breads made with oleogels or with margarine. No differences were found in the amount of fatty acids released after in vitro digestion between sweet breads made with oleogels and margarine. However, the initial rate of lipid digestibility was different depending on the type of processing, baking or steaming, used in the preparation of the breads. In addition to offering the food industry an alternative as a substitute for plastic fats, the debe lopment of hydrocolloid-based oleogels could be investigated as a strategy to modulate lipid digestion and provide health benefits. / Bascuas Véntola, SM. (2021). Estructuración de aceites mediante el uso de hidrocoloides para sustituir grasas plásticas en los alimentos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/174797 / TESIS