<p>Promene komponenata i strukture mleka ispitane su tokom fermentacije kori&scaron;ćenjem inokuluma kombuhe kultivisane na crnom čaju zaslađenom saharozom<br />u koncentraciji 10%. Fermentacija mleka sa 2,2% mlečne masti izvr&scaron;ena je na dve različite temperature (37&deg;C i 42&deg;C) i uzorci su analizirani na sledećim pH vrednostima: 6,1; 5,8; 5,4; 5,1; 4,8 i 4,6. Urađena je determinacija i identifikacija produkata fermentacije laktoze kao &scaron;to su: &scaron;ećeri, organske kiseline i masne kiseline. Ispitane su teksturalne i reolo&scaron;ke karakteristike i mikrostruktura uzoraka. Pored toga, utvrđene su sličnosti i razlike uticaja inokuluma kombuhe na proces fermentacije mleka u poređenju sa delovanjem jogurtne, odnosno probiotske starter kulture.<br />Tokom fermentacije mleka u različitim fazama procesa pri odabranim pH vrednostima na 42&deg;C transformi&scaron;e se 14,6% laktoze odnosno 18,2% na 37&deg;C. Sadržaj galaktoze i glukoze koje nastaju fermentacijom i hidrolizom laktoze raste između prve i druge tačke fermentacije (pH=6,07 i pH=5,8). Dominantne organske kiseline tokom fermentacije su L&ndash;mlečna kiselina i sirćetna kiselina. Nije utvrđena značajna razlika u sadržaju masnih kiselina tokom fermentacije mleka kombuhom na 37&deg;C i 42&deg;C. Sadržaj palmitinske kiseline u mleku i uzorcima tokom fermentacije je najveći, zatim slede miristinska, stearinska i oleinska kiselina.<br />Praćenjem procesa fermentacije mleka uz primenu kombuhe na 37&deg;C i 42&deg;C od početne pH vrednosti 6,07 do zavr&scaron;ne 4,6, najznačajnije promene teksturalnih karakteristika (čvrstoće, konzistencije, kohezivnosti i indeksa viskoziteta) i reolo&scaron;kih svojstava zabeležene su između pH=5,4 i 5,1, &scaron;to je u korelaciji sa mikrostrukturom.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Promene viskoziteta u svim uzorcima pokazuju istu regresionu liniju, sa različitim koeficijentima i visokom vredno&scaron;ću r2, osim uzorka proizvedenog primenom jogurtne kulture na pH 5,4. Uzorak dobijen kori&scaron;ćenjem inokuluma kombuhe imao je najveće vrednosti kompleksnog modula, &scaron;to je rezultiralo boljim reolo&scaron;kim karakteristikama gotovog proizvoda.<br />Da bi se definisao empirijski model procesa fermentacije laktoze u mleku delovanjem kombuhe formulisana su prethodno dva matematička modela za kinetiku fermentacije saharoze u tradicionalnom kombuha napitku (na crnom čaju) &ndash; jedan koji opisuje promenu koncentracije saharoze tokom fermentacije, i drugi koji opisuje brzinu fermentacije. Promena koncentracije laktoze na ispitivanim temperaturama 37&deg;C i 42&deg;C sastoji se od dve lag faze između kojih je faza izraženog pada koncentracije. Krive zasićenja pokazuju sigmoidalnu kinetiku na nižim koncentracijama laktoze, ukazujući na kompleksni ne&ndash;Michaelis&ndash;Mentenov tip kinetike.<br />Generalno može se istaći da su primenom inokuluma kombuhe tokom fermentacije mleka u različitim fazama procesa ustanovljene specifične promene komponenata i strukture u poređenju sa efektima delovanja jogurtne odnosno probiotske starter kulture.</p><p>&nbsp;</p> / <p>Changes of milk components and structure were examined during fermentation by kombucha inoculum cultivated on black tea switened with saccharose in a concentration of 10%. The fermentation of milk with 2.2% of milk fat was carried out at two different temperatures (37&deg;C i 42&deg;C) and samples were analyzed at the following pH values: 6.1; 5.8; 5,4; 5.1; 4.8 and 4.6. Determination and identification of the lactose fermentation products, such as: sugars, organic acids and fatty acids were carried out. Textural and rheological characteristics and microstructure of the samples were investigated. Furthermore, the effect of kombucha on the milk fermentation process was compared with the effect of yoghurt and probiotic starter culture.<br />During milk fermentation at various stages of the process 14.6% of lactose content was transformed at 42&deg;C and 18.2% at 37&deg; C. The galactose and glucose content, which are formed by lactose hydrolyses and fermentation, increased between first and second pH point of fermentation (pH = 6.07 and pH = 5.8). Dominant organic acids during fermentation are L&ndash;lactic acid and acetic acid. There is no significant difference between samples in fatty acids content during fermentation on 37&deg;C and 42&deg;C. The level of palmitic acid in milk and samples was the highest of all fatty acids, followed by myristic, stearic, and oleic acid.<br />The most significant changes in textural properties (firmness, consistency, cohesiveness and viscosity index) and viscosity during milk fermentation by kombucha at 37&ordm;C and 42&deg;C, from the initial pH value 6.07 to a final 4.6, were recorded between pH=5.4 and 5.1, which is in correlation with microstructure.<br />Viscosity changes in all samples showed the same regression line with the different coefficients and a rather high r2 except for the sample produced with standard yoghurt culture at the pH 5.4. Samples produced with kombucha had the highest values of the complex modulus, which indicates better rheological characteristics of the final product.<br />In order to define an empirical model of lactose fermentation process in milk by kombucha, two mathematical models (one for the change of saccharose concentration, during its fermentation by kombucha, and the other for the rate of the mentioned fermentation) previously were formulated. Change of lactose concentrations at 37&ordm;C and 42&ordm;C consists of two retaining stages and very steep descend in-between. Saturation curves show a sigmoidal kinetics at low lactose concentrations, indicating a complex non&ndash;Michaelis&ndash;Menten type kinetics.<br />Generally it can be concluded that specific changes in the components and structure of milk by application of kombucha inoculum during fermentation at different stages of the process were established in comparison with the effects of yoghurt and probiotic starter culture.</p>

<p>Uprkos brojnim tradicionalnim reolo&scaron;kim metodama koje se već dugi niz godina koriste u proceni kvaliteta bra&scaron;na, postoji potreba za razvijanjem novih metoda, pomoću kojih bi se za kratko vreme i uz ograničenu količinu uzorka mogao uspe&scaron;no predvideti kvalitet bra&scaron;na i gotovog proizvoda. Na taj način selekcionerima bi bila omogućena procena tehnolo&scaron;kog kvaliteta linija p&scaron;enice čija je količina ograničena, dok bi se mlinarima obezbedio brz metod procene kvaliteta. Osnovni cilj istraživanja ove disertacije je ispitivanje mogućnosti primene novog reolo&scaron;kog uređaja glutopika u proceni kvaliteta bra&scaron;na i finalnog proizvoda &ndash; hleba, kao i mogućnost zamene tradicionalnih dugotrajnih metoda novom reolo&scaron;kom metodom.<br />Kako bi se ispitale i iskoristile mogućnosti reolo&scaron;kog uređaja glutopik za procenu kvaliteta p&scaron;eničnog bra&scaron;na definisani su optimalni uslovi merenja koji su podrazumevali upotrebu NaCl kao rastvarača i zadate parametre temperature (36 &deg;C), obrtne brzine me&scaron;ača (2700 rpm) i odnos bra&scaron;na i rastvarača (8,5/9,5). Zabeležen je veliki broj korelacija između parametara glutopika i empirijskih reolo&scaron;kih pokazatelja kvaliteta bra&scaron;na i testa. Takođe je utvrđena značajna korelacija između parametara glutopika i indikatora kvaliteta hleba u pogledu specifične zapremine i teksturnih karakteristika sredine hleba. Na osnovu parametara dobijenih merenjem na glutopiku definisane su granične vrednosti. Ustanovljeno je da se primenom glutopik metode može izvr&scaron;iti klasifikacija sorti p&scaron;enice prema kvalitetu. Pored toga, utvrđeno je da glutopik ima veliki potencijal da zameni alveograf u proceni kvaliteta bra&scaron;na u mlinarskoj i pekarskoj industriji. Reolo&scaron;ki parametri koji zavise od sadržaja proteina kao &scaron;to su moć upijanja vode i žilavost testa uspe&scaron;no se mogu predvideti pomoću parametara glutopika. Primenom glutopik metode postignuta je umerena predikcija specifične zapremine hleba, dok je postignuta veoma dobra predikcija teksturnih karakteristika sredine hleba.<br />U okviru ove disertacije je ispitan uticaj sorte i lokaliteta na tehnolo&scaron;ki kvalitet bra&scaron;na p&scaron;enice kako bi se utvrdilo koja od ispitivanih sorti ispoljava ujednačen kvalitet u različitim mikroklimatskim uslovima tokom dve proizvodne godine. U obe proizvodne godine pokazatelji kvaliteta bra&scaron;na su dominantno sortno određeni, pri čemu je zabeležen određeni uticaj mikroklimatskih faktora na lokalitetima gajenja. Odličan i najstabilniji kvalitet bra&scaron;na u 2011. godini je imala sorta Gordana koja je pokazala najveću adaptabilnost na mikroklimatske uslove. Apač je uniformno imao najlo&scaron;iji kvalitet duž svih ispitivanih lokaliteta. Domaće sorte su u 2012. godini imale promenljiv kvalitet u zavisnosti od lokaliteta gajenja. Hlebove proizvedene od domaćih p&scaron;eničnih sorti je karakterisala velika zapremina, rastresita struktura sredine sa izraženim velikim porama i mala čvrstoća sredine, dok je hleb proizveden od sorte Apač imao malu zapreminu, zbijenu strukturu sredine hleba sa velikim brojem malih pora kao posledicu velike čvrstoće. Dobra predikcija kvaliteta hleba od bra&scaron;na iz 2011. godine je postignuta primenom jednog reolo&scaron;kog pokazatelja kvaliteta, dok je za uspe&scaron;nu predikciju kvaliteta hleba od bra&scaron;na iz 2012. godine neophodno izvesti nekoliko različitih reolo&scaron;kih merenja.<br />Analizom tehnolo&scaron;kog kvaliteta bra&scaron;na p&scaron;enice različitih sorti gajenih na različitim lokalitetima iz tri proizvodne godine zabeležene su velike varijacije u kvalitetu bra&scaron;na i hleba na ispitivanim lokalitetima i u proizvodnim godinama, &scaron;to jasno ukazuje na značajan uticaj interakcija između sortimenta i uslova gajenja (lokaliteta i godina), kao i značaj ispitivanja ovih interakcija i razvoja strategija koje imaju za cilj smanjenje uticaja spolja&scaron;njih faktora na kvalitet p&scaron;enice.</p> / <p>Regardless the fact that numerous traditional rheological methods have been used for many years in the flour quality assessment, there is a need for developing new methods, which could, in a short time, and with a limited amount of sample, successfully predict the quality of flour and finished products. In this way, wheat breeders would be able to evaluate the technological quality of the wheat lines with a restricted sample quantity, while the millers would be provided with a quick method of the quality evaluation. The main goal of the research of this dissertation was to examine the possibility of using a new rheological device GlutoPeak in the quality evaluation of flour and final product &ndash; bread, as well as the possibility of replacing traditional time-consuming methods with a new rheological test.<br />In order to examine the possibility of using a GlutoPeak rheological device for the flour quality evaluation, the optimal measurement conditions were defined and included the use of NaCl as a solvent, the rotational speed of the mixer (2700 rpm), temperature (36 &deg;C), the ratio of flour and solvent (8.5/9.5). Numerous correlations between GlutoPeak indices and empirical rheological parameters of dough behaviour were reported in this study. Significant correations were also observed between GlutoPeak parameters and bread specific volume and breadcrumb textural properties. The limit values were defined according to the GlutoPeak parameters values. Moreover, it was found that the GlutoPeak test could be used for wheat variety diferentiation according to the quality and has a great potential to replace Alveograph in the flour quality assessment in the milling and bakery industries. Parameters which depends on the protein content, such as, flour water absorption and dough tenacity, was successfully predicted by using parameters derived from GlutoPeak tester. A moderate prediction of loaf specific volume was achieved, while a very good prediction of breadcrumb textural characteristics was accomplished with the GlutoPeak parameters.<br />In addition, the influence of genotype and growing location on flour quality was examined in order to determine which of the tested varieties exhibited uniform quality accross different microclimatic conditions in two production years. It was revealed that in both production years flour quality indicators were predominantly influenced by genotype, with a certain influence of microclimate factors on the growing locations. Gordana variety showed excellent and uniform quality with the highest adaptability to microclimate conditions in year 2011. Apache variety showed uniformly poor quality across all tested locations. In year 2012 domestic varieties exhibited variable quality depending on the growing locations. Bread produced from domestic wheat varieties was characterized by a large volume, loose breadcrumb structure with pronounced large pores and low hardness, while the bread produced from Apache variety had a small volume, dense breadcrumb structure with a large number of small pores as a result of high breadcrumb hardness. The quality of bread produced from wheat flour from year 2011 was well predicted based on one rheological quality parameter. On the other hand, several different rheological measurements was performed to successfully predict the quality of bread produced from wheat flour from 2012 year.<br />By analyzing the technological quality of wheat flour of different varieties cultivated at different locations from three production years, large variations in the quality of flour and bread was recorded. The variations in flour and bread quality indicated the significant influence of interactions between the variety and growing conditions (locations and years), as well as the importance of examining these interactions and developing strategies aimed at reducing the impact of external factors on wheat quality.</p>

<p>Stabilizatori na bazi biopolimera postaju posebno povoljna prirodna re&scaron;enja za primenu u kompleksnim sistemima, kao &scaron;to su emulzije tipa ulja u vodi. U ovoj disertaciji je ispitan individualni i kombinovani uticaj tri stabilizatora na bazi polisaharida (vlakna &scaron;ećerne repe, pektin &scaron;ećerne repe i OSA maltodekstrin) na formiranje i stabilnost emulzija kukuruznog ulja u vodi. Ispitan je uticaj četiri različite tehnike emulgovanja (ultrazvučna homogenizacija, visokopritisna homogenizacija, membransko emulgovanje i rotor-stator homogenizacija). Sveobuhvatna karakterizacija koja je obuhvatala ispitivanje fizičko-hemijskih, strukturnih, tenziometrijskih, konduktometrijskih, viskozimetrijskih osobina ispitivanih polisaharida je prikazana u ovoj disertaciji. Dobijeni rezultati veličine kapi emulzija i njihove fizičke stabilnosti ukazuju na dobra stabilizaciona svojstva ispitivanih polisaharida. Interakcije između primenjenih stabilizatora na bazi polisaharida rezultovale su značajnim promenama veličine kapi, zeta potencijala, kriming indeksa i strukture emulzije.</p> / <p>Biopolymer based stabilizers become particularly favorable natural solutions for use in complex systems, such as oil-in-water emulsions. In following dissertation, the individual and combined effects of three polysaccharide based stabilizers (sugar beet fibers, sugar beet pectin and OSA maltodextrin) on the formation and stability of corn oil emulsions in water were tested. The influence of four different emulsion techniques (ultrasonic homogenization, high-pressure homogenization, membrane emulsification and rotor-stator homogenization) were examined. A comprehensive characterization that included the examination of physico-chemical, structural, tensiometric, conductometric, viscometric characteristics of the polysaccharides examined is presented in this dissertation. The obtained results of the emulsion droplet size and their physical stability indicate good stabilization properties of the polysaccharides examined. The interactions between the applied polysaccharide-based stabilizers resulted in significant changes in the droplet size, zeta potential, creaming index and the structure of the emulsion.</p>

<p>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</p><p>Maltodekstini, hidrolizati skroba niskog stepena konverzije (dekstrozni ekvivalent manji od 20), imaju &scaron;iroku upotrebu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U prehrambenoj industriji koriste se u niskoenergetskim prehrambenim emulzijama (majonez, salatni prelivi, namazi) kao zamena za masne materije da bi obezbedili viskozitet, poželjne senzorne osobine i smanjenje energetske vrednosti proizvoda.<br />Viskozitet razblaženih rastora maltodekstrina različitog dekstroznog ekvivalenta i botaničkog porekla meren je kapilarnim viskozimetrom i izračunate su vrednosti unutra&scaron;njeg viskoziteta za pojedine maltodekstrine. Vrednosti untra&scaron;njeg viskoziteta i molekulske mase pokoravaju se zavisnosti &Scaron;taudingerove jednačine, iako su molekuli maltodekstrina relativno kratki i ne spadaju u grupu polimera. Utvrđena je mogućnost odredivanja DE- vrednosti viskozimetrijskin putem i izvedene su jednačine za dva opsega DE (5-10 / 10-20).<br />Da bi se ispitalo pona&scaron;anje emulzija sa maltodekstrinima (emulgovanje) u procesnim uslovima, kao i osobine fmalnih proizvoda (tečljivost, mazivost) ispitivana je dinamika emulgovanja, veličina kapljica i reolo&scaron;ko pona&scaron;anje, tj. uticaj različitih faktora na disperzione karakteristike emulzija suncokretovog ulja u vodi stabilizovanih prehrambenim emulgatorom, sa dodatkom maltodekstrina u kontinualnoj fazi.<br />Utvrđeno je da osobine maltodekstina kao &scaron;to je stepen konverzije (DE-vrednost) tj. veličina molekula maltodekstrina, utiču na dispezione i reolo&scaron;ke osobine emulzija. Uticaj koncentracije ulja i maltodekstrina, kao i delimična zamena ulja maltodekstrinom, na osobine emulzija su takode ispitivane. Sa povećanjem koncentracije ulja, pri istoj koncentraciji maltodekstrina u kontinualnoj fazi, emulzije menjaju tip proticanja od pseudoplastičnog preko tiksotropnog do antitiksotrpnog. Atitiksotropija izazvana smicanjem rezultat je formiranja unutra&scaron;nje strukture emulzije usled povezivanja kapljica ulja preko molekula maltodekstrina kao i orijentacije i deformacije kapljica ulja i maltodekstrina.<br />Dodatkom maltodekstrina za pri istoj koncentraciju ulja i vremenu emulgovanja dobijene su se emulzije sitnijih kapi.<br />Emulzije sa niskom koncentracijom ulja (30%) sa maltodekstrinom u kontinualnoj fazi bile su nestabilne i pokazivale efekat isplivavanja na povr&scaron;inu (creaming), &scaron;to je posledica interakcija molekula maltodekstrina i molekula emulgatora Tween 80 u kontinualnoj fazi i na povr&scaron;ini kapi.</p> / <p>Abstract was processed by technology for Optical character recognition (OCR).</p><p>Maltodextrins, low converted products of starch hydrolysis (dextrose equivalent less than 20), have been subject of various investigations due to their wide application in food industry, cosmetics and pharmaceuticals. They are used in various low energy food emulsions (mayonnaise, salad dressing, spreads) as fat replacer to provide desirable viscosity, texture and sensory fat-like mouthfeel.<br />Viscosity of diluted maltodextrin solutions of different dextrose equivalent and botanical origin were determined by capillary visometer and intrinsic viscosity [q] of each tested maltodextrin was calculated. The values of [q] together with molecular mass M have shown applicability of Staudinger equation, regardless maltodextrin molecules are rather short. The possibility for the determination of DE-values of maltodextrins by viscometric method has been deduced and the equation was calculated for two ranges of DE (5-10/ 10-20).<br />In order to assess behavior of sunflower oil in water emulsions stabilized with food grade emulsifier with addition of maltodextrins in continuous phase in processing (emulsification), as well as end products in application (pouring, spreading) the emulsification dynamics, globule size changes and rheological behavior, as well as, the influence of different factors on dispersion characteristics of such emulsions were studied.<br />Dispersion and viscous properties of emulsions were influenced by certain specific maltodextrin characteristics such as degree of conversion (DE value) i.e. size of maltodextrin molecules. Influence of oil and maltodextrin concentration and partial substitution of oil with equivalent quantity of maltodextrin were investigated too. With increase of oil concentration at the same concentration of maltodextrin in continuous phase, emulsions undergo changes in flow type from shear-thinning to thixotropic and antithixotropic. Antithxotropy induced by shear, was result of formation of network due to two competing factors; linking of oil droplets through maltodextrin molecules as well as orientation of deformed oil droplets and maltodextrin molecules.<br />Addition of maltodextrin, at the same oil concentration and emulsification time, resulted in formation of emulsions with smaller oil droplets.<br />Emulsions with low oil concentration (30%) with maltodextrin in continuous phase were unstable, showing so called creaming effect. This was mainly due to interactions between maltodextrin and emulsifier Tween 80 molecules which took place in continuous phase and on droplet surfaces.</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>

<p>Zadatak ove teze je da se ispita uticaj zamene dela p&scaron;eničnog bra&scaron;na ekstrudiranim snek proizvodima obogaćenim dodatkom p&scaron;enične klice, pivskog tropa i tropa jabuke na svojstva testa (boja, fizička, reolo&scaron;ka) kao i na karakteristike čajnog peciva (fizičke, senzorske, nutritivne, trajnost, mikrobiolo&scaron;ke). U toku preliminarnih ispitivanja (prva faza eksperimentalnog rada) ispitan je uticaj obezma&scaron;ćene p&scaron;enične klice na kvalitet testa i čajnog peciva u cilju definisanja optimalnog nivoa zamene p&scaron;eničnog bra&scaron;na ekstrudatima kukuruzne krupice sa dodatkom sporednih proizvoda prehrambene industrije i optimalnog sadržaja vlage testa. P&scaron;enično bra&scaron;no je u količini od 5, 10 i 15 % zamenjeno obezma&scaron;ćenom p&scaron;eničnom klicom. Pored uticaja nivoa zamene p&scaron;eničnog bra&scaron;na p&scaron;eničnom klicom, ispitan je i uticaj veličine čestica p&scaron;enične klice (&lt;150 &mu;m, 150-1000 &mu;m i 800-2000 &mu;m), kao i vlage testa pri zamesu (20, 22 i 24 %). U toku druge faze eksperimentalnog rada ove doktorske disertacije, pripremljeni su ekstrudati kukuruzne krupice sa dodatkom sporednih proizvoda prehrambene industrije i to: p&scaron;enične klice, pivskog tropa i tropa jabuke u udelima 15, 30 i 45 % (odnos kukuruzna krupica:sporedni proizvod bio je 85:15, 70:30 i 55:45). Dobijeni ekstrudati su samleveni i prosejani na sitima u cilju dobijanja tri frakcije sa različitim veličinama čestica (&lt; 250 &mu;m, 250 - 1000 &mu;m i 1000 - 2000 &mu;m). Izvr&scaron;ena je karakterizacija ekstrudata u smislu određivanja hemijskog sastava, raspodele veličine čestica, boje i mikrobiolo&scaron;ke analize. Ovako dobijeni ekstrudati su zatim kori&scaron;ćeni u proizvodnji čajnog peciva kao zamena p&scaron;eničnog bra&scaron;na u količinama od 5, 10 i 15 % računato na masu bra&scaron;na. Za procenu uticaja veličine čestica ekstrudata, udela sporednog proizvoda u ekstrudatu i udela ekstrudata u čajnom pecivu na osobine testa i čajnog peciva takođe je kori&scaron;ćen Box-Behnken eksperimentalni dizajn. Rezultati su pokazali da je moguća proizvodnja funkcionalnog čajnog peciva sa dodatkom ekstrudata kukuruzne krupice obogaćene sporednim proizvodima prehrambene industrije, pri čemu se pobolj&scaron;ava nutritivni profil čajnog peciva, bez negativnih efekata na fizičke i senzorske karakteristike gotovog proizvoda.</p> / <p>The aim of this study is to examine the effect of replacing a portion of wheat flour with extruded snack products enriched with the addition of wheat germ, brewer&#39;s spent grain and apple pomace on the rheological and textural properties of dough and on characteristics of cookies (physical, sensory, nutritive, microbiological). During the preliminary analysis (the first phase of the experimental work), the influence of defatted wheat germ particle size, wheat germ content and dough moisture content on the quality of the dough and the cookies was investigated using the Box-Behnken experimental design. During the second phase of the experimental work, the extruded corn meal with the addition of by-products of the food industry (wheat germ, brewer&#39;s spent grain and apple pomace) were prepared (the ratio of corn meal: by-product was 85:15, 70:30 and 55:45). The obtained snack products are milled and sieved to obtain 3 fractions with different particle sizes (&lt;250 &mu;m, 250-1000 &mu;m and 1000-2000 &mu;m). Characterization of the extrudates in terms of determining the chemical composition, particle size distribution, color and microbiological analysis was performed. The obtained extrudates were then used in the production of cookies for the replacement of wheat flour in quantities of 5, 10 and 15%. The Box-Behnken experimental design was used to evaluate the influence of the extrudate particle size, the share of the by-product in the extrudate, and the share of extrudates in the cookies, on the dough properties and cookies characteristics.<br />The results showed that the corn snack products enriched with food industry by-products (brewer&#39;s spent grain, wheat germ and apple pomace) can be used for production of functional cookies. These additives in an amount up to 15% improving the nutritional profile of the cookies, without adverse effects on the physical and sensory characteristics of the final product.</p>

<p>Omega-3 masne kiseline su uslovne za zdravlje ljudi i imaju značajne fiziolo&scaron;ke uloge. Dijetetski proizvodi na bazi omega-3 masnih kiselina predstavljaju značajan izvor omega-3 masnih kiselina. Riblje ulje je dobar izvor polinezasićenih masnih kiselina (PUFA). Dnevni unos omega-3 polinezasićenih masnih kiselina je u većini delova sveta ispod preporučenog, uglavnom usled nedovoljne zastupljenosti ribe u ishrani. Zbog toga se danas riblje ulje nalazi u obliku različitih dijetetskih proizvoda i ponuda ovih preparata na trži&scaron;tu je veoma &scaron;iroka. Problem sa unosom ribljeg ulja kao dodatka ishrani je njegov intenzivan i neprijatan ukus i miris, &scaron;to može da dovede do neadekvatne suplementacije. Su&scaron;enje raspr&scaron;ivanjem (engl. spray drying) predstavlja tehniku koja omogućava trenutno su&scaron;enje rastvora, suspenzija ili emulzija. U pitanju je metoda koja ima &scaron;iroku primenu u farmaceutskoj industriji, a između ostalog se primenjuje i u cilju maskiranja neprijatnog ukusa lekova. Kao omotač mikrokapsula dobijenih su&scaron;enjem raspr&scaron;ivanjem je moguće koristiti proteine, ali je neophodno dobro ispitati i poznavati njihove fizičko-hemijske osobine i funkcionalnost. Inkorporiranjem mikrokapsula ribljeg ulja u čokoladu bi se dobila funkcionalna ili obogaćena hrana, &scaron;to predstavlja i finalnu formulaciju u ovom radu. Obogaćivanjem čokolade sa visokim sadržajem kakao delova mikrokapsulama ribljeg ulja kreirao bi se vi&scaron;estruko funkcionalan proizvod. Odabir čokolade kao matriksa za obogaćivanje uslovljen je činjenicom da je ona &scaron;iroko konzumiran proizvod. Ciljevi ovog rada bili su da se ispita uticaj metode su&scaron;enja raspr&scaron;ivanjem na stabilnost preformulacije ribljeg ulja, da se utvrde karakteristike mikrokapsula dobijenih su&scaron;enjem raspr&scaron;ivanjem (prinos i efikasnost mikrokapsulacije, oksidativnu stabilnost ulja, morfolo&scaron;ke osobine i veličinu mikrokapsula), zatim da se utvrdi uticaj veličine čestica na kristalizaciju u masnoj fazi suspenzije koja se koristi za izradu konditorskih proizvoda i da se utvrde fizičko-hemijske karakteristike (teksturu, boju, reolo&scaron;ke osobine) čokolade koja sadrži inkorporirane mikrokapsule ribljeg ulja u odnosu na čokoladu bez dodatka mikrokapsula. Metode su obuhvatale karakterizaciju proteina dobijenih iz soje, gra&scaron;ka, krompira, pirinča i surutke, njihovih rastvora, kao i emulzija ribljeg ulja u vodenim rastvorima tih proteina, određivanje prinosa i efikasnosti mikrokapsulacije i karakterizaciju dobijenih mikrokapsula. Prilikom ispitivanja uticaja veličine čestica na kristalizaciju u masnoj fazi suspenzije koja se koristi za izradu konditorskih proizvoda i fizičko-hemijskih osobina čokolade koja sadrži inkorporirane mikrokapsule ribljeg ulja primenjivane su metode za određivanje teksture, reolo&scaron;kih karakteristika, sadržaja čvrstih masti i boje dobijenih formulacija. Dobijeni rezultati su pokazali da se proteini pona&scaron;aju kao dobri emulgatori i da su&scaron;enje raspr&scaron;ivanjem predstavlja efikasan način za dobijanje mikrokapsula ribljeg ulja sa proteinima kao omotačima mikrokapsula. Kristalizacija masne faze u suspenziji koja predstavlja model čokolade zavisi od veličine čvrstih čestica. Kada je u pitanju proizvodnja čokolade sa inkorporiranim mikrokapsulama ribljeg ulja kod kojih su kao omotači kori&scaron;ćeni proteini soje, surutke i krompira, dodatak tih mikrokapsula ne utiče na karakteristike čokolade u meri dovoljnoj da bi se naru&scaron;io proizvodni proces izrade. Sve navedeno upućuje na zaključak da bi proizvodnja čokolade sa inkorporiranim mikrokapsulama ribljeg ulja, tehnolo&scaron;ki bila moguća.</p> / <p>Omega-3 fatty acids are essential for human health and have significant physiological roles. Dietary products based on omega-3 fatty acids are a significant source of omega-3 fatty acids. Fish oil is a good source of polyunsaturated fatty acids (PUFA). The daily intake of omega-3 polyunsaturated fatty acids is below the recommended level in most parts of the world, mainly due to the lack of fish in the diet. This is why fish oil is now found as various dietary products which are widely present in the world&rsquo;s market. The problem with fish oil intake as a dietary supplement is its intense and unpleasant taste and odor, which can lead to inadequate supplementation. Spray drying is a technique that allows instantaneous drying of solutions, suspensions or emulsions. It is a widely used method in the pharmaceutical industry and is used, among other things, to mask the unpleasant taste of medicines. It is possible to use proteins as a coating of spray-dried microcapsules, but it is necessary to test and know their physicochemical properties and functionality. Incorporating fish oil microcapsules into chocolate would make functional or enriched foods, which is consider as a final formulation in this work. Enriching the high cocoa content chocolate with fish oil microcapsules would create a multi-functional product. The choice of chocolate as a base is conditioned by the fact that it is a widely consumed product. The aim of this study was to investigate the effect of spray drying method on the stability of fish oil pre-formulation, to determine the characteristics of microcapsules obtained by spray drying (yield and efficiency of microencapsulation, oxidative stability of oil, morphological properties and size of microcapsules), to determine the effect of particle size crystallization in the oil phase of the suspension used for confectionery products and to determine the physicochemical characteristics (texture, color, rheological properties) of chocolate containing fish oil microcapsules in comparison with chocolate without the addition of microcapsules. Methods included characterization of proteins obtained from soybeans, peas, potatoes, rice and whey, their solutions, as well as fish oil emulsions in aqueous solutions of these proteins, determination of the yield and efficiency of microencapsulation, and characterization of the microcapsules obtained. In the examination of the effect of particle size on crystallization in the oil phase of the suspension used for the manufacture of confectionery and physicochemical properties of chocolate containing fish oil microcapsules, methods were used to determine the texture, rheological characteristics, solid fat content and color of the formulations obtained. The results show that proteins act as good emulsifiers and that spray drying is an effective way to obtain fish oil microcapsules with proteins as microcapsule shells. The crystallization of the oil phase in the suspension representing the chocolate model depends on the size of the solid particles. In the case of production of chocolate with incorporated fish oil microcapsules using soybean, whey and potato proteins as coating material, the addition of these microcapsules does not affect the chocolate characteristics to a degree sufficient to impair the manufacturing process. All of the above points to the conclusion that the production of chocolate with incorporated fish oil microcapsules would be technologically possible.</p>

<p>Seme tikve (Cucurbita pepo) obiluje kako uljem tako i proteinima. Nakon izdvajanja ulja, proteini se koncentri&scaron;u u uljanoj pogači, sekundarnom proizvodu procesa proizvodnje ulja, gde njihov sadrţaj dostiţe do 65%. Proteini semena tikve su primamljiv sastojak za prehrambenu, farmaceutsku i kozmetičku industriju zbog svoje farmakolo&scaron;ke aktivnosti i visoke biolo&scaron;ke vrednosti. Pored toga, budući da su mnogi proizvodi ovih industrija po svojoj koloidnoj prirodi emulzije, proteini semena tikve bi se u njima mogli naći i kao prirodne povr&scaron;inski aktivne materije. Međutim, koloidna funkcionalnost proteina semena tikve se jo&scaron; uvek potcenjuje zbog globularne strukture za koju se vezuju slabija funkcionalna svojstva u odnosu na proteine sa fleksibilnijom strukturom. Prema tome, cilj ove disertacije je ispitivanje funkcionalnih osobina proteinskog izolata semena tikve, pre svega njegovih adsorpcionih i emulgujućih svojstava, kao i ispitivanje uticaja promene proteinske strukture putem enzimske hidrolize na ispitivana svojstva.<br />Pripremljeni su izolat proteina semena tikve (IPST) i dva enzimska hidrolizata, H1 i H2. IPST, H1 i H2 su okarakterisani određivanjem sadržaja vlage, proteina i pepela, zatim, određivanjem prinosa, molekulske mase i zeta potencijala. Ispitan je uticaj koncentracije proteina/peptida (0,0001&ndash;1 g/100 cm³), pH (3&ndash;8) i jonske jačine (0&ndash;1 mol/dm³ NaCl) na rastvorljivost i adsorpciona svojstva: dinamički međupovr&scaron;inski pritisak (ulje/voda), statički povr&scaron;inski (vazduh/voda) i međupovr&scaron;inski (ulje/voda) pritisak, kinetiku adsorpcije i dilatacionu reologiju proteinskih adsorpcionih filmova. Nakon toga, ispitan je i uticaj pomenutih parametara na emulziona svojstva IPST, H1 i H2. Emulgujuća svojstva IPST, H1 i H2 su okarakterisana na osnovu prosečnog prečnika kapljica emulzija, raspodele veličina kapljica i stabilnosti emulzija.<br />Utvrđeno je da je prinos IPST veći od prinosa oba hidrolizata za oko 65 %. IPST ima najniţu rastvorljivost na pH=5, &scaron;to ujedno predstavlja i njegovu izoelektričnu tačku. Enzimskom hidrolizom IPST značajno se povećava rastvorljivost, posebno na pI=5. Povećanje jonske jačine je izazvalo salting&ndash;in ili salting&ndash;out efekat rastvorljivosti kod svih uzoraka u zavisnosti od pH. IPST, H1 i H2 poseduju povr&scaron;insku aktivnost pri čemu je povr&scaron;inski/međupovr&scaron;inski pritisak H1 i H2 manje zavistan od promene pH i jonske jačine u poređenju sa povr&scaron;inskim/međupovr&scaron;inskim pritiskom IPST. Adsorpcijom na granicu faza IPST i oba hidrolizata obrazuju adsorpcione filmove sa dominantnom elastičnom komponentom. Emulgujuća svojstva IPST, H1 i H2 zavise od koncentracije uzorka, pH vrednosti i jonske jačine kontinualne faze. Pri koncentraciji od 1 g/100 cm³ i Ic=0 mol/dm³ pripremljene emulzije su stabilne na svim pH osim emulzije IPST na pH 5. Sve emulzije podležu gravitacionoj nestabilnosti.</p> / <p>Pumpkin (Cucurbita pepo) seed is rich source of both, oil and proteins. Once the oil has been extracted, proteins concentrate in oil cake, a by&ndash;product of the oil<br />extraction process, where their content can reach up to 65%. Pumpkin seed proteins are desirable ingredient in food, pharmaceutical and cosmetic industry due to their pharmacological activities and high biological value. Moreover, since many of products of these industries are, in colloidal terms, emulsions, pumpkin seed proteins could serve as surface active materies. However, colloidal functionality of pumpkin seed proteins is still underestimated for their globular structure which entails inferior functional properties to functional properties of proteins with more flexible structure. Based on that, the aim of this dissertation is to investigate functional properties of pumpkin seed protein isolate, adsorption and emulsifying properties, in the first place, and then to investigate the influence of modification of the protein structure, by means of enzymatic hydrolysis, on the aforementioned properties.<br />Pumpkin seed protein isolate, IPST, and two enzymatic hydrolysates, H1 and H2, were prepared. IPST, H1 and H2 were characterized by determination of moisture, ash and protein content, then, by determination of protein recovery, molecular mass and zeta potential. Influence of the protein/peptide concentration (0.0001&ndash;1 g/100 cm³), pH (3&ndash;8) i ionic strength (0&ndash;1 mol/dm³ NaCl) on the solubility and adsorption properties: dynamic interfacial (oil/water) pressure, static surface (air/water) and interfacial (oil/water) pressure, adsorption kinetics and interfacial dilatational properties, was<br />investigated next. In the end, influence of the aforementioned pharameters on the emulsifying properties of IPST, H1 and H2 was investigated. Emulsifying properties of IPST, H1 and H2 were discussed in terms of mean droplet diameter, droplet size distribution and emulsion stability.<br />Protein recovery of IPST was determined to be 65 % higher than recovery of H1 and H2. Solubility of IPST was the lowest at pH 5, what presents the isoelectric point. The enzymatic hydrolysis of IPST significantly increased solubility, especialy at the isoelectric point. Increase in the ionic strenght led to salting&ndash;in or salting&ndash;out effect depending on pH of the sample. Three investigated samples, IPST, H1 and H2 exhibited surface activity, however, sufrace/interfacial pressure of H1 and H2 were found to be less influenced by change in pH or ionic strenght of the solution in comparison to the IPST. Once adsorbed to the interface IPST and both hydrolysates form interfacial film with dominant elastic component. Emulsifying properties of IPST, H1 and H2 depend on the concentration, pH and ionic strength of the continuous phase. Stabile emulsions were formed at concentration of 1 g/100 cm3 and Ic=0 mol/dm³ regardless of pH, with the exception of the IPST at pH 5. All emulsions were susceptibile to gravitational separation.</p>

<p>Sagledavajući značaj nutritivne vrednosti bezglutenskog hleba u prevenciji dodatnih zdravstvenih poremećaja kod obolelih od celijakije, kao i prisutnog trenda bezglutenske ishrane, u okviru ove disertacije analizirana je mogućnost obogaćenja bezglutenskog hleba prehrambenim vlaknima. Ispitan je uticaj različite vrste i količine (3, 5, 7%) prehrambenih vlakana (vlakna &scaron;ećerne repe i vlakna jabuke), količine hidroksipropil metil celuloze - HPMC (2, 3, 4%) i količine vode (180&ndash;230%) na reolo&scaron;ke osobine bezglutenskog testa (svojstva proticanja i viskoelastične osobine), kvalitet i nutritivnu vrednost bezglutenskog hleba. Rezultati ove disertacije ukazuju da dodatak vlakana &scaron;ećerne repe i jabuke ne umanjuje pozitivan uticaj HPMC na reolo&scaron;ke osobine bezglutenskog testa, formiranje i ojačavanje njegove strukture. Bezglutenski hleb privlačne boje, veće zapremine, manje tvrdoće sredine i odličnih senzorskih karakteristika dobijen je kod uzoraka sa 4% HPMC, 3, 5 ili 7% vlakana &scaron;ećerne repe/jabuke i 220%/190% vode. Sadržaj ukupnih prehrambenih vlakana kod uzoraka sa 3% vlakana je iznad 4,5 g/100 g, a kod uzoraka sa 7% vlakana čak oko 6 g/100 g bezglutenskog hleba. Postignut sadržaj ukupnih prehrambenih vlakana je iznad propisane vrednosti za proizvode koji mogu biti nosioci nutritivne izjave &bdquo;izvor vlakana&ldquo;, čime je ostvaren cilj ove disertacije.</p> / <p>Considering the importance of the gluten-free bread nutritional value in the prevention of additional health disorders in patients with celiac disease, as well as the arising gluten-free diet trend, the possibility of enriching gluten-free bread with dietary fibers was analyzed within this dissertation. The influence of different types and amounts (3, 5, 7%) of dietary fibers (sugar beet and apple fibers), the amount of hydroxypropylmethylcellulose - HPMC (2, 3, 4%) and the amount of water (180&ndash;230%) on rheological properties of gluten-free batter (flow and viscoelastic properties), quality and nutritional value of gluten-free bread. The results of this dissertation indicate that the addition of sugar beet and apple fibers does not diminish the positive influence of HPMC on the rheological properties of the gluten-free batter, the formation and strengthening of its structure. Gluten-free bread with appealing color, higher volume, lower hardness and excellent sensory characteristics was obtained in samples with 4% HPMC, 3, 5 or 7% sugar beet/apple fibers and 220%/190% water. The total dietary fibers content in samples with 3% fibers is above 4.5 g/100 g, and in samples with 7% fibers approximately 6 g/100 g of gluten-free bread. The accomplished total dietary fibers content is above the prescribed value for products that may bear the nutritional statement &quot;source of fiber&quot;, thus achieving the goal of this dissertation.</p>

<p>Uvod: Sistem kanala korena je složena celina koja pored glavnog korenskog kanala sadrži brojne lateralne, sekundarne, akcesorne kanale, apikalne istmuse i delte, kao i razgranatu mrežu dentinskih tubula. Kako korensko kanalni sistem ne može biti u potpunosti oči&scaron;ćen i dezinfikovan postojećim tehnikama instrumentacije, irigacije i intrakanalne medikacije, uloga kanalnog punjenja se ogleda u postizanju trodimenzionalne opturacije kanalnog prostora, &rdquo;pečaćenju&rdquo; preostalih bakterija i onemogućavanju njihovog prodora u periradikularna tkiva. Ispitivanjem reolo&scaron;kih svojstava mogu se bliže odrediti karakteristike tečenja i viskoelastična svojstva endodontskih materijala. Definisanje i razumevanje reolo&scaron;kih svojstava endodontskih silera u različitim uslovima doprinosi pravilnom rukovanju materijalom shodno primenjenoj tehnici opturacije. Cilj istraživanja: ispitivanje viskoelastičnih svojstava tri različita endodontska silera, uključujući i tečenje / prodor silera u dentinske tubule u kombinaciji sa različitim tehnikama opturacije. Materijal i metode: Ukupan uzorak činilo je 132 meziobukalna i meziolingvalna kanala korena prvih donjih molara. Nakon preparacije kanala krunično-apeksnom tehnikom i ProTaper endodontskim instrumentima, uzorak je podeljen u tri grupe u zavisnosti od ispitivanog silera (AH Plus, Sealapex i EndoREZ) i dodatno u četiri podgrupe shodno primenjenoj tehnici opturacije (hladna lateralna kompakcija, monokona tehnika, opturacija sa čvrstim nosačem gutaperke i topla vertikalna kompakcija), &scaron;to je činilo ukupno 12 grupa po 11 kanala. Nakon opturacije, uzorci su poprečno presečeni na rastojanju 3, 5 i 8mm od anatomskog foramena, kako bi se dobili preseci koji odgovaraju apikalnoj, srednjoj i koronarnoj trećini kanala. Koronarne povr&scaron;ine preseka su analizirane skening elektronskim mikroskopom (SEM). Mesto najdubljeg tubularnog prodora silera je izmereno i izraženo u mikrometrima i procentualno u odnosu na ukupno rastojanje dentinski zid kanala - spolja&scaron;nja povr&scaron;ina korena. Viskoelastična svojstva endodontskih silera su ispitana na dinamičkom oscilatornom reometru, frequency sweep testom, na četiri različite temperature: 25&deg;C, 35&deg;C, 40&deg;C i 65&deg;C. Rezultati: Tehnike opturacije silerom AH Plus koje primenjuju toplotu i pritisak daju značajno vi&scaron;u dubinu prodora silera u dentinske tubule u odnosu na tehnike koje ne primenjuju. Primena toplote i pritiska tokom opturacije silerom Sealapex nema značajnu ulogu u dubini prodora silera u dentinske tubule. Tehnike opturacije silerom EndoREZ koje ne primenjuju toplotu i pritisak daju značajno vi&scaron;u dubinu prodora silera u dentinske tubule u odnosu na tehnike koje primenjuju. Dubina prodora sva tri ispitivana endodontska silera u dentinske tubule je najvi&scaron;a u koronarnoj trećini, zatim srednjoj i značajno je niža u apikalnoj trećini kanala korena. AH Plus, Sealapex i EndoREZ ispoljavaju viskoelastični karakter sa dominantnim vrednostima elastičnog modula u odnosu na vrednosti viskoznog modula, na svim zadatim temperaturama, u opsegu primenjenih frekvencija i napona smicanja. Kompleksni viskozitet svih ispitivanih silera opada sa porastom frekvencije, na svim zadatim temperaturama. Sa porastom temperature kompleksni viskozitet silera AH Plus opada, dok za silere Sealapex i EndoREZ raste. Korelacionom analizom ustanovljena je jaka negativna korelacija između kompleksnog viskoziteta ispitivanih silera i dubine prodora u dentinske tubule: opadanjem kompleksnog viskoziteta dubina prodora silera u dentinske tubule raste. Zaključak: Odabir endodontskog silera treba da je zasnovan na tehnici opturacije koja se primenjuje.</p> / <p>Introduction: The root canal system has a complex anatomy with main root canal and many lateral, secondary, accessory canals, apical isthmuses and deltas, as well as numerous branched dentinal tubules. Due to its complexity, the root canal system cannot be completely cleaned, shaped and disinfected using available techniques of instrumentation, irrigation and intracanal medication. The aim of root canal filling is to achieve a three-dimensional obturation of the root canal space, entomb residual bacteria and prevent their penetration into the periradicular tissue. Defining and understanding the rheological properties of endodontic sealers in different conditions contributes to the proper handling of the material according to the obturation technique applied. The aim: testing the viscoelastic properties of three different endodontic sealers, including the flow / sealer penetration into dentinal tubules in combination with different obturation techniques. Materials and Methods: The total sample consisted of 132 mesiobuccal and mesiolingual root canals of first mandibular molars. After root canal preparation using ProTaper endodontic instruments, in crown-down manner, the sample is divided into three groups depending on the tested sealers (AH Plus, Sealapex and EndoREZ) and additionally into four subgroups according to the obturation technique applied (cold lateral compaction, single-cone technique, carrier &ndash; based obturation and warm vertical compaction), making a total of 12 groups of 11 canals. After root canal obturation, the samples were sectioned horizontally at 3, 5 and 8mm from the anatomical foramen, in order to get the sections that correspond to the apical, middle and coronary third of the canal. The coronal surfaces of the sections were analyzed using scanning electron microscopy (SEM). The maximum depth of sealer penetration was measured and expressed in micrometers and as a percent of the total distance: canal dentinal wall - the outer surface of the root. The viscoelastic properties of endodontic sealers were measured using frequency sweep test on dynamic oscillatory rheometer, at four different temperatures: 25&deg;C, 35&deg;C, 40&deg;C and 65&deg;C. Results: Obturation techniques with AH Plus that applied heat and pressure produced a significantly higher depth of sealer penetration into dentinal tubules as compared to techniques that did not apply. The application of heat and pressure during obturation with Sealapex had no a significant role in the depth of sealer penetration into dentinal tubules. Obturation techniques with EndoREZ that did not apply heat and pressure produced a significantly higher depth of sealer penetration into dentinal tubules as compared to techniques that applied. The depth of penetration of all three endodontic sealers into dentinal tubules was the highest in the coronary third, followed by the second and was significantly lower in the apical third of the root canal. AH Plus, Sealapex and EndoREZ exhibited viscoelastic character with dominant values of elastic over viscous modulus, at all specified temperatures, in the range of applied frequencies and shear stresses. Complex viscosity of all sealers decreased as the frequency increased at all temperatures. AH Plus showed decreased viscosity as the temperature increased, while Sealapex and EndoREZ demonstrated opposite behavior. Correlation analysis has established a strong negative correlation between the complex viscosity of the tested sealers and the depth of penetration into dentinal tubules: the decrease of complex viscosity increase the depth of sealer penetration into dentinal tubules. Conclusion: The choice of endodontic sealer should be based on the obturation technique applied.</p>