<p>Pravilna ishrana preživara je važna za održanje zdravstvenog stanja životinja, a takođe je i ključna za efikasnu i ekonomičnu proizvodnju mleka i mesa. Kod visokoproizvodnih preživara, kao &scaron;to su tovna junad i mlečne krave, energetske potrebe su velike kako bi se ostvario brz prirast telesne mase i visok prinos mleka. Termički tretmani se koriste za pobolj&scaron;anje hranljivih, higijenskih, fizičkih i hemijskih karakteristika hrane za životinje. Osnovni cilj istraživanja u okviru ove disertacije je analiza uticaja različitih termičkih tretmana na promene skrobne komponente i svarljivost kukuruza kod preživara. U tu svrhu primenjeni su tretmani peletiranja, parnog flekičenja, mikronizacije i ekstrudiranja na uzorcima kukuruza i potpune sme&scaron;e za krave muzare. Promene u strukturi skrobnih granula su praćene pomoću skening elektronske mikroskopije i diferencijalne skenirajuće kalorimetrije, dok su promene u hidrataciji i bubrenju uzoraka određene analizom kriva pastiranja, indeksa apsorpcije vode (WAI) i indeksa rastvorljivosti u vodi (WSI). In situ tehnikom je praćena promena brzine svarljivosti skroba i suve materije u buragu preživara i uticaj različitih termičkih tretmana na mesto varenja skroba kukuruza. Promene u svarljivosti organske materije (SOM) kroz ceo digestivni trakt preživara su određene in vitro multi-enzimskom metodom.<br />Na osnovu rezultata DSC analize uzoraka kukuruza i sme&scaron;a utvrđeno je da su parno flekičenje, mikronizacija i peletiranje blagi tretmani, dok je ekstrudiranje o&scaron;triji tretman koji dovodi do potpunije želatinizacije skroba. U uzorku parno flekičanog kukuruza do&scaron;lo je do interakcije degradiranih komponenti (skroba, proteina i lipida) na molekularnom nivou i nastanak jedinjenja sa većom molekulskom masom i smanjenom rastvorljivo&scaron;ću. U dva uzorka ekstrudiranog kukuruza zbog većih sila smicanja i dužeg vremena zadržavanja materijala u ekstruderu do&scaron;lo je do delimične želatinizacije koja je bila praćena dekstrinizacijom skroba. In situ metodom su za uzorak netretirane sme&scaron;e određene najniže vrednosti nestajanja SM i skroba u buragu, dok su svi primenjeni termički tretmani doveli do značajnog povećanja razgradnje SM i skroba. Najmanje povećanje razgradnje skroba u poređenju sa netretiranom sme&scaron;om je zabeleženo kod sme&scaron;e koja je sadržala parno flekičan kukuruz, dok je u svim uzorcima ekstrudiranih sme&scaron;a do&scaron;lo do razgradnje velike količine skroba već tokom prva 3h inkubacije. U poređenju sa netretiranom sme&scaron;om, svi primenjeni termički tretmani su doveli do povećanja brzine razgradnje skroba u manjoj ili većoj meri a u zavisnosti od vrste i intenziteta tretmana. Značajne razlike u karakteristikama razgradnje skroba su zabeležene nakon variranja procesnih parametara ekstrudiranja, dok su uočene razlike između sme&scaron;a koje su sadržale mikronizirani kukuruz bile mnogo manje izražene. Mobile bag metodom određena je svarljivost skroba u crevima koja je u netretiranoj i svim termički tretiranih sme&scaron;ama iznosila 100%. Statističkom obradom rezultata nije utvrđeno značajno povećanje SOM kukuruza i sme&scaron;e nakon primenjenih termičkih tretmana u poređenju sa netretiranim uzorcima.</p> / <p>Proper ruminant nutrition is important for maintaining the health of animals, and it is also crucial for the efficient and economical production of milk and meat. In high-yielding ruminants, such as fattening cattle and dairy cows, energy needs are high in order to achieve rapid weight gain and high milk yield. Thermal treatments are used to improve nutritional, hygienic, physical and chemical characteristics of animal feed. The main objective of this research is the analysis of the influence of various thermal treatments on changes in the starch component and the digestibility of corn in ruminants. For this purpose pelleting, steam flashing, micronization and extrusion of maize samples and complete mixture for dairy cows were applied. Changes in the structure of starch granules were monitored by scanning electron microscopy and differential scanning calorimetry (DSC), while changes in the hydration and swelling of samples were determined by analyzing pasting properties, water absorption index (WAI) and water solubility index (WSI) of samples. In situ technique was used to determine the changes in the rate of digestibility of starch and dry matter in rumen and the influence of various thermal treatments on the site of digestion of corn starch. Changes in the organic matter digestibility (OMD) through the entire digestive tract of the ruminants are determined by the in vitro multi-enzymatic method.<br />Based on the results of DSC analysis of corn and complete feed samples, it has been found that steam flaking, micronization and pelleting are mild treatments, while the extrusion is more severe treatment that leads to a more complete starch gelatinization. In steam flaked corn interaction of degraded components (starch, proteins and lipids) at the molecular level resulted in the formation of compounds with higher molecular weight and reduced solubility. In two samples of extruded corn, due to the higher shear rate and longer retention time of the material in the extruder, there was partial gelatinization followed by dextrinisation of starch. In untreated complete feed, the lowest values of DM and starch disappearance in rumen were determined using in situ method, while all the applied thermal treatments led to a significant increase in the degradation of DM and starch. The smallest increase in degradation of starch in comparison to untreated mixture was observed in a mixture containing steam flaked corn, while in all extruded mixtures large amount of starch was degraded during the first 3 hours of incubation. Compared to the untreated mixture, all applied thermal treatments resulted in an increase in the degradation rate of starch to a lesser or greater extent depending on the type and intensity of the treatment. Significant differences in the degradation characteristics of the starch were observed after variation of the extrusion processing parameters, while the observed differences between the mixtures containing micronized corn were much less pronounced. Digestibility of starch in the intestine was determined with mobile bag method, which was 100% in untreated and all thermally treated mixtures. Statistical analysis of the results did not show a significant increase in OMD of maize and mixtures after the applied thermal treatments compared to the untreated samples.</p>

<p>Apple pomace is a by-product of the industrial production of apple juice, amounting to approximately 20-30% of freshly processed apples. Several million tonnes of apple pomace is produced in the world annually. Fresh apple pomace is characterised by high sugar and moisture content, which makes it susceptible to microbial contamination, uncontrolled fermentation and spoiling. Despite increasingly stricter legal regulations in managing biodegradable waste, large quantities of apple pomace are still being disposed of at landfills, posing a serious environmental issue. Since apple pomace has a certain nutritive value, it seems necessary to consider possibilities for using it as animal feed.<br />The main goal of this research was to examine the possibility for using dried apple pomace as animal feed, i.e., as a raw material in the industrial production of animal feed. Accordingly, the nutritive value of dried apple pomace was examined, along with the process of pelleting, since pelleting is one of the most common technological procedures in the industrial production of animal feed.<br />The testing of the chemical composition of dried apple pomace, used to determine its nutritive value, included the analyses of the content of raw proteins, raw fats, raw fibres, ash, neutral detergent fibres (NDF), acid detergent lignin (ADL), lignin, total sugars, individual sugars &ndash; fructose, glucose and sucrose, essential amino-acids, vitamins and mineral elements. When compared with the majority of commonly used animal feeds, the dried apple pomace was found to contain large amounts of raw fibres and sugars and small amounts of proteins and fats.<br />In accordance with the determined nutritional composition of the dried apple pomace, concentrate mixtures for fattening pigs were prepared, after which a trial was performed to examine the effect of feeding the animals on the mixtures containing dried apple pomace in different concentrations on the production performance of the fattening pigs. The results of the feeding trial showed that adding 7% of dried apple pomace in the growing period and 10% in the finishing period had no negative effects on the animal health, production and meat yield.<br />In the next part of the research, the dried apple pomace was pressed into pellets, with three starting moisture contents in the unpelleted material &ndash; 10%, 13% and 16%. The examination of the produced pellets showed that they had very good physical quality in terms of the pellet durability index (PDI) and hardness. The value of PDI exceeded 99% for all three starting moisture contents. The bulk density of the pelleted dried apple pomace was nearly twice as large as it was before pelleting. Increasing the moisture content in the dried apple pomace from 13% to 16% resulted in lower temperatures and energy consumption in the process of pelleting.<br />The goal of the next part of the research was to examine the effect of adding apple pomace into the concentrate mixture models consisting of corn and sunflower meal on the physical quality of the obtained pellets, the specific electricity consumption of the pellet press and the temperature of the pellet press die. Three concentrate mixture models were prepared for the test, comprising 0%, 10% and 20% of dry apple pomace. The mixtures were conditioned by adding water to reach the moisture content of 13%, 15% and 17% and pelleted at three settings of the press die (8, 24 and 30 mm). Therefore, three parameters were varied at three levels, in a full factorial experimental design. The dependent variables (response variables) were: PDI, pellet hardness (H), dust content in the pellets, bulk density of the pellets, matrix temperature of the pellet press and the specific energy consumption of the pellet press. The results showed that adding dried apple pomace into the model concentrate mixtures led to a significant increase in pellet quality, especially in terms of increasing the PDI value and decreasing the dust content. The results of the analysis of standard scores (SS) showed that the optimum values for pellet quality, specific energy consumption and temperature of the press die were obtained for the model concentrate mixture containing 10% of dried apple pomace, using 30 mm press die and with 17% of the starting moisture content. Good results were also obtained for the model concentrate mixture containing 20% of dried apple pomace, using 24 mm press die and with 17% of the starting moisture content.<br />To define the effect of the concentration of dried apple pomace in the model mixtures, the press die thickness and the starting moisture content on the change of the response variables, the response surface methodology (RSM) was used. The analysis of variance (ANOVA) of the response models for each of the analysed quality parameters and pelleting processes, showed which of the process parameters (percentage of apple pomace in the concentrate model mixtures, press die thickness and starting moisture content) had statistically the biggest effect on creating the mathematical response models, presented in the form of the second order polynomial (SOP). The results of this research showed that the increase in the percentage of dried apple pomace, press die thickness and starting moisture content led to an increase in PDI value, hardness (H) and bulk density of the pellets and a decrease in the content of dust in the pellets. The increase in the share of apple pomace in the model mixtures and in the die thickness of the pellet press led to an increase in the specific energy consumption and die temperature. On the other hand, the increase in the starting moisture content led to a decrease in the specific energy consumption and die temperature.<br />In the last part of the research, on the basis of the determined nutritive value of the dried apple pomace the author made a calculation, in terms of optimising the concentrate mixtures containing dried apple pomace in the optimum amount for feeding particular species and categories of farm animals. The results suggest the way of practical utilization of dried apple pomace in feeding farm animals as well as in the industrial production of animal feed.</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>Aktuelni problem industrije proizvodnje hrane za ribe jeste smanjena dostupnost i visoka<br />cena ribljeg bra&scaron;na, tradicionalnog izvora proteina u hrani za ribe, koja je direktna posledica rasta sektora akvakulture i visoke potražnje za ovim kvalitetnim proteinskim hranivom. Delimična ili potpuna zamena ribljeg bra&scaron;na visokoproteinskim sirovinama biljnog porekla u recepturama za ishranu riba, uz iznalaženje novih alternativnih visokoproteinskih sirovina pristup je kojim se prevazilazi ovaj problem i koji ima potencijal da obezbedi održivost celokupne industrije hrane za ribe u budućnosti. U okviru ove disertacije predloženo je novo, relativno jednostavno i jeftino tehnolo&scaron;ko re&scaron;enje za suvo frakcionisanje suncokretove sačme, čijom bi se primenom dobile njene visokoproteinske frakcije kao potencijalne proteinske sirovine biljnog porekla za zamenu ribljeg bra&scaron;na u hrani za ribe. Shodno tome, istraživanja ove disertacije urađena su u dve odvojene faze, gde je prva, faza vazdu&scaron;ne klasifikacije, imala za cilj ispitivanje mogućnosti primene kombinacije postupaka usitnjavanja suncokretove sačme mlinom čekidarom i vazdu&scaron;ne klasifikacije ovako usitnjene sačme primenom vazdu&scaron;nog gravitacionog kaskadnog, cik-cak, klasifikatora u cilju dobijanja frakcija povedanog sadržaj proteina u odnosu na polaznu sačmu. Nezavisni parametri usitnjavanja i klasifikacije bili su prečnik otvora sita (POS) čekidara (3, 2 i 1 mm), protok<br />klasifikacionog vazduha (5, 8,7 i 12,5 m³/h) i jačina oscilacije vibro dozatora (JOVD)<br />klasifikatora (30, 60 i 90% maksimuma). Zavisne promenljive bile su sadržaj proteina u<br />dobijenim frakcijama i njihov prinos. Primenjen je 3x3x3 potpuni faktorijalni eksperimentalni dizajn prema metodi odzivne povr&scaron;ine. U cilju dobijanja frakcije sa &scaron;to<br />većim sadržajem proteina, u &scaron;to većem prinosu, kombinacija postupaka usitnjavanja i<br />vazdu&scaron;ne klasifikacije je optimizovana primenom regresione analize, analize glavnih<br />komponenata (PCA analiza), analize varijanse, kao i računske dinamike fluida (CFD analiza), kojom je dobijeni kompjuterski model vazdu&scaron;ne klasifikacije suncokretove sačme poređen sa eksperimentalno dobijenim rezultatima. Cik-cak vazdu&scaron;ni klasifikator uspe&scaron;no je primenjen za razdvajanje usitnjene suncokretove sačme na grubu i finu frakciju. Pri povećanju protoka vazduha smanjivao se prinos grube a istovremeno povećavao prinos fine frakcije. Grube frakcije suncokretove sačme dobijene pri protocima vazduha od 8,7 i 12,5 m³/h imale su za 0,5 &minus; 41,4% relativno veći sadržaj proteina u poređenju sa polaznom sačmom. Smanjenje POS i povećanje protoka vazduha uticalo je na povećanje, dok je povećanje JOVD, uticalo na smanjenje sadržaja proteina grube frakcije. Najveći sadržaj proteina (50,90%SM) imala je gruba frakcija suncokretove sačme dobijena pri sledećim parametrima: POS &minus; 1 mm; protok vazduha &minus; 12,5 m³/h; JOVD &minus; 30%. Na sadržaj proteina grube frakcije i odnos prinosa frakcija značajan uticaj (p &lt; 0,05) imali su POS čekidara i protok vazduha, dok je CFD model pokazao zadovoljavajuće poklapanje sa eksperimentalnim rezultatima. Cilj druge faze disertacije, faze ekstrudiranja, bio je najpre ispitivanje uticaja dodatka polazne suncokretove sačme (oko 37% proteina na SM) i njene dve visokoproteinske frakcije (oko 43% i 49% proteina na SM), dobijenih na osnovu odabranih parametara usitnjavanja i vazdu&scaron;ne klasifikacije, na postupak ekstrudiranja i fizički kvalitet ekstrudirane hrane za ribe. Maksimalno 20% ribljeg bra&scaron;na bilo je zamenjeno polaznom sunockretovom sačmom i njenim odabranim visokoproteinskim frakcijama, a njihov udeo u recepturi za ishranu pastrmke menjan je na osnovu dizajna sme&scaron;e. Za ekstrudiranje eksperimentalnih sme&scaron;a i dobijanje hrane u obliku granula kori&scaron;ćen je dvopužni ekstruder. Ulazni parametri ekstrudiranja bili su konstatni, osim sastava sme&scaron;e, a<br />praćeni su izlazni parametri ekstrudiranja: temperatura u cevi ekstrudera, temperatura<br />matrice, pritisak na matrici, specifična potro&scaron;nja energije (SME) i obrtni moment<br />elektromotora ekstrudera. Proizvedenim uzorcima ispitani su pokazatelji fizičkog kvaliteta: stepen ekspanzije, nasipna masa, tvrdoća, stepen otiranja, kapacitet upijanja ulja, nivo otpu&scaron;tanja ulja iz zauljenih granula, stabilnost u vodi i mikrostruktura granula. Prisutvo suncokretove sačme vi&scaron;eg sadržaja proteina i manjeg sadržaja celuloze u sme&scaron;i uticalo je na formiranje vi&scaron;e temperature matrice ekstrudera, kao i na smanjenje SME i obrtnog momenta. Povećanje sadržaja proteina suncokretove sačme doprinelo je stvaranju kompaktnije strukture granule, povećanju tvrdoće, otpornosti otiranju i stabilnosti granula u vodi, smanjenju nivoa otpu&scaron;tanja ulja, te je tako pozitivno uticalo na fizičke karakteristike granula. Visokoproteinska frakcija suncokretove sačme sa 49% proteina na SM doprinela je optimalnim fzičkim karakteristikama ekstrudirane hrane za pastrmku. Karakterizacija ove frakcije kao potencijalne nove sirovine u industriji hrane za ribe bio je krajnji cilj ispitivanja ove disertacije. U tu svrhu navedena frakcija suncokretove sačme poređena je u novom eksperimentu ekstrudiranja i ispitivanja fizičkog kvaliteta hrane za pastrmku sa ribljim bra&scaron;nom, kao i sojinim bra&scaron;nom, koje je najče&scaron;će kori&scaron;ćen izvor biljnih proteina u hrani za ribe. Kori&scaron;ćena je nova receptura sme&scaron;e ali ista postavka eksperimenta kao u prvom delu faze ekstrudiranja. Rezultati su pokazali da je prisustvo visokoproteinske suncokretove sačme sa oko 49% proteina (SM) doprinelo smanjenju temperature matrice, ali i povedanju SME i obrtnog momenta, a time i poroznosti granula &scaron;to je imalo pozitivan uticaj na kapacitet upijanja ulja granula, stabilnost granula i otpu&scaron;tanje nutrijenata u vodi, kao i negativan uticaj na stepen otiranja i nasipnu masu granula. Zamena 13,4% ribljeg bra&scaron;na u recepturi ovom viskoproteinskom frakcijom suncokretove sačme za rezultat je imala granule zadovoljavajućeg fizičkog kvaliteta. Granule najboljeg fizičkog kvaliteta dobijene su<br />kombinacijom visokoproteinske frakcije suncokretove sačme sa sojinim bra&scaron;nom, te se<br />moglo zaključiti da se funkcionalne karakteristike ove dve sirovine odlično dopunjuju, i da visokoproteinska frakcija suncokretove sačme, sa stanovi&scaron;ta tehnolo&scaron;kog kvaliteta hrane za ribu, predstavlja dobru alternativu ribljem bra&scaron;nu.</p> / <p>High price and finite availability of fish meal (FM), due to high expansion of aquaculture<br />sector in recent decades, are main concerns for modern day aquafeed industry. Partially or completely substation of fish meal in fish feed with protein sources of plant origin, together with finding novel alternative protein sources, is commonly used approach that enables sustainability of aquafeed industry in decades to come. New, relatively simple and low-cost procedure for dry fractionation of sunflower meal (SFM) was proposed within this thesis, with aim for producing high protein SFM fractions as a potential plant source alternative for FM in fish feed. Thus, thesis&rsquo;s researches were done in two phases, where the aim of the first phase, air classification phase, was to investigate the possibility of applying combination of grinding by hammer mill and air classification of ground SFM using gravitational, cascade air classifier (zigzag), in order to obtain protein enriched fractions. Independent variables of grinding and air classification were sieve openings diameter (SOD) of hammer mill (3, 2 and 1 mm), air flow (5, 8.7 and 12.5 m3/h) and bowl feeder oscillation rate (BFOR) of air classifier (30, 60 and 90% of the maximum). Depended responses were protein content and yield of obtained fractions. The experimental data were obtained using 3 x 3 x 3 full factorial experimental design according to response surface methodology (RSM). For the optimization of grinding and air classification, in order to obtain fraction with highest possible protein content and in high yield, regression analysis, principal component analysis (PCA), analysis of variance (ANOVA) and computational fluid dynamics (CFD) approach were employed. Zigzag air classifier was successfully used for fractionation of ground SFM into coarse and fine fraction. Yield of coarse fractions was decreasing, while fine fractions yield was increasing with the increase of the air flow. Coarse fractions of SFM obtained at 8.7 and 12.5 m3/h were 0.5 &minus; 41.4% relatively enriched in protein content compared to the starting SFM. Decrease of SOD and increase of air flow resulted in coarse fraction protein content increase, while increasing BFOR decreased coarse fraction protein<br />content. The coarse SFM fraction with highest protein content was obtained for the SFM<br />ground by 1 mm SOD, air flow of 12.5 m3/h, with BFOR set at 30%. Protein content of<br />coarse fraction and ratio of fractions yields were significantly affected (p &lt; 0.05) by SOD of hammer mill and air flow. CFD model coincide with the experimental results of air<br />classification. The first aim of second phase, extrusion phase, was to investigate influence of starting SFM (37% of protein at DM) and its two high protein fractions (43% and 49% of protein at DM), obtained by grinding and air classification, on extrusion process and physical quality of extruded fish feed. Maximum 20% of FM was substituted with SFM and its high protein fractions in trout feed recipe, and their share was changed according to the<br />mixture design. Twin screw extruder was used for the production of trout feed samples.<br />Primarily extrusion parameters were constant, except dry mixture composition, and<br />secondary extrusion factors were observed: extruder barrel&rsquo;s temperatures, temperature<br />and pressure at the die, specific mechanical energy (SME) and motor load as torque.<br />Selected physical properties of extruded trout feed samples were determined: radial<br />expansion, bulk density, hardness, durability, oil absorption capacity, oil leakage, water<br />stability and microstructure of feed. SFM higher in protein and lower in fiber influenced<br />higher die temperature and lower SME and torque during extrusion process. Increase in<br />protein content of SFM resulted in more compact structure of pellets, increased hardness, durability and water stability, decreased oil leakage and thus positively influenced on physical properties of feed. High protein SFM fraction with around 49% of protein (DM) contributed to the optimal physical properties of experimental feed and characterization of this SFM fraction, as a potential new raw material in fish feed industry, was definite aim of this thesis. Towards that, new set of experiments was conducted, where high protein SFM fraction was compared with FM and soybean flour (SBF) by extruding new samples of trout feed and investigating their physical quality. Results of second extrusion experiment showed that presence of high protein SFM fraction (49% of protein DM) in dry mixture decreased die temperature, while increased SME and torque, and with that also increased porosity of pellets, oil absorption capacity and water stability but decreased bulk density and durability. Substitution of 13.4% FM by high protein SFM fraction resulted in pellets with satisfactory physical quality. The highest quality pellets were obtained in combination of high protein SFM and SBF, which lead to the conclusion that functional characteristics of high protein SFM fraction and SBF are complementary, and that novel SFM, from the point of technical quality, presents good FM alternative.</p>

<p>U ovoj doktorskoj disertaciji analizirano je bra&scaron;no strnih žita (p&scaron;enice, spelte, ječma,<br />raži, tritikalea, ovsa), prosolikog žita (kukuruza) i pseudocerealija (heljde i<br />amarantusa) primenom gasne hromatografije sa masenom spektrometrijom (GC-MS) u<br />kombinaciji sa multivarijantnom analizom, u cilju ispitivanja mogućnosti za<br />određivanje autentičnosti navedenih biljnih vrsta. U tu svrhu, iz bra&scaron;na navedenih<br />cerealija i pseudocerealija ekstrahovani su mali molekuli (lipidi i &scaron;ećeri). Lipidne<br />komponente bra&scaron;na ekstrahovane su heksanom. Nakon vi&scaron;estrukog obezma&scaron;ćivanja<br />istih uzoraka bra&scaron;na heksanom i su&scaron;enja, usledila je ekstrakcija &scaron;ećernih komponenata<br />96%-tnim etanolom. Dobijeni heksanski i etanolni ekstrakti derivatizovani su<br />odgovarajućim reagensima. Za derivatizacaju lipidnih komponenata kori&scaron;ćen je<br />rastvor TMSH (trimetilsulfonijum hidroksida, 0,2 M u metanolu). Time se masne<br />kiseline prevode u odgovarajuće metil-estre. Za derivatizaciju &scaron;ećernih komponenata<br />kori&scaron;ćen je etanolni rastvor natrijum-hidroksida i hidroksilamin-hidrohlorida u<br />kombinaciji sa BSTFA (bis-(trimetilsilil-trifluoroacetamidom). Na taj način su prosti<br />&scaron;ećeri prevedeni u odgovarujuće trimetilsilil-oksime. Ovako pripremljeni ekstrakti<br />uzoraka bra&scaron;na su analizirani na GC&ndash;MS uređaju.<br />Dobijeni hromatogrami međusobno pokazuju veliku sličnost, a naročito u okviru<br />uzoraka iste botaničke vrste. U obradi hromatograma i masenih spektara, kori&scaron;ćen je<br />MSD Productivity ChemStation program uz primenu Wiley 275 biblioteke masenih<br />spektara. Dobijeni podaci analizirani su na tri načina. Prvi način podrazumeva<br />kreiranje numeričkih matrica u modu ukupne jonske struje (TIC). Drugi postupak<br />podrazumeva kreiranje numeričkih matrica izolovanjem karakterističnih fragmentnih jona sa hromatograma (kod lipida 74 m/z, a kod &scaron;ećera 73 m/z u kombinaciji sa bar<br />jednim od sledećih jona: 204 m/z, 217 m/z, i 361 m/z). Kod trećeg načina obrade<br />podataka, analiza je urađena kreiranjem matrica primenom binarnog sistema (1/0), gde<br />&bdquo;1&ldquo; označava prisustvo određene komponente, a &bdquo;0&ldquo; označava njeno odsustvo u<br />posmatranom uzorku. Tako dobijeni podaci podvrgnuti su multivarijantnoj analizi<br />primenom statističkih programa &ndash; PAST i STATISTICA. U sva tri slučaja ispitivani<br />uzorci grupisani su u međusobno jasno odvojene grupe, prema odgovarajućoj biljnoj<br />vrsti. Uočeno je jasno razlikovanje pseudocerealija (heljde i amarantusa) i prosolikog<br />žita (kukuruza) od grupe strnih žita (p&scaron;enice, spelte, ječma, raži, tritikalea i ovsa).<br />Primenjenim metodama postiže se manje selektivna klasifikacija biljnih vrsta u okviru<br />strnih žita, sa izuzetkom uzoraka ovsa i spelte. Ovi rezultati pokazuju da je novim<br />navedenim postupcima moguće utvrditi autentičnost bra&scaron;na različitih botaničkih vrsta<br />cerealija i pseudocerealija.<br />Na isti način tretirani su i uzorci proizvedenog hleba (kore i sredine) u kojima je<br />p&scaron;enično bra&scaron;no supstituisano sa 0, 20, 40, 50, 60, 80 i 100% heljdinog bra&scaron;na.<br />Multivarijantnom analizom GC-MS podataka dobijaju se jasno odvojeni klasteri u<br />skladu sa porastom udela bra&scaron;na heljde u kori i sredini hleba. Najbolji rezultati<br />postignuti su koreliranjem sastava i sadržaja ugljenohidratnih komponenata u kori<br />hleba.<br />Krajnji ishod razvoja ovih novih originalnih metoda je mogućnost njihove praktične<br />primene u cilju rutinskih kontrola kvaliteta bra&scaron;na i gotovih pekarskih proizvoda u<br />laboratorijama, proizvodnim pogonima i inspekcijskim službama. Posebna pogodnost<br />primene predloženih metoda je to &scaron;to su one semi-kvalitativnog i semi-kvantitativnog<br />karaktera, pa se mogu izvoditi bez tačne identifikacije eluirajućih malih molekula</p> / <p>In this doctoral thesis various flour samples of small grains (wheat, spelt, barley, rye,<br />triticale, oats), corn and pseudocereals (buckwheat and amaranth) were analyzed using<br />gas chromatography - mass spectrometry (GC-MS) in combination with multivariate<br />analysis, in order to examine the possibilities for determining the authenticity of the<br />plant species listed. Small molecules (lipids and sugars) were extracted from flour<br />samples of the above-mentioned cereals and pseudocereals. The lipid components of<br />the flour were extracted with hexane. The extraction of sugar components from the<br />same flour samples was performed with 96% ethanol solution, after multiple defatting<br />with hexane and drying of the samples. The obtained hexane and ethanol extracts were<br />derivatized with appropriate reagents. For the derivatization of the lipid components, a<br />solution of TMSH (trimethylsulfonium hydroxide, 0.2 M in methanol) was used. Thus,<br />the fatty acids were converted into the corresponding methyl esters. For the<br />derivatization of the sugar components, an ethanol solution of sodium hydroxide and<br />hydroxylamine hydrochloride combined with BSTFA (bis- (trimethylsilyl<br />trifluoroacetamide) was used. Thus, the free sugars were converted into the<br />corresponding trimethylsilyl oximes. The derivatized extracts prepared in this manner<br />were analyzed on a GC -MS device.<br />The obtained chromatograms were very similar, and especially within the samples of<br />the same botanical species. In the processing of the chromatograms and mass spectra,<br />MSD Productivity ChemStation program was used with the Wiley 275 Mass Spectra<br />Library. The obtained data were processed in three ways. The first method involves the<br />creation of numerical matrices in the total ion current mode (TIC). The second method<br />involves the creation of numerical matrices by isolating characteristic ion fragments from the TIC chromatograms (74 m/z for the lipid components, and 73 m/z in<br />combination with at least one of the following ions: 204 m/z, 217 m/z, and 361 m/z, for<br />the sugar components). In the third way of data processing, the analysis was done by<br />creating a matrix using a binary system (1/0), where &ldquo;1&rdquo; denotes the presence of a<br />particular component, and &ldquo;0&rdquo; denotes its absence in the observed sample. The data<br />thus obtained were subjected to multivariate analysis using statistical programs - PAST<br />and STATISTICA. In all three cases, the analyzed samples were grouped in clearly<br />separated groups according to the appropriate plant species. A clear distinction was<br />observed between pseudocereals (buckwheat and amaranth), corn and the group of<br />small grains (wheat, spelt, barley, rye, triticale, oats). The applied methods achieved a<br />less selective classification of plant species within the group of small grains, with the<br />exception of oats and spelt samples. These results show that it is possible to determine<br />the authenticity of flour of various botanical species of cereals and pseudocereals,<br />applying new methods described in this doctoral thesis.<br />The samples of produced bread (crust and crumbs) in which wheat flour was<br />substituted with 0, 20, 40, 50, 60, 80 and 100% of buckwheat flour were treated in the<br />same way. Multivariate analysis of GC-MS data provided clearly separated clusters in<br />accordance with the increase in the share of buckwheat flour in bread crusts and<br />crumbs. The best results were achieved by correlating the composition and content of<br />the carbohydrate components in bread crusts.<br />The ultimate outcome of the development of these new original methods is the<br />possibility of their practical application for the purpose of routine quality control of<br />flour and bakery products in laboratories, production facilities and inspection services.<br />A particular advantage of applying the proposed methods is that they are semiqualitative<br />and semi-quantitative. Therefore, they can be performed without the exact<br />identification of eluting small molecules (lipids and free sugars), nor their<br />quantification using analytical standards.</p>

<p style="text-align: justify;">Glavni cilj ove disertacije koji obuhvata dobijanje i hemijsku karakterizaciju ekstrakata i etarskih ulja rtanjskog čaja (Satureja montana L.), bosiljka (Ocimum basilicum L.) i korijandera (Coriandrum sativum L.), kao i njihove sme&scaron;e, je određivanje biolo&scaron;ke aktivnosti dobijenih ekstrakata u in vitro uslovima pradenjem sposobnosti neutralizacije slobodnih radikala i antiproliferativne aktivnosti.<br />Prvo je izvr&scaron;ena karakterizacija biljnih sirovina (rtanjski čaj, bosiljak i korijander), kao i njihove sme&scaron;e jednakih masenih udela (CBS) u pogledu sadržaja vlage, srednjeg prečnika čestica i sadržaja etarskog ulja. U cilju dobijanja etarskih ulja i ekstrakata iz ispitivanih sirovina su primenjeni hidrodestilacija (konvencionalni postupak) i superkritična ekstrakcija (savremena tehnika). GC-MS analizom je određen kvalitativni sastav i relativni udeo pojedinačnih monoterpenskih ugljovodonika, oksidovanih monoterpena, seskviterpena i ostalih jedinjenja. Dalje je GC-FID analizom kvantitativno određen sadržaj i prinos pojedinačnih terpena (&alpha;-pinen, &beta;-pinen, d-limonen, &gamma;-terpinen, eukaliptol, linalool, kamfor, &alpha;-terpineol, geraniol, metil-havikol, karvakrol i eugenol) i izvr&scaron;eno je poređenje uzoraka dobijenih tradicionalnim i savremenim postupcima.<br />Etarskim uljima i lipofilnim ekstraktima je određena biolo&scaron;ka aktivnost ispitivanjem antioksidativne i antiproliferativne aktivnosti. In vitro anti-oksidativna aktivnost superkritičnih ekstrakata i etarskih ulja je određena DPPH testom, dok je antiproliferativna aktivnost određena u in vitro uslovima na tri linije tumorskih delija (HeLa, MDA-MB-453, K562) i na normalne humane fibroblaste (MRC-5).<br />U cilju boljeg određivanja sličnosti između etarskih ulja i lipofilnih ekstrakata rtanjskog čaja, bosiljka, korijandera i njihove sme&scaron;e (CBS) su primenjene hemometrijska tehnike: analiza glavnih komponenata (Principal component analysis) i hijerarhijska klaster analiza (Hierarchical cluster analysis).</p> / <p>The main aim of this dissertation was recovery and chemical characterization of extracts and essential oils of winter savory (Satureja montana L.), basil (Ocimum basilicum L.) and coriander (Coriandrum sativum L.), as well as their mixture, and determination biological activity of extracts in in vitro conditions by capacity towards neutralization of free radicals and antiproliferative activity.<br />Plant materials (winter savory, basil and coriander) and their mixture (CBS) were characterized in terms of moisture content, mean particle size and essential oil content. In order to obtain essential oil and extracts from investigated plants, hydrodistillation (conventional procedure) and supercritical fluid extraction (novel technique) were applied. GC-MS analysis was used for determination of qualitative content and relative abundance of monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes and other volatile compounds. Furthermore, GC-FID analysis was used for quantitative determination of content and yield of terpene compounds (&alpha;-pinene, &beta;-pinene, d-limonene, &gamma;-terpinene, eucalyptol, linalool, camphor, &alpha;-terpineol, geraniol, methyl-chavicol, carvacrol i eugenol) and samples obtained by traditional and novel techniques were compared. Biological potential of essential oil and lipophilic extracts was determined by antioxidant and antiproliferative activity. In vitro antioxidant activity of supercritical extracts and essential oils was determined by DPPH assay, while antiproliferative activity was determined in in vitro conditions on three cancer cell lines (HeLa, MDA-MB-453, K562) and on normal human fibroblasts (MRC-5).<br />Chemometric techniques such as principal component analysis (PCA) i hierarchical cluster analysis (HCA) were applied for better understanding of similarities between essential oils and lipid extracts.</p>

<p>Strukturiranje elastomernih kompozita dodavanjem različitih vrsta nanopunila je dovelo do značajnog pobolj&scaron;anja njihovih primenskih svojstava, a samim tim i do povećanja njihove potencijalne primene kao pogodnih materijala za specijalne namene. U ovom radu, dobijene su dve grupe elastomernih hibridnih materijala za specijalne namene (na osnovu stirenbutadienskog elastomera i na osnovu termoplastičnih poliuretana).<br />U prvom delu istraživanja, veliki doprinos u razvoju industrije gume je postignut strukturiranju stirenbutadienskih nanokompozita primenom nanočestica punila silicijum(IV)oksida različitih morfolo&scaron;kih svojstava, dobijenih hidrotermičkom i termičkom obradom, primenom tri eksperimentalno modelovana punila silicijum(IV)oksida (dobijena taloženjem iz Na-vodenog stakla sa sumpornom kiselinom), kao i hibridnog punila (kombinacije čestica aktivne čađi i SiO₂ optimalnih svojstava). Izvr&scaron;ena je analiza uticaja strukture, povr&scaron;ine i povr&scaron;inske aktivnosti nanopunila na ojačanje elastomera, kao i provera koncepata, modela i teorija ojačanja na neumreženim i umreženim sistemima stirenbutadienskih elastomera ojačanih modifikovanim punilima SiO₂. Primenom mnogobrojnih metoda karakterizacije, sveobuhvatno je ispitan uticaj nanopunila na karakteristike me&scaron;anja, reolo&scaron;ka svojstva pripremljenih hibridnih nanokompozita, sposobnost umrežavanja u neumreženom materijalu, kao i na toplotna, dinamičko-mehanička i mehanička svojstva umreženih nanokompozita, radi projektovanja i optimizovanja sastava SBR hibridnih materijala za razvoj modelnog protektora sa optimalnim svojstvima za ekolo&scaron;ke ili &quot;zelene pneumatike&quot;. Drugi deo istraživanja je bio posvećen dobijanju segmentiranih poliuretanskih elastomernih nanokompozita primenom alifatičnih polikarbonatnih diola i nanočestica bentonita, koji nalaze primenu u medicini, građevinarstvu, u industriji name&scaron;taja i sportske opreme. Primenom mnogobrojnih metoda za karakterizaciju, ispitan je složen mehanizam uticaja tvrdih segmenata, termodinamičke nekompatibilnosti i prisustva nanočestica punila bentonita na strukturu i morfologiju, kao i na toplotna i dinamičko-mehanička svojstva pripremljenih poliuretanskih termoplastičnih elastomera. Dobijeni podaci o obrazovanju vodoničnih veza, termičkoj stabilnosti i termičkoj dekompoziciji, kao i o temperaturama prelaska u staklasto stanje i oblasti raskidanja čvorova fizičkih veza, predstavljaju značajan doprinos napretku strukturiranja poliuretanskih elastomera i nanokompozita na osnovu alifatičnih polikarbonatnih diola, i omogućavaju primenu ovih materijala za specijalne namene.</p> / <p>The structuring of elastomeric composites by addition of different nanofillers has led to a significant improvement of their end-use properties, and therefore, to their potential application as suitable materials for special applications. In this work, two types of elastomeric hybrid materials for special purposes were obtained (based on styrene-bustadiene elastomer or on segmented thermoplastic polyurethanes).<br />In the first part of the study, a major contribution to the development of the rubber industry was achieved by structuring styrene-butadiene nanocomposites, applying silica nanoparticles of various morphological properties: prepared by hydrothermal or thermal treatment, three experimentally prepared SiO2 fillers (obtained by precipitation from sodium silicate with sulfuric acid), as well as a hybrid filler (combination of carbon black and SiO2 fillers with optimal properties). The analysis of the influence of the nanoparticles structure, surface and surface activity on the reinforcment of SBR elastomers, as well as the verification of concepts, models and reinforcement theories on non-cross-linked and cross-linked systems of styrene-butadiene nanocomposites was performed. Using the numerous characterization methods, the influence of nanofillers on the mixing characteristics, the rheological properties of the prepared hybrid nanocomposites, as well as the thermal, dynamic-mechanical and mechanical properties of cross-linked SBR nanocomposites was studied, in order to design and optimize the composition of SBR hybrid materials for development of environmental friendly or &quot;green&quot; tyre protector model.<br />The second part of the research was devoted to the preparation of segmented polyurethane elastomeric nanocomposites using aliphatic polycarbonate diols and bentonite nanoparticles, that have found the significant application in the medicine, construction, the furniture and sports equipment industry. Applying numerous characterization methods, a complex mechanism of the influence of the hard segments, thermodynamic incompatibility and the presence of bentonite filler on the structure and morphology, as well as on the thermal and dynamic-mechanical properties of the synthesized thermoplastic elastomers was studied. The obtained data on the hydrogen bonds formation, thermal stability and thermal decomposition, as well as the glass transition temperature and physical crosslink disruption temparature range, makes a significant contribution to the progress in structuring of polycarbonate-based polyurethane elastomers and their hybrid materials, and improves their potential applications for the special purposes.</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>Adhezija i formiranje biofilma kvasaca na kontaktne povr&scaron;ine materijala je ozbiljan higijenski problem u prehrambenoj industriji, jer može biti izvor kontaminacije tokom proizvodnje, dovodeći do velikih ekonomskih gubitaka zbog kvarenja hrane i smanjenja kvaliteta proizvoda, a takođe može da &scaron;teti zdravlju potro&scaron;ača. S drge strane, mnoge infekcije u bolnici uzrokovane su adhezijom vrsta roda Candida na medicinska sredstva i implantate. Međutim, trenutno razumevanje adhezije i kolonizacije kvasaca na abiotičke povr&scaron;ine je ograničeno na samo neke vrste roda Candida, a naročito malo se zna o vrstama roda Pichia kao adhezivnim agensima.<br />Cilj istraživanja u okviru ove doktorske disertacije je bio da se proceni potencijal adhezije sojeva kvasaca Candida i Pichia na polistiren povr&scaron;inu, diskove od nerđajućeg čelika (AISI 304, Ra = 25.20 &ndash; 961.9 nm) i drveta sa različitim stepenom hrapavosti povr&scaron;ine, i ispita uticaj hrapavosti povr&scaron;ine na adheziju kvasaca. Hidrofobnost povr&scaron;ine ćelije (CSH) sojeva iz rodova Candida i Pichia je određena u cilju procene korelacije između hidrofobnosti povr&scaron;ine ćelije i adhezije kvasaca na polistiren. Pored toga, ispitan je uticaj različitih medijuma, temperatura, i različitih biljnih ekstrakata na adheziju odabranih sojeva iz rodova Candida i Pichia na povr&scaron;ine diskova od nerđajućeg čelika. Rezultati su pokazali da su svi testirani sojevi kvasaca Candida i Pichia su bili u stanju da adheriraju na polistiren, povr&scaron;ine od nerđajućeg čelika i drveta, ali u različitoj meri. Soj vrste C. albicans je imao veću sposobnost adhezije na polistiren i nerđajući čelik u odnosu na sojeve vrsta C. glabrata, C. parapsilosis i C. krusei. U slučaju kod roda Pichia, sojevi vrste P. membranifaciens su pokazali manju sposobnost adhezije na nerđajući čelik nego ispitivani soj vrste P. pijperi, &scaron;to nije slučaj kod adhezije na polistiren. Na osnovu dobijenih rezultata pokazano je da su sojevi vrsta C. glabrata, C. parapsilosis, C. krusei, P. pijperi i P. membranifaciens bili izrazito do umereno hidrofobni, dok je soj vrste C. albicans bio hidrofilan, &scaron;to ukazuje da hidrofobnost povr&scaron;ine ćelije (CSH) nije značajno u korelaciji sa količinom ćelija adheriranih na polistiren. Pored toga, na adheziju sojeva kvasaca Candida i Pichia značajno je uticala hrapavost povr&scaron;ine nerđajućeg čelika, dok hrapavost drvenih povr&scaron;ina nije značajno uticala. Dalje mi smo ispitali uticaj različitih medijuma za rast i temperature na adheziju odabranih kvasaca. Primećeno je da je količina adheriranih ćelija kvasaca C. albicans i C. glabrata na povr&scaron;inama od nerđajućeg čelika bila znatno veća u Malt Extract Broth (MEB) medijumu, dok je za C. parapsilosis, C. krusei, P. pijperi i P. membranifaciens bila u Yeast Peptone Dextrose (YPD) medijumu. Na&scaron;i podaci takođe ukazuju da je temperatura veoma važan faktor koji značajno utiče na adheziju ovih kvasaca. Problem adhezije i formiranje biofilma kvasaca na abiotičkim povr&scaron;inama i rastuća otpornost na postojeće antimikrobne agense predstavilo je izazov za nas za pronalaženjem novih alternativnih agenasa biljnog porekla. Stoga mi smo ispitali antimikrobnu i antibiofilm aktivnost biljnih ekstrakata kao &scaron;to su Humulus lupulus, Alpinia katsumadai i Evodia rutaecarpa prema C. albicans, C. glabrata i P. membranifaciens. Na osnovu dobijenih MIC vrednosti, testirani biljni ekstrakati su bili efikasni u inhibiciji kvasaca. Primećeno je da su biofilmovi C. glabrata pokazali veću otpornost na biljne ekstrakte u odnosu na C. albicans. Međutim, ekstrakti A. katsumadai i E. rutaecarpa su promovisani rast i razvoj formiranog biofilma P. membranifaciens.</p> / <p>The adhesion and biofilm formation of yeast on the contact surfaces of the material is a serious hygiene problem in the food industry, because it can be a source of contamination during production, leading to major economic losses due to food spoilage and reduced product quality, and can also affects the consumer&rsquo;s health. On the other hand, many infections in the hospital are caused by the adhesion of Candida spp. to medical devices and implants. However, the understanding of adhesion and colonization of yeasts on abiotic surfaces is limited to only some Candida species, and in particular little is known about Pichia species as adhesive agents.<br />The aim of the research in this doctoral dissertation was to assess the potential of Candida and Pichia strains to adhere to polystyrene surface, stainless steel discs (AISI 304, Ra = 25.20 - 961.9 nm) and wood (beech) with different degrees of surface roughness, and examined the influence of surface roughness on yeast adhesion. Cell surface hydrophobicity (CSH) of Candida and Pichia strains was determined in order to assess the correlation between the cell surface hydrophobicity and the yeast adhesion to polystyrene. In addition, the influence of different medium, temperature, and various plant extracts on the adhesion of selected Candida and Pichia strains to to stainless steel surfaces was examined. Our results indicated that all Candida and Pichia strains were able to adhere to polystyrene, stainless steel surfaces and wood in a species- and strain-dependent manner. C. albicans had a higher ability to adhere to polystyrene and stainless steel compared to C. glabrata, C. parapsilosis and C. krusei. Regarding Pichia species, P. membranifaciens strains were less adherent to stainless steel than P. pijperi, what is not the case in the adhesion to polystyrene. Based on the results obtained, C. glabrata, C. parapsilosis, C. krusei, P. pijperi i P. membranifaciens strains were strongly to moderately hydrophobic while only C. albicans was moderately hydrophilic, indicating that the cell surface hydrophobicity is not significantly correlated with the amount of cells adhered to polystyrene. In addition, the adhesion of Candida and Pichia strains was significantly influenced by the roughness of stainless steel surface, while the roughness of wood surfaces did not significantly influence. Further on we examined the impact of different growth medium and temperature on adhesion of selected yeasts. It was noted that the amount of adhered cells of C. albicans and C. glabrata on stainless steel surfaces were significantly higher in the Malt Extract Broth (MEB) medium, whereas for C. parapsilosis, C. krusei, P. pijperi and P. membranifaciens it was Yeast Peptone Dextrose (YPD) medium. Our data also indicated that temperature is a very important factor which considerably affects the adhesion of these yeast. The problem of yeast adhesion and biofilm formation on abiotic surfaces and its growing resistance to existing antimicrobial agents, presented a challenge for us to find new alternative agents of plant origin. Hence, we investigated antimicrobial and antibiofilm activity of plant extracts such as Humulus lupulus, Alpinia katsumadai and Evodia rutaecarpa against C. albicans, C. glabrata and P. membranifaciens. According to the MIC values, all plant extracts were effective in the inhibition of yeast strains. It was observed that biofilms of C. glabrata are more resistance to plant extracts as compared to C. albicans. However, extracts of A. katsumadai and E. rutaecarpa were promoted the growth and development of a preformed biofilm of P. membranifaciens.</p>

<p>&Scaron;iroka upotreba imunosupresivnih terapija zajedno sa antimikotičnim terapijama &scaron;itokog spektra značajno je povećala učestalost povr&scaron;inskih i sistemskih infekcija uzrokovanih patogenim kvascem Candida glabrata. Zbog povećane rezistentnosti vrste C. glabrata na klasične antimikotike, javila se potreba za pronalaskom novih alternativa u prevenciji i lečenju infekcija izazvanih ovim patogenom. Tokom poslednjih nekoliko godina se u velikoj meri razmatra potencijalni benefit probiotskih mikroorganizama na zdravlje ljudi. Pored primene brojnih probiotskih bakterija, Saccharomyces boulardii je jedina vrsta kvasca za koju je dokazano da poseduje svojstva koja karakteri&scaron;u probiotike.<br />Cilj istraživanja ove doktorske disertacije je ispitivanje uticaja probiotskog kvasca S. boulardii na adheziju kvasca C. glabrata na polistitren povr&scaron;inu pri različitim temperaturama, pH vrednostima i u prisustvu različitih koncentracija tri klinički važna antimikotika kao &scaron;to su flukonazol, itrakonazol i amfotericin B. Hidrofobnost povr&scaron;ine ćelije (CSH) sojeva kvasca C. glabrata je određena u cilju procene korelacije između ove fizičko-hemijske osobine i adhezije na polistiren povr&scaron;inu. Pored toga, ispitana je adhezija kvasca C. glabrata u ko-kulturi sa drugim vrstama mikroorganizama. Testirana su tri soja kvasca C. glabrata, kvasci Candida krusei i Saccharomyces cerevisiae, kao i dve vrste probiotskih bakterija Lactobacillus rhamnosus i Lactobacillus casei. Metoda kori&scaron;ćena za procenu adhezije bila je bojenje kristal violetom, dok je hidrofobnost povr&scaron;ine ćelije sojeva kvasca C. glabrata određena testom Mikrobne adhezije na ugljovodonike.<br />Na&scaron;i rezultati su pokazali da uprkos neadhezivnosti ćelija probiotskog kvasca S. boulardii, ovaj probiotik je značajno uticao na sposobnost adhezije kvasca C. glabrata. Ovaj efekat je bio veoma zavisan od sojeva vrste C. glabrata, i bio je antagonistički ili sinergistički. &Scaron;to se tiče faktora životne sredine, temperatura nije pokazala značajan uticaj na modulatorni efekat probiotskog kvasca S. boulardii, dok pri visokoj pH vrednosti, probiotski kvasac nije uspeo da potisne adheziju sojeva kvasca C. glabrata. Sličan efekat je primećen u eksperimentima sa antimikoticima, gde su povećane koncentracije antimikotika smanjile modulatorni efekat S. boulardii na adheziju C. glabrata. Sojevi vrste C. glabrata u ko-kulturi sa neadhezivnim patogenim sojevima vrsta C. krusei i S. cerevisiae su pokazali slabiju adheziju nego u ko-kulturi sa neadhezivnim probiotskim sojevima vrste S. boulardii, L. rhamnosus i L. casei. &Scaron;to ukazuje da se adhezivnost dve odvojene kulture ne može korisiti za predviđanje adhezivnosti njihove ko-kulture. Nije utvrđena korelacija između hidrofobnosti povr&scaron;ine ćelije i adhezije na polistiren povr&scaron;inu sojeva kvasca C. glabrata, &scaron;to ukazuje da hidrofobnost ćelijskog zida ne mora uvek da bude precizna mera adhezivnog potencijala.</p> / <p>Following the widespread use of immunosuppressive therapy together with broadspectrum antimycotic therapy, the frequency of mucosal and systemic infections caused by the pathogenic yeast Candida glabrata has increased in the past decades. Due to the resistance of C. glabrata to existing azole drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. An increasing number of potential health benefits are being attributed to probiotic treatments. They include various bacterial probiotics, while among yeast only Saccharomyces boulardii (nom. nud.) is used extensively as a probiotic and often marketed as a dietary supplement.<br />The aim of this doctoral dissertation is to investigate the effect of the probiotic yeast S. boulardii on the adhesion of C. glabrata to polystyrene surface at different temperatures, pH values, and in the presence of three clinically important antifungal drugs, namely fluconazole, itraconazole, and amphotericin B. The cell surface hydrophobicity (CSH) of the tested C. glabrata strains has been determined as well in order to test for a possible correlation between this physico-chemical property and the ability to adhere to polystyrene surface. In addition, Candida krusei, Saccharomyces cerevisiae, two bacterial probiotics Lactobacillus rhamnosus and Lactobacillus casei were tested in a co-culture with C. glabrata as well. The method used to assess adhesion was crystal violet staining. The CSH of C. glabrata strains was determined using the Microbial Adhesion To Hydrocarbon (MATH) test. Our results showed that despite the nonadhesiveness of S. boulardii cells, this probiotic significantly affected the adherence ability of C. glabrata. This effect was highly dependent on C. glabrata strain and was either antagonistic or synergistic. Regarding the extrinsic factors, temperature did not indicate any significant influence on this S. boulardii modulatory effect, while at high pH, S. boulardii did not manage to repress the adhesion of C. glabrata strains. Similar effect was observed in the experiments with antimycotics, where increased concentrations of antimycotic reduced the modulatory effect of S. boulardii on C. glabrata adhesion. C. glabrata strains in the co-cultures with non-adhesive pathogenic strains C. krusei and S. cerevisiae showed weaker adhesion than in co-cultures with non-adhesive probiotic strains S. boulardii, L. rhamnosus and L. casei. This indicates that the adhesiveness of two separate cultures could not be used to predict the adhesiveness of their co-culture. Further, there is no correlation between cell surface hydrophobicity and adhesion of C. glabrata strains to the polystyrene surface, which indicates that the hydrophobicity of the cell wall must not always be the precise measure of the adhesive potential.</p>