<p>U okviru ove disertacije su ispitane mogućnosti primene savremenih postupaka za dobijanje ekstrakata rtanjskog čaja (Satureja montana L.).<br />U ekstraktima dobijenim primenom superkritičnog ugljendioksida (različitih gustina) utvrđeno je prisustvo karvakrola kao najzastupljenije komponente. Ekstrakt sa najvećim sadržajem karvakrola je dobijen pri uslovima 350 bar i 50 &deg;C (60,82%), dok je najveći prinos karvakrola ostvaren pri pritiscima 325 i 350 bar i temperaturi 60 &deg;C, i iznosio je 2,4 g/100 g droge. Primenom ugljendioksida na većim pritiscima se ostvaruje efikasnija ekstrakcija karvakrola iz droge, kao i proizvodnja ekstrakata sa većim sadržajima karvakrola. Druge komponente prisutne u ekstraktima u znatno nižim koncentracijama su: p-cimen, borneol, trans-kariofilen, kariofilen-oksid, &gamma;-terpinen i linalool.<br />Da bi se utvrdila mogućnost unapređenja prinosa ekstrakcije superkritičnim ugljendioksidom, kao i pobolj&scaron;anja kvaliteta ekstrakata, ispitan je uticaj različitih predtretmana biljnog materijala. Ustanovljeno je da predtretman vodom najznačajnije povećava prinos ekstrakcije (za 25%), dok je ultrazvučni predtretman najadekvatniji izbor za dobijanje ekstrakata sa najvećim sadržajem karvakrola (66,46%). Međutim, najveći prinos ekstrakcije karvakrola iz 100 g droge postignut je primenom etanola i vode kao predtretmana.<br />Ekstrakti dobijeni primenom subkritične vode (uz variranje temperature i vremena ekstrakcije) su hemijski okarakterisani i radi utvrđivanja uslova ekstrakcije pri kojima se postiže najveći kvalitet ekstrakata u pogledu sadržaja polifenolnih komponenti, kao i antioksidantne aktivnosti, primenjena je metoda odzivne povr&scaron;ine (RSM). Utvrđena je prednost primene subkritične vode u odnosu na klasičnu metodu ekstrakcije u pogledu sadržaja polifenolnih komponenti i antioksidantne aktivnosti.<br />Suvi ekstrakti S. montana dobijeni spray drying tehnologijom su&scaron;enja (sa različitim koncentracijama maltodekstrina) su ispitani u pogledu fizičkih i hemijskih osobina. Takođe, radi ispitivanja mogućnosti primene u vidu funkcionalnih ili prehrambenih proizvoda, izvr&scaron;ena je senzorna analiza dobijenih suvih ekstrakata, i analizirana je njihova farmakolo&scaron;ka aktivnost u smislu ACE inhibitornog i antioksidantnog delovanja.<br />Ustanovljeno je da je najniža koncentracija maltodekstrina (10%) najadekvatnija za dobijanje suvog ekstrakta S. montana sa najvećim sadržajem polifenolnih komponenti, sadržajem etarskog ulja i u pogledu antioksidantne i ACE inhibitorne aktivnosti. Takođe, suvi ekstrakt sa 10% maltodekstrina ispunjava i ostale fizičko-hemijske parametre, kojima se osigurava kako efikasno su&scaron;enje, tako i kvalitet ekstrakta.<br />In vivo aktivnost odabranih ekstrakata S. montana ispitana je na modelu hepatotoksičnosti indukovane primenom ugljentetrahlorida. Analiziran je uticaj ekstrakata na funkciju jetre, enzimske parametre oksidativnog stresa i serumske parametre oksidativnog o&scaron;tećenja izazvanog ugljentetrahloridom i ustanovljen je hepatoprotektivni učinak ekstrakata S. montana. Takođe, ispitano je dejstvo ekstrakata na rast Ehrlich-ovih ascitnih tumora implantiranih mi&scaron;evima, kao i na biohemijske parametre oksidativnog stresa u ćelijama tumora i utvrđeno je da je vreme aplikacije ekstrakata od izuzetnog značaja.</p> / <p>This dissertation investigates the possibilities of applying contemporary processes for obtaining extracts of winter savory (Satureja montana L.).<br />Carvacrol was determined to be the most abundant component in extracts acquired by using supercritical carbon dioxide (of various densities). Extract with the richest content of carvacrol was obtained under conditions of 350 bar and 50 &deg;C (60,82%), while the highest carvacrol yield was produced under 325 bar and 350 bar pressures and at a 60 &deg;C temperature reaching 2.4 g/100 g of dry weight. By applying carbon dioxide on higher pressures, a more efficient carvacrol extraction from herbal material is performed, alongside production of extracts with higher carvacrol content. Other components in the extracts present in significantly lower concentrations are the following: p-cymen, borneol, trans-caryophyllene, caryophyllene-oxide, &gamma;-terpinene and linalool.<br />In order to recognize the possibility of improving the extraction yield produced by employing supercritical carbon dioxide and enhancing the quality of extracts, the influence of several different pre-treatments was investigated. It was determined that the water pre-treatment raises the extraction yield the most (for 25%), while the ultrasonic pre-treatment was the most adequate choice for acquiring extracts with the highest content of carvacrol (66.46%). However, the highest carvacrol extraction yield from 100 g of dry weight was achieved by applying ethanol and water as pre-treatment.<br />Extracts which were attained with subcritical water (by varying the temperature and time of extraction) were chemically characterized and Response Surface Method (RSM) was applied for the purposes of determining conditions of extractions under which the highest quality of extracts in terms of content of polyphenolic compounds and antioxidant activity is reached. The advantage of employing subcritical water over the classical method of extraction in respect of content of polyphenolic components and antioxidant activity was demonstrated.<br />Dry extracts of S. montana obtained by using the spray drying technology (with different concentrations of maltodextrine) were examined in terms of their physical and chemical characteristics. Also, in order to investigate the possibility of their use as functional or food products, sensory analysis of attained extracts was performed, and furthermore, their pharmacological activity in terms of the ACE inhibitory and antioxidant effect was analysed as well.<br />It was determined that the lowest concentration of maltodextrin (10%) was the most adequate for obtaining dry extracts of S. montana with the richest content of polyphenolic components and essential oil, and in respect of antioxidant and ACE inhibitory activities. Also, dry extract with 10% of maltodextrin meets all other physical-chemical parameters, which provide efficient drying and quality of extracts.<br />In vivo activity of selected extracts of S. montana was examined on a model of hepatotoxicity induced by applying carbon tetrachloride. The influence of extracts on liver function, enzyme parameters of oxidative stress, and serum parameters of oxidative damage caused by carbon tetrachloride was analysed and hepatoprotective effect of S. montana extracts was determined. In addition, the influence of extracts on the growth of Ehrlich ascite tumors implanted in mice was investigated, and their impact on biochemical parameters of oxidative stress in tumor cells as well, and it was determined that the time of application of extracts is of great significance.</p>

<p>U okviru ove doktorske disertacije, proučavana je ekstrakcija bosiljka (<em>Ocimum basilicum L.</em>) primenom postupka hidrodestilacije, Soxhlet ekstrakcije i ugljendioksidom u superkritičnom stanju. Određen je sadržaj etarskog ulja u drogi (0,565%), a primenom GC/MS(FID) metoda određen kvalitativni i kvantitativni sastav detektovanih komponenata. Identifikovane komponente svrstane su u nekoliko grupa (monoterpeni, seskviterpeni i njihovi oksidovani derivati). Rezultati ispitivanja pokazuju da je dominantno jedinjenje etarskog ulja bosiljka linalool (50,09%), i da ono pripada linaloolskom hemotipu (hemotip A).<br />Ispitan je uticaj temperature (40-60&deg;C) i pritiska (100&ndash;300 bar) superkritičnog ugljendioksida na promenu prinosa ekstrakta. Utvrđeno je da se kumulativni prinos ekstrakta povećava sa porastom pritiska ekstrakcije, dok u zavisnosti od temperature, prinos ekstrakcije zavisi od gustine rastvarača i napona pare komponenata u ekstraktu.<br />Primenom sukcesivne (frakcione) superkritične ekstrakcije izvr&scaron;eno je frakcionisanje, a dobijeni ekstrakti upoređivani u pogledu prinosa, kvalitativnog i kvantitativnog sastava.<br />Ispitivanja hemijskog sastava CO₂ ekstrakta (GC/MS i GC/FID) pokazala su da ekstrakti pored komponenata etarskog ulja sadrže i druga lipofilna jedinjenja (voskove, masna ulja, masne kiseline, fitosterole i sl.). Dominantne komponente u svim ispitivanim ekstraktima su linalool, eugenol i &delta;-kadinen, dok su &alpha;-bergamoten, germakren D, &gamma;-kadinen, &beta;-selinen i spatulenol komponente sa manjim saržajem.<br />Na osnovu eksperimentalnih rezultata kinetike superkritične ekstrakcije izvr&scaron;eno je modelovanje ekstrakcionog sistema bosiljak &ndash; superkritični CO₂, primenom tri modela (Kandiah i Spiro, Brunner i Esquivel i sar.). Na osnovu srednjih vrednosti relativnog odstupanja modelovanih i eksperimentalnih vrednosti prinosa ekstrakcije, utvrđeno je da model Kandiah i Spiro pokazuje prihvatljivo slaganje, dok ostali modeli pokazuju lo&scaron;ije slaganje eksperimentalno određenih i modelom izračunatih prinosa ekstrakta.<br />U zavr&scaron;noj fazi rada ispitan je antioksidativni potencijal etarskog ulja i CO₂ ekstrakata, primenom DPPH metode. Najveću antioksidativnu aktivnost pokazao je ekstrakt dobijen na 100 bar, 60&deg;C (IC50 = 18,93 &mu;g/ml), koja je 5 puta veća od antioksidativne aktivnosti etarskog ulja bosiljka.</p> / <p>In this study, the extraction of basil (O. basilicum L.) ussing the hydrodistillation process, Soxhlet extraction and supercritical extraction with carbon dioxide were investigated. The content of essential oil was determined (0,565%), and the qualitative and quantitative composition of detected coumpound was made by GC/MS(FID). The identified coumpounds were classified into five groups (monoterpenes, sesquiterpenes and their oxidative derivates). The results of investigation shows that the dominant compound of basil essential oil is linalool (50,09%), and that it belongs to linalool chemotype (chemotype A).<br />The influence of temperature (40-60&deg;C) and pressure (100&ndash;300 bar) of supercritical carbon dioxide on extraction yields were studied. It was determined that the total yield of extract increases with the increaseing of extraction pressure, while the influence of temperature on the yield depends on the density of the solvent and vapor pressure of components in the extract.<br />Fractional supercritical fluid extraction was performed, and obtained extracts were compared regarding of yield, and the qualitative and quantitative composition of the extract. Chemical analyses of CO2 extract by GC/MS and GC/FID showed that extract contains, besides essential oil componentes, other lipophilic compounds (waxes, fatty oils, fatty acids, phytosterols, etc.). The few compounds were dominant in all analyzed basil extracts: linalool, and to a lesser extent eugenol, &delta;-cadinene, &alpha;-bergamotene, germacrene D, &gamma;-cadinene, &beta;-selinene and spathulenol. Based on the experimental results of the extraction kinetics, a modeling of basil &ndash; supercritical CO2 extraction system was performed, using three models (Kandiah and Spiro, Brunner, and Esquivel et al.). Based on the average values of the relative deviations of modeled and experimental values of extraction yield, it was found that the model Kandiah and Spiro shows acceptable agreement, while other models show lower agreement of the experimentally determined and model calculated extraction yield.<br />In finale phase of work the antioxidant potential of essential oil and CO2 extracts were examined, using DPPH method. The highest antioxidant activity showed CO2 extract obtained at 100 bar, 60&deg;C (IC50 = 18,93 &mu;g/ml), which is 5 time higher then antioxidant activity of basil essential oil.</p>

<p>У овој докторској дисертацији приказани су резултати синтеза и карактеризација нано-композитних честица са језгро-омотач структуром. Нанокомпозитне честице су синтетисане у течној фази, електростатичком депозицијом in situ синтетисаних SiO2, Fe3O4, ZnFe2O4 или NiFe2O4 наночестица на површину монодисперзних и сферичних силика језгро честица (средњег пречника ~ 0,4 &mu;m). Силика језгро честице су синтетисане хидролизом и кондезацијом TEOS-a у базној средини. Силика наночестице су добијене неутрализацијом јако базног воденог раствора натријум силиката, док су феритне наночестице синтетисане копреципитацијом из воденог раствора одговарајућих нитратних соли. Да би се омогућила електростатичка депозиција нано-честица, силика језгра су функционализована са 3-аминопропилтриетоксисилан (APTES) или поли(диалилдиметиламонијум хлорид) (PDDA) чиме се повећава изоелектрична тачка силика честица. На овај начин су око силика језгро честица синтетисани једнослојни омотачи на бази SiO2, Fe3O4, ZnFe2O4 или NiFe2O4.<br />Резултати су потврдили да се униформан силика слој може депоновати на функцијонализованим силика честицама. Формиран силика омотач је имао дебљину ~ 30 nm, мезопорозну структуру са средњом величином пора од ~ 8 nm и значајном укупном запремином пора. Због тога су тако добијене силика језгро-омотач наноструктуре погодне за имобилизацију ензима али и неких других активних материја. Такође је потврђено да је оптимална pH вредност за синтезу хомогеног Fe3O4 омотача на нефункционализованим силика језгрима ~ 5,4. Добијени Fe3O4 омотач је суперпа-рамагнетан са температуром блокирања ~ 25 К. Уградња никла и цинка у феритну структуру омотача није било могуће на нижим pH вредностима. Међутим, показано је и да је на вишим pH вредностима велика брзина формирања феритних честица и њихова самоагрегација доминира над конкурентном реакцијом депозиције феритних честица на функционализована силика језгра. У циљу спречавања самоагрегације, депо-зиција ZnFe2O4 и NiFe2O4 наночестица на PDDA-функционализованим силика језгрима је обављена у присуству цитратне киселине на pH &gt; 7. Цитратна киселина пасивизира површину феритних наночестица и на тај начин инхибира самоагрегацију, омогућавајући депозицију ових честица на површину PDDA-функционализованих силика језгара.<br />У овој тези су синтетисане честице са двослојним омотачем, који се састоје од унутрашњег Fe3O4 и спољашњег силика слоја. На PDDA-функцио-нализованим SiO2-језгро/Fe3O4-омотач честицама, обављена је депозиција силика наночестица чиме је формиран спољни мезопорозни силика омотач. Добијене су композитне честице са два различита функционална слоја: унутрашњим који омогућава магнетну сепарацију честице из реакционог медијума и спољним који омогућава имобили-зацију активних материја. Добијени резултати су указали да се ове нанокомпозитне честице могу употребити у биоинжењерству и областима хертерогене катализе.</p> / <p>U ovoj doktorskoj disertaciji prikazani su rezultati sinteza i karakterizacija nano-kompozitnih čestica sa jezgro-omotač strukturom. Nanokompozitne čestice su sintetisane u tečnoj fazi, elektrostatičkom depozicijom in situ sintetisanih SiO2, Fe3O4, ZnFe2O4 ili NiFe2O4 nanočestica na površinu monodisperznih i sferičnih silika jezgro čestica (srednjeg prečnika ~ 0,4 &mu;m). Silika jezgro čestice su sintetisane hidrolizom i kondezacijom TEOS-a u baznoj sredini. Silika nanočestice su dobijene neutralizacijom jako baznog vodenog rastvora natrijum silikata, dok su feritne nanočestice sintetisane koprecipitacijom iz vodenog rastvora odgovarajućih nitratnih soli. Da bi se omogućila elektrostatička depozicija nano-čestica, silika jezgra su funkcionalizovana sa 3-aminopropiltrietoksisilan (APTES) ili poli(dialildimetilamonijum hlorid) (PDDA) čime se povećava izoelektrična tačka silika čestica. Na ovaj način su oko silika jezgro čestica sintetisani jednoslojni omotači na bazi SiO2, Fe3O4, ZnFe2O4 ili NiFe2O4.<br />Rezultati su potvrdili da se uniforman silika sloj može deponovati na funkcijonalizovanim silika česticama. Formiran silika omotač je imao debljinu ~ 30 nm, mezoporoznu strukturu sa srednjom veličinom pora od ~ 8 nm i značajnom ukupnom zapreminom pora. Zbog toga su tako dobijene silika jezgro-omotač nanostrukture pogodne za imobilizaciju enzima ali i nekih drugih aktivnih materija. Takođe je potvrđeno da je optimalna pH vrednost za sintezu homogenog Fe3O4 omotača na nefunkcionalizovanim silika jezgrima ~ 5,4. Dobijeni Fe3O4 omotač je superpa-ramagnetan sa temperaturom blokiranja ~ 25 K. Ugradnja nikla i cinka u feritnu strukturu omotača nije bilo moguće na nižim pH vrednostima. Međutim, pokazano je i da je na višim pH vrednostima velika brzina formiranja feritnih čestica i njihova samoagregacija dominira nad konkurentnom reakcijom depozicije feritnih čestica na funkcionalizovana silika jezgra. U cilju sprečavanja samoagregacije, depo-zicija ZnFe2O4 i NiFe2O4 nanočestica na PDDA-funkcionalizovanim silika jezgrima je obavljena u prisustvu citratne kiseline na pH &gt; 7. Citratna kiselina pasivizira površinu feritnih nanočestica i na taj način inhibira samoagregaciju, omogućavajući depoziciju ovih čestica na površinu PDDA-funkcionalizovanih silika jezgara.<br />U ovoj tezi su sintetisane čestice sa dvoslojnim omotačem, koji se sastoje od unutrašnjeg Fe3O4 i spoljašnjeg silika sloja. Na PDDA-funkcio-nalizovanim SiO2-jezgro/Fe3O4-omotač česticama, obavljena je depozicija silika nanočestica čime je formiran spoljni mezoporozni silika omotač. Dobijene su kompozitne čestice sa dva različita funkcionalna sloja: unutrašnjim koji omogućava magnetnu separaciju čestice iz reakcionog medijuma i spoljnim koji omogućava imobili-zaciju aktivnih materija. Dobijeni rezultati su ukazali da se ove nanokompozitne čestice mogu upotrebiti u bioinženjerstvu i oblastima herterogene katalize.</p> / <p>This thesis presents the results of the synthesis and characterization of the nanocomposite particles with core-shell structure. Nanocomposite particles were synthesized by liquid-phase technique through electrostatic deposition of in situ synthesized SiO2, Fe3O4, ZnFe2O4 or NiFe2O4 nanoparticles on the surface of spherical and monodispersed silica core particles (average size ~ 0.4 &mu;m). Silica core particles were prepared by hydrolysis and condensation of tetraethylorthosilicate in basic conditions. Silica nanoparticles were obtained by neutralization of highly basic sodium silicate solution while ferrite nanoparticles were obtained by coprecipitation from solutions of the corresponding nitrate salts. To improve electrostatic assembling of nanoparticles on the surface of silica core particles, the latter were functionalized with 3-amino-propyltriethoxysilane (APTES) or poly(diallyldimethylammonium chloride) (PDDA) which increases the isoelectric point of the silica core particles. In this way SiO2, Fe3O4 , ZnFe2O4 or NiFe2O4 shells were synthesized around the silica core particles, respectively.<br />The results confirmed that uniform silica layer can be deposited at the functionalized silica core particles. The formed silica layer had thickness of ~ 30 nm, mesoporous structure with average pore size of ~ 8 nm and high total pore volume. This makes silica shell suitable for immobilization of enzymes. Optimal conditions for synthesis of homogenous and thin Fe3O4 shell around non-functionalized silica core particles were found at pH ~ 5.4. Obtained Fe3O4 shell was superparamagnetic with blocking temperature at ~25 К. Incorporation of nickel and zinc into ferrite structure was impossible at lower pH values. However at higher pH the formation rate of Ni- and Zn-ferrite particles becomes very fast and the self-aggregation dominates the competing formation of the ferrite shell around functionalized silica cores. Because of that the self-aggregation was prevented by surface modify-cation of ZnFe2O4 and NiFe2O4 nanoparticles with citric acid before their deposition on the PDDA-functionalized silica core and homogenous and continuous shells were finally obtained at pH &gt; 7.<br />In addition, bilayered shell composed of internal Fe3O4 layer and external SiO2 layer, were also prepared. Silica nanoparticles were deposited on the surface of PDDA-functionalized SiO2-core/Fe3O4-shell particles which induced formation of external mesoporous silica shell. Obtained composite particles had two different functional layers: internal which would allow its magnetic separation from reaction mixture and external which could allow imobilization of various molecules and nanoparticles such as enzymes inside its pores. Based on these results, obtained nanoparticles could be used in bioengineering and heterogenous catalysis.</p>

<p>Cilj istraživanja u okviru ove doktorske disertacije bio je da se ispita uticaj ekstrudiranja na funkcionalno hranivo, čija bi osnovna uloga bila povećanje sadržaja omega-masnih kiselina u ishrani životinja, a naročito &alpha;-linolenske kiseline (ALA). Za proizvodnju funkcionalnog hraniva upotrebljeni su laneno seme, kao nosilac funkcionalnih osobina i suncokretova sačma, koja je dodata da se spreči isticanje lanenog ulja tokom ekstrudiranja. Nezavisni parametri ekstrudiranja čiji je uticaj ispitivan bili su: brzina obrtanja puža ekstrudera (240, 360 i 590 o/min), kapacitet punjenja (16, 24 i 32 kg/h), vlaga polaznog materijala (7, 11,5 i 16 %) i ukupna povr&scaron;ina otvora na matrici (19,8, 39,6 i 59,4 mm2). Zavisno promenljive karakteristike (odzivi) dobijenog hraniva koje su praćene bile su: sadržaj HCN u hranivu, sadržaj ALA, sadržaj slobodnih masnih kiselina (SMK) i potro&scaron;nja energije.<br />Za modelovanje zavisnosti karakteristika hraniva od procesnih parametara ekstrudiranja primenjena je metoda odzivne povr&scaron;ine (RSM), a kori&scaron;ćen je Box-Behnken-ov dizajn (BBD) za četiri faktora na tri nivoa. Za svaki od pomenutih odziva definisan je polinom drugog reda i određeni su koeficijenti polinoma, a analizom varijanse potvrđena je tačnost ovih modela. Formirani modeli upotrebljeni su za optimizaciju procesa ekstrudiranja, sa ciljem da se postigne &scaron;to veća redukcija<br />cijanogenih glikozida u hranivu, uz &scaron;to vi&scaron;i sadržaj ALA i &scaron;to niže SMK i potro&scaron;nju energije. Da bi se zadovoljili svi postavljeni uslovi optimizacije, proces ekstrudiranja bilo je potrebno izvoditi pod sledećim uslovima: brzina obrtanja puža &ndash; 417,41 o/min, kapacitet punjenja &ndash; 32 kg/h, vlaga materijala &ndash; 13,39 % i ukupna povr&scaron;ina otvora na<br />matrici &ndash; 19,80 mm2.<br />Ovako dobijeno hranivo pokazalo je nizak sadržaj HCN, čiji je stepen redukcije u odnosu na početnu vrednost iznosio 76,20 %. Sa druge strane, sadržaj ALA smanjen je za svega 0,69 %, &scaron;to ukazuje da ekstrudiranje nije negativno uticalo na masnokiselinski sastav proizvedenog ko-ekstrudata.<br />Nakon proizvodnje ko-ekstrudata, pristupilo se ispitivanju njegove održivosti. U tu svrhu uzorci su skladi&scaron;teni u klima komori sa mogućno&scaron;ću kontrolisanog pode&scaron;avanja temperature, relativne vlažnosti i cirkulacije vazduha. Za praćenje održivosti proizvoda primenjen je modifikovan Schaal-oven test. Modifikacija metode sastojala se u pode&scaron;avanju relativne vlažnosti vazduha na konstantnu vrednost od 40 %, &scaron;to klasičnom metodom nije propisano. Ova vlažnost vazduha odabrana je na osnovu relativne vlažnosti koja je u trenutku eksperimenta izmerena u prostoriji. U cilju ispitivanja uticaja antioksidanasa na oksidativnu stabilnost proizvoda, uzorcima su dodavani komercijalni preparati karvakrol (200 mg/100 g koekstrudata), vitamin E (135 mg/100 g ko-ekstrudata) i sme&scaron;a ova dva antioksidansa. Za praćenje oksidativnih i hemijskih promena ko-ekstrudata, određivani su peroksidni broj (Pbr), SMK uzorcima su dodavani komercijalni preparati karvakrol (200 mg/100 g koekstrudata), vitamin E (135 mg/100 g i masnokiselinski sastav. Takođe su ispitane mikrobiolo&scaron;ke promene u koekstrudatu. Najsnažnije antioksidativno dejstvo u ovom eksperimentu imao je vitamin E, dok sme&scaron;a vitamina E i karvakrola nije pokazala sinergističko dejstvo. Sastav masnih kiselina se u toku skladi&scaron;tenja nije statistički značajno promenio. Sa druge strane, ekstrudiranje je pokazalo statistički značajan uticaj (p = 0,032) na redukciju ukupnog broja mikroorganizama u hranivu, a najniža vrednost ukupnog broja mikroorganizama (600 cfu/g) zabeležena je u uzorku sa dodatim karvakrolom.</p> / <p>The goal of the research in this thesis was to examine the effect of extrusion on functional feed compound, whose main role was to increase the content of omega-fatty acids in animal nutrition, especially &alpha;-linolenic acid (ALA). Flax seed, as the holder of the functional properties, and sunflower meal, as an adsorbent of linseed oil during extrusion, were used for the production of functional feed compound. Independent extrusion parameters studied in the experiment were: extruder screw speed (240, 360 and 590 rpm), loading capacity (16, 24 and 32 kg/h), the moisture content of the starting material (7, 11.5 and 16 % ) and the total die opening&rsquo;s area (19.8, 39.6 and 59.4 mm2). Dependent variables (responses) of the produced feed compound were: HCN content in coextrudate, ALA content, the content of free fatty acids (FFA) and energy consumption.<br />Response surface methodology (RSM) was applied in order to model mathematical dependence between co-extrudate characteristics and the independent process parameters. The experiments were designed according to Box-Behnken&#39;s design (BBD) with four factors, each at three levels. Second-order polynomial equation was<br />developed for each of these responses, and polynomial coefficients were determined. Accuracy of each model was confirmed by analysis of variance (ANOVA). Formed polynomial models were used to optimize the extrusion process, with the aim of achieving high reduction of cyanogenic glycosides in feed compound, the highest content of ALA, as well as low FFA and low energy consumption. Obtained optimal conditions were: extruder srew speed - 417.41 rpm, loading capacity - 32 kg/h, moisture content of starting material - 13.39 % and the total die openings&rsquo; area<br />- 19.80 mm2.<br />Functional feed compound produced under these conditions showed a low concentration of HCN, and the degree of HCN reduction was 76.20 % compared to the starting HCN content. On the other hand, the ALA content was reduced by only 0.69 %, indicating that extrusion did not significantly affect the fatty acid composition of the produced co-extrudate.<br />The next step was investigation of stability of produced co-extrudate. For this purpose, the samples were stored in a climate chamber capable of setting temperature, relative humidity and air circulation. Modified Schaal-oven test was used to monitor the stability of the product. Modification of the method consisted in adjusting the relative humidity at a constant value of 40 %, which is not required by a classical method. Such a high humidity was selected based on the relative humidity at a constant value of 40 %, which is not required by a classical method. Such a high humidity was selected based on the relative humidity of air, which was measured in the experimental room at the moment. Commercial carvacrol (200 mg/100g of co-extrudate), vitamin E (135 mg/100 g of co-extrudate) and a mixture of these<br />two antioxidants were added to the samples in order to investigate the influence of antioxidants on the oxidative stability of the product. Peroxide value (PV), FFA and fatty acid composition were determined in order to monitor oxidative and chemical changes in co-extrudate. Microbial changes were also examined in the functional feed compound. The most powerful antioxidant effect in this experiment had vitamin E, and a mixture of vitamin E and carvacrol did not show a synergistic effect. The fatty acid compostion during storage was not significantly changed in any sample. On the other hand, extrusion process showed a statistically significant effect (p = 0.032) on the reduction of total number of microorganisms in feed, and the lowest value of the total number of microorganisms (600 cfu/g) was observed in the sample with added<br />carvacrol.</p>

<p style="text-align: justify;">Ispitivan je sadrţaj toksiĉnih elemenata (Pb, Cd, As i Hg) kao i esencijalnih elemenata (Cu, Zn, Fe i Mn) u odabranim uzorcima poljoprivrednog zemlji&scaron;ta na razliĉitim udaljenostima od frekventnih saobraćajnica, kao i u celom zrnu p&scaron;enice i njegovim delovima (mekinje i bra&scaron;no), primenom ICP masene spektrometrije. Analiza korelacije, ANOVA, analiza glavnih komponenata (PCA) i post-hoc Tukey&#39;s HSD testovi su upotrebljeni za statistiĉku evaluaciju dobijenih rezultata. U okviru svakog primenjenog eksperimentalnog metoda, sadrţaja toksiĉnih elemenata u uzorcima zrna p&scaron;enice je Tukey testovima pokazao znaĉajnu razliku na nivou znaĉaja p&lt;0.05, 95% granice pouzdanosti.&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ANOVA i F-test za Mn (F=3000.6), su pokazali da je kod njega varijansa veća u odnosu na ostale elemente, &scaron;to znaĉi da se uzorci na razliĉitim lokacijama znaĉajno razlikuju zbog uticaja tog Mn. Za Fe i Zn F je1609.0 i 2773.4 respektivno &scaron;to znaĉi da su analize za Mn, Fe i Zn taĉnije u poreĊenju sa drugim upotrebljenim analizama. Prema ANOVI i F-testu na p&lt;0.01 nivou, 95% granice pouzdanosti uraĊenom za sadrţaj toksiĉnih elemenata u zemlji&scaron;tu, utvrĊeno je da je Mn (F=78640.0) uticajnija varijabla za konaĉni rezultat, a zatim slede Zn (F=2885.4) ili Fe (F=2699.02).<br />Pirsonovom tabelom je utvrĊena korelacije hemijskih elemenata u zrnu p&scaron;enice u odnosu na sardţaj ispitivanih elemenata u zemlji&scaron;tu. UtvrĊeno je da sadrţaj Cd dobro koreli&scaron;e izmeĊu p&scaron;enice i zemlji&scaron;ta (0,494), &scaron;to ukazuje da se taj element unosi u p&scaron;enicu iz zemlji&scaron;ta. Pekarski proizvodi se konzumiraju svakodnevno i zbog toga su pogodni za korigovanje nedostataka vlakana u hrani. Kao sirovina bogata prehrambenim vlaknima u proizvodnji hleba i peciva koriste se p&scaron;eniĉne mekinje, pa je neophodno praćenje sadrţaja toksiĉnih elemenata kako u bra&scaron;nu tako i u mekinjama. To će omogućiti proizvodnju bezbedne hrane i spreĉiti da ovi elementi ulaze u lanac ishrane.</p> / <p>The research of content of toxic elements (Pb, Cd, As and Hg) and essential elements (Zn, Cu, Fe and Mn) in selected samples of roadside soils, as well as in the wheat grain, wheat flour and bran using Inductively Coupled Plasma Mass Spectrometry. Correlation analysis, ANOVA, Principal Component Analysis (PCA) and post-hoc Tukey&#39;s HSD tests were applied for statistical evaluation of obtained results.<br />The Tukey‟s tests have been evaluated for comparison between toxic elements content in wheat kernel samples within each of used experimental methods, and statistically significant difference has been found in almost all samples, at significance level, p&lt;0.05, 95% confidence limit. ANOVA test and F-test for Mn content (F=3000.6) showed a more influential varianble in comparison with other elements, meaning that samples taken in different locations differ significantly due to Mn influence. As for Fe and Zn, F is 1609.0 and 2773.4 respectively. These findings confirm that Mn, Fe and Zn assays are more accurate compared to other applied assays. According to ANOVA and F-test at p&lt;0.01 level, 95% confidence limit used for toxic elements content analysis in soil, it was found that Mn content (F=78640.0) was a more influential variable for final result, followed by Zn (F=2885.4) or Fe (F=2699.02). Pearson table shows correlation between chemical elements in wheat grain compared to the content of analyzed elements in soil. It was found that there is correlation between Cd content in wheat and soil (0,494), which indicates that this element entered the wheat via the soil. The results show that the concentrations of tested elements are the highest n peripheral parts of the grain, i.e. in the bran, which is especially significant for production of bread with added bran. Pastry products are consumed on a daily basis, which makes them suitable to compensate for fiber deficiency in food. Being rich in dietary fibers, wheat bran is used in bread and pastry production; therefore, monitoring of the content of toxic elements in both flour and bran is required to ensure production of safe and healthy food and to prevent them from entering the food chain.</p>

<p>Postojanje ugljeničnih nanocevi (UNC), kao jedne od brojnih alotropskih modifikacija ugljenika, zabeleženo je jo&scaron; pre vi&scaron;e od pola veka. Međutim, do prave eksplozije<br />interesovanja za ovu vrstu nanomaterijala je do&scaron;lo tek 1991. godine kada ih je &quot;ponovo&quot; otkrio japanski naučnik S. Iijima. Od tada, zbog svojih izuzetnih fizičko-hemijskih osobina, UNC počinju da privlače pažnju naučne javnosti i spajaju istraživače iz različitih oblasti sa zajedničkim imeniteljem - nanotehnologija. Otkriće UNC je u znatnoj meri omogućilo razvoj visoke tehnologije u oblastima kao &scaron;to su elektronika, optika, kompozitni materijali, kataliza, za&scaron;tita životne sredine, itd. Danas, primena nanocevi sve vi&scaron;e doprinosi lak&scaron;oj implementaciji principa održivog razvoja u pomenute oblasti. Kataliza je polje od dvostrukog interesa, jer je jedan od načina dobijanja UNC upravo katalitički, a osim toga i same cevi su interesantne kao nosač novog katalizatora.<br />Istraživanje čiji su rezultati prikazani u okviru ove doktorske disertacije je obuhvatilo vi&scaron;e oblasti proučavanja UNC, počev&scaron;i od razvoja metode za njihovu sintezu, preko preči&scaron;ćavanja i funkcionalizacije finalnog proizvoda, pa do primene nanocevi u dva procesa od značaja za oblast za&scaron;tite životne sredine.</p><p>Razvoj katalitičke metode sinteze UNC započet je primenom vertikalnog cevnog kvarcnog reaktora, iz CO i CH4 kao izvora ugljenika, pri čemu su u reakciji testirani<br />monometalni katalizatori na bazi Fe, Co i Ni na Al2O3 kao nosaču (I serija katalizatora). Rezultati ovih preliminarnih eksperimenata su pokazali malu aktivnost I serije monometalnih katalizatora, &scaron;to se može pripisati, kako neadekvatnoj hidrodinamici reaktora i lo&scaron;e odabranim reakcionim parametrima, tako i neodgovarajućoj veličini katalitičkih čestica i načina njihovog pakovanja u vertikalnom<br />reaktoru. Shodno tome, u cilju postizanja boljeg prinosa nanocevi, dalji eksperimenti sinteze izvedeni su u horizontalnom reaktoru u struji C2H4 i u prisustvu II serije<br />monometalnih katalizatora sa Al2O3 i SiO2 kao nosačima, koji se u odnosu na I seriju razlikuju po udelu aktivne faze i veličini čestica katalizatora (pra&scaron;kast oblik). Katalizatori II serije su pokazali zadovoljavajuću aktivnost u reakciji sinteze UNC, a rezultati karakterizacije dobijenih uzoraka nanocevi ukazuju na različit uticaj nosača katalizatora na morfologiju sintetisanih nanocevi. Shodno ostvarenom prinosu ugljenika, a u cilju optimizacije reakcionih parametara, katalizator na bazi Fe sa SiO2 kao nosačem je odabran kao reprezentativan za ispitivanje uticaja vremena trajanja sinteze UNC, kao i zapreminskog udela C2H4 u sme&scaron;i sa azotom, na prinos<br />nanocevi i selektivnost procesa.&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; Optimizacija reakcionih uslova je u daljoj fazi rada dovela do uvođenja bimetalnih katalizatora sa istim tradicionalnim nosačima &ndash; Al2O3 i SiO2. Najveći prinos ugljenika ostvaren je na katalizatorima sa Fe i Co kao aktivnom fazom, bez obzira na vrstu nosača. UNC sintetisane na pomenutim katalizatorima su karakterisane u cilju<br />ispitivanja uticaja primenjenih nosača na njihove fizičkohemijske osobine, pa je shodno tome i predložen vr&scaron;ni mehanizam njihovog rasta. Rezultati ispitivanja kvaliteta sintetisanih UNC su ukazali da primena SiO2, kao nosača katalizatora, za razliku od Al2O3, favorizuje rast UNC boljeg povr&scaron;inskog i ukupnog kvaliteta. S obzirom na raznolikost mogućnosti primene UNC, istraživanja u tom smeru zahtevaju čiste UNC, pa su shodno tome proizvodi sinteze preči&scaron;ćeni metodom tečne oksidacije. Rezultati fizičko-hemijske karakterizacije preči&scaron;ćenih UNC su ukazali na efikasnost primenjene metode sa aspekta uklanjanja prisutnog katalizatora, ali i na njen različit uticaj na strukturu, odnosno kvalitet preči&scaron;ćenih uzoraka. Kao posledica promena unutar strukture UNC, kao i različitog stepena njihove funkcionalizacije, ukupni kvalitet preči&scaron;ćenih nanocevi je, u zavisnosti od primenjenog nosača katalizatora, promenjen u odnosu na odgovarajuće nepreči&scaron;ćene uzorke.<br />Poslednjih godina se posebna pažnja poklanja nanomaterijalima koji se mogu primeniti za uklanjanje različitih polutanata iz životne sredine, kako u funkciji adsorbenata, tako i u funkciji katalizatora. U okviru ove doktorske disertacije obuhvaćena je primena UNC kao adsorbenta za uklanjanje insekticida tiametoksama iz vode, kao i njihova primena kao nosača katalizatora u reakciji<br />denitracije vode. Rezultati eksperimenata adsorpcije su pokazali da UNC, prethodno tretirane u ccHNO3, predstavljaju dobar adsorbent za uklanjanje insekticida tiametoksama iz vodenog rastvora. Odabir procesnih parametara za proučavanje kinetike adsorpcije, adsorpcione ravnoteže, kao i termodinamike procesa izvr&scaron;en je primenom frakcionog faktorskog dizajna na dva nivoa, 5 1 V 2 , a dobijeni rezultati su ukazali da je pomenuti proces adsorpcije spontan i kontrolisan uglavnom unutra&scaron;njom difuzijom molekula insekticida u mezopore uzorka UNC. Performanse katalizatora sa UNC kao nosačem su testirane u reakciji katalitičke denitracije, pri čemu su dobijeni rezultati pokazali da se novoformirani katalizator karakteri&scaron;e zadovoljavajućom disperzno&scaron;ću sa udelombimetalnih Pd-Cu nanočestica koje omogućavaju 60% konverzije nitratnog jona.</p> / <p style="text-align: justify;">The existance of carbon nanotubes (CNTs), as one of the carbon allotropes, was noted over half century ago. However, the true interest for these nanomaterials appeared at 1991, when they were &quot;redescovered&quot; by Japanese scientist S. Iijima. Since then, due to their unique physico-chemical properties, CNTs begin to attract attention of the scientific community and to gather researchers from different areas within the common field of interest &ndash; nanotechnology. The CNTs discovery substantially enabled the high technology development in the fields such as electronics, optics, composite materials, catalysis, environmental protection, etc. Nowdays, the application of nanotubes is increasingly contributing to easier implementation of sustainable development principles in the above mentioned areas. Catalysis is the field of double interest &ndash; one of the CNTs synthesis method is catalytical, and the nanotubes can also be used as the support of the new catalyst.<br />The research, which results are shown within this PhD Thesis, includes few different CNTs research fields, starting from the synthesis method development, over the purification and functionalization of the final product, to the application of<br />nanotubes in two processes of significance for the field of environmental protection.<br />The development of the CNTs catalytic synthesis method was started by the use of vertical quartz tube reactor, in the flow of CO and CH4 as the carbon source, and in the presence of monometallic catalysts based on Fe, Co and Ni at Al2O3 as the support (the first series of catalysts). The results of these preliminary experiments have shown the low activity of these monometallic catalysts, which can be attributed to the inadequate reactor hydrodynamics and selected reaction parameters, as well as the inadequate size of the catalytic particles and the type of their packing in the vertical reactor. Consequently, in order to achieve the higher nanotubes yield, further synthesis experiments were carried out in a horizontal reactor in the flow of C2H4 as the carbon source, and in the presence of the second series of monometallic catalysts with Al2O3 and SiO2 as the supports. The catalysts of the second series have shown satisfactory activity in the CNTs synthesis reaction, and the results of the obtained samples characterization idicate a different influence of the catalyst support on the synthesized CNTs morphology. In order to optimize the reaction parameters, Fe/SiO2 catalyst was chosen as a representative to examine the effect of the CNTs synthesis duration, as well as the volume percentage of C2H4 in the mixture with nitrogen to the CNTs yield and process selectivity. In a further phase of work, the optimization of thereaction parameters led to the introduction of the bimetallic catalysts with the same traditional supports, Al2O3 and SiO2. The highest carbon yield was achieved over Fe, Co based catalysts, regardless of the type of the catalyst support. CNTs synthesized over the above mentioned catalysts were characterized in order to study the effect of the used supports on their physico-chemical properties, and consequently the CNTs tip growth mechanism was proposed. The results of quality examination of the synthesized CNTs showed that the use of SiO2, as a catalyst support, unlike Al2O3, favors the growth of nanotubes of better surface and overall crystalline quality. In view of the diversity of possible CNTs applications, investigation in that direction requires purified CNTs and accordingly the final CNTs products were purified by liquid oxidation method. The results of physico-chemical characterization of the purified CNTs showed that the applied purification method was effective in terms of removing the present catalyst, but on the other hand it had different influence on the structure and quality of the purified samples. As a consequence of CNTs structural changes, as well as their different degree of functionalization, the overall crystalline quality of the purified nanotubes, originating from different catalyst supports, was changed in comparison to the corresponding unpurified samples. Over the past few years, special attention was focused on<br />nanomaterials that can be applied as adsorbents or catalysts for the removal of various pollutants from the environment. This PhD Thesis considers the use of CNTs, as adsorbent, for the removal of insecticide thiamethoxam from water, as well as their use as catalyst support for water denitration reaction. The results of adsorption experiments have shown that the CNTs, pretreated in ccHNO3, represent a good adsorbent for the removal of thiamethoxam from the aqueous solutions. The<br />selection of the process parameters in order to study the adsorption kinetics and equilibrium, as well as the thermodynamics of the process, was conducted using the<br />fractional factorial design at two levels, 5 1 V 2 . The obtained results showed that the adsorption process is spontaneous and controlled mainly by an internal diffusion of molecules of insecticide in the mesopores of CNTs. The performance of the catalyst with the CNTs as the support were tested in catalytic water denitration reaction, whereby the results showed that the newly formed catalyst is characterized by satisfactory dispersion of Pd-Cu bimetallic nanoparticles which enable the 60% conversion of nitrate ions.</p>

<p>Istraživanja u okviru disertacije usmerena su na razvoj vakuumskog postupka su&scaron;enja voća. Konstruisan je prototip laboratorijske vakuumske su&scaron;are i optimizovan proces su&scaron;enja vi&scaron;anja i borovnica. U cilju optimizacije procesa su&scaron;enja ispitan je uticaj nezavisno promenljivih procesa, temperature i pritiska, na parametre kvaliteta osu&scaron;enog voća (aktivnost vode, sadržaj ukupnih fenola, ukupnih monomernih antocijana i vitamina C, antioksidativnu aktivnost, promenu boje, teksturu i sposobnost rehidratacije). Proces su&scaron;enja optimizovan je kori&scaron;ćenjem metode odzivnih povr&scaron;ina (engl. Response Surface Methodology, RSM).<br />Rezultati istraživanja pokazuju da tehnika su&scaron;enja voća u vakuumu daje odlične rezultate u pogledu očuvanja visokovrednih komponenata voća i ima perspektivu za &scaron;iru primenu u zanatskim i poluindustrijskim postrojenjima.</p> / <p>Research in the framework of the thesis focuses on the development of fruit vacuum-drying process. Laboratory vacuum dryer prototype was constructed. Cherries and blueberries vacuum drying process was optimized. In order to optimize the drying process, the influence of independent variables of the process (temperature and pressure) on the quality parameters of dried fruit (water activity, total phenol content, total monomeric anthocyanins and vitamin C, antioxidant activity, colour change, texture, and rehydration capability) was investigated. The drying process was optimized using Response Surface Methodology (RSM).<br />There is the possibility of application of the results in plants at semi-industrial and industrial level.</p>

<p>U okviru disertacije analiziran je uticaj genetskih, ekolo&scaron;kih i mikroklimatskih faktora<br />tokom tri proizvodne godine na sastav glutena i tehnolo&scaron;ki kvalitet 16 sorti p&scaron;enica<br />koje su godinama zastupljene u sortimentu Srbije, a koje su bile proizvedene na istom<br />lokalitetu. Da bi se ispitao tehnolo&scaron;ki kvalitet i sastav glutena, upotrebljene su, kako<br />tradicionalne, tako i savremene metode; urađena je elektroforetska analiza gluteninskih<br />i glijadinskih podjedinica, sadržaj slobodnih &ndash;SH i &ndash;NH grupa, probno pečenje i<br />objektivno je ocenjen kvalitet dobijenog hleba u cilju formiranja baze podataka za<br />statističku analizu. Zbog obimnosti rezutata i činjenice da su pokazatelji određeni u<br />različitom broju ponavljanja uslovljenim potrebnom količinom uzorka, uobičajenim<br />brojem ponavljanja, reproduktivno&scaron;ću metoda, urađena je PCA analiza na osnovu koje<br />je izvr&scaron;en odabir najvažnijih pokazatelja. Dodatno, primenjena je Analiza značajnosti u<br />odnosnu na: klimatske faktore koji su uslovljeni proizvodnom godinom, genetske<br />faktore koji su uslovljeni genetskom slično&scaron;ću ispitivanog sortimenta p&scaron;enice, kao i<br />ekolo&scaron;kim faktorima koji se ogledaju preko različitog nivoa neodvojivih primesa koji<br />su definisani frekvencionom analizom. Cilljevi istraživanja omogućili su da se:<br />&ndash;utvrdi kako i na koji način mikroklimatski uslovi koji su vladali u tri proizvodne<br />godine, a pogotovo ki&scaron;no i nestabilno vreme u periodu od cvetanja p&scaron;enice pa sve do<br />pune zrelosti, utiču na sastav glutena i tehnolo&scaron;ki kvalitet ispitivanih sorti p&scaron;enice,<br />&ndash;utvrdi kako i na koji način ekolo&scaron;ki faktori, definisani prisutvom tri različita nivoa<br />proklijalih, steničavih, fuzarioznih i tamnokličnih zrna, utiču na sastav glutena i<br />tehnolo&scaron;ki kvalitet ispitivanih sorti p&scaron;enice<br />&ndash;utvrdi kako genetski faktori, definisani preko razlika u HMW&ndash;GS koje ispitivane<br />sorte sadrže, odnosno ne sadrže na Glu A1, Glu D1 lokusu i identičnom HMW&ndash;GS<br />sastavu, utiču na sastav glutena i tehnolo&scaron;ki kvalitet ispitivanih sorti p&scaron;enice.<br />Dobijeni rezultati predstavljaju jednu kompleksnu analizu koja je obuhvatila veliku<br />bazu ispitivanih pokazatelja i bliže odredila kako pojedinačni genetski, mikroklimatski<br />i ekolo&scaron;ki faktori utiču na sastav glutena i tehnolo&scaron;ki kvalitet p&scaron;enice.</p> / <p>In the Ph. D. Thesis was analyzed the impact of genetic, environmental and<br />microclimatic factors that prevailed during the three production years on gluten<br />composition and technological quality of 16 wheat varieties that are present in the<br />assortment of Serbia. Also, all wheat varieties were produced at the same location. The<br />traditional and sofisticated methods are used, electrophoretic analysis of glutenin and<br />gliadin subunits was performed, the content of free-SH and-NH groups are determined,<br />baking test and objective quality of the obtained bread are evaluated to examine the<br />technological quality of wheat and composition of gluten. The gained results are used<br />to established a database for statistical analysis. Due to the numerous data and the fact<br />that the properties measured in different number of repetitions which are qualifed by<br />sample amount, the usual number of repetitions, reproductivity method PCA was<br />performed toward the selection of the most important properties. After that was done<br />ANOVA in the respective to climatic factors that charatcterized the production year,<br />the genetic factors that are caused by genetic similarity of the exmined cultivars of<br />wheat and environmental factors that are reflected through the different levels of<br />inseparable impurities, which are defined by frekvency analysis. Specific objectives of<br />the study enable to:<br />&ndash;determine how microclimatic conditions that prevailed in the three production<br />years, especially the rainy and instable weather that prevailed from wheat flowering<br />until full maturity of wheat kernel influence on the composition of gluten and wheat<br />processing quality tested,<br />&ndash;determine how environmental factors that are defined by the presence of three<br />different levels of germinate kernels, kernels damaged by wheat bug, kernels infested<br />by Fussarium molds and kernels infested by Alternaria alternata molds affect on the<br />composition of gluten and technological quality of wheat cultivar and<br />&ndash;determine how genetic factors which are defined through differences in HMW-GS<br />on the Glu A1 and Glu D1 locus that cultivars contain or do not contain and identical<br />HMW-GS composition which examined cultivars possess affect on the gluten<br />composition and technological quality of tested wheat varieties.</p><p>The achieved results represent a complex analysis of the impact of various factors on<br />the composition of gluten and technological quality of wheat, which included a<br />enormous database of properites and closely determine how individual microclimatic,<br />genetic and environmental factors influence on the gluten composition and<br />technological quality of wheat.</p>

<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>U ovom radu je obrađen postupak spontane fermentacije tradicionalnog proizvoda, fermentisanog kupusa u glavicama. U prvom delu urađena je karakterizacija domaće tradicionalne populacije Futo&scaron;ki u odnosu na uvozni hibrid Bravo. Na osnovu PCA analize i analize standardnih ocena SS fizičkih, hemijskih i senzorskih paramentara odabrani su uzorci povoljni za proces fermentacije. Proces fermentacje je obavljen na temperaturama 16-18^oC, 18-20^oC i 20-20^oC, i sa razliĉitim koncentracijama soli od 1, 1,5 i 2 %. Analizirani su fizički, hemijski, mikrobiolo&scaron;ki parametri i senzorske osobine kupusa tokom fermentacije. Metodom odzivne povr&scaron;ine sa analizom varijanse (ANOVA) modela odziva za svaki od analiziranih karakteristika i obja&scaron;njeno je koji od parametara procesa temperatura, koncentracija soli i vreme trajanja procesa ima statistiĉki značajan uticaj na formiranje matematiĉkih modela odziva, prikazanih u obliku polinoma drugog reda (SOP). Zaključeno je da Futo&scaron;ki kupus postiţe brţe zavr&scaron;nu taĉku fermentacije u odnosu na hibrid Bravo. Drugi kori&scaron;ćeni tehnolo&scaron;ki postupak u ovom radu je osmotska dehidratacija. Kupus je dehidriran u tri osmotska rastvora (vodeni rastvor natrijum hlorida i saharoze, kombinacija vodenog rastvora natrijum hlorida i saharoze i melase i melasa &scaron;ećerne repe) različitih koncentracija, na tri temperature (20&deg;C, 35&deg;C i 50&deg;C) i pri tri vremena trajanja procesa (1, 3 i 5h). Mereni i računati odzivi procesa osmotske dehidratacije bili su: sadržaj suve materije, gubitak vode, prirast suve materije i indeks efiksanosti procesa. Rezultati ispitivanja pokazuju da povećanje tehnolo&scaron;kih parametara temperature i vremena procesa, kao i koncentracije osmotskih rastvora dovode do intenziviranja prenosa mase u procesu i povećanja vrednosti odzivnih parametara procesa. Takođe, zaključeno je da tokom osmotske dehidratacije u melasi &scaron;ećerne repe dolazi do obogaćivanja kupusa nutritivnim komponentama, naročito kalijumom. Treći segment ovog rada je analiza održivosti osmotski dehidriranog kupusa pakovanog u modiifikovanoj atmosferi dve različite sme&scaron;e gasova N₂ i CO₂. Analizom hemijskih, mikrobiolo&scaron;kih i senzorskih svojstava zaključeno je da ovaj osmotski dehidriran kupus pakovan na navedeni način ima održivost od 90 dana.</p> / <p>This paper describes the process of spontaneous fermentation of traditional product, fermented whole cabbage. In the first part characterization of the local traditional type Futo&scaron;ki cabbage in relation to imported hybrid Bravo was done. Based on the PCA analysis and analysis of the standard score SS physical, chemical and sensory parameters favorable samples for the process of fermentation were selected. The process of fermentation was carried out at three temperatures: 16-18^oC, 18-20^oC and 20-20^oC, and with various concentrations of salt: 1, 1.5 and 2%. The physical, chemical and microbiological parameters, as well as sensory properties of cabbage during fermentation were analyzed. Response surface method with analysis of variance (ANOVA) model response for each of the analyzed characteristics was used and it was explained which of the process parameters (temperature, salt concentration and the duration of the process) had a statistically significant effect on the formation of mathematical models of response, presented in the form of a second order polynomial (SOP). It was concluded that Futo&scaron;ki cabbage faster achieved end point of fermentation as compared to a hybrid Bravo. Another technological method used in this investigation was the osmotic dehydration. Cabbage was dehydrated with three osmotic solutions (an aqueous solution of sodium chloride and sucrose; the combination of an aqueous solution of sodium chloride and sucrose with molasses; sugar beet molasses) of different concentrations, at three temperatures (20&deg;C, 35&deg;C and 50&deg;C) and at three times of the process duration (1, 3, and 5h). The measured and calculated responses of osmotic dehydration process were: dry matter content, water loss, solid gain and the index of efficiency of the process. Test results shown that increase of the technological parameters of temperature and time of process, as well as the concentration of osmotic solutions lead to the intensification of mass transfer in the process and increase values of response parameters of the process. Also, it was concluded that during osmotic dehydration in sugar beet molasses cabbage was enriched with nutritional components, especially potassium. The third segment of this investigation was to analyze the viability of osmotically dehydrated cabbage packaged in modified atmosphere, with two different mixtures of N₂ and CO₂. Analyzing chemical, microbiological and sensory properties it was concluded that the osmotically dehydrated cabbage packaged in this manner has the sustainability of 90 days.</p>