<p style="text-align: justify; ">Hladno presovano ulje semena uljane tikve je&nbsp;proizvod specifičan za Srbiju, za razliku od zemalja u regionu koje imaju dugu tradiciju proizvodnje&nbsp;devičanskog tikvinog ulja.&nbsp;Tokom postupka hladnog presovanja sirovogosu&scaron;enog&nbsp;semena uljane tikve na pužnoj presi&nbsp;temperatura izdvojenog ulja ne prelazi 50 ^oC, &scaron;to se&nbsp;odražava na fizičko-hemijske, nutritivne i senzorne&nbsp;karakteristike kao i na oksidativnu stabilnost i&nbsp;antioksidativni potencijal ovog ulja.&nbsp;U cilju &scaron;to bolje karakterizacije ovog proizvoda na&nbsp;na&scaron;em trži&scaron;tu, ispitan je kvalitet hladno presovanog&nbsp;tikvinog ulja poreklom iz semena vi&scaron;e različitih&nbsp;slobodnooplodnih sorti i F1 hibrida, golosemenih i&nbsp;uljanih tikvi sa ljuskom, koje uspevaju u na&scaron;oj&nbsp;zemlji.&nbsp;Hladno presovano ulje semena tikve odlikuju&nbsp;specifične senzorne karakteristike: pored izuzetno&nbsp;blage arome, mirisa na sirovo seme tikve i ukusa&nbsp;koji podseća na meso tikve, ovo ulje se posebno&nbsp;izdvaja po boji koja je kod ispitivanog ulja bila&nbsp;svetlo-smedja do crvenkasta. Prema senzornim&nbsp;karakteristikama (naročito boji) izdvojili su se uzorci ulja poreklom iz semena austrijskih hibrida. Na&nbsp;osnovu sastava masnih kiselina ovo ulje pripada olinsko-linolnom tipu, &scaron;to ga svrstava u nutritivno&nbsp;veoma vredna biljna ulja, čemu doprinosi i visok&nbsp;sadržaj gama-tokoferola, koji je dominantan u&nbsp;tikvinom ulju. Određivanje sastava i sadržaja sterola je posebno bilo značajno kada je u pitanju hladno&nbsp;presovano tikvino ulje s obzirom da nema&nbsp;literaturnih podataka na tu temu. U ispitivanim&nbsp;uzorcima su bili dominantni delta-7 steroli, a određen je i izuzetno visok sadržaj skvalena, koji&nbsp;ima veoma važnu biolo&scaron;ku funkciju. Ispitivano ulje je posedovalo dobar antiradikalski potencijal, koji je&nbsp;bio u snažnoj linearnoj zavisnosti sa sadržajem fenolnih materija. Ulje dobijeno ekstrakcijom iz&nbsp;pogače, koja je zaostala nakon hladnog presovanja&nbsp;semena, posedovalo je veći antiradikalski potencijal&nbsp;u odnosu na hladno presovano &scaron;to je rezultat&nbsp;sadržaja fenolnih materija u većem procentu i ne&scaron;to&nbsp;nižeg sadržaja tokoferola u odnosu na hladno<br />presovano ulje.</p> / <p> Cold-pressed pumpkin oil is a product specific<br /> to Serbia, given that other countries in the<br /> region traditionally produce virgin pumpkin oil.<br /> In the process of cold pressing raw-dried<br /> pumpkin seeds by screw press, the<br /> temperature of extracted oil does not exceed<br /> 50oC, which affects physical, chemical,<br /> nutritional and sensory characteristics of this<br /> oil, as well as its oxidative stability and<br /> antiradical capacity.<br /> For the purpose of more precise<br /> characterization of this product in the domestic<br /> market, the quality of cold pressed oil from<br /> seeds of many free breeding varieties and F1<br /> hybrids &ndash; of both naked and husk seed<br /> pumpkins being grown in our country &ndash; was<br /> examined.<br /> Specific sensorial properties: light brown to<br /> reddish color, mild aroma, a smell similar to<br /> that of raw pumpkin seeds and a taste<br /> resembling that of pumpkin pulp are<br /> characteristic for this oil. As for sensory<br /> characteristics, the samples of oil from<br /> Austrian hybrid seeds, stood out. On the basis<br /> of fatty acid content, this oil belongs to the<br /> oleic-linoleic type, meaning it is a highly<br /> nutritional vegetable oil, which is also due to<br /> high levels of dominant gamma-tocopherol. Determination of the types and content of</p> <p> sterols was particularly important, given that<br /> there are no data specific to cold-pressed<br /> pumpkin oil in the literature. Delta-7 sterols are<br /> the most dominant sterols in examined oil<br /> samples and also very high content of<br /> squalene was found, which a compound with<br /> an important biological function is. The oil has<br /> an excellent antiradical capacity, showing a<br /> strong linear correlation with the amounts of<br /> phenolic compounds. Oil extracted from the<br /> cake, left over after the cold pressing of<br /> pumpkin seeds, had greater antiradical<br /> capacity than the samples of cold pressed oil,<br /> due to higher percentage of phenolic<br /> compounds and a slightly lower content of<br /> tocopherols compared to cold pressed oil.</p>

<p>Cilj ovog rada je ispitivanje uticaja procesnih<br />parametara (transmembranski pritisak, protok i<br />koncentracija suspenzije) na vrednost fluksa<br />permeata, sa i bez prisustva statičkog me&scaron;ača,<br />tokom procesa mikrofiltracije suspenzija<br />p&scaron;eničnog skroba na keramičkim membranama<br />različitih veličina pora (200 nm i 500 nm).<br />Mikrofiltracija je izvođena u uslovima<br />recirkulacije i koncentrisanja napojne suspenzije.<br />Za modelovanje zavisnosti procesa mikrofiltracije<br />suspenzija skroba od procesnih parametara<br />primenjen je postupak odzivne povr&scaron;ine.<br />Ispitivanjem mikrofiltracije suspenzija p&scaron;eničnog<br />skroba na membranama sa različitim srednjim<br />prečnikom pora (200 i 500 nm) uočeno je da sa<br />povećanjem veličine pora vrednost fluksa<br />permeata opada.<br />U posmatranom eksperimentalnom opsegu<br />procesnih parametara postignuto je relativno<br />povećanje stacionarnog fluksa od 25% do 50% u<br />uslovima recirkulacije napojne suspenzije, dok je<br />u uslovima koncentrisanja napojne suspenzije<br />relativno povećanje srednjeg fluksa iznosilo od<br />20% do 80%. Porast fluksa do kojeg dolazi<br />postavljanjem statičkog me&scaron;ača u kanal membrane</p><p>uslovljen je uspostavljanjem turbulentnih uslova<br />proticanja i karakterističnog kretanja fluida duž<br />kanala membrane, koja je posledica<br />karakterističnog povezivanja helikoidnih<br />elemenata Kenics statičkog me&scaron;ača.<br />Kako u uslovima recirkulacije napojne sme&scaron;e,<br />tako i u uslovima koncentrisanja, vrednost<br />relativne specifične potro&scaron;nje energije zavisi skoro<br />isključivo od vrednosti protoka napojne sme&scaron;e. Sa<br />povećanjem protoka specifična potro&scaron;nja energije<br />u prisustvu statičkog me&scaron;ača naglo raste i<br />relativno povećanje protoka nije dovoljno da bi<br />kompenzovalo gubitak hidrauličke snage. U<br />opsegu protoka od 80 do 100 L/h su obezbeđene<br />pozitivne vrednosti relativne promene specifične<br />potro&scaron;nje energije, te je upotreba statičkog me&scaron;ača<br />opravdana sa ekonomskog aspekta.<br />Optimizacija eksperimentalnih uslova urađena je<br />postupkom istovremene maksimizacije fluksa<br />permeata u sistemima sa statičkim me&scaron;ačem i<br />relativne promene specifične potro&scaron;nje energije.<br />Optimalni uslovi izvođenja procesa mikrofiltracije<br />suspenzija p&scaron;eničnog skroba u uslovima<br />recirkulacije napojne suspenzije ukazuju da je<br />proces potrebno izvoditi pri maksimalnoj<br />vrednosti transmembranskog pritiska od 0,9 bara,<br />protocima od 85 do 100 L/h i koncentraciji od 5<br />do 6 g/L.<br />Optimalni uslovi izvođenja procesa mikrofiltracije<br />suspenzija p&scaron;eničnog skroba u uslovima<br />koncentrisanja napojne suspenzije ukazuju da je<br />proces potrebno izvoditi pri vrednosti<br />transmembranskog pritiska od 0,85 do 0,9 bara,<br />protocima od 85 do 100 L/h i koncentraciji od 5<br />do 7 g/L.<br />Pored ispitivanja na laboratorijskoj<br />aparaturi, cilj ovog rada je bio i ispitivanje uticaja<br />procesnih parametara na proces mikrofiltracije<br />suspenzija skroba u poluindustrijskim uslovima<br />(na jednokanalnoj i vi&scaron;ekanalnoj membrani<br />srednjeg prečnika pora 200 nm), odnosno &scaron;ireg<br />opseg vrednosti transmembranskog pritiska i<br />protoka suspenzije na pomenute odzive u<br />uslovima koncentrisanja napojne suspenzije.</p> / <p> The aim of this study was to investigate the effect of<br /> process parameters (transmembrane pressure, flow<br /> rate and suspension concentration) on the permeate<br /> flux in the system with and without the presence of<br /> static mixer. Microfiltration of wheat starch<br /> suspensions was performed in recirculation and<br /> concentration mode using ceramic membranes with<br /> different pore size (200 nm and 500 nm). Response<br /> surface methodology was applied for modeling<br /> cross-flow microfiltration of starch suspensions.<br /> During investigation of starch suspension<br /> microfiltration process on membranes with different<br /> pore size diameter (200 and 500 nm) it was<br /> observed that with increasing pore size the permeate<br /> flux declined.<br /> In the experimental range of process parameters,<br /> flux increase had values between 25% and 50% in<br /> recirculation mode, while in concentration mode<br /> this improvement was in range between 20% and 80%. The increase in flux that occurs by placing a</p> <p> static mixer in the membrane channel was caused<br /> by the establishment of turbulent flow conditions<br /> and the characteristic flow of fluid along the<br /> membrane channel, which is a consequence of the<br /> characteristic geometry of Kenics static mixer.<br /> Both in recirculation and concentration mode, the<br /> reduction of specific energy consumption depends<br /> almost exclusively on the value of the suspension<br /> flow rate. Specific energy consumption increased<br /> rapidly with increasing flow rate in the presence of<br /> static mixers and flux improvement is not high<br /> enough to compensate the loss of hydraulic<br /> dissipated power. The flow rate in the range from<br /> 80 to 100 L/h provided positive values of the<br /> reduction of specific energy consumption and the<br /> use of static mixers was justified from the<br /> economical point of view.<br /> Optimization of experimental conditions was done<br /> by a procedure of simultaneous maximization of<br /> permeate flux in systems with static mixers and<br /> reduction of specific energy consumption. Optimal<br /> conditions of the wheat starch suspension<br /> microfiltration in recirculation mode indicate that<br /> the process should be conducted at the maximum<br /> value of transmembrane pressure of 0.9 bar, flow<br /> rates from 85 to 100 L/h and concentration of 5 to 6<br /> g/L.<br /> Optimal conditions of the wheat starch suspension<br /> microfiltration in concentration mode indicate that<br /> the process should be conducted when the value of<br /> transmembrane pressure from 0.85 to 0.9 bar, flow<br /> rates from 85 to 100 L/h and concentration of 5 to 7<br /> g/L.<br /> Apart from investigations in laboratory conditions,<br /> the aim of this study was to examine the influence<br /> of process parameters on the starch suspensions<br /> microfiltration in the pilot plant (one channel and<br /> multichannel membrane with pore diameter 200<br /> nm) and wider range of transmembrane pressure<br /> and suspension flow rate on the mentioned<br /> responses in concentration mode.</p>

<p>U okviru doktorske disertacije su razvijeni i optimizovani postupci pripreme uzoraka hrane (žitarica, sirovina, poluproizvoda i prehrambenih proizvoda na bazi žitarica, voća i povrća) i stočne hrane, kao i simultano određivanje tropanskih i glikoalkaloida primenom gasne i tečne hromatografije uz maseno-spektrometrijsku detekciju. Razdvajanje alkaloida primenom gasne hromatografije je izvedeno na kapilarnoj koloni (HP-5MS UI), uz detekciju sa kvadrupolnom masenom spektrometrijom SIM tehnikom, u intervalu m/z 50&ndash;550 a.m.u. Pri optimizovanim uslovima postignuto je razdvajanje homatropina, atropina i skopolamina u vremenu od 12.75 min, pri čemu<br />tropin i anisodamin nisu mogli biti detektovani. Glikoalkaloidi nisu direktno mogli biti određivani gasnom hromatografijom usled njihove visoke molekulske mase i male isparljivosti. Za simultano određivanje tropanskih alkaloida (tropin, l-hiosciamin, atropin, skopolamin, homatropin i anisodamin) i glikoalkaloida (&alpha;-solanin i &alpha;-kakonin) validirana je brza i osetljiva multirezidualna LC&ndash;MS/MS metoda. Kori&scaron;ćena je disperzivna čvrsto-fazna ekstrakcija sa 0.5% mravlje kiseline u acotonitrilu/vodi (75:25, v/v), solima magnezijum sulfat, natrijum hlorid i natrijum citrat kao i C₁₈ sorbent. Analiti su razdvojeni na Chirobiotic V koloni, sa mobilnom fazom sastavljenom od 10 mM amonijum formata u voda/acetonitril (90:10, v/v) i metanol/acetonitril (50:50, v/v), me&scaron;anim u odnosu 20:80 (v/v). Detekcija komponenti je izvedena u pozitivnom elektrosprej modu (ESI+), kori&scaron;ćenjem reakcionog vi&scaron;estrukog monitoring akvizacionog moda (MRM). Optimizovana tečno hromatografska metoda je podrazumevala brz i jednostavan proces ekstrakcije, sa prinosom od 61-111% za pojedine alkaloide, dobru linearnost u &scaron;irokom opsegu (5-80 &mu;g/kg, r²=0.998), dobru selektivnost, robusnost i preciznost (CV &lt; 5%). Granica detekcije (LOD) za sve alkaloide je bila u opsegu od 0.74 do 0.79 ng/g dok se granica kvantifikacije (LOQ) kretala od 2.17 do 2.46 ng/g u svim žitaricama, izuzev za tropin u soji i lanenom semenu (LOD = 1.55 i LOQ = 4.91 ng/g). Pri analizi uzoraka sa trži&scaron;ta alkaloidi nisu detektovani u analiziranim uzorcima hrane, kao &scaron;to su: p&scaron;enica, raž, kukuruz, bra&scaron;no od me&scaron;anih žitarica, kukuruzno bra&scaron;no, biskvit i krekeri. Stočna hrana namenjena ishrani svinja i peradi je sadržala atropin, skopolamin, &alpha;-solanin i &alpha;-kakonin u koncentracionom opsegu od 3.6 do 21.7 ng/g. Atropin i skopolamin su detektovani u koncentracionom opsegu od 2.8 do 9.8 ng/g u hrani namenjenoj ishrani krava i zečeva, dok u hrani nemenjenoj ishrani konja i divljih životinja alkaloidi nisu detektovani. U analiziranim uzorcima voća i povrća (jabuka, kru&scaron;ka, avokado, mrkva, krastvac i paprika) po prvi put u ovom radu su detektovani glikoalkaloidi, &alpha;-solanin i &alpha;-kakonin. Koncentracija oba glikoalkaloida se kretala u opsegu od 0.3 do 15 ng/g. Sadržaj glikoalkaloida u krompiru i čipsu (8708.9-18794.7 ng/g) se nalazio u okviru preporučenog ukupnog sadržaja glikoalkaloida od 200 mg/kg (sirova odvaga) (FAO/WHO, 1999). Apsorpcija i translokacija alkaloida od strane p&scaron;enice u koren, listove i stabljiku je ustanovljena upotrebom atropina ¹⁴C. Utvrđeno je da biljka nakon 15 dana apsorbuje 4.30% i 2.28% atropina ¹⁴C za niži (13676 dpm/g soil) i vi&scaron;i (37203 dpm/g soil) sadržaj standarda sa kojim je zemlji&scaron;te spajkovano, redom. Količina apsorbovanog atropina se smanjivala tokom rasta biljke. Biljka starosti 90 dana je apsorbovala 0.38% i 0.21% atropina ¹⁴C za niži i vi&scaron;i sadržaj standarda, redom. Povećanje koncentracije supstance u zemlji&scaron;tu nije uticalo na dalje povećanje apsorpcije. Do nagomilavanja supstance je do&scaron;lo u listovima (83%) dok su niže koncentracije zabilježene u korenu (8.6%), stabljici (4.2%) i semenu (4.1%). U analiziranim uzorcima vode, koja je poticala od ispiranja zemlji&scaron;ta obogaćenog atropinom ¹⁴C, nakon 30 dana supstanca je detektovana u koncentraciji od 0.5%. Tokom vremena je ustanovljeno smanjenje ispiranja ove supstance (0.01% nakon 90 dana). Analiza uzoraka zemlji&scaron;ta nakon 30 i 60 dana je pokazala značajne adsorpcione osobine atropina, tako da je količina čvrsto adsorbovanog (neekstrahovanog) atropina iznosila 60% i 70%, redom. Zaostali atropin je bio stabilan i nakon 90 dana.</p> / <p>The methods of sample preparation have been developed and optimized for food (grains, raw materials, food products based on grains and fruits and vegetables) and feed analyses for the purpose of simultaneous determination of tropane and glycoalkaloids by gas and liquid chromatography hyphenated to mass spectrometry. Separation of alkaloids by gas chromatography was achieved by using capillary column HP-5MS UI. The alkaloids have been detected by using a quadrupole mass spectrometer inSIM mode for the range of m/z 50&ndash;550 a.m.u. Under optimised conditions, good separation of homatropine, atropine and scopolamine was achieved after 12.75 min, while tropine and anisodamine couldn`t be detected. Glycoalkaloids could not be analysed directly by gas chromatography due to their high molecular weight and low volatility. For simultaneous determination of tropane alkaloids (tropine, atropine, scopolamine, homatropine, anisodamine) and glycoalkaloids (&alpha;-solanine, &alpha;-chaconine) fast and sensitive multiresidue LC&ndash;MS/MS method was validated. In sample preparation dispersive solid phase extraction (DSPE) was performed with 0.5% formic acid in acetonitrile/water (75:25, v/v) and a mixture of magnesium sulphate, sodium chloride, sodium citrate and C18 sorbent. The analytes were separated by isocratic HPLC on a Chirobiotic V column with the mobile phase that consisted of 10 mM ammonium formate in water/acetonitrile (90:10, v/v) and methanol/acetonitrile (50:50, v/v), mixed in the ratio of 20:80 (v/v).<br />Compounds were detected in positive electrospray ionization mode (ESI+), using multi reaction monitoring (MRM). Optimised liquid-chromatographic method exhibited good linearity in the range 5-80 ng/g (r²=0.998). The method has shown to be specific, selective, accurate (recoveries from 61- 111%), precise (CV &lt; 5%) and rugged. Calculated limits of detection (LOD) for all alkaloids were in the range 0.74-0.79 ng/g, while the limits of quantitation (LOQ) were in the range 2.2-4.9 ng/g in all grains, except for tropine in soybean and linseed (LOD = 1.55 and LOQ = 4.91 ng/g). The proposed method was applied in the analyses of samples obtained from local supermarkets. The alkaloids were not detected in following food samples:<br />wheat, rye, maize, mixed grain flour, corn flour, biscuits and crackers. The feeds for pigs and chicken were the most contaminated with atropine, scopolamine, &alpha;-solanine and &alpha;-chaconine with the contents of alkaloids in the range of 3.6 to 21.7 ng/g. Atropine and scopolamine were detected in cattle and rabbit feed in concentrations ranging from 2.8 to 9.8 ng/g, while in feed for horses and wild animals none of the target alkaloids were detected. Conducted research reports for the first time the presence of glycoalkaloids, &alpha;-solanine and &alpha;-chaconine in fruit and vegetable samples (apple, pear, avocado, carrot, cucumber and paprika). The concentrations of these alkaloids were in the range of 0.3 to 15 ng/g. The content of glycoalkaloids in potato and chips complied with the recommended content of total glycoalkaloids concentration of 200 mg/kg (raw weight) (FAO/WHO, 1999). Absorption and translocation of alkaloids in wheat (roots, leaves, stem) was determined by using atropine ¹⁴C. It was found that young wheat after 15 days absorbed approximately 4.30% and 2.28% of atropine ¹⁴C for low (13676 dpm/g soil) and high (37203 dpm/g soil) spiked levels in soil, respectively. Increase in the spiked concentration in the soil did not affect higher absorption of atropine ¹⁴C in wheat. The highest accumulation of atropine ¹⁴C was observed in the leaves (83%) while lower<br />concentrations were detected in the roots (8.6%), stems (4.2%) and seeds (4.1%). In collected water samples during the soil leaching, atropine ¹⁴C was detected in the concentration of 0.5%. Leaching decreased with the time (0.01% after 90 days). Analyses of soil samples after 30 and 60 days showed strong adsorption of atropine to the soil and quantity of adsorbed atropine was 60% and 70%, respectively. Adsorbed atropine in the soil was stable after 90 days.</p>

<p>U ovom radu su razvijene elektrohemijske metode za određivanje histamina. U svim<br />elektrohemijskim ispitivanjima kori&scaron;ćena je hronopotenciometrija. Istraživanja su obuhvatila optimizaciju uslova elektroanalitičkih tehnika i upoređivanje mehanizama generisanja analitičkog signala primenom različitih radnih elektroda, razvoj odgovarajućeg postupka pripreme uzoraka za analizu i samo određivanje histamina u hrani i piću. Ispitana je mogućnost primene čvrste zlatne elektrode, tankoslojne živine i tankoslojne niklove elektrode za elektrohemijsko određivanje histamina. U slučaju elektrooksidacije histamina, razja&scaron;njeni su mehanizmi generisanja signala na primenjenim elektrodama. Optimizacija uslova elektroanalitičkih tehnika obuhvatila je odabir odgovarajućeg pomoćnog elektrolita i njegove koncentracije, ispitivanje uticaja početnog potencijala i struje oksidacije na analitički signal analita. Pored toga, za svaki elektrohemijski sistem definisana su osetljivost i reproduktivnost, selektivnost, kao i opseg linearnosti. Primenom tankoslojne niklove elektrode uočena je pojava adsorpcionog koncentrovanja analita, te su u slučaju ovog elektrohemijskog sistema ispitani i uticaji vremena adsorpcije i temperature ispitivanog medijuma na analitički signal histamina. Na tankoslojnoj živinoj elektrodi analitički signal se generisao usled direktne oksidacije histamina primenom konstantne struje. Na ostale dve elektrode, pored elektrodnih reakcija odvijale su se i hemijske reakcije, tako da se oksidacija histamina u oba slučaja odigravala po ECE mehanizmu (elektrodna reakcija &ndash; hemijska reakcija &ndash; elektrodna reakcija). Na čvrstoj zlatnoj elektrodi, generisanje signala je bilo posledica oksidacije histamina elektrogenerisanim hlorom, dok se u slučaju tankoslojne niklove elektrode radilo o kombinovanoj katalitičko‐adsorpcionoj hronopotenciometriji. Tankoslojna živina elektroda je pokazala dobru selektivnost pri koncentracijama aminokiselina i histamina nižim od 5 mg/dm³, dok je pri vi&scaron;im koncentracijama dolazilo do preklapanja analitičkih signala. Ostali elektrohemijski sistemi nisu pokazali odgovarajuću selektivnost. Najveća osteljivost je ostvarena primenom tankoslojne niklove elektrode (LOD = 0,11 mg/dm³), zatim sledi čvrsta zlatna elektroda (LOD = 0,27 mg/dm³) i na kraju tankoslojna živina elektroda (LOD = 1,31 mg/dm³). U okviru definisanja postupka pripreme uzoraka, ispitana je efikasnost različitih ekstrakcionih tehnika i različitih ekstragenasa u pogledu izdvajanja histamina iz uzoraka. Pored toga razvijeni su odgovarajući postupci preči&scaron;ćavanja ekstrakata primenom preparativnih hromatografskih tehnika, i to na tankom sloju i na stubu adsorbensa. Po definisanju optimalnih uslova elektrohemijskog određivanje histamina, kao i razvijanja postupka pripreme uzoraka, histamin je određen u različitoj hrani i piću.</p> / <p>In this work, the electrochemical methods for the determination of histamine were<br />developed. All electrochemical investigations were carried out by chronopotentiometry. The research included optimization of the experimental parameters of electroanalytical techniques and comparison of the mechanism of the analytical signal generation by using the different working electrodes. Upon the development of sample preparation procedure, histamine was determined in different food and beverages. The possibility of applying solid gold electrodes, thin film mercury electrode and thin film nickel electrode for electrochemical determination of histamine was examined. The mechanisms of histamine electrooxidation on different working electrodes were explained and elaborated. Optimization of the experimental parameters of electroanalytical techniques included the selection of appropriate supporting electrolyte and its concentration, and investigation of the influence of initial potential and oxidation current on histamine analytical signal. Beside this, for each electrochemical system sensitivity and reproducibility, selectivity as well as linearity range were defined. The use of thin nickel film electrode resulted in adsorptive accumulation, and in that case the effects of accumulation time and medium temperature on histamine analytical signal were defined. On thin film mercury electrode, histamine analytical signal was generated<br />due to direct oxidation of histamine by a constant current. On other two electrodes, electrode reactions were coupled with chemical reaction, and histamine oxidation was by ECE mechanism (electrode reaction &ndash; chemical reaction &ndash; electrode reaction). On solid gold electrode histamine was oxidized indirectly by electrogenerated chlorine, while in the case of thin film nickel electrode combination of catalytic and adsorptive chronopotentiomety was responsible for signal generation. Thin film mercury electrode showed good selectivity for histamine and amino acids concentrations below 5 mg/dm³, but higher concentrations caused the overlapping of analytical signals. Other electrochemical systems did not show adequate selectivity. The best sensitivity was achived by thin film nickel electrode (LOD = 0.11 mg/dm³),<br />followed by a solid gold electrode (LOD = 0.27 mg/dm³), and by thin film mercury electrode (LOD = 1.31 mg/dm³). In order to define adequate sample preparation procedure, the efficiency of different extraction techniques and different solvents were tested for histamine extraction from the samples. Appropriate procedures for purification of extracts were defined as well, by applying preparative thin layer and column chromatography. After optimization of the electrochemical methods for histamine determination, as well as the procedure of sample preparation, developed methods were applied for histamine determination in various food and beverages.</p>

<p>Cilj istraživanja u okviru ove teze je bio da se ispita mogućnost upotrebe pogače uljane tikve golice, nusproizvoda pri proizvodnji devičanskog ulja, za proizvodnju namaza sličnom kikiriki maslacu, kako po spolja&scaron;njem izgledu i teksturi, tako i po reolo&scaron;koj stabilnosti. Namazi su formulisani tako da imaju visok sadržaj omega-6 i omega-3 masnih kiselina, uz njihov izbalansirani odnos prema principima kvalitetne ishrane i preporukama nutricionista, prijatna senzorska svojstva i dobru oksidativnu stabilnost. Upotrebom dvo-faktorskog eksperimentalnog dizajna na pet nivoa i metode odzivnih povr&scaron;ina, kao i statističke analize podataka, izvr&scaron;ena je optimizacija tehnolo&scaron;kog procesa za proizvodnju namaza sa definisanim poželjnim funkcionalnim karakteristikama proizvoda sa nutricionističkog i teksturalnog aspekta. Rezultati su pokazali da je pogača (na 100 g proizvoda) veoma bogata mineralima, uz izuzetno visok sadržaj fosfora, gvožđa, magnezijuma i cinka koji prevazilazi 100% dnevnih potreba prema Pravilniku (2004), a takođe sadrži i velike količine mangana, kalijuma i bakra, te opravdava valorizaciju iste za proizvodnju nutritivno visokovrednog namaza. Devičansko tikvino ulje, poreklom iz pogače, je znatno doprinelo i nutritivnoj vrednosti namaza, budući da je isto bogato omega-6 masnim kiselinama (51.04%) i &gamma;-tokoferolima (704 mg/kg). Konopljino ulje je veoma uticalo na senzornu ocenu namaza, pre svega na ukus i teksturu, kao i na oksidativnu stabilnost. Ustanovljeno je da rok trajanja namaza zavisi od stepena oksidacije ulja u njegovom sastavu, pre svega od količine i kvaliteta konopljinog ulja, i može biti najduže do 6 meseci pri sobnoj temperaturi čuvanja. Utvrđeno je da izdvajanje ulja na povr&scaron;ini namaza zavisi od količine dodatog stabilizatora, a najbolji rezultati su postignuti dodatkom 1.6% stabilizatora. Optimalna vrednost za dobijanje namaza najprihvatljivijeg nutritivnog i senzornog kvaliteta, oksidativne stabilnosti i teksture, je sadržaj stabilizatora od 1.2-1.4% uz 40-60% dodatog konopljinog ulja u masnu fazu proizvoda. Svi proizvedeni namazi su sadržali esencijalnu omega-3 masnu kiselinu uz mogu&scaron;nost deklarisanja kao &bdquo;izvor omega-3 polinezasićenih masnih kiselina&ldquo;, od kojih su pojedini uzorci imali vrlo visok sadržaj (0.98 i 1.24 g) po konzumnoj jednici (15 g). Svi proizvedeni namazi su sadržali i omega-6 masne kiseline, od kojih su pojedini uzorci imali visok sadržaj po konzumnoj jedinici (2.5-3 g), uz mogućnost deklarisanja kao &bdquo;izvor omega-6 polinezasićenih masnih kiselina&ldquo;. Svi namazi (izuzev jednog) su imali odlično izbalansiran odnos između omega-6 i omega-3 masnih kiselina (2-3:1).</p> / <p> The goal of this research was to investigate the possible use of hull-less pumpkin seed oil press cake, a by-product of the pumpkin seed oil pressing process, for the manufacturing of a spread. The spread would be similar to a peanut butter, in appearance, texture and rheological stability. Spreads were formulated in such way that they would have pleasant sensory attributes, good oxidative stability with a high omega-6 and omega-3 fatty acids content, while providing their balanced ratio based on modern healthy food principles as recommended by nutritionists. Optimization of the spread manufacturing technology was conducted based on the results of the two factorial experimental design on five levels using response surface methodology and statistical analysis (ANOVA). Desirable functional characteristics of the spreads were defined based on nutritional and textural attributes. Results have shown that pumpkin seed oil press cake (per 100 g) is very rich in minerals, especially phosphorus iron, magnesium and zinc that exceeds recommended daily intake (Pravilnik, 2004) over 100%. In addition, it contains high amounts of manganese, potassium and copper, which justifies the use of the seed oil press cake for investigation of the possibility for its use in nutritious spread manufacturing. Cold pressed hull-less pumpkin oil significantly contributed to the nutritional value of the spreads, since it is rich in omega-6 fatty acids (51.04%) and &gamma;-tocopherols (704 mg/kg). Hemp oil had a significant effect on the sensory evaluation of the spreads, primarily on the taste and texture, as well as the oxidative stability of the spreads. It was confirmed that the shelf life of the spreads depended on the oxidation of the oils present in the spread, and primarily depended on the hemp oil quantity and quality. All spreads had a shelf life of maximum 6 months at ambient temperature. It was also confirmed that oil separation on the spreads&rsquo; surface depended on the amount of added stabilizer, where the best results were achieved with the addition of 1.6% stabilizer. Considering nutritional value, sensory evaluation, oxidative stability and texture, the optimal spreads were made using the stabilizer at 1.2-1.4% and hemp oil at 40-60% added to the fatty phaze of the spread. All prepared spreads contained omega-3 essential fatty acid that could be declared as a &ldquo;source of omega-3 polyunsaturated fatty acids&ldquo;. Few samples had a very high content of omega-3 fatty acids (0.98 and 1.24 g) per serving size 15 g). In addition, all prepared spreads contained omega-6 fatty acids, where some samples had a high content of omega-6 fatty acids per serving size (2.5-3 g), and could be declared as a &ldquo;source of omega-6 polyunsaturated fatty acids&ldquo;. All prepared spreads (except one) had a well balanced ratio between omega-6 and omega-3 fatty acids (2-3:1).</p>

<p>Izmenama u konstrukciji vertikalne me&scaron;alice zamenom originalne obloge pužnice sa oblogama koje su imale 13,5%, 27% i 40% perforacija je pobolj&scaron;an proces me&scaron;anja. Ova pobolj&scaron;anja se ogledaju u skraćenju vremena me&scaron;anja 15%, 30% i 50% u odnosu na originalnu konstrukciju, smanjenju utro&scaron;ka rada i energije i otvaranja mogućnosti vraćanja ove vrste me&scaron;alica u masovniju upotrebu, jer su tro&scaron;kovi kupovine i održavanja ove vrste me&scaron;alica daleko niži u odnosu na druge. Izrađen je model sistem za cilindričnu me&scaron;alicu, na bazi primene teorije Markovljevog niza, kao pogodan način za predviđanje procesa me&scaron;anja u ovoj vrsti me&scaron;alica, čak i u industrijskim uslovima. Dobijeni rezultati<br />su pokazali slaganje sa eksperimentalno dobijenim rezultatima, pri čemu je utvrđeno vreme neophodno za postizanje homogenosti u cilindričnoj me&scaron;alici iznosilo 5 minuta za odnos me&scaron;anja 1:10.000, dok za odnos me&scaron;anja 1:100.000 i vreme od 5 minuta, homogenost nije postignuta Poređenjem rezultata programa za analizu slike, koji je prethodno razvijen u okviru metode Microtracer-a, sa ručno dobijenim rezultatima, utvrđen je visok stepen korelacije (R=0.995, 0.979 i 0.987) i ovaj program je ocenjen kao značajno pobolj&scaron;anje i skraćenje vremena potrebnog za dobijanje rezultata.</p> / <p>Changes in the construction of vertical mixers by replacement of the original screw barrel with barrel which had 13.5%, 27% and 40% perforation generally have improved process of mixing. These improvements are reflected in shortening the mixing time of 15%, 30% and 50% comparing to the original construction, reduction of labor and energy and create the possibility of returning these types of mixers in the more common, as the cost of purchasing and maintaining these types of mixers is far lower compared to others. A model system for the cylindrical mixer, based on the theory of Markov chain, as a convenient way to predict the mixing process in this type of mixer, even in industrial conditions. The results show agreement with experimental results, with a determined time necessary to achieve homogeneity in a cylindrical mixer was 5 minutes for mixing ratio 1:10,000, and more than 5 minutes for the mixing ratio 1:100,000. Comparing the results of program for image analysis, which was previously developed under a Microtracers methods with manually obtained results revealed a high degree of correlation (R = 0995, 0979 and 0987) and this program was rated as significantly improving and shortening the time needed to obtain results</p>

<p>Predmet istraživanja ove doktorske disertacije<br />je bio formiranje i proučavanje osobina i<br />pona&scaron;anja organskih aerosola nastalih<br />atomiziranjem stabilnih emulzija dominantno<br />pod dejstvom centrifugalne sile. Kori&scaron;ćene su<br />vodene emulzije komercijalnih sredstava za<br />hlađenje i podmazivanje (SHP), koja se koriste<br />pri obradi metalnih odlivaka. Cilj istraživanja je<br />bio ispitati i objasniti uticaj koncentracije SHP<br />emulzije, brzine strujanja vazduha, prirode kako<br />ulja, tako i osobina emulzija, kao &scaron;to su gustina,<br />viskoznost, povr&scaron;inski napon, kao i udaljenost<br />od mesta atomiziranja na masenu koncentraciju,<br />broj i veličinu kapi aerosola u kontrolisanim<br />laboratorijskim uslovima.<br />Uslovi eksperimenta isključili su uticaj toplote<br />nastale kao posledica trenja alata i delova koji<br />se obrađuju. Pored toga isključeno je prisustvo<br />čvrstih mikronskih čestica koje potiču od delova<br />koji se obrađuju, kao i prisutvo plivajućeg<br />hidrauličnog ulja i mikroorganizama koji uvek<br />prate realan industrijski fluid.<br />Eksperimentalni program je realizovan na tri<br />komercijalna SHP sredstva različitog porekla.<br />Proučavani su aerosoli formirani atomiziranjem<br />emulzije tri različite koncentracije uljne faze: 1,<br />6 i 10 %. Pri jednakim eksperimentalnim<br />uslovima ispitivan je i aerosol formiran, od<br />vode kori&scaron;ćene za pripremu emulzija. Određene<br />su osobine ulja i emulzija koje su od značaja za<br />atomiziranje tečnosti. Proučavan je i uticaj<br />brzine ventilacionog vazduha na osobine<br />aerosola. Eksperimenti su realizovani pri<br />brzinama vazduha od 1, 3, 6, 8 m/s.<br />Uzorkovanje aerosola je realizovano u komori,<br />na ulazu u ventilacini vod i duž ventilacione<br />cevi dužine 8m na pet mernih tačaka koje se<br />nalaze na 0,5, 1, 2, 4, 6, 8 m u odnosu na<br />komoru.<br />Značajan doprinos ove doktorske disertacije je<br />postavljanje teorije da atomiziranjem emulzije<br />kao heterogene tečnosti, nastaje heterogen<br />aerosol, pri čemu mogu nastati kapi različite<br />prirode, između ostalog i kapi čistog ulja. Na taj<br />način je obja&scaron;njen fenomen da porastom<br />koncentracije emulzije raste veličina kapi<br />nastalog aerosola. Aerosoli nastali od<br />koncentrovanijih emulzija pokazuju uređenije<br />strujanje kroz ventilacionu cev, &scaron;to je od<br />značaja za uspe&scaron;nije projektovanje ventilacionih<br />sistema i filtara za njihovu separaciju u cilju<br />za&scaron;tite zdravlja radnika i za&scaron;tite okoline.</p> / <p> This PhD Thesis presents an experimental<br /> study of organic aerosols formed from stable<br /> water emulsions, predominantly by centrifugal<br /> force under laboratory conditions. Emulsions of<br /> metalworking fluids (MWF) were used in the<br /> experiments. The aim of this investigation was<br /> to explain the influence of MWF emulsion<br /> concentration, oil and emulsion properties<br /> (density, viscosity, and surface tension), air<br /> velocity, as well as distance from atomization<br /> generator on aerosol behavior and properties as<br /> size distribution, mass and number<br /> concentration. The experimental conditions<br /> excluded the influence of the heat arising from<br /> the friction between the tool and the<br /> workpieces. In this way the mechanism of<br /> aerosol formation by the<br /> evaporation/condensation is minimized.<br /> Besides, the presence of solid micrometer sized<br /> particulates originated from the work piece is<br /> excluded, as well as the presence of tramp oil<br /> and microorganisms, always accompanying a<br /> real industrial fluid.<br /> Three different commercial MWFs were<br /> investigated at three different oil-in-water<br /> emulsion concentrations, 1, 6, and 10 %<br /> respectively. Water aerosol was investigated<br /> under same experimental conditions. Properties<br /> of MWF oils and emulsion, which are important<br /> for liquid atomization, were determined.<br /> Influence of ventilation air velocity on aerosol<br /> properties was investigated as well.<br /> Experiments were realized under four different<br /> air velocities: 1, 3, 6, and 8 m/s. Samples were<br /> taken at three different points: at the camber, at<br /> the entrance of ventilation pipe, and at five<br /> sampling points along the pipe. Ventilation pipe<br /> was 8 m long, and sampling point were at 0.5, 1,<br /> 2, 4, 6, 8 m from the aerosol camber.<br /> The main contribution of this dissertation is<br /> the new theory that atomization of emulsion as a<br /> heterogeneous fluid leads to the formation of<br /> heterogeneous aerosol, containing droplets of a<br /> different nature, including droplets of pure oil.<br /> This theory explains the phenomenon that the<br /> aerosol droplet sizes increase with the increase<br /> of the emulsion concentration. Obtained results<br /> show that aerosols formed from the emulsions<br /> of higher concentration (6 and 10 %) have less<br /> chaotic flow through the ventilation pipe. This<br /> observation is important for better design of<br /> ventilation systems and filters for mist<br /> separation in order to protect human health and<br /> the environment.&nbsp;</p>

<p>Etanolni ekstrakti tropa odabranih sorti cvekle (Detroit, Cardeal-F1, Egipatska, Bikor i Kestrel) preči&scaron;ćeni su primenom ekstrakcije na čvrstoj fazi (SPE). Sadržaj ukupnih<br />fenolnih jedinjenja, flavonoida i betalaina u preči&scaron;ćenim ekstraktima određeni su spektrofotometrijskim metodama. HPLC analizom utvrđen je kvalitativni i kvantitativni sastav fenolnih jedinjenja i betalaina ekstrakata tropa odabranih sorti cvekle. ESR spektroskopijom ispitana je antiradikalska aktivnost ekstrakata topa cvekle na stabilne DPPH i reaktivne superoksid anjon i hidroksil radikale.<br />Spektrofotometrijski je određena antioksidativna aktivnost na DPPH radikale i redukciona sposobnost po Oyaizu u ekstraktima odabranih sorti cvekle. Ispitana je in vitro<br />antiproliferativna aktivnost frakcija ekstrakata, njihovim delovanjem na rast tri histolo&scaron;ki različite humane ćelijske linije: MCF-7 (adenokarcinom dojke), HeLa (epitelni karcinom cerviksa)i MRC-5 (fetalni fibroblastni karcinom pluća). U zavr&scaron;noj fazi rada određena je antimikrobna aktivnost ekstrakata tropa odabranih sorti cvekle.</p> / <p> Beetroot (Detroit, Cardeal-F1, Egipatska, Bikor i Kestrel)<br /> pomace ethanol extracts were purified using solid phase<br /> extraction (SPE). Contents of total phenols, flavonoids and<br /> betalains in purified extracts were determined by spectrophotometric<br /> methods. HPLC analysis were used for quantitative<br /> and qualitative characterization of phenolic compounds<br /> and betalains in investigated extracts. ESR spectroscopy<br /> was used for investigation of antiradical activity of<br /> beetroot pomace extracts on stable DPPH and reactive<br /> superoxide anion and hydroxyl radicals. Antioxidant activity<br /> was determined spectrophotometrically on DPPH radicals<br /> and reducing power according to Oyaizu in the beetroot pomace<br /> extracts. Antiproliferative activity of investigated extracts<br /> was determined in vitro, testing their influence on the<br /> growth of three histologically different human cell lines:<br /> MCF-7 (breast adenocarcinoma), HeLa (cervix epithelioid<br /> carcinoma) and MRC-5 (fetal lung). Also, antimicrobial activity<br /> of beetroot pomace extracts was determined.</p>

<p>Predmet doktorske disertacije je izučavanje različitih bioprocesa za modifikovanje biljnih globulina radi unapređenja njihovih funkcionalnih karakteristika. Istraživanja su zasnovana na karakterizaciji i enzimskoj modifikaciji glavnog rezervnog proteina (12S), kukurbitina, iz semena uljane tikve (<em>Cucurbita pepo</em>). Osnova istraživanja je enzimska konverzija globulina i dobijanje proteinskih modifikata delovanjem hidrolaza i transferaza. U okviru istraživanja, enzimski procesi modifikacije globulina izučavani su sa dva aspekta: enzimska hidroliza i enzimsko umrežavanje (cross-linking), primenom komercijalnih enzimskih preparata. Takođe istraživanja obuhvataju i razvoj i kontrolu samih bioprocesa definisanjem i optimizacijom procesnih parametara (temperature, pH, koncentracije enzima i supstrata, vreme reakcije). Ovako definisani procesi eksploatisani su u cilju kreiranja željenih funkcionalnih karakteristika proteina spram njihove potencijalne primene u formulacijama hrane. Odabir i optimizacija procesnih parametara i modelovanje bioprocesa izvedeno je implementiranjem nove kompjuterske i analitičke metodologije</p> / <p>The PhD thesis research is aimed at development of different bioprocesses for modification of plant globulins in order to improve their functional properties. Studies are based on characterization and enzymatic modification of major storage protein (12S), cucurbitin derived from pumpkin oil seed (<em>Cucurbita pepo</em>). The base of research is enzymatic conversion of cucurbitin by hydrolase and transferase. Two different enzymatic processes are used for protein modification: (i) enzymatic hydrolysis and (ii) enzymatic cross-linking. To monitor, control the bioprocesses, and definition of process parameters, such as temperature, pH, enzyme-substrate ratio, reaction time, Response Surface Methodology (RSM) was used. In addition, RSM was employed for production of protein modification with desired functional properties.</p>

<p>Sintetisane su klasične alkidne smole polazeći od ricinolne kiseline, anhidrida ftalne<br />kiseline i tri poliola (glicerina, trimetilolpropana i etoksilovanog pentaeritritola), kao i<br />hiperrazgranati alkidi na osnovu ditrimetilolpropana, dimetilolpropionske kiseline i<br />ricinolne kiseline. Smole su karakterisane određivanjem hidroksilnog i kiselinskog broja,<br />viskoznosti, srednjih molskih masa i njihove raspodele. Struktura sintetisanih smola je<br />potvrđena infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR).<br />Sintetisani alkidi imaju veliki sadržaj hidroksilnih grupa, a mali kiselinski broj. Prisustvo<br />hidroksilnih grupa, kao krajnjih funkcionalnih grupa, omogućuje modifikaciju alkidnih<br />smola i dobijanje materijala različitih svojstava. Sintetisani alkidi su umrežavani sa<br />triizobutoksimetil i heksametoksimetil melaminskom smolom u cilju dobijanja umreženog materijala željene strukture i svojstava za primenu u premazima. Umrežavanje sme&scaron;a smola praćeno je FTIR spektroskopijom, dinamičko skanirajućom kalorimetrijom (DSC), reometrijom, kao i određivanjem sadržaja gela. Ispitivana su toplotna svojstva, dinamičkomehaničko pona&scaron;anje, fizičko-mehaničke karakteristike i hemijska otpornost filmova premaza. Umrežavanje sme&scaron;a smola teče uglavnom preko hidroksilnih i karboksilnih grupa alkida sa izobutoksimetil i metoksimetil grupama u melaminskim smolama. Sintetisane klasične alkidne smole u sme&scaron;i sa melaminskim smolama umrežavaju u temperaturnom opsegu od 90 do 170&nbsp;⁰C, a hiperrazgranati alkidi od 80 do 170&nbsp;⁰C, &scaron;to su uobičajene temperature u tehnologiji lakova koji umrežavaju &ldquo;pečenjem&ldquo;. Umreženi filmovi premaza su toplotno veoma stabilni, budući da početak razgradnje premaza započinje na temperaturama od 281 do 330 ⁰C. Potvrđeno je da postoji linearna zavisnost između modula izgubljene energije na 25 ⁰C, koji je mera viskoznog odgovora materijala, i tvrdoće premaza određene metodom klatna. Svi projektovani premazi, bez obzira na nesavr&scaron;enost nastale polimerne mreže, su pokazali zadovoljavajuća svojstva. Najbolja svojstva od klasičnih alkidnih premaza ima onaj na osnovu sme&scaron;e alkida sa etoksilovanim pentaeritritolom i heksametoksimetil melaminske smole. Kori&scaron;ćenje hiperrazgranatih alkidnih smola kao veziva u ekolo&scaron;ki prihvatljivim premazima ima prednost zbog manjeg sadržaja organskih rastvarača i manje viskoznosti u odnosu na klasične smole. Pretpostavljeno je da bi sme&scaron;e sintetisanih klasičnih i hiperrazgranatih alkida sa melaminskim smolama (maseni odnos 70:30) bile pogodne za primenu u industriji boja i lakova. Potvrđeno je da su sistemi alkid/melaminska smola veoma složeni. Dobijeni rezultati omogućuju da se objasni uticaj građe prekursora na strukturu nastale polimerne mreže, a time i na svojstva premaza.</p> / <p>Conventional alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol), as well as hyperbranched alkyds based on ditrimethylolpropane, dimethylol propionic acid and ricinoleic acid were synthesized. Prepared alkyds were characterized by the determination of hydroxyl and acid numbers, viscosity, average molecular masses and molecular masses distribution. The structure of synthesized resins is confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Obtained alkyd resins have high content of hydroxyl groups and low acid number. The presence of hydroxyl groups as functional end groups opens up a high potential for further chemical modifications and for obtaining materials with different properties. Synthesized alkyds were cured by triisobutoxymethyl- and hexamethoxymethyl melamine resins, in order to obtain crosslinked material with desired structure and properties for coating applications. Curing of the resin mixtures were examined by FTIR spectroscopy, dynamic scanning calorimety (DSC), rheometry and by the determination of gel content. Thermal properties, dynamic mechanical behavior, physico-mechanical characteristics and chemical resistance of coated films were determined. Curing of the resin mixtures proceeds via the reactions between hydroxyl and carboxyl groups of alkyds with isobutoxymethyl and metoxymethyl groups in melamine resins. Synthesized alkyd/melamine resin mixtures became cured in the temperature range from 80 to 170 0C, which is the usual temperature range employed in the baking enamel technology. Cured films are thermally very stable since the onset of films degradation starts at high temperatures (from 281 to 330 0C). It is confirmed that there is a linear dependence between the loss modulus at 25 0C, which is the measure of the material viscosity response, and the coating hardness determined by pendulum method. All projected coatings, despite of defects in the resulting polymer networks, show satisfying properties. Among the conventional systems coating based on mixture of alkyd with ethoxylated pentaerythritol and hexamethoxymethyl melamine resin show the best properties. Application of hyperbranched alkyd resins, as binders in environment friendly coatings has an advantage due to less content of organic solvent and lower viscosity, compared to conventional alkyd resins. It is supposed that the combination of synthesized conventional and hyperbranched alkyds with melamine resins (weight ratio of 70:30 based on dried mass) could be employed as new materials for the industrial preparation of baking enamels. It is confirmed that alkyd/melamine resin systems are very complex. Results obtained enable to explain the effect of precursor type on the structure of resulting polymer network, and thus, on the coating properties.</p>