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Kukuruz šećerac je vaţna povrtarska vrsta koja se koristi za ishranu ljudi i to u mleĉnoj fazi razvoja endosperma kada zrno sadrţi najveći procenat saharoze. U ovom radu je ispitivan sadrţaj šećera hibrida superslatkog kukuruza šećerca gajenog na otvorenom polju i u zaštićenom prostoru. Istraţivanja su izvedena u ataru sela Bogojevce, opština Leskovac, na zemljištu tipa aluvijum, direktnom setvom kukuruza šećerca tokom maja meseca. Sadrţaj ukupnih šećera, redukujućih šećera, invertnog šećera i saharoze je odreĊen volumetrijski, metodom po Luf-Šurlu (Luff-Schoorl). Sva merenja su izvedena u triplikatu, a rezultati su izraţeni u procentima na sveţu materiju. Sadrţaj ukupnih šećera je bio veći pri gajenju kukuruza šećerca na otvorenom polju u odnosu na onaj odgajan u zaštićenom prostoru i iznosio je 11,04%, odnosno 8,04%. Isti trend je zabeleţen i kod sadrţaja saharoze (6,88% i 4,02%), kao i kod sadrţaja invertnog šećera (7,24% i 4,23%). Znaĉajne razlike u sadrţaju redukujućih šećera nije bilo izmeĊu proizvodnje u zaštićenom prostoru i na otvorenom polju. Ovim istraţivanjem je pokazano da na kvalitet kukuruza šećerca naĉin gajenja moţe znaĉajno da utiĉe., Sweet corn is an important vegetable species that is used for human nutrition in the milky stage of endosperm development when the grain contains the highest percentage of sucrose. In this work, the sugar content of the super-sweet sweet corn hybrid grown in an open field and in a sheltered area was investigated. The research was carried out in the soil of the village of Bogojevce, municipality of Leskovac, on alluvium type soil, by direct sowing of sweet corn during the month of May. The content of total sugars, reducing sugars, invert sugar and sucrose was determined volumetrically, using the Luff- Schoorl method. All measurements were performed in triplicate, and the results were expressed as percentages of fresh material. The total sugar content was higher when sweet corn was grown in the open field compared to that grown in a protected area, amounting to 11.04% and 8.04% respectively. The same trend was observed in sucrose content (6.88% and 4.02%), as well as invert sugar content (7.24% and 4.23%). There was no significant difference in the content of reducing sugars between the production in the protected area and in the open field. This study has demonstrated that the quality of corn can be significantly influenced by the way it is grown.

U okviru ovog rada prikazana je provera kvaliteta kakao i čokoladnih proizvoda. Eksperimentalni deo se sastoji od proučavanja fizičko-hemijskih metoda kao i proveri samog kvaliteta proizvoda i da li zadovoljava uslove pravilnika.

The influence of different hydroxides, applied to activate carbon black, on the electrochemical properties of activated carbon was investigated. The carbon material was prepared by hydrothermal treatment of sucrose and afterwards thermally activated using KOH, NaOH and LiOH. The electrochemical properties of the obtained samples were examined by cyclic voltammetry and electrochemical impedance spectroscopy and correlated to their physicochemical properties. All samples showed characteristic capacitor-like behaviour. The highest specific capacitance was obtained for the KOH-treated sample, while the increase in capacitance follows the sequence of the growth of ionic radius of a metal from an alkali which is used for activation. It was found that the dependence on the type of hydroxide is due to differences in the radii of a metal. The alkalies of larger radii of metal generated make pores wider and consequently the structure of a porous layer become more accessible to the charge transfer of capacitive response.

Determination of sugars, especially in fruit juices, is very significant bearing in mind their nutritive importance and the increased demands in food control, especially for fractions of carbohydrates in fresh products. Home-made juices as 'functional food' are in the focus of scientific attention because of the expansion of industrial manufacturing of fruit juices and importance of monoand disaccharides stability for the products quality. In this work determination of content of basic sugars in fruit juices, by applying a high performance liquid chromatography (HPLC), was performed. Content of glucose, fructose and saccharose was analysed in currant, cherry, peach, apricot and strawberry juices as well as in home-made cherry and apricot syrups. Quantification was based on comparison of chromatograms of standard solutions of saccharose, glucose and fructose with our samples. With isocratic elution applied temperature was 90˚C, water as a mobile phase and column Nucleogel Sugar Ca, refractometric detection was applied. The obtained results showed that concentrations of gucose, fructose and saccharose vary in the range 3,149-38,405 g/100 mL, 1,931-30,851 g/100 mL and 0,670-6,072 g/100 mL, respectively. Concerntrations of glucose and fructose do not exhibit significant variations in juices however, they are ten times higher in syrups. In all samples, juices and syrups, concentrations of saccharose do not differ significantly, except for one syrup sample where much lower content could be explained with possible enzymatic decomposition., Određivanje šećera u voćnim sokovima je veoma važno, imajući u vidu njihov nutritivni značaj, ali i povećane zahteve u kontroli hrane kada su u pitanju pojedine frakcije ugljenih hidrata u sveže pripremljenim proizvodima. S obzirom na to da postoji porast industrijske proizvodnje voćnih sokova i značaj stabilnosti monoi disaharida za kvalitet proizvoda, domaći sokovi, kao funkcionalna hrana, postaju sve značajniji. U ovom radu je analiziran sadržaj osnovnih šećera u voćnim sokovima i sirupima kućne izrade primenom visokoefikasne tečne hromatografije (HPLC). Analiziran je sadržaj glukoze, fruktoze i saharoze u sokovima od ribizle, višnje, breskve, kajsije i jagode, kao i u sirupima od višnje i kajsije. Određivanje se zasnivalo na poređenju hromatograma rastvora standarda šećera i naših uzoraka. Uz izokratsko eluiranje analiza je izvođena pri temperaturi od 90 ˚C. Sa vodom kao mobilnom fazom i kolonom Nucleogel Sugar Ca, primenjena je refraktometrijska detekcija. Analizom je pokazano da sadržaj glukoze, fruktoze i saharoze varira u rasponu 3,149-38,405 g/100 ml, 1,931-30,851 g/100 ml i 0,670-6,072 g/100 ml, respektivno. Sadržaj glukoze i fruktoze se ne razlikuje značajno između sokova, a u sirupima je za deset puta veći. Sadržaj saharoze takođe se ne razlikuje značajno među ispitivanim uzorcima, osim u jednom sirupu zbog najverovatnije enzimske razgradnje ovog šećera.

Pankreas je žlezda sa egzokrinom i endokrinom funkcijom. Proizvodi njegove egzokrine komponente od vitalnog su značaja za proces varenja hrane. Endokrine ćelije pankreasa grupisane u Langerhansova ostrvca proizvode insulin i glukagon, hormone koji regulišu metabolizam pre svega ugljenih hidrata i neophodni su za održavanje optimalne koncentracije glukoze u krvi. Sekretna aktivnost pankreasa, naročito njegove endokrine komponente, pod kontrolom je kompleksnih endokrinih, parakrinih i neuralnih mehanizama. Hormoni tireoidne žlezde ključni su regulatori bazalnog metabolizma, rasta i razvića. Potrebni su za normalno funkcionisanje gotovo svih organa i organskih sistema, a njihov značaj u metabolizmu ugljenih hidrata poznat je već decenijama. Funkcije endokrinog pankreasa i tireoidne žlezde, kao i efekti koje ostvaruju njihovi hormoni, uzajamno su povezani i međusobno zavisni. U kliničkoj praksi relativno je česta koegzistencija disfunkcije tireoidne žlezde i razvoj insulinske rezistencije, koja je predvorje nastanka dijabetesa tipa 2. Ishrana bogata prostim šećerima, uz smanjen nivo fizičke aktivnosti karakteristika je savremenog načina života, naročito u industrijski razvijenijim zemljama sveta. Pri kontinuiranom unosu ugljenih hidrata pankreas radi pod povećanim opterećenjem, intenzivno proizvodeći insulin, što dugoročno gledano može dovesti do patofizioloških procesa na nivou unutarćelijskih organela i eventualno do gubitka β- ćelija, odnosno do dijabetesa tipa 2. Osnovni cilj ove teze bio je da se detaljnom analizom stekne uvid u morfofunkcionalne karakteristike pankreasa pacova pod uticajem ishrane obogaćene saharozom, u uslovima sistemskog hipotireoidizma indukovanog metimazolom. U tronedeljnom eksperimentu korišćeni su mužjaci albino pacova Wistar soja, držani pod standardnim laboratorijskim uslovima. Životinje su u odnosu na ponuđeni rastvor u vodi za piće podeljene u četiri grupe. Kontrolna grupa životinja pila je čistu česmensku vodu, hipotireoidizam je induko, The pancreas is a gland with both exocrine and endocrine function. The products of its exocrine component are vital to the food digestion. Its endocrine function is based on secretory action of several types of endocrine cells that cluster together to form islets of Langerhans. Some of them produce insulin and glucagon, hormones that regulate primarily carbohydrate metabolism and are essential for maintaining optimal blood glucose concentrations. Secretory action of the pancreas, especially its endocrine component, is controlled by a complex endocrine, paracrine and neural mechanisms. Thyroid hormones are key regulators of the basal metabolism, growth and development. They are necessary for normal function of almost all organs and organ systems; their importance in the metabolism of carbohydrates has been known for decades. The functions of the endocrine pancreas and thyroid gland, and effects of their hormones are mutually connected and interdependent. In clinical practice the coexistence of thyroid dysfunction and the development of insulin resistance, which is a good prognostic factor for type 2 diabetes occurrence, is relatively frequent. A diet rich in simple sugars, along with reduced physical activity is a feature of modern lifestyle in developed countries of the world. Continuous intake of carbohydrates represents a form of stress in which pancreas intensively produces insulin, which in the long term can lead to pathophysiological processes at the level of intracellular organelles, and eventually to loss of β-cells, i.e. to type 2 diabetes. The aim of this work was to gain an insight into the detailed morpho-functional characteristics of the rat pancreas under the influence of sucrose rich diet, in terms of systemic hypothyroidism induced by methimazole. The obtained results show that: - Moderate systemic hypothyroidism was established after three-week methimazole treatment, regardless of the diet. Levels of thyroid hormones in the circulation were reduced

The highest number of commercial sweet maize hybrids is based on one or more recessive alleles that alter a carbohydrate content of endosperm. Sweet maize is consumed as human food in the milk stage of the endosperm development when the kernel is soft, sweet and succulent. Different genes used in sweet maize breeding stipulate a diverse carbohydrate content and grain quality that differ from standard quality maize. Sucrose is the dominant sugar in sweet maize grain in the milk stage of the endosperm development. It gives gain its sweetness and determines quality of immature grain that is used for consumption. Timely harvest of sweet maize is very important as the maximum sucrose content means very high grain quality. Attention came to focus on changes of the carbohydrate content during the endosperm development of five ZP sweet maize hybrids. The contents of sucrose, glucose and fructose were determined 10, 15, 20, 23, 25 and 28 days after pollination. The obtained results show a maximum sucrose content on the 23rd day after pollination meaning that time is a right time for harvest., Najveći broj komercijalnih hibrida kukuruza šećerca se zasniva na jednom ili više recesivnih alela koji menjaju ugljenohidratni sastav endosperma. Kukuruz šećerac se koristi za ljudsku ishranu u mlečnoj fazi razvoja endosperma, kada je zrno slatko, nežno i sočno. Različiti geni koji se koriste u oplemenjivanju kukuruza šećerca uslovljavaju drugačiji ugljenohidratni sastav i kvalitet zrna koji se razlikuje od kukuruza standardnog kvaliteta. Dominantan šećer u zrnu šećerca u mlečnoj fazi razvoja endosperma jeste saharoza. Ona daje slatkoću zrnu i određuje kvalitet nezrelog zrna koje se koristi za potrošnju. Veoma je važno da se berba kukuruza šećerca obavi u pravo vreme, kada je sadržaj saharoze maksimalan jer je i kvalitet zrna u to vreme visok. U radu su praćene promene ugljenohidratnog sastava tokom razvoja endosperma pet ZP hibrida kukuruza šećerca. Određivan je sadržaj saharoze glukoze i fruktoze nakon 10, 15, 20, 23, 25 i 28 dana posle oplodnje. Rezultati pokazuju da je maksimalan sadržaj saharoze kod ispitivanih hibrida 23 dana posle oplodnje što znači da je tada pravo vreme za berbu.

The highest number of commercial sweet maize hybrids is based on one or more recessive alleles that alter a carbohydrate content of endosperm. Sweet maize is consumed as human food in the milk stage of the endosperm development when the kernel is soft, sweet and succulent. Different genes used in sweet maize breeding stipulate a diverse carbohydrate content and grain quality that differ from standard quality maize. Sucrose is the dominant sugar in sweet maize grain in the milk stage of the endosperm development. It gives gain its sweetness and determines quality of immature grain that is used for consumption. Timely harvest of sweet maize is very important as the maximum sucrose content means very high grain quality. Attention came to focus on changes of the carbohydrate content during the endosperm development of five ZP sweet maize hybrids. The contents of sucrose, glucose and fructose were determined 10, 15, 20, 23, 25 and 28 days after pollination. The obtained results show a maximum sucrose content on the 23rd day after pollination meaning that time is a right time for harvest., Najveći broj komercijalnih hibrida kukuruza šećerca se zasniva na jednom ili više recesivnih alela koji menjaju ugljenohidratni sastav endosperma. Kukuruz šećerac se koristi za ljudsku ishranu u mlečnoj fazi razvoja endosperma, kada je zrno slatko, nežno i sočno. Različiti geni koji se koriste u oplemenjivanju kukuruza šećerca uslovljavaju drugačiji ugljenohidratni sastav i kvalitet zrna koji se razlikuje od kukuruza standardnog kvaliteta. Dominantan šećer u zrnu šećerca u mlečnoj fazi razvoja endosperma jeste saharoza. Ona daje slatkoću zrnu i određuje kvalitet nezrelog zrna koje se koristi za potrošnju. Veoma je važno da se berba kukuruza šećerca obavi u pravo vreme, kada je sadržaj saharoze maksimalan jer je i kvalitet zrna u to vreme visok. U radu su praćene promene ugljenohidratnog sastava tokom razvoja endosperma pet ZP hibrida kukuruza šećerca. Određivan je sadržaj saharoze glukoze i fruktoze nakon 10, 15, 20, 23, 25 i 28 dana posle oplodnje. Rezultati pokazuju da je maksimalan sadržaj saharoze kod ispitivanih hibrida 23 dana posle oplodnje što znači da je tada pravo vreme za berbu.

The carbohydrate grain composition was studied on hybrids ZPSC 504su and ZPSC 311su. High pressure liquid chromatography method was used for qualitative separation and quantitative determination of carbohydrate grain components of the selected sweet corn hybrids. Changes in the carbohydrate grain composition were observed during the maturation process. The carbohydrate grain composition of the investigated hybrids varied during maturation. Fructose and glucose content decreased, whereas sucrose content increased. Sucrose content reached its maximum in the period 23-24 days after pollination., Kukuruz šećerac se koristi za ljudsku ishranu u mlečnoj fazi razvoja endosperma kada je zrno slatko, nežno i sočno. Šećerac, zbog specifičnih osobina i načina nasleđivanja tih osobina, zahteva posebnu pažnju u procesu selekcije, u semenskoj proizvodnji i u proizvodnji konzumnog šećerca. Da bi obezbedili uspeh u selekciji za neke osobine, neophodni su specijalni postupci u oceni, kao određivanje sadržaja šećera, arome i nežnosti, ujednačenosti, izgled zrna, konfiguracija i raspored redova, itd. Najveći broj komercijalnih hibrida šećerca zasnovan je na jednom ili više recesivnih alela koji menjaju ugljenohidratni sastav zrna (su, sh2, fl1, fl2, ae, se, itd.). Praćene su promene sadržaja saharoze, glukoze i fruktoze u endospermu tokom razvoja: 5, 10, 15, 20, 23, 25 i 30 dana posle oplodnje. Najviši nivo saharoze kod ispitivanih hibrida (ZPSC 504su i ZPSC 311 su) je 23-24 dana posle oplodnje. Saharoza daje slatkoću zrnu kukuruza šećerca.

The carbohydrate grain composition was studied on hybrids ZPSC 504su and ZPSC 311su. High pressure liquid chromatography method was used for qualitative separation and quantitative determination of carbohydrate grain components of the selected sweet corn hybrids. Changes in the carbohydrate grain composition were observed during the maturation process. The carbohydrate grain composition of the investigated hybrids varied during maturation. Fructose and glucose content decreased, whereas sucrose content increased. Sucrose content reached its maximum in the period 23-24 days after pollination., Kukuruz šećerac se koristi za ljudsku ishranu u mlečnoj fazi razvoja endosperma kada je zrno slatko, nežno i sočno. Šećerac, zbog specifičnih osobina i načina nasleđivanja tih osobina, zahteva posebnu pažnju u procesu selekcije, u semenskoj proizvodnji i u proizvodnji konzumnog šećerca. Da bi obezbedili uspeh u selekciji za neke osobine, neophodni su specijalni postupci u oceni, kao određivanje sadržaja šećera, arome i nežnosti, ujednačenosti, izgled zrna, konfiguracija i raspored redova, itd. Najveći broj komercijalnih hibrida šećerca zasnovan je na jednom ili više recesivnih alela koji menjaju ugljenohidratni sastav zrna (su, sh2, fl1, fl2, ae, se, itd.). Praćene su promene sadržaja saharoze, glukoze i fruktoze u endospermu tokom razvoja: 5, 10, 15, 20, 23, 25 i 30 dana posle oplodnje. Najviši nivo saharoze kod ispitivanih hibrida (ZPSC 504su i ZPSC 311 su) je 23-24 dana posle oplodnje. Saharoza daje slatkoću zrnu kukuruza šećerca.

Sweet corn is consumed as human food in the milk stage of grain development when grain is tender, soft and sweet. Sucrose, a dominant sugar at this stage of the endosperm development, causes sweetness of grain. The changes of grain carbohydrate composition of two genotypes (ZPSC 311 su and ZPSC 450 su) were monitored over stages of maturity (10, 15, 20, 23 and 28 days after pollination). This composition was determined by high pressure chromatography on the column with chemically bound stationary phase, type NH2 and polar mobile phase of acetonitrile-water. Carbohydrate composition of grain changed during the endosperm development in a way that the percentage share of fructose and glucose decreased, while the share of sucrose increased. The maximum value of a sucrose content on the 25th day after pollination amounted to 77.00% and 89.81% in ZPSC 450 su and 78.38% and 77.92% in ZPSC 311 su, in 1999 and 2000, respectively. Thereafter opposite changes occurred. Significant differences (of glucose, fructose) in the share of certain sugars over developmental stages in, were determined. A strong rank correlation between contents of glucose and fructose was detected indicating that the increased glucose content resulted in the increased fructose content and vice versa. Negative values for rank correlation was determined between contents of sucrose and glucose and contents of sucrose and fructose indicating that the increase of the sucrose content leads to the decrease of glucose and fructose contents and vice versa., Kukuruz šećerac se upotrebljava za ishranu ljudi u mlečnoj fazi razvoja zrna kada je ono nežno, sočno i slatko. U toj fazi dominantan šećer u endospermu je saharoza koja daje slatkoću zrnu. U ovom radu praćene su promene ugljenohidratnog sastava zrna dva genotipa kukuruza šećerca (ZPSC 311 su i ZPSC 450 su) po fazama zrenja (10, 15, 20, 23 i 28 dana posle oplodnje). Ugljenohidratni sastav zrna određivan je metodom visokopritisne hromatografije na koloni sa hemijski vezanom stacioniranom fazom tipa NH2 i polarnom mobilnom fazom acetonitril-voda. Dobijeni rezultati pokazuju da se ugljenohidratni sastav zrna menjao tokom procesa razvoja endosperma, tako što se smanjivao udeo fruktoze i glukoze, a istovremeno povećavao udeo saharoze. Maksimalna vrednost sadržaja saharoze utvrđena je u fazi 25 dana posle oplodnje, 77,00% i 89,81% za ZPSC 450 su i 78,38% i 77,92% za ZPSC 311 su, tokom 1999. i 2000. godine. Nakon toga odvijale su se suprotne promene. Utvrđene su statistički značajne razlike u udelu pojedinih šećera po fazama zrenja, odnosno u zavisnosti od broja dana od oplodnje. Utvrđena je jaka korelativna veza između sadržaja glukoze i fruktoze, što ukazuje na to da se povećanjem sadržaja glukoze povećava i sadržaj fruktoze i obrnuto. Negativne vrednosti korelacije ranga nađene su između sadržaja saharoze i glukoze i sadržaja saharoze i fruktoze, što znači da se povećanjem sadržaja saharoze smanjuje sadržaj glukoze i fruktoze, i obrnuto.

Sweet corn is consumed as human food in the milk stage of grain development when grain is tender, soft and sweet. Sucrose, a dominant sugar at this stage of the endosperm development, causes sweetness of grain. The changes of grain carbohydrate composition of two genotypes (ZPSC 311 su and ZPSC 450 su) were monitored over stages of maturity (10, 15, 20, 23 and 28 days after pollination). This composition was determined by high pressure chromatography on the column with chemically bound stationary phase, type NH2 and polar mobile phase of acetonitrile-water. Carbohydrate composition of grain changed during the endosperm development in a way that the percentage share of fructose and glucose decreased, while the share of sucrose increased. The maximum value of a sucrose content on the 25th day after pollination amounted to 77.00% and 89.81% in ZPSC 450 su and 78.38% and 77.92% in ZPSC 311 su, in 1999 and 2000, respectively. Thereafter opposite changes occurred. Significant differences (of glucose, fructose) in the share of certain sugars over developmental stages in, were determined. A strong rank correlation between contents of glucose and fructose was detected indicating that the increased glucose content resulted in the increased fructose content and vice versa. Negative values for rank correlation was determined between contents of sucrose and glucose and contents of sucrose and fructose indicating that the increase of the sucrose content leads to the decrease of glucose and fructose contents and vice versa., Kukuruz šećerac se upotrebljava za ishranu ljudi u mlečnoj fazi razvoja zrna kada je ono nežno, sočno i slatko. U toj fazi dominantan šećer u endospermu je saharoza koja daje slatkoću zrnu. U ovom radu praćene su promene ugljenohidratnog sastava zrna dva genotipa kukuruza šećerca (ZPSC 311 su i ZPSC 450 su) po fazama zrenja (10, 15, 20, 23 i 28 dana posle oplodnje). Ugljenohidratni sastav zrna određivan je metodom visokopritisne hromatografije na koloni sa hemijski vezanom stacioniranom fazom tipa NH2 i polarnom mobilnom fazom acetonitril-voda. Dobijeni rezultati pokazuju da se ugljenohidratni sastav zrna menjao tokom procesa razvoja endosperma, tako što se smanjivao udeo fruktoze i glukoze, a istovremeno povećavao udeo saharoze. Maksimalna vrednost sadržaja saharoze utvrđena je u fazi 25 dana posle oplodnje, 77,00% i 89,81% za ZPSC 450 su i 78,38% i 77,92% za ZPSC 311 su, tokom 1999. i 2000. godine. Nakon toga odvijale su se suprotne promene. Utvrđene su statistički značajne razlike u udelu pojedinih šećera po fazama zrenja, odnosno u zavisnosti od broja dana od oplodnje. Utvrđena je jaka korelativna veza između sadržaja glukoze i fruktoze, što ukazuje na to da se povećanjem sadržaja glukoze povećava i sadržaj fruktoze i obrnuto. Negativne vrednosti korelacije ranga nađene su između sadržaja saharoze i glukoze i sadržaja saharoze i fruktoze, što znači da se povećanjem sadržaja saharoze smanjuje sadržaj glukoze i fruktoze, i obrnuto.