Doctor of Philosophy / Food Science Institute / J. Scott Smith / The International Agency for Research on Cancer (IARC) has classified 4(5)-methylimidazole (4-MeI) as a possible human carcinogen. Also, the National Toxicology Program (NTP) has concluded that 4-MeI is a probable cancer causing agent. Even though 4-MeI has been detected in several processed foods no research has been conducted to measure levels of 4-MeI in processed meat. A method using isobutylchloroformate (IBCF) and gas chromatography mass-spectrometry (GC-MS) was developed to detect and quantify 4-MeI in processed meat products. Levels of 4-MeI ranged from 0.04 to 1.01 μg/g with recovery of 94.76 to 103.94%. Formation of 4-MeI in glucose-amino acid model system was studied. [subscript]D-Glucose (Glu) was mixed individually in equimolar concentrations of 0.05, 0.1, or 0.15 M and equal volume with [subscript]L-Alanine (Ala), [subscript]L-Arginine (Arg), Glycine (Gly), [subscript]L-Lysine (Lys), and [subscript]L-Serine (Ser); and the mixtures were heat treated at 60, 120, and 160°C for 1 h. Among all tested amino acids, Glu-Arg produced the highest level of 4-MeI. The Glu-Lys model system showed higher browning and lower concentrations of 4-MeI. The effect of ascorbic acid (ASA), a strong antioxidant, was studied in the Glu-Arg model system. Four concentrations of ASA (0.0375, 0.075, 0.15, and 0.3 M) were mixed with 0.15 M equimolar of Glu-Arg and heat treated at 160°C for 1h. ASA inhibited formation of 4-MeI by 40.29, 69.94, 75.13, and 96.25% for the 0.0375, 0.075, 0.15, and 0.3 M concentrations. Contrarily, ascorbic acids increased the browning in all treatments compared to control treatment by 10.67, 15.47, 18.4, and 28.8% for the 0.0375, 0.075, 0.15, and 0.3 M concentrations. Adding ASA to processed food may reduce formation of 4-MeI and increase the browning that is a desired attribute to processed meat products.

Made available in DSpace on 2014-12-17T14:08:55Z (GMT). No. of bitstreams: 1 AngeloASO_DISSERT.pdf: 1949187 bytes, checksum: e1a09a3868062ecaf1e44bef8c6c67fb (MD5) Previous issue date: 2013-11-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Ionic liquids (ILs) are organic compounds liquid at room temperature, good electrical conductors, with the potential to form as a means for electrolyte on electrolysis of water, in which the electrodes would not be subjected to such extreme conditions demanding chemistry [1]. This paper describes the synthesis, characterization and study of the feasibility of ionic liquid ionic liquid 1-methyl-3(2,6-(S)-dimethyloct-2-ene)-imidazole tetrafluoroborate (MDI-BF4) as electrolyte to produce hydrogen through electrolysis of water. The MDI-BF4 synthesized was characterized by thermal methods of analysis (Thermogravimetric Analysis - TG and Differential Scanning Calorimetry - DSC), mid-infrared spectroscopy with Fourier transform by method of attenuated total reflectance (FTIR-ATR), nuclear magnetic resonance spectroscopy of hydrogen (NMR 1H) and cyclic voltammetry (CV). Where thermal methods were used to calculate the yield of the synthesis of MDI-BF4 which was 88.84%, characterized infrared spectroscopy functional groups of the compound and the binding B-F 1053 cm-1; the NMR 1H analyzed and compared with literature data defines the structure of MDI-BF4 and the current density achieved by MDI-BF4 in the voltammogram shows that the LI can conduct electrical current indicating that the MDI-BF4 is a good electrolyte, and that their behavior does not change with the increasing concentration of water / Os l?quidos i?nicos (LIs) s?o compostos org?nicos l?quidos ? temperatura ambiente, bons condutores el?tricos, com potencial para constitu?rem como meio eletr?lito para a eletr?lise da ?gua, no qual os eletrodos n?o seriam submetidos a condi??es t?o extremas de exig?ncia qu?mica [1]. O presente trabalho descreve a s?ntese, a caracteriza??o e o estudo da viabilidade do l?quido i?nico tetrafluoroborato de 1-metil-3(2,6-(S)-dimetiloct-2-eno)-imidazol (MDI-BF4) como eletr?lito para a produ??o de hidrog?nio atrav?s da eletr?lise da ?gua. O MDI-BF4 sintetizado foi caracterizado por: m?todos t?rmicos de an?lise (An?lise Termogravim?trica - TG e Calorimetria Explorat?ria Diferencial - DSC); espectroscopia de infravermelho m?dio com transformada de Fourier pelo m?todo da reflect?ncia total atenuada (FTIR-ATR); espectroscopia de resson?ncia magn?tica nuclear de hidrog?nio (RMN 1H) e voltametria c?clica (VC). Onde os m?todos t?rmicos foram utilizadas para calcular o rendimento da s?ntese do MDI-BF4 que foi de 88,84 %; a espectroscopia de infravermelho caracterizou os grupos funcionais do composto e a liga??o B-F em 1053 cm-1; o RMN 1H analisado e comparado com dados da literatura define a estrutura do MDI-BF4 e a densidade de corrente alcan?ada pelo MDI-BF4 no voltamograma mostra que o LI consegue conduzir corrente el?trica indicando que o MDI-BF4 ? um bom eletr?lito e que seu comportamento n?o sofre altera??o com o aumento da concentra??o de ?gua

Настоящая работа состоит из 3 глав и посвящена бесферментному количественному определению креатинина, глюкозы, мочевины с использованием медь(II)-имидазольных каркасов. В ходе работы проведено формирование электрокаталитически активного слоя на поверхности рабочего электрода. Таким образом, каталитически активный слой с наибольшей чувствительностью сформирован на печатном электроде 3-в-1 с использованием многостенных углеродных нанотрубок (cMWCNT), электроосаждённым золотом и медь(II)-имидазольного каркаса, состоящего из иона меди(II) и 2-меркаптоимидазола и 2-метилимидазола. Проведены исследования селективности полученного каталитически активного слоя. / This work consists of 3 chapters and is devoted to the enzyme-free quantitative determination of creatinine, glucose, urea using copper(II)-imidazole frameworks. In the course of the work, the formation of an electrocatalytically active layer on the surface of the working electrode was carried out. Thus, the catalytically active layer with the highest sensitivity is formed on a 3-in-1 printed electrode using multi-walled carbon nanotubes (cMWCNT) electrodeposited with gold and copper(II)-imidazole framework consisting of copper(II) ion and 2-mercaptoimidazole and 2-methylimidazole. The selectivity of the obtained catalytically active layer has been studied.