Pastaraisiais dešimtmečiais atliktų tyrimų rezultatai rodo, jog gyventojų mitybos įpročiai palaipsniui blogėja, mažiau kreipia dėmesį į suvartojamų riebalų, kalorijų kiekį. Tai įtakoja nutukimą, sergamumą širdies ir kraujagyslių ligomis, cukriniu diabetu, skatina onkologinių ligų atsiradimą. Pasaulio sveikatos organizacija (PSO) rekomenduoja, kad trans riebalų rūgštys sudarytų mažiau nei 1 proc. nuo bendrojo energijos suvartojimo kiekio. Darbo tikslas: Įvertinti lietuviškų gaminių saugumą riebalų rūgščių trans izomerų atžvilgiu. Tyrimo uždaviniai: 1. Literatūros apie riebalų rūgščių trans izomerų susidarymą jūrinių žuvų gaminiuose apžvalga. 2. Nustatyti riebalų rūgščių trans izomerų kiekius ir įvertinti jų atitikimą Lietuvoje reglamentuojamiems dydžiams skirtingų gamintojų silkės, lašišos, skumbrės gaminiuose. 3. Atlikti riebalų rūgščių trans izomerų kiekio lietuviškuose tirtuose žuvies gaminiuose monitoringą, palyginti su kitų tyrėjų duomenimis, įvertinti gaminius saugos aspektu. 4. Apdoroti gautus duomenis statistiškai, suformuoti išvadas. Išvados: 1. Žuvies ir jos gaminiuose dažniausiai nustatomos šios riebalų rūgščių trans izomerai elaidino ( C18:1n9t ) ir linolo ( C18:2n6t ). 2. Riebalų rūgščių trans izomerų buvo aptikta net 60 proc. ( % ) iš visų tirtų mėginių, o likusiuose nebuvo rasta. Riebalų rūgščių trans izomerų kiekiai svyravo nuo 0,1 iki 1,86 proc. ( % ). 3. Vertinant žuvies gaminius daugiausiai riebalų rūgščių trans izomerų marinuotoje Atlantinių silkių... [toliau žr. visą tekstą] / Purpose: to evaluate the safety of Lithuanian products trans fatty acid isomers against. Tasks: 1. Literature on trans fatty acid isomers formation of marine fish products review. 2. The set fatty acid trans isomers and assess their compliance with Lithuania regulated sizes from different manufacturers herring, salmon, mackerel products. 3. Perform trans fatty acid isomers in Lithuanian studied in fish monitoring in comparison with data of other researchers, to assess product safety. 4. Process received data statistically to form conclusions. Research. Fatty acids - saturated, unsaturated, monounsaturated, poliansaturated and trans izomer were analyzed in fish products: in salmon, herring, mackerel and technologically processed fish products. The research was performed in Chemistry laboratory of Food Institute of Kaunas University of Technology. Investigations were carried out in 2010 september – 2013 february. Results. Trans fatty acid isomers were found as much as 60 percent of all samples tested. most fatty acids, trans isomers were found smoked herring 1,86±0,35 proc. ( % ) and smoked scomber 0,60±0,01 proc. ( % ). Trans isomers depends on the technology and technology process. Chilled salmon were no found trans isomers. Fish products are safe if they are used about as little as possible heat-treated. Fish is high in saturated fatty acids, polyunsaturated fatty acids and monounsaturated fatty acids. trans isomers of fatty acids is undesirable in fish. Conclusion... [to full text]

We developed an approach to the β-thioenamide linkage contained in the S-(2-aminovinyl)cysteine (avCys) residue of thioviridamide.1,2 Kinetic and thermodynamic control of radical additions of thiols to ynamides were studied for the formation of β-thioenamide linkage. Thiyl radicals are electrophilic and ynamides are electron-rich alkynes. This complementary polarity of the radical and acceptor increases the likelihood of a successful radical addition reaction. Because little is known about these types of compounds (β-thioenamides), we were unsure what kinds of yields and stereoselectivities (cis vs. trans) to expect. The adduct stability is another issue to consider. Fortunately, under typical radical addition conditions, the two separable isomers (cis and trans) are formed in good yield. Selective formation of kinetic (cis) and thermodynamic (trans) isomers are controlled by reaction time and equivalents of thiol. We converted the kinetic isomer to the thermodynamic isomer to confirm that isomerization can occur under the reaction conditions. Alkyl and aryl thiols including cysteine-derived thiols with different ynamides were used in this process.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-10T19:19:55Z No. of bitstreams: 1 2012 - Felipe Reis Rodrigues.pdf: 1576034 bytes, checksum: f91efa30a06e540cab9e32f343fe64b0 (MD5) / Made available in DSpace on 2017-05-10T19:19:55Z (GMT). No. of bitstreams: 1 2012 - Felipe Reis Rodrigues.pdf: 1576034 bytes, checksum: f91efa30a06e540cab9e32f343fe64b0 (MD5) Previous issue date: 2012-07-20 / CAPES / In Brazil on December 23, 2003 the National Agency of Sanitary Surveillance - ANVISA has published the resolution number 360 (360 RDC). The purpose of this resolution was to repeal the laws related to nutrition labeling of packaged foods ready for consumption (DRC 39 and 40). The legislation of 2003 had the requirement on the labeling of food content of trans fatty acids, as well as specific characteristics of the information contained therein. Currently, epidemiological studies have be associated the consumption of trans fats to the risk of developing cardiovascular and chronic degenerative diseases. In addition, health professionals report that the children have shown high rates of obesity, a situation directly related to excessive consumption of manufactured products. In order to ensure the maintenance and promotion of health, the accuracy of food labels sold in Brazil, mainly in relation to lipid content present in them should be more effectively monitor. This work aimed to make a critical analysis of the nutritional labeling of ?minibolos? sold in the city of Rio de Janeiro, relating lipid profile and content of trans fatty acids and their claim presented. The methodology used for derivatization of fatty acids is characterized by the extraction transesterification. It consists of an acidic or basic catalysis, where there is a double exchange of glycerides of esters of fatty acids. The method described by Huang (2006) for methylation of fatty acids was subjected to the validation process to ensure the accuracy of the results. The determination and quantification of fatty acids were performed by gas chromatography (GC-FID) using fused silica capillary column CP-Sil 88 (100 mx 0.25 mm), at the Analytical Laboratory of Food and Beverage - LAAB. We analyzed the products containing the information to be free of trans fatty acids to quantify the actual levels of these products in order to ascertain whether the labels were described in reliable information. From the results, the obligation to inform in the labels quantities of trans fatty acids was sufficient to make available to brazilian consumers which foods are free of trans fatty acids and which still have trans fatty acids in the food industry. There were no trans fatty acids in the composition of the samples, what means that is a real assertion to be exempt from the same type of fatty acid. / No Brasil no dia 23 de dezembro de 2003 a Agencia Nacional de Vigil?ncia Sanit?ria ? ANVISA publicou a resolu??o de n?mero 360 (RDC 360). O objetivo desta resolu??o era revogar as legisla??es relacionadas a rotulagem nutricional de alimentos embalados prontos para consumo (RDC 39 e 40). A legisla??o de 2003 teve como principal caracter?stica a exig?ncia de se constar no r?tulo dos alimentos o teor de ?cidos graxos trans, al?m de caracter?sticas especificas das informa??es contidas no mesmo. Atualmente, estudos epidemiol?gicos t?m associado o consumo de gorduras trans ao risco do desenvolvimento de doen?as cardiovasculares e cr?nico-degenerativas. Al?m disso, profissionais da ?rea de sa?de relatam que a popula??o infantil tem apresentado ?ndices elevados de obesidade, situa??o diretamente relacionada ao consumo excessivo de produtos industrializados. Com o intuito de zelar pela manuten??o e promo??o da sa?de da popula??o, deve-se fiscalizar de forma mais efetiva a veracidade dos r?tulos dos alimentos comercializados no Brasil, principalmente em rela??o aos teores lip?dicos presentes nos mesmos. O presente trabalho teve por objetivos fazer uma an?lise cr?tica da rotulagem nutricional de minibolos comercializados em estabelecimentos varejistas na cidade do Rio de Janeiro, relacionando o perfil lip?dico e o teor de ?cidos graxos trans e sua alega??o apresentada. A metodologia empregada para a derivatiza??o dos ?cidos graxos ? caracterizada pela transesterifica??o. Ela consiste em uma cat?lise ?cida ou b?sica, onde h? uma dupla troca de acilglicer?is em ?steres de ?cidos graxos. O m?todo descrito por Huang (2006) para metila??o dos ?cidos graxos foi submetido ao processo de valida??o para assegurar a veracidade dos resultados obtidos. A determina??o e quantifica??o dos ?cidos graxos foram realizadas por cromatografia gasosa (CG-FID), utilizando coluna capilar de s?lica fundida CP-Sil 88 (100 m x 0.25 mm), do Laborat?rio Anal?tico de Alimentos e Bebidas ? LAAB. Foram analisados os produtos que cont?m a informa??o de serem isentos de ?cidos graxos trans para quantificar os teores reais destes produtos, visando averiguar se o descrito nos r?tulos eram informa??es fidedignas. A partir dos resultados, verificou-se em que medida a obrigatoriedade de informar nos r?tulos as quantidades de AG trans foi suficiente para tornar dispon?veis aos consumidores brasileiros quais os alimentos que s?o livres de ?cidos graxos trans e quais ainda possuem ?cidos graxos trans na ind?stria aliment?cia no Brasil. N?o foram encontrados AG trans na composi??o das amostras analisadas, sendo real a alega??o das mesmas serem isentas desse tipo de ?cido graxo.

Doctor of Philosophy / Department of Physics / Daniel Rolles / Imaging the structures of molecules, understanding the molecular dynamics in onization and dissociation processes and, most importantly, observing chemical reactions, i.e. the making and breaking of chemical bonds in real time, have become some of the most exciting topics in the atomic and molecular physics. The rapid advances of experimental tools such as synchrotron radiation light sources, free-electron lasers and continuing advances of tabletop femtosecond ultrashort lasers that provide laser pulses at a variety of wavelengths have opened new avenues for understanding the structure of matter and the dynamics of the chemical interactions. In addition, significant improvements in computational techniques and molecular dynamic simulations have provided complementary theoretical predictions on structures and chemical dynamics. The Coulomb explosion imaging method, which has been developed and applied in many studies in the last three decades, is a powerful way to study molecular structures. The method has mostly been applied to small diatomic molecules and to simple polyatomic molecules. In this thesis, Coulomb explosion imaging is applied to study the structure of isomers, molecules that have the same chemical formula but different chemical structures. Specifically, by taking inner-shell photoionization as well as strong-field ionization approaches to ionize and fragment the molecules and by using coincidence electron-ion-ion momentum imaging techniques to obtain the three-dimensional momentum of fragment ions, structures of isomers are distinguished by using the correlations among product ion momentum vectors. At first, the study aims to understand if the Coulomb explosion imaging of geometrical isomers can identify and separate cis and trans structures. Secondly, in order to extend the application of the Coulomb explosion imaging method to larger organic molecules to test the feasibility of the method for identifying structural isomers, photoionization studiesof 2,6- and 3,5-difluoroiodobenzene have been conducted. In addition, using the full three-dimensional kinematic information of multi-fold coincidence channels, breakup dynamics of both cis/trans geometric isomers and structural isomers, and in particular, sequential fragmentation dynamics of the difluoroiodobenzene isomers are studied. Furthermore, for each study, Coulomb explosion model simulations are conducted to complement the experimental results. The results of the Coulomb explosion imaging reseach in this thesis paves the way for future time-resolved Coulomb explosion imaging experiments aiming to understand the transient molecular dynamics such as photoinduced ring opening reactions and cis/trans isomerization processes in gas-phase molecules.