Submitted in fulfillment for the Degree of Doctor of Philosophy (Biotechnology), Durban University of Technology, Durban, South Africa, 2016. / Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis (TB) has infected approximately one-third of the world population, with 9.6 million TB cases in 2014. The emergence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) strains of MTB has further complicated the problem of TB control. It is now imperative that novel antimycobacterial compounds are discovered in order to treat infections and reduce the duration of current TB therapy courses. For centuries, medicinal plants have been used globally worldwide for the treatment and prevention of various ailments. This occurs particularly in developing countries where infectious diseases are endemic and modern health facilities and services are inadequate. In recent years, the use and search for plant drug derivatives have been fast-tracked. Ethnopharmacologists, botanists, microbiologists, and natural product chemists are trying to discover phytochemicals which could be developed for the treatment of infectious diseases, especially TB. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimycobacterial activity. In the search for new lead compounds, nine medicinal plant species, Buddleja saligna, Capparis tomentosa, Carpobrotus dimidiatus, Dichrostachys cinerea, Ekerbergia capensis, Ficus Sur, Gunnera perpensa, Leonotis leonurus and Tetradenia riparia were collected in Kwa-Zulu Natal (KZN) following report of their therapeutic use in traditional medicine to treat symptoms and infections related to TB. They were tested in vitro for their activity against Mycobacterium smegmatis, Mycobacterium tuberculosis H37Rv (ATCC 25177) and three well-characterized clinical isolates of MDR-TB and XDR-TB using the agar incorporation method. The minimum inhibitory concentration of the active plant extracts was determined using the broth microdilution method. Our findings show that five of the nine plants screened have antimycobacterial activity with concentrations ranging from 125 µg/ml to 1000 µg/ml. The aqueous extracts of G. perpensa and T. riparia; and the methanolic extracts of B. saligna, C. tomentosa, and C. dimidiatus possessed significant activity against M. smegmatis, M. tuberculosis H37Rv (ATCC 25177) and the three well-characterized clinical isolates of MDR-TB and XDR-TB. The cytotoxic effect of the active plant extracts was evaluated against the mouse BALB/C monocyte-macrophage (J774.2) and peripheral blood mononuclear cells (PBMCs). The toxic effects of the active plant extracts were evaluated using the brine shrimp lethality assay. Except for a high concentration of G. perpensa none of the other plants which possessed antimycobacterial activity showed any toxic or cytotoxic activity. The active plant extracts were thereafter assessed to determine if they had any effect on the survival or death of mycobacterial species, M. smegmatis, bound within the macrophage (J774.2) cell line at a concentration of 100 µg/ml. B. saligna had inactivated most of the phagocytosed bacilli after 24 hours of treatment therefore, it has a bactericidal effect on the mycobacteria located within the mouse macrophage. A phytochemical investigation of the leaves of B. saligna led to the isolation of two isomeric pentacyclic triterpene compounds namely Oleanolic Acid (OA) and Ursolic Acid (UA) using thin layer chromatography followed by silica gel column chromatography. The structures of these compounds were fully characterized by detailed NMR investigations, which included 1H and 13C NMR. Ursolic acid was isolated from this plant for the first time. Two-dimensional (2D) and three-dimensional (3D) quantitative structure-activity relationship (QSAR) studies were carried out to provide insight on the interaction of the compounds with the enzyme. Molecular docking studies predicted the free binding energy of the triterpenes inside the steroid binding pocket of Mycobacterium tuberculosis fadA5 thiolase compared to a reported inhibitor. Thus, their ability to inhibit the growth of Mycobacterium tuberculosis was predicted and was confirmed to possess significant antimycobacterial activity when tested against M. smegmatis, M. tuberculosis H37Rv (ATCC 25177), clinical isolates of MDR-TB and XDR-TB using the Microplate Alamar Blue Plate (MABA) assay. The present study has scientifically validated the traditional use of medicinal plant B. saligna. / D

Orientadora: Marcia Aparecida Silva Graminha / Banca: Jean Leandro dos Santos / Banca: Maria José Soares Mendes Giannini / Banca: Sergio de Albuquerque / Banca: André Luiz Pedrosa / Resumo: As leishmanioses são doenças causadas pelo protozoário parasito do gênero Leishmania e transmitidas pela picada do insetor vetor, o flebotomíneo. As leishmanioses apresentam diferentes manifestações clínicas, sendo elas leishmaniose cutânea, mucocutânea, cutânea difusa e visceral. Os fármacos atualmente disponíveis para o tratamento das leishmanioses apresentam diversos efeitos colaterais, além de problemas associados às vias de administração e surgimento de cepas resistentes. Os furoxanos e benzofuroxanos são compostos heterocíclicos contendo a função N-óxido com múltiplas atividades, incluindo anti-T. cruzi e anti-Leishmania. Neste trabalho, uma série de derivados de furoxano (compostos 3, 4a-b, 13a-b, e 14a-f) e benzofuroxano (7 e 8a-c) foram avaliados em ensaios in vitro frente as espécies L. (L.) amazonensis, L. (L.) mexicana e L. (L.) infantum. Os compostos foram também avaliados quanto à citotoxicidade em macrófagos murinos e quanto à sua capacidade de produção de óxido nítrico in vitro e em macrófagos infectados com o parasito. A atividade leishmanicida (EC50) dos derivados em estudo variou de 2,0 a 96,0 µM, enquanto que a citotoxicidade de 5,0 a 250,0 µM. A molécula doadora de óxido nítrico 14e revelou ser a mais promissora dentre os derivados analisados, exibindo ação pH-dependente. Adicionalmente, o derivado 14e mostrou ser capaz de inibir a enzima cisteíno protease de Leishmania, importante fator de virulência deste parasito. Estes ensaios mostraram que 14e inibe ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Leishmaniases are diseases caused by the protozoan parasite of Leishmania genus and transmitted by the bite of insect vetor, phlebotomine. Leishmaniases present different clinical manifestations, including cutaneous, mucocutaneous, diffuse cutaneous and visceral leishmaniasis. The currently available drugs for leishmaniasis treatment show several side effects, besides problems associated with the administration routes and the emergence of resistant strains. Furoxan and benzofuroxan are heterocyclic compounds containing the N-oxide function showing several activities, including anti-T. cruzi and antiLeishmania. In this work, a series of furoxan (compounds 3, 4a-b, 13a-b, and 14a-f) and benzofuroxan (7 and 8a-c) derivatives were tested against the species L. (L.) amazonensis, L. (L.) mexicana e L. (L.) infantum. The compounds were also evaluated for cytotoxicity against murine macrophages and as to its ability to produce nitric oxide in vitro and in macrophages infected with the parasite. The antileishmanial activity (EC50) of the derivatives studied ranged from 2.0 to 96.0 μM, whereas the cytotoxicity of 5.0 to 250.0 μM. The nitric oxide donor molecule 14e revealed to be the most promising of the analyzed derivatives, exhibiting a pH-dependent action. Futhermore, the derivative 14e was shown to be capable of inhibiting the cysteine protease enzyme of Leishmania, an important virulence factor of this parasite. These assays showed that 14e inhibits the cysteine protease B 2.8 re... (Complete abstract click electronic access below) / Doutor

O presente trabalho teve como foco principal, a preparação one pot de compostos orgânicos alquílicos e vinílicos contendo o grupamento butiltelurenila em sua estrutura, e o estudo do comportamento desses em variados tipos de reações. Uma delas foi a reação de troca Te/Li. Assim, teluretos foram utilizados como equivalentes sintéticos de vários reagentes organometálicos. Os teluretos foram submetidos à reação de troca Te/Li, e os respectivos compostos organolítio gerados, transformados em reagentes organometálicos de zinco, cobre e cério através de reações de transmetalação. Esses reagentes gerados in situ foram submetidos à reação com variados eletrófilos. Os reagentes organometálicos de zinco e cobre gerados foram submetidos à reação de acilação frente a cloreto de ácidos, resultando em 1,4-hidroxicetonas. Um exemplo dessas hidroxicetonas foi obtido em sua forma enantiopura utilizando um telureto quiral, e esse utilizado na síntese formal e enantiosseletiva da (-)-Pirenoforina. Diferentes estequiometrias de cupratos e outros reagentes organometálicos oriundos de um telureto também foram preparados, e esses testados em reações de substituição de tosilatos e abertura de epóxidos. Os substratos gerados dessas reações foram empregados na síntese das moléculas bioativas Endo-Brevicomina e Frontalina. Apresentaremos também, o resultado obtido na reação direta entre uma espécie di-litiada quiral na presença de benzonitrila. A hidroxicetona assim produzida é um análogo do Ipomeanol, um composto com atividade contra câncer de pulmão. Será apresentado também, o comportamento de entidades di-aniônicas contendo grupamentos silila em reações catalisadas por CeCl3, em que a captura desses com eletrófilos como aldeídos, forneceram 1,4-enedióis em bons rendimentos químicos e alta diastereosseletividade. Será apresentado também o estudo do comportamento de teluretos com hibridização sp2 em reações pericíclicas. A reação pericíclica estudada compreende compostos contendo telúrio (II) e (IV) em reações de Diels-Alder. / One of the main purposes of this work was to develop a new direct methodology to prepare functionalized organic tellurides, to be submitted to a series of different reactions, as for example the Te/Li exchange reaction, aimed to afford synthetic equivalents of several organometallic reagents. Zinc, copper and cerium organometallic compounds were generated via a transmetalation reaction of the lithium species, and were reacted with several electrophiles. As a result, 1,4-hydroxyketones could be successfully prepared. According to this methodology, an enantioenriched 1,4-hydroxyketone could be obtained, using a chiral telluride as starting material. This chiral nonracemic intermediate was employed in an enantioselective formal synthesis of (-)-Pyrenophorin. Cuprates and other organometallic reagents, prepared from a specific telluride and using the above described methodology, were the choosen nucleophiles for performing some aliphatic substitution reactions and, in particular, for the ring opening of epoxides. The resulting products were employed as building blocks for the synthesis of the bioactive cyclic compounds Endo-Brevicomin and Frontalin. The direct reaction of the chiral dilithiated specie with benzonitrile afforded a 1,4-hydroxyketone as an analogue of Ipomeanol, a bioactive compound for cancer therapy. Bis-anionic sililated species, prepared from a telluride, were submitted to reaction with a series of aldehydes. Such reactions, in which CeCl3 was employed as catalyst, showed to be highly diastereoselectives, affording (E)-1,4-enediols in good yields. The pericyclic reaction of insaturated tellurides was also investigated. It is worth mentioning that the same Diels-Alder reaction could be performed either with tellurium II or tellurium IV species.

Os frutos da pitangueira pertencem à família Myrtaceae e podem ser encontrados em três variedades da mesma espécie, reconhecidos de acordo com a cor dos frutos como amarelo, vermelho e roxo. O objetivo deste estudo é caracterizar as três variedades de frutos de pitanga, com relação aos principais carotenoides e compostos fenólicos, e seu comportamento durante o desenvolvimento. Os frutos foram obtidos da região de Campinas (IAC) e fornecidos pela EMBRAPA - (RS). Os extratos metanólico dos frutos foram caracterizados quanto ao conteúdo antocianinas monoméricas, onde somente a variedade roxa, das diferentes plantas e região, apresentou aumento de concentração de antocianinas monoméricas com o desenvolvimento (0,59 a 1,94 mg cy-3-glu eq/g b.s. e 1,43 a 8,47 cy-3-glu eq/g b.s. para o estádio intermediário e maduro, respectivamente. Além disso, a variedade roxa no estádio maduro apresentou maior concentração de fenólicos totais (6,52 a 18,42 mg de AG/g b.s.) quando comparados às outras. O ácido cítrico foi identificado, por CLAE/DAD, como o ácido orgânico majoritário, seguido pelos ácidos succínico e málico, em todas as variedades, com maior concentração no estádio verde. De acordo com a concentração de ácido ascórbico, a pitanga não é uma boa fonte de vitamina C, apresentando valor máximo de 4,0 mg/g b.s no estádio maduro. Os açúcares majoritários encontrados foram a glicose e a frutose. A antocianina majoritária, identificada por LC-ESI-MS/MS, da variedade roxa, no estádio maduro foi a cianidina-3-glicosídeo, com uma variação de 8,05 a 640,53 mg/100g b.s, já o flavonoide majoritário na variedade amarela e vermelha foram miricetina e quercetina em ambas variedades. O carotenoide majoritário identificado por CLAE/DAD, em todas variedades no estádio maduro foi o licopeno, onde a variedade vermelha se destaca pela maior concentração. Dessa forma, o perfil de flavonoides não é alterado com o desenvolvimento, mas é observado uma redução no seu conteúdo nas variedades vermelha e amarela; já a variedade roxa apresenta alteração no perfil de flavonoides, com a expressão de antocianinas no estádio maduro. Por outro lado, o perfil de carotenoides em todas as variedades não sofreu alteração. / The fruits of the pitangueira belong to the family Myrtaceae and can be found in three varieties of the same species, recognized according to the color of the fruits as yellow, red and purple. The aim of this study was characterize the fruits of three pitanga varieties, according to the carotenoids and phenolic compounds composition, and their behavior during ripening. The fruits were obtained from the Campinas region and also provided by EMBRAPA - (RS). Monomeric anthocyaninswere detected only on purple variety, presenting 0.59 to 1.94 mg cy-3-Ο-glu eq/g d.w. and 1.43 to 8.47 cy-3-Ο-glu eq/g d.w.) for the intermediate and mature stages, respectively. In addition, the purple variety at the mature stage had the highest total phenolics concentration (6.52 to 18.42 mg of AG/g d.b.) as compared to other varieties. The citric acid was identified as the major organic acid, followed by succinic and malic acids, in all varieties, with a higher concentration in the green stage. According to the concentration of ascorbic acid, pitanga could not be considered a good source of vitamin C, presenting the highest amount of the 4.0 mg/g d.w. at the mature stage. The major soluble sugars found were glucose and fructose. The major anthocyanin of the purple variety, identified by LC-ESI-MS/MS in the mature stage, was cyanidin-3-Ο-glucoside, ranging from 8.05 to 640.53 mg /100g d.w., whereas the major flavonoids in the yellow and red varieties were myricetin and quercetin. The flavonoid profile was not altered with ripe developing, but a decrease in its content was observed in the red and yellow varieties; on the other hand, the purple variety presented a change in the flavonoid profile, with the expression of anthocyanins in the mature stage. The carotenoids profile in all varieties was the same. The major carotenoid identified by HPLC/DAD, at the mature stage, was lycopene, where the red variety presented the highest concentration.

Este trabalho teve como objetivo a produção e caracterização de farinhas e amidos de mashua (M) e olluco (O) originários da cidade de Tarma (Peru). As farinhas foram produzidas por moagem seca e passagem em peneiras de 45, 120 e 400 mesh Tyler. Os amidos foram isolados a partir dos tubérculos por moagem úmida. As farinhas e os amidos foram caracterizados em função da distribuição do tamanho de partículas (por difração a laser com espalhamento estático de luz), composição centesimal, morfologia (por microscopia eletrônica de varredura - MEV), cristalinidade, propriedades térmicas (por termogravimetria - TG e calorimetria diferencial de varredura - DSC), e espectroscopia de infravermelho por transformada de Fourier (FTIR). As farinhas de mashua e olluco também foram caracterizadas em função da cor, atividade antioxidante, teor de fenólicos totais, antocianinas, betaxantinas, betacianinas e carotenoides totais. As frações de farinhas de mashua e olluco apresentaram tamanhos médios de partícula na faixa de 37,9 a 273,6 ?m, e 31,7 a 274,4 ?m, respectivamente. A fibra e o amido foram os principais componentes das farinhas de mashua e olluco, sendo que a fibra encontra-se em maior concentração na fração mais grossa e o amido, na fração mais fina, independente da espécie de tubérculo. Os amidos dos tubérculos apresentaram padrão de cristalinidade tipo B, avaliados por difração de raios-x (DRX). Na mashua, os formatos dos grânulos foram ovais e esféricos com distribuição polimodal de tamanho de partículas com diâmetros médios das populações entre 1,7 e 31 ?m. Os grânulos de amido de olluco foram maiores (1,9 - 92,3 ?m) com formatos mais assimétricos e irregulares. Com o refino das farinhas, houve um aumento no índice de cristalinidade das frações de farinhas para ambos os tipos de tubérculos sendo quase semelhante aos amidos isolados. O amido de mashua apresentou menor temperatura de pico de gelatinização (60oC) do que o olluco (64,7oC). A cor, atividade antioxidante, teor de compostos fenólicos totais, antocianinas, betaxantinas, betacianinas e carotenoides variaram em função da granulometria das farinhas e/ou do tipo de tubérculo. Conclui-se que o refino das farinhas influenciou no teor de amido, amilose, fibras, cristalinidade, xix estabilidade térmica, cor e teor de compostos antioxidantes. Devido ao seu alto teor de amido e compostos bioativos estas farinhas podem ser usadas como aditivos na indústria de alimentos e farmacêutica, ou para produção de filmes com possíveis propriedades bioativas. / This study aimed to produce and characterize flours and starches from mashua (M) and olluco (O) originating in the city of Tarma (Peru). The flours were produced by dry milling and sieved through 45, 120, and 400 Tyler mesh sieves. Starches were isolated from the tubers by wet grinding. The flours and starches were characterized in terms of particle size distribution (by diffraction laser scattering), chemical composition, morphology (by Scanning Electron Microscopy), crystallinity, thermal properties (by Thermogravimetric Analysis - TG and Differential Scanning Calorimetry - DSC), and Fourier Transform Infrared Spectroscopy (FTIR). Mashua and olluco flours were also studied for their color, antioxidant activity, and total phenolics, anthocyanin, betaxanthin, betacyanin, and carotenoid contents. The particle sizes ranged from 37,9 to 273,6 ?m and from 31,7 to 274,4 ?m for the mashua and olluco flour fractions, respectively. Total fibers and starch were the main components of the tuber flours. Fibers and starch were the major components in the thicker and thinner fractions, respectively, regardless of the tuber crop. Mashua starch granules exhibited oval and spherical shape, and particle sizes with polymodal distribution and average diameter between 1,7 to 31 ?m. Olluco starch granules were larger (1,9-92,3 ?m) and more asymmetric and irregular than mashua starch granules. Tuber starches showed crystallinity type B, evaluated by X-ray diffraction. Considering the same tuber species, the flour fraction containing thinner particles and the isolated starch presented similar crystallinity index. Mashua starch had lower gelatinization peak temperature (60 oC) than olluco starch (64.7 oC). Color, antioxidant activity, and total phenolics, anthocyanin, betaxanthin, betacyanin, and carotenoid contents varied according to the flour particle sizes and/or the tuber species. Therefore, refining tuber flours influenced starch, amylose, and fiber contents, crystallinity, thermal stability, color, and antioxidant activity of the resulting flours. Because of their high contents of starch and bioactive compounds, these flours can be used as additives in the food industry and pharmacy, and they can also be employed in the production of bioactive films.

As espécies da família Zingiberaceae são caracterizadas por suas raízes. Constituintes fenóis como curcuminóides e gingeróis destacam-se por suas atividades biológicas. A irradiação de alimentos é um meio de preservação eficiente, porém, é importante garantir que suas propriedades funcionais sejam preservadas. Este trabalho vem avaliar o efeito do processamento por radiação gama de 60Co em doses de 0, 5, 10, 15 e 20kGy sobre espécies de Zingiberaceae: açafrão (Curcuma longa L.), gengibre (Zingiber officinale Roscoe) e zedoária (Curcuma zedoaria (Christm.) Roscoe). A determinação qualitativa do perfil de compostos bioativos foi realizada por cromatografia de camada delgada. A quantificação de compostos fenólicos foi realizada pelo método Folin-Ciocalteu e a avaliação do potencial da atividade antioxidante pelo teste de captação do radical livre [2,2 difenil-1-pricril-hidrazil (DPPH)] e método Rancimat®. A quantificação de curcumina e 6-gingerol foram realizadas por Cromatografia Líquida de Alta Eficiência. Não houve mudança no perfil fitoquímico das espécies após o tratamento por irradiação. Em relação às amostras controle, houve perdas significativas no teor de compostos fenólicos nas amostras de açafrão nas doses de 15kGy e 20kGy. Ocorreu decréscimo significativo da capacidade de captação do DPPH nos extratos de gengibre irradiados e no extrato de zedoária irradiado com 20kGy. O Índice de Atividade Antioxidante foi significativamente menor nos extratos de açafrão irradiados com 5kGy e 15kGy e nos extratos irradiados de zedoária. A quantificação de curcumina foi significativamente menor nos extratos de açafrão irradiados com 15 kGy e não houve diferença significativa na quantificação de 6-gingerol entre os extratos de gengibre. Conclui-se que a tecnologia de processamento de Zingiberaceae por radiação gama pode ser viável para as indústrias. Para segurança da manutenção da atividade antioxidante as doses devem ser de até 10kGy. / The species of Zingiberaceae family are characterized for rhizome. Phenolic constituents like curcuminoids and gingerols have had reports of biological activities. Food irradiation is an effective means of preservation, however it is important to ensure that their functional properties are not compromised. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co in doses of 0, 5, 10, 15 and 20 kGy on species of Zingiberaceae: turmeric (Curcuma longa L.), ginger (Zingiber officinale Roscoe) and zedoaria (Curcuma zedoaria (Christm.) Roscoe). The qualitative determination of bioactive compounds profile was performed by thin layer chromatography. The quantification of phenolic compounds was performed by Folin-Ciocalteu method and assessing the potential of antioxidant activity by the free radical [2,2 difenil-1-pricril-hidrazil (DPPH)] scavenging and by Rancimat® method. The curcumin and 6-gingerol quantification was performed by High Performance Liquid Chromatography. Compared to control, there were significant losses of total phenolic compounds in turmeric samples irradiated with 15kGy and 20kGy. There were significant decreases in the ability to scavenge DPPH in irradiated ginger extracts and zedoaria extract irradiated with 20kGy. The Antioxidant Activity Index was significantly lower in 5kGy and 15kGy irradiated turmeric extracts and in irradiated zedoaria extracts. The curcumin quantification was significantly lower in 15kGy irradiated turmeric extracts and there was no significant difference in the 6-gingerol quantification between ginger extracts. It is concluded that gamma radiation processing technology in Zingiberaceae can be viable for industry. To maintain safety of antioxidant activity it should be applied doses up 10kGy.

As espécies da família Zingiberaceae são caracterizadas por suas raízes. Constituintes fenóis como curcuminóides e gingeróis destacam-se por suas atividades biológicas. A irradiação de alimentos é um meio de preservação eficiente, porém, é importante garantir que suas propriedades funcionais sejam preservadas. Este trabalho vem avaliar o efeito do processamento por radiação gama de 60Co em doses de 0, 5, 10, 15 e 20kGy sobre espécies de Zingiberaceae: açafrão (Curcuma longa L.), gengibre (Zingiber officinale Roscoe) e zedoária (Curcuma zedoaria (Christm.) Roscoe). A determinação qualitativa do perfil de compostos bioativos foi realizada por cromatografia de camada delgada. A quantificação de compostos fenólicos foi realizada pelo método Folin-Ciocalteu e a avaliação do potencial da atividade antioxidante pelo teste de captação do radical livre [2,2 difenil-1-pricril-hidrazil (DPPH)] e método Rancimat®. A quantificação de curcumina e 6-gingerol foram realizadas por Cromatografia Líquida de Alta Eficiência. Não houve mudança no perfil fitoquímico das espécies após o tratamento por irradiação. Em relação às amostras controle, houve perdas significativas no teor de compostos fenólicos nas amostras de açafrão nas doses de 15kGy e 20kGy. Ocorreu decréscimo significativo da capacidade de captação do DPPH nos extratos de gengibre irradiados e no extrato de zedoária irradiado com 20kGy. O Índice de Atividade Antioxidante foi significativamente menor nos extratos de açafrão irradiados com 5kGy e 15kGy e nos extratos irradiados de zedoária. A quantificação de curcumina foi significativamente menor nos extratos de açafrão irradiados com 15 kGy e não houve diferença significativa na quantificação de 6-gingerol entre os extratos de gengibre. Conclui-se que a tecnologia de processamento de Zingiberaceae por radiação gama pode ser viável para as indústrias. Para segurança da manutenção da atividade antioxidante as doses devem ser de até 10kGy. / The species of Zingiberaceae family are characterized for rhizome. Phenolic constituents like curcuminoids and gingerols have had reports of biological activities. Food irradiation is an effective means of preservation, however it is important to ensure that their functional properties are not compromised. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co in doses of 0, 5, 10, 15 and 20 kGy on species of Zingiberaceae: turmeric (Curcuma longa L.), ginger (Zingiber officinale Roscoe) and zedoaria (Curcuma zedoaria (Christm.) Roscoe). The qualitative determination of bioactive compounds profile was performed by thin layer chromatography. The quantification of phenolic compounds was performed by Folin-Ciocalteu method and assessing the potential of antioxidant activity by the free radical [2,2 difenil-1-pricril-hidrazil (DPPH)] scavenging and by Rancimat® method. The curcumin and 6-gingerol quantification was performed by High Performance Liquid Chromatography. Compared to control, there were significant losses of total phenolic compounds in turmeric samples irradiated with 15kGy and 20kGy. There were significant decreases in the ability to scavenge DPPH in irradiated ginger extracts and zedoaria extract irradiated with 20kGy. The Antioxidant Activity Index was significantly lower in 5kGy and 15kGy irradiated turmeric extracts and in irradiated zedoaria extracts. The curcumin quantification was significantly lower in 15kGy irradiated turmeric extracts and there was no significant difference in the 6-gingerol quantification between ginger extracts. It is concluded that gamma radiation processing technology in Zingiberaceae can be viable for industry. To maintain safety of antioxidant activity it should be applied doses up 10kGy.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Brewer’s spent grain (BSG), a solid residue obtained from brewing beer, is gaining attention in the food, cosmetics and pharmaceutical industry due to its use as natural source of colorants, texturisers, functional ingredients and preservatives. It is therefore necessary to develop an economically viable method for the extraction, isolation or enrichment of these compounds. Although literature shows the technical feasibility of extraction of bioactive compounds from BSG at laboratory bench scale, none of the reviewed literature could provide adequate information necessary to determine the economic feasibility of the process at commercial scale. The aim of this study was to investigate the technical and economic viability of a commercial process for the recovery of antioxidant rich polyphenolic compounds from brewers spent grain using organic solvents and/or water. The objectives were to select the best solvent, perform the optimisation and kinetic study, as well as to model and simulate the extraction process with the aim of performing an economic analysis. In selecting the best solvent, maceration and soxhlet extraction were used for the recovery of polyphenolic compounds. Acetone and acetone: water mixtures, ethanol and ethanol: water mixtures as well as pure water were used as solvents. The evaluation of the best solvent was measured by the total phenolic content (TPC), flavonol content, the antioxidant activity using 2.2-diphenyl-1-picrylhydrazyl (DPPH) assay and ferric reducing antioxidant power (FRAP) assay. The study performed optimisation for various operational parameters (time, temperature, solvent to feed ratio and shaking speed) using response surface method. The effect of temperature on the extraction kinetics was also investigated with experiments being carried out at 20°C, 40°C and 80°C. Antioxidant activity was detected in all BSG extracts, but water showed the highest global yield and rates of extraction. The optimum conditions were found at 15 min reaction time, temperature of 40 °C, shaking speed of 185 rpm and solvent to solid ratio of 27.5: 1. So-Macdonald model was a suitable fit for the experimental data with a R2-value range of (0.85 < r2 < 0.995). A processing scenario was proposed as a base case, upon which subsequent scenarios were generated to improve the operation or the economics. SuperPro Designer® (Intelligen, Inc) was used for modelling the proposed process, for simulation and for the economic evaluation. Four alternative schemes from the base case simulation were developed for optimisation of the process. The process was found to be economically feasible and attractive with a return of investment (ROI) of 48.45 % for alternative scheme 4. The results in this thesis highlight the likely economic feasibility of the extraction of polyphenolic compounds from BSG at commercial scale by the maceration method.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Restricted until October 2006. Bibliography: leaves 108-134.