Diversos estudos com compostos fenólicos têm demonstrado os efeitos benéficos destas substâncias frente a diversas patologias, incluindo alguns tipos de câncer. Considerando que os polifenóis da dieta, não absorvidos, podem permanecer no trato gastrointestinal por um período prolongado, e as células do epitélio intestinal podem ser regularmente expostas a estes compostos, é importante avaliar seu potencial efeito benéfico no trato gastrointestinal. Entretanto, é necessário determinar como o processo de digestão afeta a estabilidade e propriedades químicas destes compostos. O objetivo deste estudo foi avaliar a bioacessibilidade dos polifenóis de sucos de frutas da família Myrtaceae: cagaita (Eugenia dysenterica DC), camu-camu (Myrciaria dubia Mc Vaugh) e jaboticaba (Myrciaria cauliflora B.), o efeito da digestão gastrintestinal in vitro sobre sua atividade antioxidante, e a ação dos polifenóis dos sucos digeridos sobre a proliferação, ciclo celular e apoptose em células Caco-2 de adenocarcinoma de cólon humano. A digestão simulada in vitro causou perdas de alguns compostos, tais como os derivados de cianidina encontrados na jaboticaba, possivelmente devido às condições do pH intestinal. No entanto, o conteúdo de ácido elágico livre aumentou em todos os sucos analisados, indicando a ocorrência de hidrólise durante o processo de digestão in vitro, liberando ácido elágico a partir dos elagitaninos. A atividade antioxidante dos polifenóis foi afetada de forma diferente pela digestão in vitro, de acordo com o suco, provavelmente relacionado à composição de polifenóis. Quanto à proliferação, ciclo celular e apoptose, os polifenóis a partir da fração bioacessível do camu-camu apresentou aproximadamente 30% de inibição da proliferação, seguido pela cagaita com 24%, ambos na maior concentração testada (50 µg EAG/mL). Jaboticaba não apresentou efeito inibitório nas concentrações testadas, entretanto os compostos fenólicos de todas as frações bioacessíveis (50 µg EAG/mL) apresentaram parada no ciclo celular na fase G2/M sem induzir apoptose nas células Caco-2. Os resultados sugerem que os polifenóis das Myrtaceae podem modular a proliferação nas células Caco-2 por bloqueio da progressão do ciclo celular na fase G2/M e assim oferecer efeitos benéficos para a saúde do trato gastrointestinal. / Several studies with phenolic compounds have shown the beneficial effects of these substances across various diseases, including some types of cancer. Considering that most of the polyphenols and their conjugates, unabsorbed, can remain in the lumen for a prolonged period, and epithelial cells lining the intestine are regularly exposed to these compounds, it is important to evaluate their potential beneficial effects in the gastrointestinal tract. However it is necessary to evaluate how the digestion process affects the stability and chemical properties of these compounds. The aims of this study were to evaluate the bioaccessibility of polyphenols in juices from Brazilian native fruits of the Myrtaceae family (cagaita, camu-camu and jaboticaba), the effect of in vitro gastrointestinal digestion on their antioxidant activity, and the action of polyphenols from digested juices on proliferation, cell cycle and apoptosis in human colon cancer Caco-2 cells. The results showed that in vitro gastrointestinal digestion caused losses of some polyphenols, such as cyanidins derivatives from jaboticaba, possibly due to the exposure to conditions of intestinal pH. However, contents of free ellagic acid increased in all the juices analyzed, indicating the occurrence of hydrolysis during in vitro digestion process, releasing ellagic acid from the ellagitannins. The antioxidant activity was affected for different forms by the in vitro digestion, demonstrating be related to individual components present in each sample and the mechanisms by which they act as antioxidants. Regarding the evaluation of proliferation, cell-cycle and apoptosis, polyphenols from bioaccessible fractions of camu-camu showed about 30% of inhibition of proliferation, followed by cagaita with 24%, both at the highest concentration tested (50 µg GAE/mL). Jaboticaba did not show inhibitory effect at the concentrations tested but the phenolic compounds of all bioaccessible fractions (50 µg GAE/mL) showed arrest in G2/M phase of cell-cycle without inducing apoptosis in the Caco-2 cells. Results suggest that Myrtaceae polyphenols may modulate the proliferation of Caco-2 cells by blocking the progression of cell-cycle at G2/M phase, providing beneficial effects to gastrointestinal health.

A jabuticaba-sabará (Plinia jaboticaba (Vell.) Berg) é uma fruta nativa da Mata Atlântica que possui alto teor de antocianinas, proantocianidinas e elagitaninos, fenólicos associados com diversos benefícios à saúde. O objetivo deste trabalho foi avaliar o efeito de dois extratos ricos em compostos fenólicos da jabuticaba-sabará sobre a massa corporal e o metabolismo da glicose e dos lipídios de camundongos alimentados com dieta rica em lipídios e sacarose (HLS). Foram utilizados 40 camundongos machos C57BL/6J com oito semanas de idade e alimentados com ração padrão para camundongos ou dieta HLS durante oito semanas. Os animais foram divididos aleatoriamente em quatro grupos de dez. Os dois primeiros grupos receberam, respectivamente, ração padrão para camundongos ou dieta HLS e água ad libitum, sendo denominados, nesta ordem, grupo controle (Ct) e grupo HF. Os dois últimos grupos foram alimentados com dieta HLS recebendo, por gavagem, os extratos ricos em compostos fenólicos, sendo denominados grupo C18 e PA, respectivamente. Para o grupo C18 foi administrado o extrato obtido por extração em fase sólida (EFS) em colunas de octadecilsilano (C18), possuindo maior concentração de taninos. O grupo PA recebeu o extrato obtido por EFS em colunas de poliamida (PA), resultando em um extrato com menor concentração de taninos em relação ao extrato C18. A dose de fenólicos administrada aos animais foi de 50 mg equivalentes de ácido gálico (EAG)/kg de massa corporal para ambos os grupos. Na sexta semana foi realizado o teste de tolerância à insulina (ITT) e, na sétima, o teste oral de tolerância à glicose (OGTT). Além da massa corporal, os animais foram também avaliados quanto a glicemia, insulinemia e perfil lipídico (colesterol total, HDL, LDL e triacilgliceróis). Os grupos suplementados apresentaram menor ganho de massa dos tecidos adiposos brancos em comparação ao grupo HF (43% para o grupo C18 e 28% para o grupo PA). Além disto, ambos os extratos atenuaram os níveis de glicose e o extrato C18 melhorou os níveis de insulina plasmática, colesterol total e triacilgliceróis hepáticos. Portanto, extratos ricos em compostos fenólicos da jabuticaba-sabará foram eficientes na prevenção do ganho de massa corporal, evitando o crescimento excessivo dos tecidos adiposos brancos, de altos níveis de glicose, insulina, colesterol total e triacilgliceróis hepáticos em camundongos alimentados com dieta rica em lipídios e sacarose. / Sabará jaboticaba is a Brazilian Atlantic Forest fruit rich in anthocyanins, proanthocyanidins and ellagitannins, phenolic compounds that have been associated to several benefits to health. This work aimed to evaluate the effect of the administration of two phenolic-rich extracts from Sabará jaboticaba on body weight gain and on glucose and lipid metabolism of high-fat-sucrose-fed mice. Forty 8-week old male C57BL/6J mice were fed a low-fat chow diet or a high fat, high-sucrose (HFHS) diet for 8 weeks. The animals were randomly divided into four groups of ten mice each. The first two groups received, respectively, a low-fat chow diet or a HFHS diet and water ad libitum and were nominated, in order, control (Ct) and HF group. The last two groups were fed a HFHS diet and received by gavage the phenolic-rich extracts, being respectively nominated C18 and PA group. The C18 group received an extract obtained by solid phase extraction (SPE) in octadecylsilane (C18) column, therefore the most concentrated in tannins. The PA group received an extract obtained by SPE in polyamide (PA) column, therefore less concentrated in tannins. The dose of phenolics administered to animals was of 50 mg acid gallic equivalent (GAE)/kg body weight, for both groups. The insulin tolerance test (ITT) was performed in the sixth week and the oral glucose tolerance test (OGTT) in the seventh week. In addition, the animals were assessed for glycaemia, insulinemia and lipid profile (total-, HDL-, LDL-cholesterol and triacylglycerols). The supplemented groups had lower white adipose tissue gain than HF group (43% for the C18 group and 28% for the PA group). In addition, both extracts attenuated hyperglycemia and the C18 extract improved the plasmatic insulin levels, total cholesterol and hepatic triacylglycerol content. Thus, phenolic-rich extracts from Sabará jaboticaba were effective in preventing body weight gain, avoiding the overgrowth of white adipose tissues, and high levels of glucose, insulin, total cholesterol and hepatic triacylglycerols in HFHS-fed C57BL/6J mice.

Crescem a cada dia os índices globais de obesidade associada à síndrome metabólica (SM) e à inflamação. Sob este aspecto, os compostos fenólicos (CFs) exercem papel importante, especialmente no que diz respeito às suas propriedades anti-inflamatória e antiobesogênica. A jabuticaba Sabará (Myrciaria jaboticaba (Vell.) Berg) é uma fruta nativa bem aceita pelos brasileiros e rica em CFs. O objetivo deste trabalho foi avaliar o efeito da administração diária de extratos ricos em CFs desta fruta a camundongos C57BL/6, alimentados com dieta hiperlipídica com alto teor de sacarose (HFHS) por 8 semanas. Os extratos ricos em CFs foram obtidos por extração do fruto inteiro em solução metanol/água (80:20, v/v), seguida de rotaevaporação e extração em fase sólida (EFS). Os animais foram distribuídos em 5 grupos: o grupo Padrão recebeu dieta padrão de laboratório e veículo (água) por gavagem, o grupo HFHS recebeu dieta HFHS e veículo, o grupo EB recebeu 200 mg b. s. (base seca)/kg de peso corporal (PC) de extrato bruto (EB), o grupo C18 recebeu 50 mg EAG (equivalentes de ácido gálico)/kg de PC do extrato obtido em sorvente octadecil silano (C18) (que permite a obtenção de todos os CFs da fruta) e o grupo PA recebeu 50 mg EAG/kg de PC do extrato obtido em sorvente poliamida (PA) (que permite a obtenção de todos os CFs da fruta, exceto os elagitaninos). O grupo C18 apresentou menores ganho de peso, adiposidade e eficiência energética, comparado ao grupo HFHS. Já o grupo EB teve menor expressão gênica do fator de necrose tumoral alfa (TNF-α) no tecido adiposo branco epididimal, e menor concentração deste mesmo marcador no fígado. Estes resultados sugerem que os elagitaninos têm um papel importante na redução do risco do desenvolvimento de obesidade em camundongos que receberam dieta indutora de obesidade e SM, enquanto o EB da fruta parece contribuir para a redução da inflamação destes animais, porém os mecanismos para tal ainda não estão esclarecidos. / The incidence of obesity is increasing associated with other disorders as metabolic syndrome (MS) and low-grade inflammation. Phenolic compounds (PC) have some well-known properties, such as anti-inflammatory, antidiabetic and antiobesity capacities. Jaboticaba Sabará (Myrciaria jaboticaba (Vell.) Berg) is a brazilian fruit well accepted in this country and it has a high PCs amount. The aim of this study was to investigate the effects of phenolic-rich jaboticaba extracts in C57Bl/6J mice fed a high fat/high sucrose (HF/HS) diet during 8 weeks. The phenolic-rich jaboticaba extracts were prepared from fruit extraction in methanol/water solution (80:20, v/v), followed by rotary evaporation and solid phase extraction (SPE). The mice were distributed in 5 groups: the Chow group was fed a chow diet and gavaged daily with vehicle (water), the HFHS group was fed a HF/HS diet vehicle as well, the CE group received 200 mg of jaboticaba crude extract (CE)/kg body weight (BW), the C18 group received 50 mg AGE (acid galic equivalent)/kg BW of phenolic-rich jaboticaba extract obtained by octadecyl silane (C18) sorbent (which permits to extract every PCs from the fruit) and the PA group were gavaged with 50 mg AGE/kg BW of this fruit extract obtained by polyamide (PA) sorbent (which allows to extract every PCs from jaboticaba, excepting ellagitannins). The C18 group had the lowest BW gain, adiposity and energy efficiency, compared to the HFHS group. The CE group presented low tumor necrose factor-α (TNF-α) gene expression on epididymal white adipose tissue and it had also a low hepatic concentration of this inflammatory marker, compared to HFHS group. These results suggest ellagitannins has an important role on reducing risk of obesity in HF/HS-fed mice, while jaboticaba CE seems to contribute on reduction of inflammation in these animals, but the mechanisms are still not understood.

Os grãos de quinoa possuem excelente balanço nutricional além das propriedades funcionais, comparativamente superior à dos cereais. A quinoa é cultivada em diversos países e, devido às suas características, têm aumentado o interesse de pesquisadores e consumidores. A quinoa contém pericarpo branco, no entanto, existem grãos com pericarpo vermelho e preto, e todos os tipos são utilizados como alimento em diferentes preparações. Com o objetivo de avaliar as características de grãos de quinoa, amostras de cor branca, preta e vermelha foram analisadas quanto às propriedades físico-químicas e funcionais dos grãos e do amido extraído das diferentes amostras. O amido, extraído pelo método alcalino, foi submetido as análises de teor de amilose, difração de raios X, microscopia eletrônica de varredura (MEV), propriedades térmicas (por DSC-Differential Scanning Calorimeter) e propriedades de pasta (por RVA- Rapid Visco Analyser), além de suscetibilidade à hidrólise enzimática e cor. A composição físico-química dos grãos de quinoa apresentou como principais diferenças o teor de cinzas, fibras e amido. O teor de amilose variou de 13,6% a 21,3%, entre as amostras de amido; os padrões de cristalinidade dos amidos foram de tipo A, típico dos cereais; e, a cristalinidade relativa variou de 25,4 a 29,6 %; as micrografias obtidas por MEV apresentaram as formas poliédricas dos grânulos de amido. Os viscoamilogramas, obtidos para os diferentes amidos, mostraram um comportamento semelhante entre as amostras brancas e pretas. As propriedades térmicas de retrogradação das amostras de quinoa vermelha apresentaram uma menor taxa de retrogradação que variou de 7,5 a 8,5 %; as cultivares brancas apresentaram as maiores taxas de retrogradação de 19,0 a 25,4 %. A hidrólise enzimática dos grânulos de amido, analisada em equivalentes de maltose, variou de 7,2 a 8,7 mg/mL, com uma velocidade maior para a cultivar BSyB, em 60 minutos. O amido extraído das amostras brancas de quinoa apresentou valor de luminosidade de 99,0 e os amidos extraídos das amostras de cor vermelha e preta apresentaram em torno de 97,0. As análises realizadas neste estudo ampliam o conhecimento das características da quinoa de cor branca, vermelha e preta, além de mostrar que a cultivar brasileira (BSyB) apresenta características diferenciadas em vários parâmetros. Devido as suas propriedades todas as amostras analisadas possuem potencial para futuras aplicações tecnológicas. / The quinoa grain have excellent nutritional balance beyond functional properties, comparatively higher than that of cereals. Quinoa is cultivated in many countries and due to its characteristics; this has increased the interest of researchers and consumers. Quinoa contains white pericarp, however, there are red and black grain pericarp and all of kinds are used as food in different preparations. In order to evaluate the quinoa grain characteristics, samples of white, black and red color were analyzed for physical-chemical and functional properties of the grains and starch extracted from different samples, aiming a future technology use. Starch from quinoa grains was extracted by the alkaline method and analyzed for amylose content, X-ray diffraction, scanning electron microscopy (SEM), thermal properties (by Differential Scanning Calorimeter, DSC) and properties folder (by Rapid Visco Analyser, RVA), susceptibility to enzymatic hydrolysis and color. The physicochemical composition of quinoa grains presents major differences as the ash content, fiber and starch. The amylose content ranged from 13.6% to 21.3% among starch samples; patterns crystallinity of starches of type A were typical cereal; and the relative crystallinity ranged from 25.4 to 29.6%; SEM micrographs obtained showed the polyhedral forms of starch granules. The viscoamilogramas obtained for the different starches, show a similar behavior between the white and black samples. The thermal properties of retrogradation of red quinoa samples showed less retrogradation rate ranged from 7.5 to 8.5%; white cultivars showed the highest rates of downgrading from 19.0 to 25.4%. The enzymatic hydrolysis of the starch granules analyzed to maltose equivalents, ranged from 7.2 to 8.7 mg / ml, at a higher speed for cultivating BsyB in 60 minutes. The starch extracted from samples of white quinoa showed 99.0 brightness value and starches extracted from samples of red and black color had around 97.0. The analyzes performed in this study extend the knowledge of quinoa characteristics of white, red and black, in addition to showing that the Brazilian cultivar (BsyB) has different characteristics on various parameters. Because of their properties, all samples have the potential for future technological applications.

O Brasil possui uma imensa diversidade biológica, na qual muitos compostos bioativos podem ser encontrados e utilizados em beneficio à sociedade. No entanto, processos de degradação do ambiente e introdução de espécies exóticas têm contribuído ao conhecimento e uso limitadosde muitas plantas nativas, sendopequena a quantidade de estudos sobre sua composição química e potencial biológico. A prevenção de doenças crônicas constantemente vem sendo associada à atividade antioxidante de metabólitos secundários dos vegetais, principalmente os fenólicos. Assim, o objetivo deste trabalho foi avaliar a atividade antioxidante e composição fenólica de cinco espécies frutíferas nativas do Brasil (G. brasiliensis, E. leitonii, E. involucrata, E. brasiliensis e E. myrcianthes). Os métodos capacidade de redução do Folin-Ciocalteau, autoxidação do sistema ?-caroteno/ácido linoleico, capacidade de absorção de radicais oxigênio (ORAC), sequestro dos radicais livres DPPH e ânion superóxido foram aplicados na determinação da atividade antioxidante dos extratos etanólicos de folha, casca, semente e polpa das espécies selecionadas. As amostras demonstraram significativa atividade antioxidante e, em alguns casos, superior as frutas comumente consumidas pela população brasileira. Em geral, folhas apresentaram as maiores atividades, mas o destaque foi a semente de E. leitonii que exibiu os melhores resultados em quatro dos cinco métodos utilizados: 120,67 mg AG.g-1 na redução do reagente Folin; 7,08 Gmol Trolox.g-1 no ?-caroteno; EC50 de 0,26 mg.mL-1 e 0,07 mg.mL-1 no sequestro do ânion superóxido e DPPH, respectivamente; 514,75 Gmol Trolox.g-1 no ORAC para o qual a folha de E. involucrata obteve o maior valor (1393,3 Gmol Trolox.g-1). Os extratos das espécies nativas também demonstram efeito antioxidante contra radicais de relevância biológica, como peroxila e superóxido. Por meio de CG-EM e CLAE acoplado a arranjo de fotodiodos, os principais compostos fenólicos encontrados nos extratos vegetais foram catequina, epicatequina e ácido gálico. Este trabalho demonstrou o grande potencial antioxidante das frutíferas nativas brasileiras, evidenciando assim possível efeito positivo em sistemas biológicos. / Brazil has a great biodiversity, in which many bioactive compounds can be found and used to benefit the society. However, environmental degradation processes and introduction of exotic species have contributed to limited use and knowledge of many native plants, reflecting in few studies about chemical composition and biological potential. The prevention of chronic diseases has been constantly associated with the antioxidant activity of plants secondary metabolites, mainly the phenolics. The objective of this study was to evaluate the antioxidant activity and the phenolic composition of five Brazilian native fruitful species (G. brasiliensis, E. leitonii, E. involucrata, E. brasiliensis e E. myrcianthes). The methods of Folin-Ciocalteau reducing capacity, co-oxidation of ?-carotene/linoleic acid system, oxygen radical absorbance capacity (ORAC), DPPH and superoxide free radical scavenging were used to determine the antioxidant activity of ethanolic extracts of leaf, peel, seed and pulp of the selected species. The samples showed significant antioxidant activity and, in some cases, it was superior to fruits commonly consumed by Brazilian population. In general, leaves presented the highest activities, but the seed of E. Leitonii stood out exhibiting the best results in four of the five methods: 120.67 mg GA.g-1 in the Folin reducing; 7.08 Gmol Trolox.g-1 in the ?-carotene; EC50 of 0.26 mg.mL-1 and 0.07 mg.mL-1 in the superoxide and DPPH scavenging, respectively; 514.75 Gmol Trolox.g-1 in the ORAC, for which the E. Involucrata leaf had the highest value (1393.3 GmolTrolox.g-1). The extracts of native species also demonstrate antioxidant effect against radicals of biological relevance, such as peroxyl and superoxide. By GC-MS and HPLC coupled to a photodiode array, the major phenolic compounds found in the plant extracts were catechin, epicatechin and gallic acid. In this study, Brazilian native fruitful presented high antioxidant potential, showing a possible positive effect on biological systems.

Na busca por vinhos tintos de grande cor, aroma, corpo e identidade, enólogos forçam a extração dos compostos fenólicos durante a maceração. Nesta etapa, que ocorre durante a fermentação do mosto, estes compostos são extraídos da casca e sementes e modificados em sua estrutura à formas mais estáveis ao longo do tempo. Fatores como sistema de encubagem e remontagem do mosto, tempo de contato entre o mosto e as partes sólidas da baga, e a temperatura são críticos neste processo. A alteração do ciclo da videira para colheita no período de inverno na região sudeste do Brasil permitiu avanço na maturação fenólica das bagas. As uvas colhidas neste período apresentam potencial para a elaboração de vinhos de guarda, entretanto faltam estudos para estabelecer as melhores técnicas de vinificação para este novo ciclo de produção. Este trabalho teve como objetivo avaliar o emprego de baixas temperaturas na extração e estabilidade de antocianinas, taninos e do precursor de aroma acetato de isoamila. Uvas da variedade Syrah colhidas no inverno foram submetidas a vinificação com maceração pré-fermentativa a frio (5 - 8°C) e posterior fermentação alcoólica na presença das cascas a baixa temperatura (15 °C), e também pelo método tradicional (maceração e fermentação alcoólica entre 20 e 23°C). Teores de polifenóis totais, antocianinas, intensidade e tonalidade de cor, compostos fenólicos, flavanóis, índice de pigmentos polimerizados e acetato de isoamila foram avaliados durante a maceração e nas etapas de fermentação malolática, engarrafamento e envelhecimento em garrafa. Os vinhos com 14 meses de envelhecimento foram submetidos a um painel sensorial. O método de maceração tradicional permitiu maior extração de antocianinas e, consequentemente, maior intensidade de cor. Entretanto, o emprego do frio preservou os tons azuis (OD 620%) durante o envelhecimento, o que indica menor oxidação do vinho. A concentração de compostos fenólicos também foi maior na maceração tradicional. O vinho submetido ao frio apresentou maior índice de pigmentos polimerizados e maior preservação de tons vermelhos e compostos fenólicos totais durante o envelhecimento, além de menores teores de acetato de isoamila. Não houve diferença estatística entre os descritores apresentados na análise sensorial; entretanto, a média do parâmetro de preferência global foi maior no método tradicional. Os resultados indicam potencial de preservação dos compostos fenólicos pelo uso do tratamento a frio, entretanto outras técnicas devem ser avaliadas para melhorar a extração desses compostos em uvas colhidas no inverno. / In an attempt to elaborate red wines of great color, aroma, body and identity, winemakers overextract phenolic compounds at maceration. At this step, which occurs during must fermentation, grape solids are extracted from skins and seeds and their structure are modified to more stable forms over time. Factors such as types of maceration, pumping-over, maceration time and temperature are critical in this red winemaking step. The modification of grapevine cycle in the southeastern region of Brazil to harvest grapes in the winter season has improved phenolic ripeness of the berries. Grapes harvested at this period have potential to ageing, however there are few studies to establish the best winemaking techniques for these berries. This study aimed to evaluate the use of low temperature in the extraction and stability of anthocyanins, tannins and flavor precursor isoamyl acetate. Syrah grapes harvested in winter season were processed with pre-fermentative cold maceration (5 - 8 °C) and then allowed to start alcoholic fermentation in the presence of pomace at low temperature (15 °C), and also processed by the conventional method (maceration and alcoholic fermentation between 20 and 23°C). Total polyphenols, anthocyanins, intensity and color hue, phenolic compounds, flavanols, polymerized pigments index and isoamyl acetate were evaluated during maceration, malolactic fermentation, bottling and bottle ageing steps. Wines aged in bottles for 14 months were subjected to a sensory panel. The conventional method allowed more anthocyanins extraction and consequently resulted in wines with more color intensity. However, the use of cold temperatures preserved the blue component (OD 620%) during ageing, which indicates less wine oxidation. The concentration of phenolic compounds was also higher in wines from the conventional method. Cold macerated wines showed higher polymerized pigments index and preservation of the red component of color and total phenolic compounds during ageing, and lower levels of isoamyl acetate. There was no statistical difference among sensory descriptors presented in the sensorial analysis; however, the parameter of overall preference was higher scored for the conventional method. Results showed potential for phenolic compounds stabilization by the use of cold treatment, but other techniques should be evaluated to improve the extraction of these compounds in grapes harvested in winter season.

Na busca por vinhos tintos de grande cor, aroma, corpo e identidade, enólogos forçam a extração dos compostos fenólicos durante a maceração. Nesta etapa, que ocorre durante a fermentação do mosto, estes compostos são extraídos da casca e sementes e modificados em sua estrutura à formas mais estáveis ao longo do tempo. Fatores como sistema de encubagem e remontagem do mosto, tempo de contato entre o mosto e as partes sólidas da baga, e a temperatura são críticos neste processo. A alteração do ciclo da videira para colheita no período de inverno na região sudeste do Brasil permitiu avanço na maturação fenólica das bagas. As uvas colhidas neste período apresentam potencial para a elaboração de vinhos de guarda, entretanto faltam estudos para estabelecer as melhores técnicas de vinificação para este novo ciclo de produção. Este trabalho teve como objetivo avaliar o emprego de baixas temperaturas na extração e estabilidade de antocianinas, taninos e do precursor de aroma acetato de isoamila. Uvas da variedade Syrah colhidas no inverno foram submetidas a vinificação com maceração pré-fermentativa a frio (5 - 8°C) e posterior fermentação alcoólica na presença das cascas a baixa temperatura (15 °C), e também pelo método tradicional (maceração e fermentação alcoólica entre 20 e 23°C). Teores de polifenóis totais, antocianinas, intensidade e tonalidade de cor, compostos fenólicos, flavanóis, índice de pigmentos polimerizados e acetato de isoamila foram avaliados durante a maceração e nas etapas de fermentação malolática, engarrafamento e envelhecimento em garrafa. Os vinhos com 14 meses de envelhecimento foram submetidos a um painel sensorial. O método de maceração tradicional permitiu maior extração de antocianinas e, consequentemente, maior intensidade de cor. Entretanto, o emprego do frio preservou os tons azuis (OD 620%) durante o envelhecimento, o que indica menor oxidação do vinho. A concentração de compostos fenólicos também foi maior na maceração tradicional. O vinho submetido ao frio apresentou maior índice de pigmentos polimerizados e maior preservação de tons vermelhos e compostos fenólicos totais durante o envelhecimento, além de menores teores de acetato de isoamila. Não houve diferença estatística entre os descritores apresentados na análise sensorial; entretanto, a média do parâmetro de preferência global foi maior no método tradicional. Os resultados indicam potencial de preservação dos compostos fenólicos pelo uso do tratamento a frio, entretanto outras técnicas devem ser avaliadas para melhorar a extração desses compostos em uvas colhidas no inverno. / In an attempt to elaborate red wines of great color, aroma, body and identity, winemakers overextract phenolic compounds at maceration. At this step, which occurs during must fermentation, grape solids are extracted from skins and seeds and their structure are modified to more stable forms over time. Factors such as types of maceration, pumping-over, maceration time and temperature are critical in this red winemaking step. The modification of grapevine cycle in the southeastern region of Brazil to harvest grapes in the winter season has improved phenolic ripeness of the berries. Grapes harvested at this period have potential to ageing, however there are few studies to establish the best winemaking techniques for these berries. This study aimed to evaluate the use of low temperature in the extraction and stability of anthocyanins, tannins and flavor precursor isoamyl acetate. Syrah grapes harvested in winter season were processed with pre-fermentative cold maceration (5 - 8 °C) and then allowed to start alcoholic fermentation in the presence of pomace at low temperature (15 °C), and also processed by the conventional method (maceration and alcoholic fermentation between 20 and 23°C). Total polyphenols, anthocyanins, intensity and color hue, phenolic compounds, flavanols, polymerized pigments index and isoamyl acetate were evaluated during maceration, malolactic fermentation, bottling and bottle ageing steps. Wines aged in bottles for 14 months were subjected to a sensory panel. The conventional method allowed more anthocyanins extraction and consequently resulted in wines with more color intensity. However, the use of cold temperatures preserved the blue component (OD 620%) during ageing, which indicates less wine oxidation. The concentration of phenolic compounds was also higher in wines from the conventional method. Cold macerated wines showed higher polymerized pigments index and preservation of the red component of color and total phenolic compounds during ageing, and lower levels of isoamyl acetate. There was no statistical difference among sensory descriptors presented in the sensorial analysis; however, the parameter of overall preference was higher scored for the conventional method. Results showed potential for phenolic compounds stabilization by the use of cold treatment, but other techniques should be evaluated to improve the extraction of these compounds in grapes harvested in winter season.

<p>Cilj istraživanja doktorske disertacije je bio da se u<br />konitnuitetu ispita sadržaj ukupnih fenola, fenolnih kiselina i<br />anitoksidativna aktivnost (antiradikalska aktivnost na DPPH i<br />hidroksil radikale) u toku proizvodnje slada i piva (u ječmu,<br />namočenom ječmu, zelenom sladu, sladu, sladovini, ohmeljenoj<br />sladovini, sladovini tokom fermentacija, mladom pivu i pivu)<br />proizvedenih od tri priznate sorte pivskog ječma: NS 525, NS<br />565 i NS 583.<br />Sadržaj ukupnih fenola u uzorcima ječma je bio: NS 525 -<br />0,76; NS 565 - 0,75 i NS 583 - 0,70 mg GAE/g suve materije.<br />Sadržaj ukupnih fenola u svim proizvednim sladovima (0,96;<br />0,94 i 0,91 mg GAE/g suve materije za NS 525; NS 565 i NS<br />583) je bio vi&scaron;i od sadržaja u ječmu. Sorta NS 525 je imala<br />najvi&scaron;i sadržaj ukupnih fenola tokom svih faza sladovanja, dok<br />su sorte NS 565 i NS 583 imale niže sadržaje ukupnih fenola.<br />Najniži sadržaj ukupnih fenola imala je sorta NS 583.<br />U svim ispitivanim sortama ječma ferulna, p-kumarinska i<br />vanilinska kiselina su bile dominantne u uzorcima ječma,<br />tokom sladovanja i u proizvedenom sladu.<br />Sadržaj ukupnih fenolnih kiselina u ječmu je iznosio za sortu<br />NS 525 - 200,98; NS 565 - 184,10 i za NS 583 &ndash; 177,27 &mu;g/g suve<br />materije. Sadržaj ukupnih fenolnih kiselina je rastao kod svih<br />ispitivanih sorti tokom močenja i dostigao maksimum u toku<br />prvog dana klijanja za NS 525 &ndash; 548,31; NS 565 &ndash; 518,65 i NS<br />583 &ndash; 517,17 &mu;g/g suve materije. Dobijeni rezultati su pokazali<br />da je proces sladovanja imao značajan uticaj na sadržaj<br />pojedinačnih i ukupnih fenolnih kiselina.<br />Sorta NS 525 je imala najvi&scaron;u antiradikalsku aktivnost na<br />DPPH radikale (EC50 za NS 525 - 0,658; NS 565 - 0,667 i NS<br />583 - 0,758 mg/ml) &scaron;to pokazuje da sorta ječma ima uticaja na<br />antiradikalsku aktivnost na DPPH radikale. Za ispitivane sorte<br />ječma, antiradikalska aktivnost na DPPH radikale se povisila<br />značajno tokom močenja. U proizvedenim sladovima<br />antiradikalska aktivnost na DPPH radikale bila je vi&scaron;a nego u<br />ječmu. Trend porasta i smanjenja antiradikalske aktivnosti na<br />DPPH radikale tokom sladovanja je bio isti za sve ispitivane<br />sorte ječma.<br />Antiradikalska aktivnost na hidroksil radikale, izražena kao<br />EC50 vrednost, u ispitivanim sortama ječma je iznosila: NS 525<br />&ndash; 0,352; NS 565 &ndash; 0,385 i NS 583 &ndash; 0,455 mg/ml. Može se<br />zaključiti da je sorta NS 525 imala najvi&scaron;u antiradikalsku<br />aktivnost na hidroksil radikale. Antiradikalska aktivnost na<br />hidroksil radikale se znatno povisila tokom močenja. U<br />proizvedenom sladu je antiradikalska aktivnost na hidroksil<br />radikale bila vi&scaron;a nego u ječmu. Trend porasta i smanjenja<br />antiradikalske aktivnosti na hidroksil radikale tokom<br />sladovanja je bio isti za sve ispitivane sorte ječma.<br />Sorta NS 525 je imala najvi&scaron;i sadržaj ukupnih fenola kao i<br />najvi&scaron;u antioksidativnu aktivnost tj. DPPH i hidroksil<br />antiradikalsku aktivnost. Ovi rezultati pokazuju da sorta<br />ječma može da utiče na antiradikalske osobine slada. Sorta NS<br />525 je imala najvi&scaron;i sadržaj ukupnih fenola, ukupnih fenolnih<br />kiselina i najvi&scaron;u antiradikalsku aktivnost na DPPH i hidroksil<br />radikale u toku sladovanja.<br />U svim proizvedenim sladovinama, ohmeljenim sladovinama i<br />pivima, ferulna, p-kumarinska, vanilinska i sinapinska kiselina<br />su imale najvi&scaron;e sadržaje. Sadržaj svih ispitivanih fenolnih<br />kiselina je povi&scaron;en nakon hmeljenja. Najvi&scaron;i ukupni sadržaj<br />fenolnih kiselina je odre&ntilde;en u ohmeljenim sladovinama (NS<br />525 - 461,41, NS 565 - 426,22 i NS 583 - 423,56 &mu;g/100ml).<br />Sadržaj ukupnih fenolnih kiselina je u svim proizvedenim<br />pivima bio niži u odnosu na odgovarajuće ohmeljene sladovine.<br />U sladovini proizvedenoj iz slada NS 525 je odre&ntilde;ena najvi&scaron;a<br />antiradikalska aktivnost na DPPH i hidroksil radikale &scaron;to<br />ukazuje da antiradikalska aktivnosti komponenti slada ima<br />uticaja na antiradikalsku aktivnost proizvedene sladovine. U<br />ispitivanim sladovinama, nakon hmeljenja se znatno povisila<br />antiradikalska aktivnost na DPPH i hidroksil radikale.<br />Antiradikalska aktivnost na DPPH i hidroksil radikale se<br />smanjila tokom glavne i naknadne fermentacije.<br />U sladovini proizvedenoj od slada NS 525 sa najvi&scaron;im<br />sadržajem ukupnih fenola i ukupnih fenolnih kiselina<br />odre&ntilde;ena je najvi&scaron;a antiradikalska aktivnost na DPPH i<br />hidroksil radikale. Tokom proizvodnje piva sadržaj ukupnih<br />fenola se blago smanjio, &scaron;to ukazuje da je proces proizvodnje<br />imao uticaja na njihov sadržaj. Trend smanjenja<br />antiradikalske aktivnosti na DPPH i hidroksil radikale<br />odgovara smanjenju sadržaja ukupnih fenola i ukupnih<br />fenolnih kiselina tokom procesa proizvodnje piva.<br />Primenjena GC-MS metoda za odre&ntilde;ivanje sadržaja fenolnih<br />kiselina tokom procesa proizvodnje slada i piva se pokazala<br />kao osetljiva, specifična i dobre ponovljivosti. Može se<br />primeniti za odre&ntilde;ivanje sadržaja fenolnih kiselina u ječmu,<br />namočenom ječmu, zelenom sladu, sladu, sladovini, ohmeljenoj<br />sladovini, tokom fermentacije i u pivu.<br />Sadržaj ukupnih fenola, fenolnih kiselina i antioksidativna<br />aktivnost slada, koji se koristi za proizvodnju piva, imaju<br />značajan uticaj na antioksidativnu aktivnost piva.<br />Razumevanje promena sadržaja fenolnih kiselina i<br />antioksidativne aktivnosti tokom proizvodnje slada i piva može<br />nam pružiti vredne informacije o za&scaron;titi endogenih<br />antioksidanata u proizvodnji piva. Na taj način mogu se<br />proizvoditi piva sa vi&scaron;om antioksidativnom aktivno&scaron;ću i prema<br />tome i povi&scaron;enom otporno&scaron;ću prema lipidnoj oksidaciji i<br />starenju piva.</p> / <p>Studies carried out in the frame of the doctorial thesis<br />aimed at continuous determination of the content of<br />total phenolics, phenolic acids and antioxidant activity<br />(antiradical activity on DPPH and hydroxyl radicals)<br />during malt and beer production (in barley, steeped<br />barley, green malt, malt, wort, hopped wort,<br />fermenting wort, green beer, and beer) produced from<br />three accepted brewer&rsquo;s barley varieties: NS 525, NS<br />565, and NS 583.<br />The total phenolics content in the barley samples was<br />0.76 for NS 525, 0.75 for NS 565 and 0.70 mg GAE/g<br />dry matter (d.m.) for NS 583. Higher content of total<br />phenolics was determined in the malt samples in<br />comparison with the barley samples: (0.96, 0.94, and<br />0.91 mg GAE/g d.m. for NS 525, NS 565, and NS 583,<br />respectively). Variety NS 525 was the highest in total<br />phenolics content during all stages of malting when<br />compared to the other varieties. The lowest content of<br />total phenolics was found in the variety NS 583.<br />In all examined samples, ferulic, p-coumaric and<br />vanillic acid dominated in the barley samples, during<br />malting and in the produced malts.<br />Content of total phenolic acids in the barley samples<br />was 200.98 for NS 525, 184.10 for NS 565 and 177.27<br />mg/g d.m. for NS 583. During steeping, the content of<br />total phenolic acids increased for all samples reaching<br />the maximum at the first day of germination (NS 525 &ndash;<br />548.31; NS 565 &ndash; 518.65, and NS 583 &ndash; 517.17 &mu;g/g<br />d.m.). The obtained results revealed that the malting<br />process had significant impact on the content of total<br />and individual phenolic acids.<br />Variety NS 525 showed the highest antiradical activity<br />on DPPH radicals (EC50 for NS 525 was 0.658, for NS<br />565 0.667, and for NS 583 0.758 mg/ml) indicating that<br />barley variety influences the antiradical activity on<br />DPPH radicals. Antiradical activity on DPPH radicals<br />significantly increased during steeping for all<br />investigated barley varieties. Higher antiradical<br />activity on DPPH radicals was determined in<br />produced malts when compared to corresponding<br />barley varieties. Similar increasing and decreasing<br />trends in the antiradical activity on DPPH radicals<br />during malting were observed in all investigated<br />barley varieties.<br />The antiradical activity on hydroxyl radicals,<br />expressed as EC50 value, in investigated barley<br />varieties, was: 0.325 for NS 525, 0.385 for NS 565, and<br />0.455 mg/ml for NS 583. It can be concluded that<br />barley variety NS 525 showed the highest antiradical<br />activity on hydroxyl radicals. The antiradical activity<br />on hydroxyl radicals significantly increased during<br />steeping. Higher antiradical activity on hydroxyl<br />radicals was determined in produced malts when<br />compared to corresponding barley varieties. Similar<br />increasing and decreasing trends in the antiradical<br />activity on hydroxyl radicals during malting were<br />observed in all investigated samples.<br />Variety NS 525 had the highest content of total<br />phenolics and exhibited the highest antioxidant<br />activity that is antiradical activity on DPPH and<br />hydroxyl radicals. These results suggest that variety<br />can influence the malt antiradical properties. Variety<br />NS 525 was the highest in total phenolics content, total<br />phenolic acids content and antiradical activity on<br />DPPH and hydroxyl radicals during malting.<br />The highest contents of ferulic, p-coumaric, vanillic,<br />and sinapic acids were determined in all wort, hopped<br />wort and beer samples. Increased contents of all<br />phenolic acids were observed after hopping. The<br />highest content of total phenolic acids was determined<br />in the hopped worts (461.41 for NS 525, 426.22 for NS<br />565, and 423.56 &mu;g/100 ml for NS 583. The beers<br />contained less total phenolic acids when compared to<br />the corresponding hopped worts.<br />Wort produced from NS 525 malt showed the highest<br />antiradical activity on DPPH and hydroxyl radicals<br />which indicates that the antiradical activity of malt<br />components affects the antiradical activity in produced<br />wort. After hopping, antiradical activity on DPPH and<br />hydroxyl radicals significantly increased in all worts.<br />The antiradical activity on DPPH and hydroxyl<br />radicals decreased during primary and secondary<br />fermentation.<br />Wort produced from NS 525 malt contained the<br />highest total phenolic content, total phenolic acids<br />content and showed the highest antiradical activity on<br />DPPH and hydroxyl radicals. During beer production,<br />content of total phenolic compounds slightly decreased<br />which indicates that production process had an<br />influence on their content. Similar decreasing trends<br />between the antiradical activity on DPPH and<br />hydroxyl radicals and the contents of total phenolics<br />and total phenolic acids during beer production were<br />observed.<br />The applied GC-MS method for determination of<br />phenolic acids contents during malt and beer<br />production was sensitive, specific and had good<br />repeatability. It can be used for determination of<br />phenolic acids content in barley, steeped barley, green<br />malt, malt, wort, hopped wort, during fermentation<br />and in beer.<br />The content of total phenolics, phenolic acids and<br />antioxidant activity of malt used for beer production<br />have significant influence on the beer antioxidant<br />activity. Understanding how the phenolic acids and<br />antioxidant activity change during malt and beer<br />production can provide valuable information about<br />the protection of endogenous antioxidants in beer<br />production. In this way, the production of beer with<br />enhanced antioxidant activity is possible and therefore<br />higher resistance to lipid oxidation and longer shelflife<br />could be introduced.</p>

Protea cynaroides L. (King Protea) is a well known cutflower. Seeds and stem cuttings are commonly used to propagate P. cynaroides. However, the success rate and rooting rate of seeds and cuttings, are inconsistent and slow. The potential of in vitro propagation as an alternative method to produce P. cynaroides plantlets was investigated. In vitro studies consisted of in vitro germination of mature zygotic embryos, micrografting and direct somatic embryogenesis of zygotic embryos and excised cotyledons. In the germination study, temperature was the most important factor in obtaining a high germination percentage. Alternating temperatures of 21±2ºC/12±2ºC (light/dark) was suitable for germination and over 90% of embryos germinated, while the germination percentage of embryos at 25±2ºC was poor. Plantlets were successfully established in ex vitro conditions when planted in a peat/coir/sand mixture. Micrografting of P. cynaroides was done by grafting microshoots (microscion), which was taken from in-vitro-established nodal explants, onto roots of decapitated in-vitro-germinated seedlings. After the graft union formed, buds on the microscion sprouted. A protocol to induce direct somatic embryogenesis was developed. Direct somatic embryogenesis was achieved on both P. cynaroides mature zygotic embryos and excised cotyledons. The addition of auxins such as NAA and 2,4-D singly or in combination with TDZ, BAP or kinetin suppressed the formation of somatic embryos. Formation of somatic embryos was observed in medium lacking growth regulators. Germination of somatic embryos was highest in medium containing GA3. The roles of starch and phenolic compounds in the rooting of P. cynaroides cuttings were also studied. Starch and total soluble phenol analyses results revealed a positive correlation between high root formation and increased starch and phenolic content. NMR and MS analyses identified high amounts of 3,4-dihydroxybenzoic acid in stems of P. cynaroides. In vitro bioassay showed that 3,4-dihydroxybenzoic acid stimulated and inhibited root growth of P. cynaroides explants, depending on the concentration. A link was made between the endogenous concentration levels of 3,4-dihydroxybenzoic acid and rooting of P. cynaroides stem cuttings. Findings of this study contribute towards a better understanding of the roles starch and phenolic compounds play in the rooting of P. cynaroides. / Thesis (PhD (Horticulture))--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted

This master thesis deals with the investigation of selected chemical and sensory characteristics of ciders, which were made from four selected apple varieties. The theoretical part describes the chemical composition of apples, cider, the technology of production and production in the world. The next section describes the analytical methods used to determine chemical characteristics not only in ciders but also in other alcoholic beverages. The experimental part focuses on the determination of chemical characteristics such as the content of organic acids, carbohydrates, total phenolic content, alcohol antioxidant activity and elemental composition. The purpose of the work was to find out how different varieties differ in chemical composition. The produced ciders were subjected to sensory analysis to evaluate the selected cider sensory parameters, which were in the natural state and with the addition of carbon dioxide. The results show that ciders of different varieties differ in chemical composition. Malic acid was the most cider's abundant of the organic acids in the range of 2759 – 4411 mg·l-1. Another acid represented was lactic acid in the range of 166,2 – 288,1 mg·l-1. The glucose content of each cider was determined between 845,3 – 1159,8 mg·l-1and fructose 32,6 – 406,7 mg·l-1. Potassium 944,29 – 1073,98 mg·l-1 was the most represented of all elements. The total phenolic content was determined to be in the range of 164,2 – 214,1 mg of GAE·l-1and the antioxidant activity of 0,192 – 0,318 mg·l-1. These differences in chemical composition were also reflected in sensory evaluation. According to the overall assessment, the best cider was made from the Granny Smith variety, which contained the most organic acids and carbohydrates. It has been found that by adding carbon dioxide, sensory parameters such as colour, taste and smell are altered.