27 research outputs found

    The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

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    Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

    Influence of post harvest processing conditions on yield and quality of ground turmeric (Curcuma longa L.)

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    Studies were carried out to evaluate the influence of post harvest processing conditions on yield and quality of ground turmeric. Rhizomes were peeled, cooked (autoclave or immersion) in water or alkaline media, sliced, dehydrated, ground, sieved, packaged in polyethylene bags and stored for 60 days at room temperature. Yields ranged from 9.84 to 14.51 g of powder/100 g of rhizome with moisture varying from 8.84 to 9.86 g/100 g. Peel removal caused 30% mass loss but the powder obtained had higher intensity of yellow and red. Cooking caused a reduction in dehydration time and provided a powder with lower moisture content, higher levels of curcuminoid pigments and higher Hunter CIE L*, a* and b* values. Cooking by immersion provided higher quality powder compared to autoclave. Use of alkaline media resulted in a product with lower curcuminoid content, and higher intensity of yellow. There was no change in pigment and colour characteristics during storage.A influĂȘncia do processamento no rendimento e na qualidade da cĂșrcuma em pĂł foi investigada. Os rizomas foram descascados, cozidos (autoclave ou imersĂŁo) em ĂĄgua ou meio alcalino, fatiadas, desidratadas, moĂ­das, peneiradas, embaladas em polietileno e armazenadas por 60 dias Ă  temperatura ambiente. O rendimento variou de 9,84 a 14,51 g de pĂł/100 g de rizoma com teores de umidade de 8,84 a 9,86 g/100 g. A remoção da casca causou perda de 30% de massa mas o pĂł obtido apresentou maior intensidade de amarelo e vermelho. O cozimento causou uma redução no tempo de secagem e forneceu um pĂł com menor teor de umidade, maiores teores de pigmentos curcuminĂłides e maiores valores de Hunter CIE L*, a* e b*. O cozimento por imersĂŁo forneceu um pĂł de melhor qualidade comparado Ă quele por autoclave. O uso de meio alcalino resultou em um produto com menor teor de pigmentos curcuminĂłides, e maior intensidade de amarelo. NĂŁo foi observada alteração nos teores de pigmentos e nas caracterĂ­sticas de cor do pĂł durante armazenamento

    Identificação de compostos volĂĄteis da cĂșrcuma empregando microextração por fase sĂłlida e cromatografia gasosa acoplada Ă  espectrometria de massas Identification of volatile compounds of turmeric using solid phase microextraction and gas chromatography coupled to mass spectrometry

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    Compostos volĂĄteis da cĂșrcuma (Curcuma longa L.) cultivada no Brasil foram isolados por microextração por fase sĂłlida. Os rizomas foram cozidos em solução de bicarbonato de sĂłdio 0,1%, fatiados, secos e triturados. Visando estabelecer o sistema ideal para a microextração, fibras de polidimetilsiloxano de 100”m de espessura foram expostas ao headspace de frascos de 10mL. Estudou-se a influĂȘncia das seguintes variĂĄveis sobre o rendimento dos compostos volĂĄteis obtidos: amostras em pĂł (0,1 a 1,0g) e em solução (40mg/L), diferentes temperaturas (40 a 70ÂșC) e tempos (2 a 20min) de partição. O efeito da temperatura (210 a 240ÂșC) e do tempo (3 e 5min) de dessorção tambĂ©m foi avaliado. As melhores condiçÔes para a partição dos compostos volĂĄteis foram 0,1g do pĂł, 70ÂșC e 5min. A temperatura de 220ÂșC e o tempo de 5 minutos foram os de maior eficiĂȘncia para a dessorção. A cromatografia gasosa foi conduzida em coluna capilar, detecção por ionização de chama e identificação por espectrometria de massas. A anĂĄlise dos espectros de massas obtidos para os nove compostos volĂĄteis predominantes indicou a presença de ar-curcĂșmeno, ar-turmerona, zingibereno, beta-sesquifelandreno, sabineno, 1,8-cineol e 1,4-terpineol.<br>Volatile compounds from turmeric (Curcuma longa L.) cultived in Brazil were isolated by solid phase microextraction. The rhizomes were cooked in 0.1% sodium bicarbonate solution, sliced, dried and ground. Polydimethyldiloxanes fibers (100 mm diameter) were exposed to the headspace of 10 mL flasks with the aim of establishing an ideal microextraction system. The influence of the following parameters on the volatile substances obtained was studied: powder samples (0.1 to 1.0 g) and dissolved samples (40 mg/L), different temperatures (40 to 70ÂșC) and partition periods (2 to 20 min). The effect of temperature (210 to 240ÂșC) and time (3 to 5 min) on desorption efficiency was also evaluated. Optimum conditions for the partition of the volatiles were 0.1 g of powder sample, 70ÂșC and 5 min. A temperature of 220ÂșC and a 5 min period were of better efficiency for desorption. Gas chromatography was performed using capillary column and flame ionization detector. The eluates were identified by mass spectrometry. The mass spectra obtained for the predominant volatile compounds indicated the presence of ar-curcumene, ar-tumerone, zingeberene, beta-sesquiphellandrene, sabinene, 1,8-cineol and 1,4-terpineol
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