60 research outputs found

    Effects of spray-drying and storage on astaxanthin content of Haematococcus pluvialis biomass

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    The main objective of this study was to evaluate the stability of astaxanthin after drying and storage at different conditions during a 9-week period. Recovery of astaxanthin was evaluated by extracting pigments from the dried powders and analysing extracts by HPLC. The powders obtained were stored under different conditions of temperature and oxygen level and the effects on the degradation of astaxanthin were examined. Under the experimental conditions conducted in this study, the drying temperature that yielded the highest content of astaxanthin was 220°C, as the inlet, and 120°C, as the outlet temperature of the drying chamber. The best results were obtained for biomass dried at 180/110°C and stored at −21°C under nitrogen, with astaxanthin degradation lower than 10% after 9 weeks of storage. A reasonable preservation of astaxanthin can be achieved by conditions 180/80°C, −21°C nitrogen, 180/110°C, 21°C nitrogen, and 220/80°C, 21°C vacuum: the ratio of astaxanthin degradation is equal or inferior to 40%. In order to prevent astaxanthin degradation of Haematococcus pluvialis biomass, it is recommended the storage of the spray dried carotenized cells (180/110ºC) under nitrogen and −21°C.info:eu-repo/semantics/publishedVersio

    Polyphenol oxidase activity and colour changes of ‘Starking’ Apple cubes coated with alginate and dehydrated with air

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    The objective was to study the effect of alginate coating on polyphenol oxidase (PPO) activity and colour of ‘Starking’ apple cubes during dehydration with hot air. Apple cubes were dehydrated at 20°C, 35°C or 40°C, with a parallel air-flow. Analysis of PPO activity, colour (L*, a*, b*) and dry matter were performed along the dehydration process at each temperature. All samples presented a peak in relative PPO activity in the beginning of the drying. Exponential models fitted well the experimental data after the peak. Cubes without coating presented lower PPO activity, suggesting lower browning than coated samples throughout the dehydration process, for all temperatures. Better results for coated samples were obtained with a perpendicular airflow drying at 40°C, after dipping the whole apple in water at 60°C for 10 minutes. In order to prevent coated samples from browning, drying by perpendicular airflow preceded by a thermal treatment of the whole apple is required.info:eu-repo/semantics/publishedVersio

    Salicornia as a fermented product: development of an optimised procedure for a controlled process

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    [PORT] Com o intuito de desenvolver um produto fermentado à base de rebentos de salicórnia conduziu-se esta experiência para monitorizar o processo fermentativo. Os dados inicialmente obtidos por caracterização fenotípica revelaram a inexistência de bactérias do ácido láctico na flora indígena da planta. Consequentemente, optou-se pela utilização de culturas de arranque, tendo-se monitorizado as condições de pH, acidez titulável e salinidade em soro de couve estéril, com e sem salicórnia, quando expostas a diferentes bactérias fermentativas: Lactobacillus plantarum, Leuconostoc mesenteroides e Pediococcus acidilactici. Apenas se verificaram alterações significativas no processo fermentativo com a introdução da salicórnia no caso da fermentação com L. plantarum, tendo-se observado um aumento significativo na variação do pH e da % de ácido láctico, no decorrer do processo, e comparativamente com as restantes estirpes. Os resultados obtidos para a acidez titulável são satisfatórios já que foi detectado, aproximadamente, 1 % de ácido láctico como resultado da actividade fermentativa nas diferentes culturas de arranque. A espécie predominante no final da fermentação foi L. Plantarum, sendo esta a que produziu maior percentagem de ácido láctico. [ENG] In order to develop a fermented product with young stems of salicornia/pickleweed, an experiment was worked out and the fermentative process was studied. Initial data on the bacterial fauna of the plants revealed the existence of no lactic acid bacteria. Therefore, we chose to use of starting cultures. Sterile “heart cabbage” juice was the base for different fermentative bacteria: Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococcus acidilactici, and pH, titrated acidity and salinity were evaluated. The same experiment was undertaken with and without the glasswort or salicornia. Significant differences were observed only with L. plantarum: pH variation and percentage of lactic acid suffered a significant increase during the fermentative process, specially when salicornia was introduced in the juice. Results obtained for the titrated acidity were also good, since approximately 1% lactic acid was detected, as a result of the fermentative activity in the different starting cultures. Predominant species by the end of the fermentation was L. plantarum, being the one that produced higher quantities of lactic acid.Este trabalho foi financiado pelo Programa Ideia - Prime, ADI 13-02-04-FDR-01269 – Desenvolvimento de aplicações para a planta halófila Salicornia. Os autores agradecem à Necton, Belamandil, Portugal, o fornecimento de semestes de Salicornia

    Salicornia as a fermented product: development of an optimised procedure for a controlled process

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    In order to develop a fermented product with young stems of salicornia/pickleweed, an experiment was worked out and the fermentative process was studied. Initial data on the bacterial fauna of the plants revealed the existence of no lactic acid bacteria. Therefore, we chose to use of starting cultures. Sterile “heart cabbage” juice was the base for different fermentative bacteria: Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococcus acidilactici, and pH, titrated acidity and salinity were evaluated. The same experiment was undertaken with and without the glasswort or salicornia. Significant differences were observed only with L. plantarum: pH variation and percentage of lactic acid suffered a significant increase during the fermentative process, specially when salicornia was introduced in the juice. Results obtained for the titrated acidity were also good, since approximately 1% lactic acid was detected, as a result of the fermentative activity in the different starting cultures. Predominant species by the end of the fermentation was L. plantarum, being the one that produced higher quantities of lactic acid

    Water-sediment physicochemical dynamics in a large reservoir in the Mediterranean region under multiple stressors

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    Nowadays, the Mediterranean freshwater systems face the threat of water scarcity, along with multiple other stressors (e.g., organic and inorganic contamination, geomorphological alterations, invasive species), leading to the impairment of their ecosystem services. All these stressors have been speeding up, due to climate variability and land cover/land use changes, turning them into a big challenge for the water management plans. The present study analyses the physicochemical and phytoplankton biomass (chlorophyll-a) dynamics of a large reservoir, in the Mediterranean region (Alqueva reservoir, Southern Portugal), under diverse meteorological conditions and land cover/land use real scenarios (2017 and 2018). The most important stressors were identified and the necessary tools and information for a more effective management plan were provided. Changes in these parameters were further related to the observed variations in the meteorological conditions and in the land cover/land use. The increase in nutrients and ions in the water column, and of potentially toxic metals in the sediment, were more obvious in periods of severe drought. Further, the enhancement of nutrients concentrations, potentially caused by the intensification of agricultural activities, may indicate an increased risk of water eutrophication. The results highlight that a holistic approach is essential for a better water resources management strategy

    The metabolic microenvironment of melanomas: prognostic value of MCT1 and MCT4

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    BRAF mutations are known drivers of melanoma development and, recently, were also described as players in the Warburg effect, while this reprogramming of energy metabolism has been identified as a possible strategy for treating melanoma patients. Therefore, the aim of this work was to evaluate the expression and prognostic value of a panel of glycolytic metabolism-related proteins in a series of melanomas. The immunohistochemical expression of MCT1, MCT4, GLUT1, and CAIX was evaluated in 356 patients presenting melanoma and 20 patients presenting benign nevi. Samples included 20 benign nevi, 282 primary melanomas, 117 lymph node and 54 distant metastases samples. BRAF mutation was observed in 29/92 (31.5%) melanoma patients and 17/20 (85%) benign nevi samples. NRAS mutation was observed in 4/36 (11.1%) melanoma patients and 1/19 (5.3%) benign nevi samples. MCT4 and GLUT1 expression was significantly increased in metastatic samples, and MCT1, MCT4 and GLUT1 were significantly associated with poor prognostic variables. Importantly, MCT1 and MCT4 were associated with shorter overall survival. In conclusion, the present study brings new insights on metabolic aspects of melanoma, paving the way for the development of new-targeted therapies.This work was supported by FAPESP grant to VLV (2012/04194-1) and CP (2015/25351-6). VMG received a doctoral fellowship (SFRH/BD/51997/2012) from Fundacao para a Ciencia e a Tecnologia (FCT) and ON. 2 SR&TD Integrated Program (NORTE-07-0124-FEDER-000017) co-funded by Programa Operacional Regional do Norte (ON.2- O Novo Norte), Quadro de Referencia Estrategico Nacional (QREN), through Fundo Europeu de Desenvolvimento Regional (FEDER).info:eu-repo/semantics/publishedVersio

    A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing

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    Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe

    Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis

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    Background: Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis. Methods: Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry. Results: All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting. Conclusion: These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC.This work was supported by the Fundação para a Ciência e a Tecnologia (FCT) grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘Programa Operacional Temático Factores de Competitividade’ (COMPETE) of ‘Quadro Comunitário de Apoio III’ and co-financed by the Fundo Europeu De Desenvolvimento Regional (FEDER). Ricardo Amorim was recipient of the fellowship SFRH/BD/98002/2013, from Fundação para a Ciência e a Tecnologia (FCT Portugal).info:eu-repo/semantics/publishedVersio
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