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- Salicórnia como produto fermentado: desenvolvimento de condições óptimas para um processo controladoPublication . Raposo, M. F. de J; Silva, J. V.; Neri, M.; Morais, R. M.
- Evaluation of the soil fertilization with encapsulates of Chlorella vulgaris and a C. vulgaris/Pseudomonas putida consortium for the growth of meadow clover plantletsPublication . Raposo, M. F.; Oliveira, S. A.; Morais, R. M. S. C.
- Potencial biotecnológico das microalgasPublication . Carvalho, A. P.; Meireles, L. A.; Malcata, F. X.; Oliveira, G.; Raposo, M. F.; Morais, R.
- The growth of microalgae using an effluent from a brewery as the culture nutrient mediumPublication . Oliveira, S.; Raposo, M. F. J.; Castro, Paula M. L.; Morais, R. M.
- Influence of sulphate on the composition and antibacterial and antiviral properties of the exopolysaccharide from Porphyridium cruentumPublication . Raposo, Maria Filomena de Jesus; Morais, Alcina Maria Miranda Bernardo de; Morais, Rui Manuel Santos Costa deAims: The influence of two culture media and three different concentrations of sulphate in the medium on the growth of two strains of Porphyridium cruentum and on the production, composition and viscoelastic characteristics, and antimicrobial properties of the sulphated exopolysaccharide (EPS) were studied. Mainmethods: A Bohlin C50 rheometerwas used to evaluate the viscosity and elasticity of the EPS solutions. HSV virus, types 1 and 2, Vaccinia virus and Vesicular stomatitis virus were used along with two Gram-negative (Escherichia coli and Salmonella enteritidis) and one Gram-positive (Staphylococcus aureus) bacteria, for testing the antimicrobial activity of EPS. Key-findings: The growth ofmicroalgae was higher in NTIP medium and the production of EPS was enhanced by sulphate 21 mM. The protein content of the EPS was enhanced by the addition of sulphate 52mMand 104mM; this concentration also induced an increase in sulphate content of the EPS. However, neither the contents of EPS in carbohydrates and uronic acidswere affected by the culturemediumsupplementation in sulphate. In general, the EPS from the Spanish strain presented a higher antiviral activity than the EPS from the Israeli strain. All EPS extracts revealed a strong activity against V. stomatitis virus, higher than the activity of all chemical compounds tested. The EPS from the Israeli strain also presented antibacterial activity against S. enteritidis. Significance: Enrichment of the culture mediumwith sulphate improved protein and sulphate content of EPS. EPS extracts presented a relevant activity against V. stomatitis virus and S. enteritidis bacterium.
- Controlled atmosphere storage for preservation of Salicornia ramosissimaPublication . Raposo, M. F.; Morais, R. M. S. C.; Morais, A. M. M. B.Salicornia is a halophytic plant that grows near salt marshes and salted wetlands, very rich in vitamins, minerals and highly unsaturated oils. Because of its biochemical composition and despite salinity, Salicornia is considered a gourmet product. Since stems present a short shelf life, the aim of this work was to evaluate the effect of controlled atmosphere on quality of Salicornia ramosissima during four weeks at 4°C. Vitamin C and chlorophyll contents were determined, and microbiological and sensory analyses were performed. Salicornia shoots preserved better the visual appearance and L-ascorbic acid for three weeks of storage under CA with 3% oxygen and 10% carbon dioxide, although chlorophyll was better preserved in air. All samples were microbiologically safe during all storage. CA storage, especially in 3% oxygen and 10% carbon dioxide seems to be a good method to preserve Salicornia ramosissima shoots
- Microbiological and sensorial analysis of salicornia shoots preservedin controlled atmospherePublication . Raposo, M. F.J.; Silva, J.V. N.; Sousa, C. C.; Morais, Alcina M. M. B.; Morais, R. M.
- Carotenoids, foodstuff and human healthPublication . Raposo, M. F. de J; Mendes-Pinto, M. M.; Morais, Rui
- Salicórnia como produto fermentado: desenvolvimento de condições óptimas para um processo controladoPublication . Raposo, M. F.; Silva, J. V.; Neri, Margarida; Morais, R. M. S. C.In order to develop a fermented product with young stems of salicomia/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 salicomia. 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 salicomia 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.
- Effects of spray-drying and storage on astaxanthin content of Haematococcus pluvialis biomassPublication . Raposo, Maria Filomena J.; Morais, Alcina M. M. B.; Morais, Rui M. S. C.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.