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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.
- Impact of processing upon dry blueberry fruit aqueous extractsPublication . Silva, S.; Costa, E. M.; Costa, M. R.; Pereira, M. F.; Morais, R. M. S. C.; Pintado, M. E.
- 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.
- Effect of salt concentration and light intensity on carotenogenesis of Haematococcus pluvialisPublication . Rijo, Paula; Tsavalos, A.; Morais, R.; Young, A.
- 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
- Production of a carotenoid-rich product by alginate entrapment and fluid-bed drying of Dunaliella salinaPublication . Leach, Gareth; Oliveira, Gisela; Morais, RuiA new carotenoid-rich product was formed by entrapment of Dunaliella salina in calcium alginate beads of di†erent alginate concentrations, followed by drying in a Ñuid-bed dryer. The drying process yielded b-carotene recoveries of between 79 and 89% and produced a change in the 9-cis/all-trans ratio of b-carotene isomers. The carotenoid stability of the product was dependant on both the storage conditions and alginate content (range 3É3È7É3 g litre~1) of the beads. In the presence of light and oxygen total carotenoid degraded following a Ðrst order kinetic model with degradation constants between 0É016 and 0É039 days~1, with the lowest degradation occurring with the lowest alginate concentration. Product stored in the dark and Ñushed with nitrogen produced Ðrst-order degradation constants of 0É012 and 0É020 days~1 for the two higher alginate concentrations ; that with the lowest alginate content showed no noticeable degradation after 58 days storage. During storage, the 9-cis isomer was signiÐcantly more unstable showing a relative loss under all conditions, degrading almost completely when stored in the presence of light and oxygen and reaching an equilibrium ratio with the all-trans isomer when stored in the dark and Ñushed with nitrogen.
- Osmotic dehydration with sorbitol combined with hot air convective drying of apple cubesPublication . Assis, Fernanda R.; Morais, Rui M. S. C.; Morais, Alcina M. M. B.The aim of the present work was to study the effect of the osmotic dehydration (OD) pre-treatment on the mass transfer kinetics and water activity (aw) of apple cubes during hot air drying. The adequacy of different mathematical models to describe the moisture content of the product during this process was also evaluated. Apple cubes were osmotically dehydrated with sucrose or sorbitol solutions at 60 °C, and then dried by air at 25-80 °C. Overall, the OD and rise of the air temperature resulted in an increased water loss rate and a reduction of the aw. The osmotic agent used in the OD was not relevant to the air drying kinetics, but the pre-treatment with sorbitol solutions produced dried samples with lower aw. Newton's, Page's, modified Page's, Henderson and Pabis', Two-term, Two-term exponential, Logarithmic, Midilli et al.'s models could describe the moisture content well during the air drying process.