Authors:D. Figueiredo, B. Castro, M. Pereira and A. Correia
In 2005, a severe drought occurred in Portugal, with several reservoirs becoming dry in the southern region. A set of 20 Portuguese water bodies were analysed through denaturing gradient gel electrophoresis (16SrDNA-DGGE) and DNA sequencing to assess its bacterioplankton diversity under these particular conditions. Environmental parameters were determined to assess the trophic conditions of each water body. Most water bodies fell into the meso-to eutrophic and hypereutrophic state. In general, the levels for conductivity, pH and total suspended solids were higher than the average data from previous years. Dominant phylotypes belonged to Cyanobacteria, Actinobacteria Alphaproteobacteria, Betaproteobacteria and Bacteroidetes groups. Despite the geographic distance, common phylotypes could be recorded among water bodies. Bacteroidetes dominated at Sousa River and were related to high nutrient levels. Cyanobacteria dominated at Alentejo reservoirs and correlated with higher conductivity values. However, Actinobacteria showed ubiquitous phylotypes throughout several samples, suggesting its persistence over geographically distant water bodies. This study showed a clear deterioration of water quality, from a physico-chemical point of view; furthermore, dominance of Cyanobacteria and Actinobacteria in reservoirs used for drinking water supply were also detected, which may become a concerning issue. However, the most severe bacterial community composition variations between summer 2005 and others were mainly related to higher water residence times. Thus, along with the expected intensification of drought episodes, with severe effects particularly in Southern Europe, it is clearly predictable an intensification in risks for water quality maintenance and even Public Health.
Authors:M. Neves, M. Miguel, L. Pedro, J. Barroso, A. Figueiredo, D. Martins and S. Dandlen
The fatty acid composition and stability of three Portuguese monovarietal olive oils, Cobrançosa, Maçanilha and Verdeal, was studied, maintaining the olive oils at 60 °C for 75 and 102 days, respectively. Oleic acid was the main fatty acid (64–69%) in three olive oils cultivars, followed by palmitic acid (15–18%). The highest percentages of palmitic acid were observed in Maçanilha olive oil (17–18%). Linolenic acid content was 3%, on average. Storing the oils at 60 °C over 75 days did not affect the levels of fatty acids. Cobrançosa and Maçanilha olive oils were more resistant to hydroperoxide formation than Verdeal olive oil, whereas this oil and that of Maçanilha were more resistant to the degradation of those peroxides. Cobrançosa olive oil possessed higher levels of phenols and higher ability for scavenging free radicals than the remaining oils. α-Tocopherol content was higher in Cobrançosa and Maçanilha oils than in Verdeal, but a similar high degradation of this vitamin was observed in all oils, disappearing after 5 to 8 days of storage at 60 °C.
Authors:G. Lalor, M. Vutchkov, C. Grant, J. Preston, A. Figueiredo and D. Favaro
The biological standard reference materials Orchard Leaves SRM 1571 and Oyster Tissue SRM 1566a was analysed by instrumental neutron activation analysis (INAA) at the International Centre for Environmental and Nuclear Sciences, Jamaica at (ICEN) and at the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil. The comparison of the results with those obtained with the more powerful reactor are used to evaluate the possibilities of INAA for the analysis of biological samples at ICENS. The detection limits, the precision and accuracy of the results obtained in both laboratories are compared. The advantages and disadvantages of the different irradiation facilities are discussed. Some results obtained for Jamaican biological samples are also presented.
Authors:M. Vasconcellos, M. Saiki, D. Fávaro, V. Maihara, A. Figueiredo and M. Catharino
The Research Reactor Center (CRPQ) of IPEN/CNEN-SP operates the IEA-R1 Research Reactor, at a nominal power of 2 MW thermal,
on a 64 hour per week continuous cycle. The IEA-R1 is a pool type reactor, moderated and cooled by light water, with graphite
as a reflector. One of the main activities of CRPQ is the neutron activation analysis, which is applied to many fields of
research, in collaboration with other institutes and universities. The Research Reactor installations are also intensely used
for human resources development in the field of radiochemistry and neutron activation analysis, at graduate and post-graduate
levels. In the present paper, an overview will be presented of some of the neutron activation analysis research lines that
are being developed, comprising environmental and health-related applications.
This study is aimed at performing the determination of bioactive compounds, antioxidant activity, and the identification of the minerals in the flours produced with the tropical fruit peels of mango, papaya, melon, and pineapple. The results showed that the papaya peel flour has the highest amount of ascorbic acid and lycopene when compared with the other studied flours. The mango peel flour has a high content of total extractable polyphenols and a high antioxidant activity. Regarding the mineral content, the by-product of melon stood out with 523.24±26.12 mg/100 g of potassium, 104.15±3.52 mg/100 g of calcium and 6.62±0.30 mg/100 g of iron. The flours prepared with mango, papaya, melon, and pineapple peels are potential sources of bioactive compounds and minerals, also presenting good antioxidant activity, being, therefore, recommended to be used in food products to improve the nutritional quality of the product.