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In vitro bioacessibility and transport across Caco-2 monolayers of haloacetic acids in drinking water
Publication . Melo, A.; Faria, M.A.; Pinto, E.; Mansilha, C.; Ferreira, I.M.P.L.V.O.
Water disinfection plays a crucial role in water safety but it is also a matter of concern as the use of disinfectants promotes the formation of disinfection by-products (DBPs). Haloacetic acids (HAAs) are one of the major classes of DBPs since they are frequently found in treated water, are ubiquitous, pervasive and have high water solubility, so a great concern emerged about their formation, occurrence and toxicity. Exposure to HAAs is influenced by consumption patterns and diet of individuals thus their bioavailability is an important parameter to the overall toxicity. In the current study the bioacessibility of the most representative HAAs (chloroacetic acid - MCAA, bromoacetic acid - MBAA, dichloroacetic acid - DCAA, dibromoacetic acid - DBAA, and trichloroacetic acid - TCAA) after simulated in vitro digestion (SIVD) in tap water and transport across Caco-2 monolayers was evaluated. Compounds were monitored in 8 points throughout the digestion phases by an optimized LC-MS/MS methodology. MCAA and MBAA were not bioaccessible after SIVD whereas DCAA, DBAA and TCAA are highly bioaccessible (85 ± 4%, 97 ± 4% and 106 ± 7% respectively). Concerning transport assays, DCAA and DBAA were highly permeable throughout the Caco-2 monolayer (apparent permeability and calculated fraction absorbed of 13.62 × 10(-6) cm/s and 90% for DCAA; and 8.82 × 10(-6) cm/s and 84% for DBAA), whereas TCAA showed no relevant permeability. The present results may contribute to efficient risk analysis studies concerning HAAs oral exposure from tap water taking into account the different biological behaviour of these chemically similar substances.
The impact of cooking methods on the nutritional quality and safety of chicken breaded nuggets
Publication . Albuquerque, T.G.; Oliveira, M.B.; Sanches-Silva, A.; Bento, A.C.; Costa, H.S.
The impact of cooking methods (industrial pre-frying, deep-fat frying and baking) on the nutritional
quality and safety of chicken breaded nugget samples from supermarket and commercial brands was
evaluated. The changes in the quality characteristics (nutritional composition, fatty acids profile, cholesterol
and salt) of the fried food and frying oil, after ten consecutive frying operations, were evaluated.
The total fat content of nuggets varied between 10.9 and 22.7 g per 100 g of edible portion and the salt
content ranged from 0.873 to 1.63 g per 100 g. Taking into account one portion of nuggets, the daily
intake of salt can reach 49%, which can have a significant impact on the health of those who regularly
consume this type of food, especially considering the prevalence of hypertension around the world. The
analysed chicken breaded nuggets are rich in unsaturated fatty acids, which have been related with potential
health benefits, namely regarding cardiovascular diseases. The cholesterol content of baked samples
was two times higher when compared with the fried ones. The trans fatty acids and polar compounds
contents of the frying oil used for frying significantly increased, but the values were still away from the
maximum recommended by legal entities for its rejection. From a nutritional point of view, it is possible to
conclude that the applied cooking methods can significantly influence the nutritional quality and safety of
the analysed chicken breaded nuggets. This study will contribute to important knowledge on how the
applied cooking methods can change the nutritional quality and safety of foods, namely of chicken
nuggets, and can be very useful for dietary recommendations and nutritional assessment.
Firefighters' exposure biomonitoring: Impact of firefighting activities on levels of urinary monohydroxyl metabolites
Publication . Oliveira, Marta; Slezakova, Klara; Alves, Maria José; Fernandes, Adília; Teixeira, João Paulo; Delerue-Matos, Cristina; Pereira, Maria do Carmo; Morais, Simone
The concentrations of six urinary monohydroxyl metabolites (OH-PAHs) of polycyclic aromatic hydrocarbons, namely 1-hydroxynaphthalene, 1-hydroxyacenaphthene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 1-hydroxypyrene (1OHPy), and 3-hydroxybenzo[a]pyrene, were assessed in the post-shift urine of wildland firefighters involved in fire combat activities at six Portuguese fire corporations, and compared with those of non-exposed subjects. Overall, median levels of urinary individual and total OH-PAHs (ΣOH-PAHs) suggest an increased exposure to polycyclic aromatic hydrocarbons during firefighting activities with ΣOH-PAH levels in exposed firefighters 1.7-35 times higher than in non-exposed ones. Urinary 1-hydroxynaphthalene and/or 1-hydroxyacenapthene were the predominant compounds, representing 63-98% of ΣOH-PAHs, followed by 2-hydroxyfluorene (1-17%), 1-hydroxyphenanthrene (1-13%), and 1OHPy (0.3-10%). A similar profile was observed when gender discrimination was considered. Participation in fire combat activities promoted an increase of the distribution percentage of 1-hydroxynaphthalene and 1-hydroxyacenaphthene, while contributions of 1-hydroxyphenanthrene and 1OHPy decreased. The detected urinary 1OHPy concentrations (1.73×10(-2) to 0.152μmol/mol creatinine in exposed subjects versus 1.21×10(-2) to 5.44×10(-2)μmol/mol creatinine in non-exposed individuals) were lower than the benchmark level (0.5μmol/mol creatinine) proposed by the American Conference of Governmental Industrial Hygienists. This compound, considered the biomarker of exposure to PAHs, was the less abundant one from the six analyzed biomarkers. Thus the inclusion of other metabolites, in addition to 1OHPy, in future studies is suggested to better estimate firefighters' occupational exposure to PAHs. Moreover, strong to moderate Spearman correlations were observed between individual compounds and ΣOH-PAHs corroborating the prevalence of an emission source.
Diversity of methicillin-resistant staphylococci among wild Lepus granatensis: first detection of mecA-MRSA in hares
Publication . Silva, Vanessa; Pereira, José Eduardo; Maltez, Luís; Ferreira, Eugénia; Manageiro, Vera; Caniça, Manuela; Capelo, José L.; Igrejas, Gilberto; Poeta, Patrícia
MRSA in humans, pets and livestock have been widely investigated, nevertheless, there is still little information of MRSA in wild animals. Therefore, this study aimed to investigate the occurrence and antimicrobial resistance profiles of methicillin-resistant staphylococci (MRS) in wild Iberian hares and to characterize their genetic lineages. Samples from 83 wild hares (Lepus granatensis) were collected during the hunting season. Isolation of MRS was accomplish using Oxacillin Resistant Screening Agar medium with 2 mg/L of oxacillin. The susceptibility of the isolates was tested by the Kirby-Bauer disc diffusion method. The presence of resistance and virulence genes was studied by PCR. S. aureus strains were further characterized by multilocus sequence typing, agr, spa and SCCmec typing. From the 83 samples, 12 (14.45%) coagulase-negative staphylococci and 3 (3.6%) MRSA strains were isolated. Nine coagulase-negative isolates showed resistance to at least one antibiotic. One MRSA isolate showed a multidrug-resistant profile with resistances to ß-lactams, aminoglycosides, macrolides and lincosamides. All MRSA strains were ascribed to ST2855, t1190 and SCCmec type III. The frequency of MRSA strains in wild hares was low, nevertheless, the presence of MRSA in game animals is considered a public health problem and may represent a route of transmission between animals and humans.
Occurrence of Trihalomethanes in Chlorinated Waters from Different Sources Used for Urban Supply
Publication . Melo, Armindo; Mansilha, Catarina; Margarida, Teixeira; Ferreira, Isabel M.P.L.V.O.
Trihalomethanes (THMs) are the most common disinfection by-products formed by the reaction of chlorine and/or bromide with organic matter. Total THMs in chlorinated treated water are defined as the sum of the concentrations of chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM). The monitoring of trihalomethanes in distribution tap water collected in from five regions of Portugal, from North to South, in a total of 33 samples, during spring to summer season, is described. Solid phase microextraction coupled to gas chromatography and electron capture detector methodology was applied to determine whether THMs concentrations in urban water supply systems are is in agreement with European Regulations. It was found a great discrepancy in total THMs concentration values, with concentrations varying from 1.8-97.7 μg/L, although the results were below the European parametric value of 100 μg/L. Regarding the Environmental Protection Agency regulations, however, only 97% of samples fulfilled the established criterion of 80 μg/L. and investigate if the individual compounds trihalomethanes content in was also investigated in order to determine if there is observed distribution tap water follows a common or a different THMs pattern in close geographical areas. In the geographical areas under study, mean values of concentrations measured revealed two different clusters: one including the three groups from the North geographical areas, with samples revealing a similar pattern (TCM>BDCM>DBCM>TBM), and another including the two groups from South with a different THMs pattern (DBCM>BDCM>TCM>TBM). A great degree of variation in the concentrations of THMs in tap water was observed, although the results the total THMs concentrations were below the European parametric value (100 μg/L). Mean results of samples grouped by five geographical areas revealed a similar pattern in samples collected from North and Centre TCM>BDCM>DBCM>TBM, whereas samples from South presented a different pattern, DBCM>BDCM>TCM>TBM. The origin of raw water (surface or groundwater) seems to influence this different pattern formation of brominated compounds.
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Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
5876
Funding Award Number
UID/QUI/50006/2013