Browsing by Author "Costa, Maria do Céu"
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- Characterization of laurel fruit oil from Madeira Island, PortugalPublication . Castilho, Paula C.; Costa, Maria do Céu; Rodrigues, Ana; Partidário, AnaThe fixed oil extracted from Laurus spp. fruit from Madeira Island, Portugal, is used in local traditional medicine for a wide variety of health complaints. Physical properties, density and refractive index, as well as the TAG FA composition, sterols, and waxes were determined. The oil was found to have an un usually high content of volatiles (ca. 10%), with trans-ocimene and germacrene D predominating. Oleic (30%) and linoleic (20%) acids were the main unsaturated FA, whereas lauric (18%) and palmitic (up to 22.5%) acids were the main saturated FA in the neutral lipid fraction. The oil had a sterol content on the same order as olive oil, with β-sitosterol (84%) predominating. Two sesquiterpene lactones, dehydrocostuslactone and costunolide, accounted for 5% of the overall composition. Madeira laurel oil is not currently used as an edible oil because of its very strong flavor. Its claimed medicinal properties have not yet been vali dated, and this is the first report on the characterization of the commercial product.
- Characterization of triacylglycerols in Madeira laurel oil by HPLC-atmospheric pressure chemical ionization-MSPublication . Castilho, Paula C.; Costa, Maria do Céu; Rodrigues, Ana; Branco, Pedro Costa; Costa, MafalaaMadeira laurel oil was fractionated by liquid ex traction combined with TLC, and TAGs were analyzed by HPLC coupled with atmospheric pressure chemical ionization-MS (APCI-MS). Eluted molecular species compositions of the eluted TAG in the complex natural mixture were determined by GC identification of FAME and by LC-atmospheric pressure chemi cal ionization (APCI)-MS analysis of the lipid. The APCI-MS spectra of most TAG exhibited [M + H]+ and [M − RCOO]+ ions, which defined the M.W. and the molecular association of fatty acyl residues, respectively. Despite the relatively high de gree of saturation, with a saturated/unsaturated ratio of 0.70, no totally saturated TAG nor mixed asymmetric TAG with two sat urated FA (SSM or SSU, where S is saturated, M is monounsatu rated, and U is unsaturated) were found. This type of molecular structure provides a possible explanation for the relatively low m.p. (12–15°C) and also the high oxidative resistance observed.
- Direct identification and quantitative determination of costunolide and dehydrocostuslactone in the fixed oil of Laurus novocanariensis by13C-NMR spectroscopyPublication . Ferrari, Bernard; Castilho, Paula; Tomi, Félix; Rodrigues, Ana Isabel; Costa, Maria do Céu; Casanova, JosephThe fixed oil of Laurus novocanariensis (previously L. azorica) contains mostly glycerides together with minor non-saponifiable compounds. The direct identification and quantitative determination of costunolide and dehydrocostuslactone, two sesquiterpene lactones components of the oil that exhibit biological activities, is described. The analysis was carried out using 13C-NMR spectroscopy (signal acquisition with inverse gated decoupling of protons; diglyme as internal standard) without separation, derivatisation or any sample preparation.
- New contributions to deepen the quality-based safety assessment in the consumption of edible nasturtium flowers: the role of VolatilomePublication . Perestrelo, Rosa; Lopes, Maria da Graça; Silva, Alda Pereira da; Costa, Maria do Céu; Câmara, José S.; Perestrelo, Rosa; Câmara, JoséThe garden Nasturtium (Tropaeolum majus L.) is increasingly consumed worldwide due to its culinary appeal and perceived health benefits. However, the chemical markers underlying its functional properties remain insufficiently characterized. Building on evidence from a recent human pilot study confirming both high acceptability and dietary safety, we conducted a comprehensive volatilomic and phytochemical analysis of T. majus flowers and their juice. Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) was employed to establish the volatilomic fingerprint of floral tissues and juice. Our analysis revealed a striking dominance of benzyl isothiocyanate and benzonitrile, which together accounted for 88% of the total volatile organic metabolites (VOMs) in the juice, 67% and 21%, respectively. In the floral tissues, benzyl isothiocyanate was even more prevalent, representing 95% of the total volatile profile. Complementary in vitro assays confirmed a substantial total phenolic content and strong antioxidant activity in the flowers. These findings provide a robust chemical rationale for the potential health-promoting attributes of T. majus, while identifying key volatilomic markers that could support future functional and safety claims. In parallel, a benefit–risk assessment framework is discussed in accordance with the European Food Safety Authority (EFSA) guidelines for the Qualified Presumption of Safety (QPS) of edible flowers. Given that both benzyl isothiocyanate and benzonitrile are classified as Cramer Class III substances, a conservative intake threshold of 1.5 μg/kg body weight per day is proposed. To enable quantitative exposure modeling and support the derivation of a tolerable daily intake (TDI), future studies should integrate organic solvent-based extraction methodologies to estimate the total volatile load per gram of floral biomass. This would align risk–benefit assessments with the EFSA’s evolving framework for novel foods and functional ingredients.