2017
Authors
Gouvinhas, I; Machado, N; Sobreira, C; Dominguez Perles, R; Gomes, S; Rosa, E; Barros, AIRNA;
Publication
MOLECULES
Abstract
Olive oil displays remarkable organoleptic and nutritional features, which turn it into a foodstuff appreciated by consumers, and a basic component of the Mediterranean diet. Indeed, the noticed benefits of including olive oil in the diet have been assigned to the presence of diverse bioactive compounds with different molecular structures. These compounds confer a wide range of biological properties to this food matrix, including the prevention of distinct human diseases as well as the modulation of their severity. The most relevant bioactive compounds present in olive oil correspond to benzoic and cinnamic acids, phenolic alcohols and secoiridoids, and also flavonoids. Over the last decades, several studies, devoted to gaining a further insight into the relative contribution of the separate groups and individual compounds for their biological activities, have been conducted, providing relevant information on structure-activity relationships. Therefore, this paper critically reviews the health benefits evidenced by distinct phenolic compounds found in olive oils, thus contributing to clarify the relationship between their chemical structures and biological functions, further supporting their interest as essential ingredients of wholesome foods.
2017
Authors
Machado, NFL; Dominguez Perles, R;
Publication
MOLECULES
Abstract
Grape and wine phenolics display a noticeable structural diversity, encompassing distinct compounds ranging from simple molecules to oligomers, as well as polymers usually designated as tannins. Since these compounds contribute critically to the organoleptic properties of wines, their analysis and quantification are of primordial importance for winery industry operators. Besides, the occurrence of these compounds has been also extensively described in winery residues, which have been pointed as a valuable source of bioactive phytochemicals presenting potential for the development of new added value products that could fit the current market demands. Therefore, the cumulative knowledge generated during the last decades has allowed the identification of the most promising compounds displaying interesting biological functions, as well as the chemical features responsible for the observed bioactivities. In this regard, the present review explores the scope of the existing knowledge, concerning the compounds found in these winery by-products, as well as the chemical features presumably responsible for the biological functions already identified. Moreover, the present work will hopefully pave the way for further actions to develop new powerful applications to these materials, thus, contributing to more sustainable valorization procedures and the development of newly obtained compounds with enhanced biological properties.
2017
Authors
Machado, NFL; Marques, MPM; de Carvalho, LAEB; Castro, JL; Otero, JC;
Publication
JOURNAL OF RAMAN SPECTROSCOPY
Abstract
Raman and SERS spectra of benzaldehyde (Bz-CHO) and chromone-3-carboxaldehyde (Ch-CHO) on silver colloids have been analyzed, being subsequently compared to the spectra of the corresponding acids. In the SERS spectra of both aldehydes, the band corresponding to the.(C =O) stretching mode of the carboxaldehyde group at ca. 1700cm (-1) ismissing, while a newband at 13501400cm(-1), characteristic of the symmetric stretching mode of carboxylate group, is appearing in both cases. These results point out that aldehydes are oxidized to their corresponding acidswhen adsorbed on silver nanoparticles. This conclusion has been confirmed by means of HPLC-MS analysis and supported on the basis of DFT calculations. Copyright (c) 2016 John Wiley & Sons, Ltd.
2016
Authors
Domínguez-Perles, R; Machado, N; Abraão, AS; Carnide, V; Ferreira, L; Rodrigues, M; Rosa, EA; Barros, AI;
Publication
Journal of Food Composition and Analysis
Abstract
2016
Authors
Dominguez Perles, R; Machado, N; Abraao, AS; Carnide, V; Ferreira, L; Rodrigues, M; Rosa, EADS; Barros, AIRNA;
Publication
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
Abstract
Biodiversity of cowpea, along with the interesting agricultural and nutritional properties, has encouraged research with local landraces of Portugal. This work deals with the composition of dry beans of cowpea from 28 different Portuguese cultivars concerning dry matter (DM), crude proteins (CP), fat content (FC), ash, and concentration of free essential and non-essential amino acids. Data obtained on these traits showed contents of DM, FC, ash, and CP in the ranges of 95.7-98.9%, 1.0-1.6%, 2.7-4.7%, and 18.6-26.9%, respectively. The content in free amino acids was evaluated as an indicator of germinating potential of the diverse cultivars assessed. The amino acids content was the highest in the varieties 'Vg50' and 'Vg58'. Cluster and principal component analyses of the data allowed the identification of the most promising Portuguese landraces of cowpea to be used for breeding new varieties with improved germination potential and nutritional traits.
2016
Authors
Gouvinhas, I; Dominguez Perles, R; Machado, N; Carvalho, T; Matos, C; Barros, AIRNA;
Publication
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
Abstract
The nutritional properties and safety of olive oil are strongly dependent on the content of mineral nutrients and trace elements. Hence, this work assesses the content for quality and toxic metals of olive oils from three major Portuguese cultivars ('Galega', 'Cobran double dagger osa' and 'Picual') obtained from olives in different ripening stages. This evaluation was achieved by flame atomic spectrometry and atomic absorption in a graphite furnace, depending on the metal to be analysed. The results showed mean concentrations of the mineral nutrients Ca and Mg of 20.00 A mu g g(-1), and K and Na of 40.00 and 170.00 A mu g g(-1), respectively, while the trace elements Fe, Co, Cu, Mn, Zn and Ni had mean values of 0.53, a parts per thousand currency sign 0.01, 0.33, 0.10, 1.09 and 0.64 A mu g g(-1), respectively. The mean content of the toxic metals Al, Cd, Pb and As were 27.46, 0.03, 0.09 and 0.36 A mu g g(-1), respectively, which were according to the values proposed by European regulations. The evaluation of the data obtained by partial least square regression allowed the identification of the minerals with the strongest potential to discriminate between the season (Na, Cu, Zn and Ni) and the cultivar employed in the olive oil performance (Fe and Mn).
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