Kinetic-thermodynamic study of the oxidative stability of Arbequina olive oils flavored with lemon verbena essential oil

Arbequina extra-virgin olive oils were flavored with lemon verbena (Aloysia citrodora) essential oil (0.10.4%, w/w), being evaluated quality parameters (free acidity, peroxide value, UV-extinction coefficients), oxidative stability, antioxidant and total reducing capacity. The kinetic-thermodynamic nature of the lipid oxidation was evaluated by Rancimat (110150 °C). The essential oil addition promoted the antioxidant and total reducing capacities but, unfortunately, increased primary and secondary related quality parameters. Moreover, flavoring decreased the oils' oxidative stability. The kinetic-thermodynamic data showed that unflavored oils had significantly lower oxidation reaction rates (0.0550.06492 h1), more negative temperature coefficient (0.0268°C1), higher temperature acceleration factor (1.852), greater activation energy (82.7 kJ mol1) and frequency factor (10.9 × 109 h1), higher positive enthalpy of activation (79.4 kJmol-1), lower negative entropy of activation (131.8 J mol1K1) and greater positive Gibbs free energy of activation (129.95135.23 kJ mol1), showing that oils oxidation was negatively influenced by the essential oil incorporation. Overall, oxidation had a non-spontaneous, endothermic and endergonic nature. Finally, olive oils could be satisfactorily classified (principal component and linear discriminant analysis) according to the flavoring level, using quality-antioxidant-stability or kinetic-thermodynamic datasets. The latter showed a less predictive performance, although ensuring the full discrimination of unflavored from flavored oils.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020) and to BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Nuno Rodrigues thanks the National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Pool boiling on modified surfaces using R-123

This article has been made available through the Brunel Open Access Publishing Fund.Saturated pool boiling of R-123 was investigated for five horizontal copper surfaces modified by different treatments, namely, an emery-polished surface, a fine sandblasted surface, a rough sandblasted surface, an electron beam-enhanced surface, and a sintered surface. Each 40-mm-diameter heating surface formed the upper face of an oxygen-free copper block, electrically heated by embedded cartridge heaters. The experiments were performed from the natural convection regime through nucleate boiling up to the critical heat flux, with both increasing and decreasing heat flux, at 1.01 bar, and additionally at 2 bar and 4 bar for the emery-polished surface. Significant enhancement of heat transfer with increasing surface modification was demonstrated, particularly for the electron beam-enhanced and sintered surfaces. The emery-polished and sandblasted surface results are compared with nucleate boiling correlations and other published data. © 2014 Syed W. Ahmad, John S. Lewis, Ryan J. McGlen, and Tassos G. Karayiannis Published with license by Taylor & Francis

A kinetic-thermodynamic study of the effect of the cultivar/total phenols on the oxidative stability of olive oils

Physicochemical parameters, total phenols contents (TPC), and oxidative stabilities at 120160 °C were evaluated for two monovarietal (Arbequina and Cobrançosa cultivars, cvs.) and one blend extravirgin olive oil, confirming the label quality grade and allowing grouping them according to the different TPC (TPC = 88±7, 112±6 and 144±4mg CAE/kg, for cv. Arbequina, blend and cv. Cobrançosa oils, respectively). The lipid oxidation rate increased with the decrease of the TPC, being Cobrançosa oils (higher TPC) more thermally stable. Kineticthermodynamic parameters were determined using the activated complex/transitionstate theory and the values did not significantly differ for Cobrançosa and blend oils, which had the highest TPC, suggesting a hypothetically threshold saturation of the beneficial effect. Cobrançosa oils had a significant more negative temperature coefficient, higher temperature acceleration factor, greater activation energy and frequency factor, higher positive enthalpy of activation, lower negative entropy of activation, and greater positive Gibbs free energy of activation, probably due to the higher TPC. The results confirmed that lipid oxidation was a nonspontaneous, endothermic, and endergonic process with activated formed complexes structurally more ordered than the reactants. A negative deviation from the Arrhenius behavior was observed for all oils being the superArrhenius behavior more marked for Arbequina oils that had the lowest TPC. Finally, the kineticthermodynamic parameters allowed classifying oils according to the binomial olive cultivar/total phenols level, being the temperature acceleration factor and the Gibbs free energy of activation at 160 °C the most powerful discriminating parameters.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (UIDB/00690/2020) and to CEB (UIDB/04469/2020) units and to BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte). Nuno Rodrigues thanks to National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Salt effect on physiological, biochemical and anatomical structures of two Origanum majorana varieties (Tunisian and Canadian)

In this study, we evaluated the salt concentration effect on plant growth, mineral composition, antioxidant responses and anatomical structure of two varieties of Origanum majorana after exposure to NaCl treatment. Our results show an inclusive behaviour of the two varieties, since the majority of sodium was exported and accumulated in their aerial parts. The Canadian variety (CV) appeared relatively more tolerant to salt than the Tunisian one (TV). Transversal section of leaves showed a thickening of dorsal and ventral cuticle, more importantly in CV than in TV, in the presence and in absence of salt. This was accompanied by an increase in the length of palisade cells, and the width of spongy collenchyma lacuna. The stem had a subquadrangular shape in TV and quadrangular in the Canadian variety. At mature stage, the stem pit was reabsorbed in the TV and replaced by a large cavity, whereas it remained unchanged in CV. The relative salt tolerance of the CV was related to: (1) a good selectivity in favour of K+: (2) a strong peroxidase activity and (3) an increase in the lengthening of palisade cell accompanied with an increase of lacunae in spongy parenchyma in CV.Key words: Origanum majorana, salinity, growth, mineral nutrition, leaves, stems, anatomical, antioxidant

Informe de la Campaña ARGELIA0203-DP para la evaluación de recursos demersales profundos en las costas de Argelia (Mediterráneo Sud-Occidental)

RESUMEN: Del 5 al 24 de marzo de 2003 se llevó a cabo la campaña de prospección pesquera con arrastre de fondo ARGELIA0203-DP en aguas de Argelia, a bordo del B/O Vizconde de Eza. Se realizaron 55 pescas (3 nulas) entre 200 y 800 m de profundidad. Se presentan los resultados de las capturas realizadas en esta campaña y se analizan los índices de abundancia y biomasa de las especies más importantes, por sector y área geográficos y estrato batimétrico, así como su distribución de tallas por sector geográfico y estrato batimétrico. Se comparan los rendimientos y las tallas obtenidos con los de otras campañas realizadas en el Mediterráneo (MEDITS y BALAR)RÉSUME: Rapport de la campagne ARGELIA0203-DP portant evaluation des ressources demersales des côtes Algeriennes (Mediterrane sud-occidental).- Du 05 au 24 Mars 2003, s’est réalisée une campagne de prospection par chalutage du fond ARGELIA0203-DP des côtes Algériennes, abord du B/O Vizconde de Eza. 55 traits de pêche (3 annulées) ont été effectue entre 200 et 800 m de profondeur. Les résultats des captures réalisées durant cette campagne et l’analyse des indices d’abondance et biomasse des espèces les plus importantes sont présentés, par secteur, par aire géographique et strate bathymétrique, ainsi que leurs distributions de tailles par secteur géographique et strate bathymétrique. Les rendements et les tailles obtenus ont fait l’objet d’une comparaison avec les autres campagnes réalisées dans la Méditerranée (MEDITS et BALAR)ABSTRACT: Report of the ARGELIA0203-DP survey for the assessment of the deep-sea demersal resources off Algerian coasts (southwestern Mediterranean).- From March 5th to 24th 2003 the bottom-trawl survey ARGELIA0203-DP was developed in waters off Argelia, on board R/V Vizconde de Eza. Fifty-five hauls (3 null) were carried out between 200 and 800 m depth. The results of the captures obtained during this survey are shown and abundance and biomass indexes of the most important species are analyzed by geographic sector and area, and bathymetric stratum, as their size distribution by geographic sector and bathymetric stratum. Yields and sizes obtained are compared to those from other surveys carried out in the Mediterranean (MEDITS and BALAR)

Informe de la campaña ARGELIA0204 para la evaluación de recursos demersales en las costas de Argelia (Mediterráneo sud-occidental)

RESUMEN: Del 5 de Febrero al 8 de Marzo de 2004 se llevó a cabo la campaña de prospección pesquera con arrastre de fondo ARGELIA0204 en aguas de Argelia, a bordo del B/O Vizconde de Eza. Se realizaron 114 pescas (6 nulas) entre 40 y 760 m de profundidad. Se presentan los resultados de las capturas realizadas en esta campaña y se analizan los índices de abundancia y biomasa de las especies más importantes, así como su distribución de tallas, por sector geográfico y estrato batimétrico. Se comparan los rendimientos y las tallas obtenidos con los de la campaña realizada en 2003 en la misma área y con otras campañas realizadas en el Mediterráneo.RÉSUME: Rapport de la campagne ARGELIA0204 portant évaluation des ressources demersaux des côtes Algériennes (Méditerranée sud-occidental).- Du 05 du Février au 8 du Mars 2004, s’est réalisée une campagne de prospection par chalutage du fond ARGELIA0204 des côtes Algériennes, a bord du B/O Vizconde de Eza. 114 traits de pêche (6 annulées) ont été effectue entre 40 et 800 m de profondeur. Les résultats des captures réalisées durant cette campagne et l’analyse des indices d’abondance et biomasse des espèces les plus importantes sont présentés, par secteur, par aire géographique et strate bathymétrique, ainsi que leurs distributions de tailles par secteur géographique et strate bathymétrique. Les rendements et les tailles obtenus ont fait l’objet d’une comparaison avec les autres campagnes réalisées dans la Méditerranée.ABSTRACT: Report of the ARGELIA0204 survey for the assessment of the deep-sea demersal resources off Algerian coast (south-western Mediterranean).- From 5 February to 8 March 2004 the bottom-trawl survey ARGELIA0204 was developed in waters off Argelia, on board R/V Vizconde de Eza. 114 hauls (6 null) were carried out between 40 and 800 m depth. The results on the captures obtained during this survey are shown and abundance and biomass indexes of the most important species are analyzed by geographic sector and area, and bathymetric stratum, as their size distribution by geographic sector and bathymetric stratum. Yields and sizes obtained are compared to those from other surveys carried out in the Mediterranea

The effect of the symmetrical deformation y = xk + 1 on the optimization of the symmetrical multiple channeled white light color filter

In this paper, we consider a hybrid photonic crystal symmetrically deformed (Bg5/Cu3/Bg5) consisting of the third generation of the copper mean sequence (Cu3), sandwiched between two Bragg mirrors at the fifth generation (Bg5). Our system realizes a polychromatic filter that transmits five wavelengths in the visible spectrum independently of the polarization of the light transverse electric or transverse magnetic. Secondly, the photonic crystal (Bg5/Cu3/Bg5) undergoes the deformation y = xk + 1 (where k is the degree of deformation, x and y are respectively the coordinates of the system before and after the deformation). With a proper choice of the degree of deformation k, this photonic crystal maintains its property of polychromatic filter whose transmission wavelength is independent of the polarization’s state. Thanks to this deformation, we can disperse the optical windows in different spectra of visible light and exactly in the violet, blue, green, and orange light. This system can be used in the fabrication of color filter devices and the white light emitting diodes