Detection of corn and sunflower oil adulterations of olive oils using fluorescence spectroscopy

A novel approach for the detection of admixtures of vegetable (corn and sunflower) oils in commercially available olive oils on a qualitative level is presented. Chemical analysis of the contents of fatty acids in each of the model systems under study is performed. The dependence of the ratio of the two main fluorescence intensity peaks 1 2 F / F and that of the linoleic to oleic acids C18:2 / C18:1 is studied. It is shown that an increase of the concentration of the adulterant the maximum of the first fluorescence peak exhibits a wavelength shift. Fluorescence analysis can be used for a qualitative real time determination of the presence of adulterants in olive oil by comparison of the observed particular fluorescence spectrum with those from a database of spectra of olive oils and adulterants from a particular region

Magnetic field structure in single late-type giants: Beta Ceti in 2010 - 2012

The data were obtained using two spectropolarimeters - Narval at the Bernard Lyot Telescope, Pic du Midi, France, and ESPaDOnS at CFHT, Hawaii. Thirty-eight circularly-polarized spectra have been collected in the period June 2010 - January 2012. The Least Square Deconvolution method was applied for extracting high signal-to-noise ratio line profiles, from which we measure the surface-averaged longitudinal magnetic field Bl. Chromospheric activity indicators CaII K, H_alpha, CaII IR (854.2 nm) and radial velocity were simultaneously measured and their variability was analysed together with the behavior of Bl. The Zeeman Doppler Imaging (ZDI) inversion technique was employed for reconstruction of the large-scale magnetic field and two magnetic maps of Beta Ceti are presented for two periods (June 2010 - December 2010 and June 2011 - January 2012). Bl remains of positive polarity for the whole observational period. The behavior of the line activity indicators is in good agreement with the Bl variations. The two ZDI maps show a mainly axisymmetric and poloidal magnetic topology and a simple surface magnetic field configuration dominated by a dipole. Little evolution is observed between the two maps, in spite of a 1 yr interval between both subsets. We also use state-of-the-art stellar evolution models to constrain the evolutionary status of Beta Ceti. We derive a mass of 3.5 M_sun and propose that this star is already in the central-helium burning phase. Taking into account all our results and the evolutionary status of the star, we suggest that dynamo action alone may not be eficient enough to account for the high magnetic activity of Beta Ceti. As an alternate option, we propose that it may be an Ap star descendant presently undergoing central helium-burning and still exhibiting a remnant of the Ap star magnetic field.Comment: 10 pages; 5 figures; 3 table

Long-term spectropolarimetric monitoring of the cool supergiant Betelgeuse

We report on a long-term monitoring of the cool supergiant Betelgeuse, using the NARVAL and ESPaDOnS high-resolution spectropolarimeters, respectively installed at Telescope Bernard Lyot (Pic du Midi Observatory, France) and at the Canada-France-Hawaii Telescope (Mauna Kea Observatory, Hawaii). The data set, constituted of circularly polarized (Stokes V) and intensity (Stokes I) spectra, was collected between 2010 and 2012. We investigate here the temporal evolution of magnetic field, convection and temperature at photospheric level, using simultaneous measurements of the longitudinal magnetic field component, the core emission of the Ca II infrared triplet, the line-depth ratio of selected photospheric lines and the radial velocity of the star.Comment: Proceedings of the Betelgeuse Workshop, Paris, 26-29 Nov 201

Magnetic fields in single late-type giants in the Solar vicinity: How common is magnetic activity on the giant branches?

We present our first results on a new sample containing all single G,K and M giants down to V = 4 mag in the Solar vicinity, suitable for spectropolarimetric (Stokes V) observations with Narval at TBL, France. For detection and measurement of the magnetic field (MF), the Least Squares Deconvolution (LSD) method was applied (Donati et al. 1997) that in the present case enables detection of large-scale MFs even weaker than the solar one (the typical precision of our longitudinal MF measurements is 0.1-0.2 G). The evolutionary status of the stars is determined on the basis of the evolutionary models with rotation (Lagarde et al. 2012; Charbonnel et al., in prep.) and fundamental parameters given by Massarotti et al. (1998). The stars appear to be in the mass range 1-4 M_sun, situated at different evolutionary stages after the Main Sequence (MS), up to the Asymptotic Giant Branch (AGB). The sample contains 45 stars. Up to now, 29 stars are observed (that is about 64 % of the sample), each observed at least twice. For 2 stars in the Hertzsprung gap, one is definitely Zeeman detected. Only 5 G and K giants, situated mainly at the base of the Red Giant Branch (RGB) and in the He-burning phase are detected. Surprisingly, a lot of stars ascending towards the RGB tip and in early AGB phase are detected (8 of 13 observed stars). For all Zeeman detected stars v sin i is redetermined and appears in the interval 2-3 km/s, but few giants with MF possess larger v sin i.Comment: 4 pages, 3 figures, Proceedings IAU Symposium No. 302, 201

Componentes biológicamente activos y beneficios para la salud del aceite de semilla de ortiga

The biologically active components of nettle seed oil and important lipid indices, which are criteria for the health benefits of the oil, have been examined. Linoleic acid predominates in triacylglycerols (77.7%), followed by oleic (16.2%). Sterols in the lipids are present at 1.1% and β-sitosterol is the main component (90.1%). The oil contains 711 mg/kg tocopherols and γ-tocopherol predominates (36.1%), followed by α-tocopherol (28.9%) and δ-tocopherol (26.9%). Atherogenicity and thrombogenicity index values are significantly low, which determine the best anti-atherogenic and anti-thrombogenic properties of the oil. The cholesterolemic index and the ratio of polyunsaturated and saturated fatty acids are considerably higher than 1.0 and reveal good hypocholesterolemic potential and nutritional value. The content of biologically active components of nettle seed oil indicates that it is a rich source of essential fatty acids, sterols and tocopherols and this oil can be used in food, cosmetics, and pharmaceutical products.Se han determinado los componentes biológicamente activos del aceite de semilla de ortiga y los índices lipídicos más importantes, como criterios sobre los beneficios para la salud del aceite. El ácido linoleico predomina en los triacilgliceroles (77,7%), seguido por oleico (16,2%). Los esteroles son el 1,1% siendo el β-sitosterol el componente mayoritario (90,1%). Los tocoferoles son 711 mg/kg y predomina el γ-tocoferol (36,1%), seguido por α-tocoferol (28,9%) y δ-tocoferol (26,9%). Los valores de los índices de aterogenicidad y trombogenicidad son significativamente bajos, lo que determina las buenas propiedades antiaterogénicas y antitrombogénicas del aceite. El índice hipo/hipercolesterolémico y la proporción de ácidos grasos poliinsaturados y saturados presentan valores altos (superiores a 1,0), lo cual indica un buen potencial hipocolesterolémico y valor nutricional del aceite. El contenido de componentes biológicamente activos del aceite de semilla de ortiga muestra que es un producto rico de ácidos grasos esenciales, esteroles y tocoferoles, y por eso se puede utilizar en alimentos, cosméticos y productos farmacéuticos

A dominant magnetic dipole for the evolved Ap star candidate EK Eridani

EK Eri is one of the most slowly rotating active giants known, and has been proposed to be the descendant of a strongly magnetic Ap star. We have performed a spectropolarimetric study of EK Eri over 4 photometric periods with the aim of inferring the topology of its magnetic field. We used the NARVAL spectropolarimeter at the Bernard Lyot telescope at the Pic du Midi Observatory, along with the least-squares deconvolution method, to extract high signal-to-noise ratio Stokes V profiles from a timeseries of 28 polarisation spectra. We have derived the surface-averaged longitudinal magnetic field Bl. We fit the Stokes V profiles with a model of the large-scale magnetic field and obtained Zeeman Doppler images of the surface magnetic strength and geometry. Bl variations of up to about 80 G are observed without any reversal of its sign, and which are in phase with photometric ephemeris. The activity indicators are shown to vary smoothly on a timescale compatible with the rotational period inferred from photometry (308.8 d.), however large deviations can occur from one rotation to another. The surface magnetic field variations of EK Eri appear to be dominated by a strong magnetic spot (of negative polarity) which is phased with the dark (cool) photometric spot. Our modeling shows that the large-scale magnetic field of EK Eri is strongly poloidal. For a rotational axis inclination of i = 60{\deg}, we obtain a model that is almost purely dipolar. In the dipolar model, the strong magnetic/photometric spot corresponds to the negative pole of the dipole, which could be the remnant of that of an Ap star progenitor of EK Eri. Our observations and modeling conceptually support this hypothesis, suggesting an explanation of the outstanding magnetic properties of EK Eri as the result of interaction between deep convection and the remnant of an Ap star magnetic dipole.Comment: 8 pages, 6 figures, accepted for publication in Astronomy & Astrophysic

Composición de lípidos biológicamente activos de aceites de semilla Lamiaceae

The content of glyceride oil, phospholipid, sterol and tocopherol composition of 7 species of fam. Lamiaceae seeds were investigated. 8.7-28.6 % of glyceride oil in the seeds were determined. The content of phospholipids in the oils was found to be 1.0-1.6 %. Phosphatidylcholine (35.5-63.1 %), phosphatidylinositol (19.1-30.2 %) and phosphatidyl ethanolamine (5.8-21.6 %) were the main components in the phospholipid fraction. In the sterol fraction (0.1-0.3 % total sterols in the oils) 64.8-86.3 % are in free form and 13.7-35.2 % as sterol esters. β -Sitosterol predominates in all glyceride oils (48.8-87.9 %), followed by campesterol (1.5-22.5 %) and stigmasterol (1.1-12.8 %). 6.3-649.7 mg/kg tocopherols were found, mainly α -tocopherol (48.5-99.9%).Se estudia el contenido en aceite, fosfolípidos, esteroles y tocoferol de semillas pertenecientes a 7 especies de la Familia Lamiaceae. Se encontraron valores comprendidos entre 8.7-28.6 % para los aceites en las semillas. El contenido en fosfolípidos para los aceites fue del 1.0-1.6 %. Los principales componentes de la fracción fosfolípido fueron: fosfatidilcolina (35.5-63.1 %), fosfatidilinositol (19.1-30.2 %) y fosfatidiletanolamina (5.8-21.6 %). En la fracción de esteroles (0.1-0.3 % de esteroles totales en las muestras de aceites), 64.8-86.3 % estaban presentes en forma libre y 13.7-35.2 % como esteres de esteroles. El β -Sitosterol es el que predomina (48.8-87.9 %), seguido de campesterol (1.5-22.5 %) y stigmasterol (1.1-12.8 %). Se encontró un contenido en tocoferoles de 6.3-649.7 mg/kg, principalmente α -tocopherol (48.5-99.9 %)