Important Minor Constituents Research Articles

Sterols and Triterpene Dialcohols in Virgin Olive Oil: A Comprehensive Study on Their Transition from Fruits Depending on Malaxation Conditions and Ripening Degree

AbstractSterols are important minor constituents of the unsaponifiable fraction of virgin olive oil. They have critical roles in determining the authenticity of the oil and they are known to be affected by process conditions and maturity. Here, optimization of the malaxation temperatures at between 21 and 49 °C and times at between 24 and 66 min by response surface methodology is aimed in terms of oil yield, and contents of individual sterols and triterpene dialcohols of oils from olives at three maturity stages (spotted, purple, black). Results show that the amount of sterols is varied in different extents depending on the malaxation conditions as well as maturity stages. Mathematical models display high prediction performance to explain the variation in the studied responses of apparent β‐sitosterol, total sterol, β‐sitosterol, campesterol, and stigmasterol for all maturity stages. The optimum conditions of malaxation temperature and time are 31 °C/44 min, 36 °C/26 min, and 37 °C/24 min from spotted, purple, and black fruits, respectively. In end, this study proves transition to the highest desired sterols with oil yield, and the lowest undesired sterols and triterpene dialcohols from fruits to oil by malaxating at moderate temperatures, not cold and hot pressing.Practical applications: Sterols and triterpene dialcohols make up a large part of the minor components of olive oil. This group has gained high importance, especially after their significant impacts on the authenticity of olive oil. Sterolic content and triterpene dialcohols of olive oil depend especially on the fruit's maturity and processing methods. Malaxation temperature and time were optimized to achieve the transferability of the highest desired sterols and the lowest undesired sterols and triterpene dialcohols according to limits of the Commission Regulation (EEC). The current study was also evaluated by the change of total sterol content and individual sterol and triterpene diols profile of oils obtained from olives at different maturity stages. The optimized malaxation conditions are successful to achieve goals. Overall, it can be stated that olive oils with high desired sterols and low triterpene diols and undesired sterols in terms of EEC limits are economically precious.

Making Sense of Olive Oil: Simple Experiments To Connect Sensory Observations with the Underlying Chemistry

In the last decade, our understanding of the chemistry of olive oil has dramatically improved. Here, the essential chemistry of olive oil and its important minor constituents is described and related to the typical sensory categories used to rate and experience oils: color, aroma, bitterness, and pungency. We also describe experiments to explore some of the characteristics of olive oil related to its status as a new health food. Simple qualitative experiments on olive oil can be done in conjunction with tastings of the oil. First, we establish the relationship between the color of an object and the absorption of light by its molecular constituents using gummy candies and laser pointers. Then, the color of the various oils can be measured quantitatively using an iPhone app (Irodori). Illuminating the oil with a green laser produces a startling red fluorescence in the presence of the natural chlorophyll in some olive oils. Relatively straightforward colorimetric assays can reveal the presence of unsaturated fatty acids, healthy antioxidants such as phenols (unique to olive oils), contaminating peroxides, and the level of free fatty acid that is a telltale sign of poorly treated or stale oils. A final comparison of the sensory observations from tasting with the chemical and spectroscopic analysis provides an introduction to the science behind food standards and the sensitivity of our own sensory apparatus.

NMR Analyses and Diffusion Coefficient Determination of Minor Constituents of Olive Oil: Combined Experimental and Theoretical Studies

Combined experimental and computational studies on biologically important minor constituents of olive oil, i.e., 1-eicosanol, squalene, α-tocopherol, erythrodiol, stigmasterol, β-sitosterol, campesterol, and cycloartenol, have been performed for analyzing their 1H and 13C NMR spectra. The correlation equations for estimating experimental 1H and 13C NMR chemical shifts from the calculated chemical shifts have been derived and tested for the molecules in which dispersion is effective. The presently obtained experimental NMR signals of these molecules were then assigned on the basis of quantum chemical calculations. The discriminative NMR signals of the minor constituents were determined and discussed. 1H diffusion ordered spectroscopy (DOSY) NMR has been employed to discriminate the minor constituents and determine their diffusion coefficients in deuterated chloroform. We calculated some physicochemical parameters of these molecules involving their shapes and sizes as well as their interaction with solvent. Then, we found a regression equation that can be used in estimating diffusion coefficients of other compounds.

Anthropogenic effects on the distribution of minor chemical constituents in the mesosphere/lower thermosphere – A model study

We investigate the influence that rising concentrations of methane, nitrous oxide and carbon dioxide have had upon the chemistry of the mesosphere since 1961. Calculations were performed using our global 3D-model LIMA (Leibniz-Institute Middle Atmosphere), designed for the investigation of the MLT-region (Mesosphere-Lower Thermosphere) and particularly for the extended mesopause region. LIMA utilizes observed tropospheric and lower stratospheric temperature and horizontal wind data up to 35km altitude by assimilating ECMWF/ERA-40 and ECMWF operational data. Real Lyman-α flux values are employed to determine the variable water vapor dissociation rate. Three different calculations were carried out and analyzed: (1) use of the same annual variation of the model dynamics in the chemical transport model (CTM) for all years according to the dynamics of the solar minimum year 1964 and employment of a realistic growth of the anthropogenic gases; (2) use of constant concentrations of the anthropogenic constituents at the lower border, but employment of the varying model dynamics; (3) the so-called realistic case, which considers both the long-term increase in the anthropogenic minor constituents and the varying dynamics according to LIMA calculations. The analysis of these three cases shows that the dynamics are able to counteract the impact of anthropogenic growth of minor constituents in the upper mesosphere-mesopause-lower thermosphere region in middle to high latitudes in summer. The water vapor mixing ratio increases due to rising methane concentration. The reason for this lies in a positive feedback process of autocatalytic water vapor production. The change in concentration of the minor constituents impacts both the cooling rate and the chemical heating rate. We present the relative and absolute deviations between the solar activity minimum years 1964 and 2008 for the most important minor constituents. We discuss the long-term behavior, particularly of water vapor, with regard to the impact on the NLC-region.

Chemical Composition of the Hydrosol and the Essential Oil of Three Different Species of the Pinaceae Family : Picea glauca (Moench) Voss., Picea mariana (Mill.) B.S.P., and Abies balsamea (L.) Mill.

The chemical composition of the oils and hydrosols collected from wild plantations of three species of the Pinaceae family of conifers in the Grondines region of the province of Quebec, Canada, were determined by GC-FID and GC-MS analyses. The components obtained from the hydrosol of Picea glauca (Moench) Voss., (White Spruce) were mainly monoterpene alcohols, aldehydes and ketones. The major compound by far was camphor (65 %) with borneol (10 %) as an important minor constituent. In contrast, the essential oil was composed mainly of β-pinene (20 %) and camphor (20 %) followed by α-pinene (12 %) and bornyl acetate (12 %). Bornyl acetate (34.2 %) was the main compound identified in the Picea mariana (Mill.) B.S.P., (Black Spruce) oil and monoterpenes, mainly α-pinene (12.9 %) and camphene (16.4 %), constituted at least 45 % of the oil. On the contrary, due to their very low water solubility, monoterpene hydrocarbons were barely present in the hydrosol in which alcohols were the main components. They were oc-terpineol and borneol (each ˜14 %), terpinen-4-ol and camphene hydrate (each ˜6 %) as well as several aliphatic alcohols (cis-3-hexen-1-ol - 6.5 %). Bornyl acetate was also a significant component (7.8 %). Monoterpenes were the main components of the essential oil of Abies balsamea (L.) Mill. (Canadian Fir oil). They were β-pinene (33.5 %), Δ3-carene (14 %), oc-pinene (11.3 %) as well as limonene and β-phellandrene (each ˜7 %). Bornyl acetate was also a significant component (10 %). α-terpineol (˜41 %) was by far the main component observed in the hydrosol followed by borneol (6.4 %). Of particular interest was the presence of maltol (˜15 %). To our knowledge, this is the first report on the hydrosol composition obtained from a coniferous tree.

Limonia acidissima, a rich source of β-pinene, from the Western Ghats of India

essential oil (0.5%) and showed that methyl chavicol is the major constituent (91.2%). The other important minor constituents are -pinene, myrcene, limonene, linalool, anisaldehyde, and p-methoxycinnamaldehyde. Interestingly, the samples collected locally from Bangalore and Mysore showed a low percentage of oil, and -pinene as the major compound. This prompted us to collect more samples from different regions for the investigation. All the other four samples from the central part of the Western Ghats and nearby plains, which are in the Karnataka State region, gave from 0.3 to 0.2% as the oil yield and -pinene as the major compound, ranging from 63.9–76.9%. The other major compounds that contribute to these samples are -pinene (4.7–6.1%), sabinene (4.4–6.0%), and limonene (4.5–6.2%) (Table 1). The other important minor constituents are camphene, myrcene, E--ocimene, linalool, -terpineol, methyl chavicol, -caryophyllene, -cadinene, and glubulol.

A warm layer in Venus' cryosphere and high-altitude measurements of HF, HCl, H2O and HDO

Venus has thick clouds of H2SO4 aerosol particles extending from altitudes of 40 to 60 km. The 60-100 km region (the mesosphere) is a transition region between the 4 day retrograde superrotation at the top of the thick clouds and the solar-antisolar circulation in the thermosphere (above 100 km), which has upwelling over the subsolar point and transport to the nightside. The mesosphere has a light haze of variable optical thickness, with CO, SO2, HCl, HF, H2O and HDO as the most important minor gaseous constituents, but the vertical distribution of the haze and molecules is poorly known because previous descent probes began their measurements at or below 60 km. Here we report the detection of an extensive layer of warm air at altitudes 90-120 km on the night side that we interpret as the result of adiabatic heating during air subsidence. Such a strong temperature inversion was not expected, because the night side of Venus was otherwise so cold that it was named the 'cryosphere' above 100 km. We also measured the mesospheric distributions of HF, HCl, H2O and HDO. HCl is less abundant than reported 40 years ago. HDO/H2O is enhanced by a factor of approximately 2.5 with respect to the lower atmosphere, and there is a general depletion of H2O around 80-90 km for which we have no explanation.

Hydration and hydration products of two-phase Portland cement clinker doped with Na2O

Alkalis are important minor constituents of ordinary Portland cement clinker. Na2O, in particular, is incorporated into the aluminate phase and alters its crystal structure. For this study, well defined Portland cement clinkers consisting of alite and aluminate doped with different amounts of Na2O were used. Isothermal conduction calorimetry of cements made from this clinker revealed that doping with Na2O activates the initial heat evolution of the clinker during the initial hours. It also influences the main reaction. In situ X-ray diffraction for monitoring cement hydration demonstrates that the dissolution of C3A and gypsum is accelerated by the incorporation of Na2O. The formation of crystalline ettringite and monosulphate during the first few hours of hydration is delayed. After 90 days of hydration, most of the C3A has reacted to monosulphate, detectable by differential scanning calorimetry, scanning electron microscopy and 27Al nuclear magnetic resonance. An increase of the Na2O content brought about less ettringite in the hydrated samples and changed the morphology of monosulphate to thinner and smaller hexagonal plates.

Impact of a stratospheric warming event in January 2001 on the minor constituents in the MLT region calculated on the basis of a new 3D-model LIMA of the dynamics and chemistry of the middle atmosphere

The impact of a stratospheric warming event upon the minor constituents in the MLT region has been investigated by means of a new 3D-model of the dynamics and chemistry of the middle atmosphere. The Leibniz-Institute Middle Atmosphere (LIMA) model assimilates the temperature and wind data of the troposphere/lower stratosphere according to global European Centre for Medium-Range Weather Forecasts (ECMWF) data for the year 2001 and calculates their effect on the mesospheric dynamics and chemistry. In a case study of an individual event at the end of January 2001, we discuss the marked aeronomic changes connected with the stratospheric warming event. In particular, we consider the diurnal variations of the most important minor constituents such as ozone and hydrogen radicals. Additionally, we also calculate the chemical heating rate which is important for the dynamics of the mesopause region.

Aluminum substitution in stishovite and MgSiO3 perovskite: High-resolution 27Al NMR

Aluminum is an important minor constituent of a number of high-pressure mantle silicates in which it substitutes for octahedrally coordinated silicon. In several cases, its solid solution may be linked to the presence of oxygen vacancies; in others, to charge balance with H+. Here we present new data from high-resolution, high-field (18.8 Tesla) 27Al NMR of aluminous stishovite and of a non-stoichiometric perovskite with nominal composition MgSi0.95Al0.05O2.975. For the stishovite, we characterize the local structure of the symmetrical, octahedral site for Al. These results, combined with 27Al{1H} REDOR NMR, are consistent with hypothesized H+ charge balance, although the presence of a significant fraction of randomly distributed oxygen vacancies could remain undetected. As in a recent previous study of a related perovskite composition, the observed ratio of Al at symmetrical octahedral B sites to that of Al at large, central A sites is about 2:1, indicating the presence of oxygen vacancies to account for charge neutrality in this phase. Such vacancies are not preferentially associated with the Al octahedra, however, suggesting a random distribution in the structure.

The Ozone Hole Breakup in September 2002 as Seen by SCIAMACHY on ENVISAT

Abstract An unprecedented stratospheric warming in the Southern Hemisphere in September 2002 led to the breakup of the Antarctic ozone hole into two parts. The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) on the European Environmental Satellite (ENVISAT) performed continuous observations of limb-scattered solar radiance spectra throughout the stratospheric warming. Thereby, global measurements of vertical profiles of several important minor constituents are provided with a vertical resolution of about 3 km. In this study, stratospheric profiles of O3, NO2, and BrO retrieved from SCIAMACHY limb-scattering observations together with polar stratospheric cloud (PSC) observations for selected days prior to (12 September), during (27 September), and after (2 October) the ozone hole split are employed to provide a picture of the temporal evolution of the Antarctic stratosphere’s three-dimensional structure.

Mineral chemistry of sphalerite and galena from Pb-Zn mineralization hosted by the Transvaal Supergroup in Griqualand West, South Africa

The relative and absolute abundance of minor and trace elements in ore-forming sphalerite and galena can yield important constraints regarding the metallogenesis of carbonate-hosted Pb-Zn deposits. This contribution presents an extensive set of mineral chemical data for sphalerite and galena from two deposits and several subeconomic occurrences of Pb-Zn mineralization in the Transvaal Supergroup on the Ghaap Plateau in Griqualand West. Significant differences are recognised between different localities and different styles of mineralization, but results obtained compare rather well with literature data of Phanerozoic Mississippi Valley-type deposits. Fe and Cd constitute the two most important minor constituents in sphalerite from the Ghaap Plateau. Average concentrations vary between 0.54 weight % and 3.21 weight % for Fe and 0.13 weight % and 0.67 weight % for Cd. A first order correlation exists between average Fe/Mn ratios in sphalerite and host rock lithologies, while variations in concentrations of Co (7 to 177ppm), Ni (9 to 21ppm), Ga (2 to 99ppm) can only tentatively be attributed to differences in mineralization style, host rock, and metal source. Compared to sphalerite, trace element contents, in galena are very low with only Cd and Ag occurring in concentrations that consistently exceed 10ppm. Concentrations of more than 1000ppm Ag are reported for structurally-controlled Pd-rich subeconomic breccia runs close to the Griquatown fault zone.

Essential Oils from Bolivia II. Asteraceae: Ophryosporus heptanthus (Wedd.) H. Rob. et King

The essential oil of the aerial parts of Ophryosporus heptanthus (Asteraceae) from Bolivia was analyzed by GC and GC/MS. The oil was characterized by a high percentage of santolinatriene (∼ 47%) and the presence of precocene II (∼ 8%) as the most important minor constituent. The other compounds were monoterpenes (∼ 16%), with p-cymene as the major compound (∼ 4.8%), sesquiterpenes (∼ 6%), oxygenated sesquiterpenes (∼ 8%) and oxygenated monoterpenes (∼ 4.5%).

Modelling the effects of the October 1989 solar proton event on mesospheric odd nitrogen using a detailed ion and neutral chemistry model

Abstract. Solar proton events and electron precipitation affect the concentrations of middle atmospheric constituents. Ionization caused by precipitating particles enhances the production of important minor neutral constituents, such as nitric oxide, through reaction chains in which ionic reactions play an important role. The Sodankylä Ion Chemistry model (SIC) has been modified and extended into a detailed ion and neutral chemistry model of the mesosphere. Our steady-state model (containing 55 ion species, 8 neutral species, and several hundred chemical reactions) is used to investigate the effect of the October 1989 solar proton event on odd nitrogen at altitudes between 50–90 km. The modelling results show that the NO concentration is significantly enhanced due to the proton precipitation, reaching 107 –108 cm-3 throughout the mesosphere on the 20 October when the proton forcing was most severe. A comparison between the chemical production channels of odd nitrogen indicates that ion chemical reactions are an important factor in the total odd nitrogen production during intense ionization. The modelled electron concentration for the 23 October is compared with EISCAT incoherent scatter radar measurements and a reasonable agreement is found.Key words. Atmospheric composition and structure (Middle atmosphere – composition and chemistry); Ionosphere (Particle precipitation)

Codeposition of Apolipoprotein A-IV and Transthyretin in Senile Systemic (ATTR) Amyloidosis

Protein material was extracted from amyloid-rich sections of formalin-fixed and paraffin-embedded heart tissue from an individual with senile systemic amyloidosis, known to contain wild-type transthyretin as major amyloid fibril protein. Amino acid sequence analysis of tryptic peptides of this material revealed in addition to transthyretin sequences, also amino acid sequence corresponding to an N-terminal fragment of apolipoprotein A-IV. In immunohistochemistry, an antiserum to a synthetic apolipoprotein A-IV peptide labeled amyloid specifically. This peptide formed spontaneously amyloid-like fibrils in vitro and enhanced fibril formation from wild-type transthyretin. We conclude that several apolipoproteins, including apolipoprotein A-IV, may be important minor amyloid constituents, promoting fibril formation.

A three-dimensional dynamic model of the minor constituents of the mesosphere

A global three-dimensional model of the dynamics and chemistry of the mesosphere—lower thermosphere region (30–150 km) has been developed. This model is used to calculate the distributions of the most important minor and plasma constituents. Additionally, the mass fluxes of those constituents subjected to transport and the chemical heating rates have been computed. In view of the connection between the stratospheric and mesospheric odd-oxygen distribution, we concentrate here on discussing the mesospheric ozone chemistry at the equinox.

Spaceborne measurements of the upper stratospheric HCL vertical distribution in early 1992 and the trend in total stratospheric chlorine since 1985

The GRILLE infrared spectrometer was part of the shuttle pay load during the first ATLAS mission in March‐April 1992. This experiment measured the vertical distribution of several important minor constituents in the middle to high atmosphere by solar occultation mid‐infrared absorption spectroscopy. Among the molecules observed is the stratospheric chlorine reservoir species HCl. This paper discusses the vertical profiles measured, including their validation with respect to correlative measurements from ATMOS on board the same mission and from HALOE on board UARS. The most important conclusion drawn from the measured HCl volume mixing ratio of (3.6±0.2) ppbv above 50 km presently measured by GRILLE in comparison with published ATMOS data from 1985 is that the actual GRILLE data confirm the increase of the upper stratospheric total chlorine loading by about 40% with respect to 1985, as reported and/or predicted earlier.

Photochemistry of Cyanoacetylene at 193.3 nm

Cyanoacetylene (CA) is an important minor constituent in the Titan atmosphere and is present in the interstellar medium. The absorption cross section of CA has been measured in the region from 190 to 255 nm with a resolution of 1 nm. The photochemistry of CA at 193.3 nm has been studied using a quadrupole mass spectrometer and a Fourier transform infrared spectrometer for product analysis. From the photolysis of HC3N−D2 and HC3N−CD4 mixtures and a plateau value of 0.3 for the quantum yield (QY) of DC3N (C3N + D2 → DC3N + D), it is concluded that the main dissociation process is HC3N + hν → H + C3N with a QY of 0.30 ± 0.05 and a minor process is HC3N + hν → C2H + CN with a QY equal to or less than 0.02. The remaining process is the formation of metastable CA (a triplet or carbene). The photolysis of CA induces a noticeable pressure decrease and a concomitant formation of a mist. The QY of CA disappearance is 4.5 ± 0.5, which is much higher than that of diacetylene (QY = 2.0 ± 0.5) and of acetylene (QY = 2.3). The rapid mist formation in CA may explain a haze observed in the Titan atmosphere. A detailed mist formation process is not known. The C3N radical disappears partially by C3N + HC3N → C6N2 + H and 2C3N → C6N2. To explain the formation of minor products, HCN, C2H2, HC5N, and C4N2, two processes involving an unspecified CA metastable state or states may be proposed: HC3N* + HC3N → HC5N + HCN and C4N2 + C2H2.

An interim reference model for the variability of the middle atmosphere water vapor distribution

Water vapor is an important minor constituent in the studies of the middle atmosphere for a variety of reasons, including its role as a source for active HO y chemicals and its use in analysis of transport processes. A number of in situ and remote techniques have been employed in the determination of water vapor distributions. Two of the more complete data sets have been used to develop an interim reference profile. First, there are the 7 months of Nimbus 7 LIMS data obtained during November 1978 to May 1979 over the range 64S to 84N latitude and from about 100-mb to 1-mb. By averaging radiances before retrieval, LIMS random errors have been reduced, and the results have been improved and extended recently from 1.5-mb to 0.5-mb. Secondly, the ground-based microwave emission technique has provided many profiles from 0.2-mb to 0.01-mb in the mid mesosphere at several fixed Northern Hemisphere mid latitude sites. These two data sets have been combined to give a mid latitude, interim reference water vapor profile for the entire vertical range of the middle atmosphere and with accuracies of better than 25 percent. The daily variability of stratospheric water vapor profiles about the monthly mean has also been established from these data sets for selected months. Information is also provided on the longitudinal variability of LIMS water vapor profiles about the daily, weekly, and monthly zonal means. Generally, the interim reference water vapor profile and its variability are consistent with prevailing ideas about chemistry and transport.

High performance liquid chromatography of anthraquinones: analysis of plant and insect extracts and dyed textiles

Separation and quantitative determination of anthraquinones is achieved by high performance liquid chromatography in mixtures of methanol, water and formic acid on a reversed-phase stationary phase. The products are identified by retention time and, more accurately, by standard additions and UV-visible spectroscopy. This methodology has been applied to extracts of plant roots and insects, commonly used in earlier times as the source of red dyestuffs for dyeing textiles. Quantitative evaluation of the anthraquinone derivatives present in ancient red dyes was earned out after acid hydrolysis of 0·2 to 2·0mg of textile fibre. Due to the great sensitivity of the method, important minor constituents, such as kermesic acid in cochineal, can be detected.