IR spectroscopy for analysing solvent extraction efficiency of oil extracts

Solvent extraction is a method for purifying oil extracts, which are used as oil-plasticisers for industrial rubber goods, from cancerogenic hydrocarbons. The efficiency of this method is mainly determined by the selectivity and solvent properties of a separating agent. However, when carrying out a comparative analysis of promising extraction methods, it is necessary to use real-time methods for studying the composition of the resulting products. The purification efficiency of oil extracts from polycyclic aromatic components, including carcinogenic hydrocarbons (benzo[a]pyrene, benzo[e]pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, etc.), was evaluated depending upon the nature of selective solvents. The structure-group composition of the purified oil extracts and those at the second-stage of purification was determined by FTIR spectroscopy. It was found that the extraction efficiency of the studied solvents towards polycyclic aromatic hydrocarbons from oil extracts increases in the following order: dimethyl sulfoxide < N-methylpyrrolidone + 10 wt% ethylene glycol <N-methylpyrrolidone +50 wt% triethylene glycol. When using a solvent comprising N-methylpyrrolidone + 50 wt% triethylene glycol, the proportion of polyalkyl-substituted and condensed aromatic structures in the purified oil extract decreases by 16.8%; the oil extract yield increases by over 25 wt% in contrast to extraction with N-methylpyrrolidone + ethylene glycol mixture, which meets the requirements of the European Union for oil extract purification (Directive No. 2005/69/EC). Therefore, we recommend the solvent comprising N-methylpyrrolidone + 50 wt% triethylene glycol for purifying oil extracts from components having a technogenic impact on the environment and human health and IR spectroscopy for efficiency assessment of solvent extraction of oil extracts.

The Essential Oil Components of Helichrysum pallasii Flowers

The genus Helichrysum contains many species displaying therapeutical effects and use in folk medicine. Helichrysum pallasii (Spreng.) Ledeb. is one of these species, used in the region for traditional medicine and ornamental purposes. Plants have been used in the treatment in folk medicines since the earliest times of human history. Chemical composition, antimicrobial and other medicinal properties of plants are being investigated in laboratories throughout the world using the extracts and essential oils derived from medicinal plants. Essential oils are usually complex mixtures of natural compounds of both polar and apolar structure. Essential oils consist mainly of terpenoids and their oxygenated derivatives. Essential oils, which have antioxidant and antimicrobial activities, have therapeutic properties and are the raw materials of cosmetics, as well as acting as natural additives in foods and food products. In this study, the volatile components of the H. pallasii plants were investigated which collected from its natural habitat in the Armutlu district of Bayburt province (Turkey) at the time of flowering. The proportion of essential oils of the plant harvested during the full flowering period and the aromatic components in the essential oil of the plant were determined using the SPME (Solid Phase Microextraction) method in a Gas Chromatography (GC-MS) device. Almost 37 different components were found as a result of the analysis. The main components were found as α-Springene (34.89%), (-)-Isoledene (7.11%), δ-Selinene (5.79%) and Aristolene (5.09).

SEPARATION OF OIL-WATER EMULSIONS

Одним из наиболее серьёзных осложнений при добыче и транспортировке нефти является интенсивное выпадение асфальто-смолистых и парафиновых отложений (АСПО). В данной работе проводилась оценка эффективности растворителей разной химической природы для удаления АСПО. На основании лабораторных данных были сделаны выводы о использовании неиногенного типа ПАВ, спиртов с различной молекулярной массой, оптимального соотношения алканового и ароматического компонента для растворения АСПО парафинового типа. One of the most serious complications in oil production and transportation is the intensive deposition of as-falto-resinous and paraffin deposits (ASPs). In this work, the effectiveness of solvents of different chemical nature for the removal of ASPs was evaluated. Based on laboratory data, conclusions were drawn about the use of noninogenic surfactants, alcohols with different molecular weights, and the optimal ratio of the alkane and aromatic components for the dissolution of paraffin-type ASPs.

A Guide to Elucidate the Hidden Multicomponent Layered Structure of Plant Cuticles by Raman Imaging

The cuticle covers almost all plant organs as the outermost layer and serves as a transpiration barrier, sunscreen, and first line of defense against pathogens. Waxes, fatty acids, and aromatic components build chemically and structurally diverse layers with different functionality. So far, electron microscopy has elucidated structure, while isolation, extraction, and analysis procedures have revealed chemistry. With this method paper, we close the missing link by demonstrating how Raman microscopy gives detailed information about chemistry and structure of the native cuticle on the microscale. We introduce an optimized experimental workflow, covering the whole process of sample preparation, Raman imaging experiment, data analysis, and interpretation and show the versatility of the approach on cuticles of a spruce needle, a tomato peel, and an Arabidopsis stem. We include laser polarization experiments to deduce the orientation of molecules and multivariate data analysis to separate cuticle layers and verify their molecular composition. Based on the three investigated cuticles, we discuss the chemical and structural diversity and validate our findings by comparing models based on our spectroscopic data with the current view of the cuticle. We amend the model by adding the distribution of cinnamic acids and flavonoids within the cuticle layers and their transition to the epidermal layer. Raman imaging proves as a non-destructive and fast approach to assess the chemical and structural variability in space and time. It might become a valuable tool to tackle knowledge gaps in plant cuticle research.

Aromatic Constituents from the Leaves of Actinidia arguta with Antioxidant and α-Glucosidase Inhibitory Activity

As the leaf of Actinidia arguta has shown antioxidant activity, a study was conducted to identify the active ingredients. Forty-eight compounds were isolated from the leaves of A. arguta through various chromatographic techniques. Further characterization of the structures on the basis of 1D and 2D NMR and MS data identified several aromatic compounds, including phenylpropanoid derivatives, phenolics, coumarins, flavonoids and lignans. Among them, five compounds were newly reported, naturally occurring, and named argutosides A–D (1–4), which consist of phenylpropanoid glycosides that are conjugated with a phenolic moiety, and argutoside E (5), which is a coumarin glycoside that is conjugated with a phenylpropanoid unit. The isolated compounds showed good antioxidant and α-glucosidase inhibitory activity with differences in activity depending on the structures. Molecular docking analysis demonstrated the interaction between the hydroxyl and carbonyl groups of compounds 1 and 5 with α-glucosidase. Taken together, the leaves of A. arguta are rich in aromatic compounds with diverse structures. Therefore, the leaves of A. arguta and their aromatic components might be beneficial for oxidative stress and glucose-related diseases.

Aroma Profile of Arabica Coffee Based on Ohmic Fermentation

Aromatic components contained in coffee are the important components. Several technologies can be used to improve the aroma quality of coffee, for example with ohmic technology. This study established a specialty coffee processing system focused on ohmic-based fermentation technology. The aim of this study was to identify the aroma compound in coffee that fermented by ohmic technology. The SPME method by gas chromatography-mass spectrometry is used in this study. The temperatures (30, 35, and 40°C) and fermentation time were set for this study (2, 6, 12, and 18 h). The results of the sensory test of sample coffee from Indonesia with specification of areas of origins Enrekang and Gowa in comparison with a sample of coffee from Japan can conclude that the panelist provided a rating profile liking the sample coffee from Japan, but the overall results of the quantitative descriptive analysis (QDA) of the second sample are similar or nonsignificantly different. Compound pyrazine identified in GC-MS is earthy odor which has a correlation with the results of sensory taste QDA on sample coffee from Japan.

Processes of chemical transformations in heavy aromatic hydrocarbons of the Surakhan oil under the action of UV rays

Photooxidative transformations and mechanisms of oxidative reactions in aromatic groups of hydrocarbons isolated from heavy Surakhan (Azerbaijan) petroleum under atmospheric conditions have been investigated. Polycyclic aromatic hydrocarbons, which are part of the aromatic components of heavy Surakhan petroleum, after irradiation with UV rays for 1÷11 hours in the presence of oxygen undergo chemical transformations: endoperoxides polycyclic aromatic hydrocarbons, quinones, etc. are formed. It was found that oxidation products under atmospheric conditions can be formed as follows: during the oxidation of acenes (naphthalene, anthracene), which are part of the aromatic groups of petroleum components, excited aromatic hydrocarbons (donor) interact with atmospheric oxygen (acceptor) in the triplet state with the transition of the acceptor to excited state with the formation of singlet oxygen 1O2, in this case the donor molecule returns to the ground state. When phenanthrene is photooxidized, quinones are formed (the reaction is irreversible).

Volatile aroma component of natural and roasted hazelnut varieties using solid-phase microextraction gas chromatography/mass spectrometry

Hazelnut is a very important nutrient in terms of human health. It is widely consumed as natural and roasted. Aromatic components could be used as marker for export criteria in hazelnut. Thus, this study aimed preliminary to compare the aroma profile of some hazelnut varieties and to determine the effect of roasting on aroma component in natural hazelnuts. Hazelnut varieties (18 Turkish and 2 foreign varieties) were obtained and then roasted at 135°C for 30 min. The volatile aroma components of hazelnuts were characterized via solid phase microextraction-gas chromatography-mass spectrometry (SPME/GC-MS). A total of 20 and 29 aroma compounds were detected by SPME/GC-MS in natural and roasted hazelnuts, respectively. Concerning natural hazelnut samples, the highest values among the Turkish and foreign varieties were obtained from nonanal in ‛Kalınkara’, ‛Kan’ and ‛Negret-N9’, which are mainly characterized by citrus, rosy, fatty flavor. In roasted samples, 2(3H)-furanone was determined in highest level in ‛Cavcava’, ‛Mincane’ and ‛Negret-N9’ and the flavor attributes of these varieties were oily-nut-like. In particular, Turkish hazelnut varieties such as ‛Acı’ and ‛Kalınkara’ could be promising in terms of the highest amount of aromatic components in roasted hazelnuts.