Concentrations Of Aromatic Compounds Research Articles

New Approaches for Textile Colouration and Surface Pattern Using Enzyme-based Biotechnology

The research presented in this paper gives an overview of a study which was undertaken to investigate the potential offered by the enzyme laccase (EC.1.10.3.2) as a creative design tool for innovative colouration and decorative surface pattern of textiles with a focus on providing sustainable alternatives to conventional processes used in industry. Research was conducted in two parts. The control (scientific) phase explored laccases potential for transforming a range of colourless aromatic compounds into coloured polymeric products via its reaction mechanism, and its ability to facilitate the colouration of most commonly used textile fibre types. Reaction processing parameters such as temperature, pH values, aromatic compound concentrations, and reaction times were investigated to achieve a diverse colour palette, ranging from light–medium to dark shades of blue, green, pink, purple, and yellow hues. Wool and nylon fibre types were found to be most suitable for laccase-catalyzed colouration. The creative phase investigated the design potential offered by the enzymatic colouration process developed; different and contrasting substantivity properties offered by various fibre types were exploited to produce shadow, reserve, and contrasting coloured effects on specially woven jacquard fabrics. The research demonstrates the potential offered by laccase as a transformative tool to replace conventional industrial colouration and surface pattern design processes with biological systems, which offer important advantages of simpler processing using milder conditions that eliminate additional chemical use and reduce energy consumption. The adoption of enzyme-based biotechnologies could help the textile industry transition towards a sustainable future.

Insights into organic metagenesis using Raman spectroscopy and high resolution mass spectrometry: A case study of the Shahezi formation, deep Songliao basin, China

The maturity of sedimentary organic matter is a key parameter for evaluating oil and gas resources. Existing maturity indicators have different evaluation principles and application scopes. This study investigated samples of high to overmature lacustrine source rocks (Ro = 1.33%–4.24%) from the deep Shahezi formation in the Songliao basin, including the zone of catagenesis and metagenesis. Various methods, including vitrinite reflectance, Tmax, laser Raman spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were used to evaluate the samples' maturity. Through laser Raman analysis of representative samples from the Shahezi formation, most laser Raman parameters showed an inflection point or reversal when the thermal evolution of deep source rocks in the Shahezi formation reaches a certain stage. The variation trend of some Raman parameters and Ro has strong regularity (1.33% < Ro < 3.52%). Based on FT-ICR MS, this research analyzed the relative content and molecular composition of polycyclic and heterocyclic aromatic compounds in soluble organic matter of lake source rock samples and comparison samples (marine shale). Quantitative maturity evaluation of organic matter was performed by converting the signal intensity of each compound. The fitting results of maturity parameter based on FT-ICR MS and Tmax indicated that the maturity parameter of the samples have high coefficient of correlations with maturity in the vitrinite reflectance (Ro) range of 1.33%–2.5% and the Tmax range of 420 °C–600 °C. The maturity parameter values decreased as Ro exceeded 2.5% and Tmax exceeded 600 °C. These findings are attributed to the thermal stability of organic compounds and the formation of pyrobitumen and graphite. The parameters of laser Raman spectroscopy also confirmed the growth of aromatic rings reflected by the maturity parameters of FT-ICR MS. These two methods revealed the structural changes of organic matter in the thermal evolution process from multiple perspectives and provided insights for the maturity evaluation of deep source rocks.

Synergetic Effect of Metschnikowia pulcherrima and Lachancea thermotolerans in Acidification and Aroma Compounds in Airén Wines.

On the one hand, the species Lachancea thermotolerans is known for its high genetic diversity, allowing for the existence of strains that produce high concentrations of lactic acid. In contrast, the species Metschnikowia pulcherrima is renowned for its high enzymatic activity capable of producing aromatic esters during fermentation. By enhancing acidity and boosting the concentration of aromatic compounds, both species are currently used to enhance the organoleptic profile of wines. In this regard, ternary fermentations with M. pulcherrima and L.&amp;nbsp;thermotolerans were carried out and the wines produced were further analysed with GC-FID, FTIR, and UV-Vis spectrophotometry. The outcomes showed that the species M. pulcherrima favored an increase in ethyl lactate (between 37 and 41 mg/L) along with an increased concentration of 2-phenylethyl alcohol (between 30 and 35 mg/L), whereas the species L. thermotolerans was able to produce 1 g/L of lactic acid in ternary fermentations. Additionally, pH levels were slightly lower in these fermentations and the color of the white wines produced showed less chemical oxidation as hue values were lower than the control. Finally, the ternary fermentations of L. thermotolerans and M. pulcherrima had higher overall rating in the tasting. In conclusion, ternary fermentations involving these two non-Saccharomyces species are suggested as a substitute for spontaneous fermentations in the production of wines from neutral varieties to express freshness more vividly. This biotechnology may be further favored by the possibility of applying emerging technologies for the removal of microorganisms in grapes and musts.

Conventional and high-field pulsed EPR experimental studies on Bazhenov oil formation under the influence of 50 Hz electromagnetic field

Heavy and extra-heavy oil are generating considerable interest in terms of replacing light oil role in the next few years. Nowadays, various enhanced oil recovery (EOR) methods are under development for an effective exploration and oil refining of unconventional oil sources. Electrical methods are among the most commonly discussed types of EOR techniques. Despite this interest, no one as far as we know has studied the effectiveness and mechanisms of electromagnetic (EM) heating influence on heavy oil conversion. It is common knowledge that heavy oils often contain stable paramagnetic centers, which potentially can serve as at least signaling species to follow the EOR upgrading degree. For the first time, to the best of our knowledge, pulsed and high-frequency (high-field, with 3.4 T detection magnetic field) electron paramagnetic resonance (EPR) techniques were exploited to investigate the EM heating influence on Bazhenov formation heavy oil by subjecting it to 50 Hz (0.75 T) electromagnetic field in laboratory conditions. The obtained samples were analyzed by a set of physico-chemical methods including SARA analysis (S: Saturates, A: Aromatics, R: Resins, A: Asphaltenes), gas chromatography–mass spectrometry (GCMS) in addition to pulsed and conventional (cw) EPR spectroscopy. SARA analysis has shown an increase in the content of asphaltenes from 1.2 ± 0.3 wt% in the initial oil to 1.4 ± 0.4, 1.4 ± 0.3, 1.3 ± 0.2, 1.3 ± 0.5 wt% in the samples obtained at 10, 20, 30 and 40 min respectively. Interestingly, this content has drastically dropped to 0.2 ± 0.05 and 0.3 ± 0.02 wt% in the samples obtained at 50 and 60 min of EM heating. Analogically for resins content change which has firstly increased from 1.5 ± 0.5 wt% in the initial oil to 1.9 ± 0.5, 2.6 ± 0.6, 3.0 ± 0.2, 3.0 ± 0.6 wt% in the samples obtained at 10, 20, 30 and 40 min respectively. Then this content has decreased to 0.5 ± 0.05 and 1.0 ± 0.04 wt% in the samples obtained at 50 and 60 min of EM heating. The content of saturated and aromatic compounds has been found to reach 99.3 ± 0.6 wt% in the sample obtained at 50 min comparing to 97.3 ± 1.1 wt% in the initial oil. Moreover, the GCMS data have showed a significant increase in the content of normal alkanes, which resulted from the processes of oil high molecular compounds fractions conversion as a consequence of alkyl substituents elimination. Our data points towards the idea that the investigated oil sample EPR signal intensity and their spectroscopic characteristics do not change with the EM heating either in the X- or W-band frequencies. g|| and g⊥ were found equal to 2.0024 and 2.0015 respectively at 3357 and 3358 mT for the initial sample and the obtained sample after 60 min of EM heating. Similar results (g||=2.0004 and g⊥=1.9991) were obtained for these samples at 3360 and 3362 mT. The findings of this study can help for better understanding of the mechanisms ruling the impact of electromagnetic heating on enhancing oil recovery.

Contrasting catchment soil pH and Fe concentrations influence DOM distribution and nutrient dynamics in freshwater systems

Organic matter (OM) quantity, quality, and nutrient dynamics within twelve shallow lakes in the Czech Republic were assessed in the context of catchment soil pH and iron (Fe) concentration. The catchments of the lakes were classified into two categories: (i) slightly acidic (soil pH = 5.1–6.3) with Fe-rich soils (H_Fe; Fe = 315–344 mg kg−1 in Mehlich 3 extract); and (ii) neutral (soil pH = 6.8–7.6) with Fe-poor soils (L_Fe; Fe = 126–259 mg kg−1 in Mehlich 3 extract). The quality of OM in the two lake types was characterized using a combination of spectroscopic techniques (UV–Vis, fluorescence, and Fourier Transform Infrared spectroscopy). We show that dissolved nutrient and dissolved organic carbon (DOC) concentrations, as well as the amount of aromatic and protein-like compounds in the water column and sediment porewater were significantly (p < 0.01) lower in the H_Fe lakes compared to the waterbodies located within L_Fe catchments. The FTIR analyses of the H_Fe sediments contained higher relative concentrations of aromatic compounds with hydroxyl-containing functional groups and carbohydrates, while more aliphatic and oxidised OM was found in the L_Fe lake sediments. These results suggest that the pH value of catchment soils and, particularly, their Fe content have profound geochemical effects on the mobility of OM and nutrients in the sediments of recipient waters. Because the OM-Fe association stabilises OM in sediments, waterbodies within L_Fe catchments are likely more vulnerable to increasing eutrophication and oxygen depletion compared to those in H_Fe catchments and this has important implications for water quality management, risk assessment, and predictions of aquatic ecosystem vulnerability under conditions of accelerating climate change.

Study into the effect of plasticizer nature on the properties of polymer-bitumen compositions via fluorescence microscopy

The paper studies how the nature of the plasticizer affects the properties of polymer-bitumen compositions using the fluorescence microscopy. The current petroleum road bitumen used for the construction of road, bridge, and airfield pavements does not meet the requirements for cracking/heat resistance, elasticity, and adhesion to the mineral material surface. Pavement performance characteristics can be significantly improved by introducing thermoplastic elastomers, plasticizers, and surfactants into the composition of petroleum road bitumen. The best results were obtained when using a block copolymer of styrene and butadiene, industrial oil, and cationic surfactant on the basis of polyaminoamides and polyaminoimidazolines. The choice of industrial oil as a plasticizer is attributed to its good compatibility with bitumen and polymer, as well as its high flash point (200 °С). The content of paraffin-naphthenic hydrocarbons in industrial oil is over 70%. Although industrial oil is produced in large quantities, an acute shortage of this petrochemical product is observed due to its wide application; thus, intensive studies are underway to replace industrial oil in the composition of the polymer-bitumen binder. It is proposed to use heavy gas oil produced via catalytic cracking and delayed coking, heavy pyrolysis tar, solvent-extracted oil, and tall oil as plasticizers in the creation of the polymer-bitumen binder. In this connection, the effect of proposed plasticizers on the colloidal structure of the polymer-bitumen binder was studied using the method of fluorescence microscopy. Initial polymer-bitumen binders were produced at ANHK (Angarsk) according to GOST R 52056-2003 Polymer-Bitumen Road Binders Based on Styrene-Butadiene-Styrene-Type Block Polymers. The group composition of the plasticizers under study was determined. It was shown that in order to obtain a polymer-bitumen binder resistant to stratification, plasticizers having a content of aromatic compounds of over 60% are required.

Alkylated Polycyclic Aromatic Hydrocarbons Are the Largest Contributor to Polycyclic Aromatic Compound Concentrations in the Topsoil of Huaibei Coalfield, China.

Alkyl polycyclic aromatic hydrocarbons (APAHs) are more toxic and persistent than their parent compounds. Here, the concentrations, composition profiles, and spatial distribution of polycyclic aromatic compounds (PACs) in 127 topsoil samples from Huaibei coalfield were analyzed. The PAC concentrations in different functional areas were significantly different: mining area > industrial area > residential area > agricultural area. APAHs were the major contributors to PACs, accounting for 71–83% of total PACs. Alkylnaphthalenes and alkylphenanthrenes were the primary APAH components, accounting for 83–87% of APAHs. Principal component analysis showed that petrogenic source, coal and biomass combustion, and vehicle emissions were the primary sources of PACs. By comparing the fingerprint information of soil, coal, and coal gangue, it was hypothesized that the petrogenic source of PAC pollution in typical mining areas and surrounding areas are coal particle scattering and coal gangue weathering. Some coal mining and industrial areas potentially pose risks to children, whereas others do not. There are limited evaluation criteria for alkyl PAHs; hence, the estimated risk is likely lower than the actual risk. In addition to the conventional 16 PAHs, it is critical to consider a broader range of PACs, especially APAHs.

Contamination characteristics of alkyl polycyclic aromatic hydrocarbons in dust and topsoil collected from Huaibei Coalfield, China.

Alkyl polycyclic aromatic hydrocarbons (APAHs) are more toxic and persistent than their parent compounds. In this study, the concentrations of polycyclic aromatic compounds (PACs) in dust, topsoil and coal gangue from Huaibei Coal mine, China were analyzed by gas chromatography-mass spectrometry, confirming APAHs were the dominant pollutants. The mean concentrations of APAHs were substantially higher than those of 16 PAHs in both dust and topsoil. The mean concentration of APAHs in dust was 9197µgkg-1, accounting for 80% of the total mean concentration of PACs. The mean concentration of APAHs in topsoil was 2835µgkg-1, accounting for 77% of the mean concentration of PACs. Alkyl naphthalenes and alkyl phenanthrenes were the primary pollutants in APAHs. Their mean concentrations in dust and topsoil were 7782µgkg-1 and 2333µgkg-1, respectively. This accounted for 85% and 82% of the concentration of APAHs, respectively. Additionally, low-molecular-weight APAHs dominated the PACs of the coal mine, exhibiting petrogenic characteristics; distribution of C1-C4 NAP and C1-C4 PHE exhibited "bell shape" pattern indicated as petrogenic source. Source identification indicated that the PACs were mainly derived from petrogenic sources and vehicle emissions, followed by biomass and coal burning. Fingerprinting information of dust and topsoil were consistent with coal gangue, indicating that PACs are most likely derived from coal gangue. Coalfields comparable to our study area are widely distributed in China. Therefore, investigating PAC pollution derived from coal gangue warrants further attention.

Characteristics of particle-bound polycyclic aromatic hydrocarbons (PAHs) in indoor PM2.5 of households in the Southwest part of Ulaanbaatar capital, Mongolia

Air pollution, including PM2.5 concentration in Ulaanbaatar (capital of Mongolia) is a serious matter of concern. As the majority of households use coal in large areas of the city, indoor air quality is also posing a serious risk to human health. This study investigated the concentration of polycyclic aromatic compounds (PAHs) in indoor particulate matter (PM2.5) in 10 non-smoker households. Sampling was conducted in winter of 2018, between 27 January and 09 February. Concentrations of PM2.5 in the indoor air of households ranged between 62.8 and 324.8 µg m−3. Total concentration of PAHs also varied in a relatively wide range, between 46.2 and 175.7 ng m−3. Five-ring PAHs represented a considerably high fraction of total PAHs between 25 and 53%, benzo[b]fluoranthene (BbF) and benzo[a]pyrene (BaP) were the two predominant compounds within five-ring PAHs. Significant correlation was found between indoor and outdoor particulate matter levels in wintertime. Considering individual characteristic PAHs, heavier PAHs homologues (4- to 5-ring and 6-ring PAHs) were detected in all households, which suggested the influence of coal combustion and traffic exhaust. Health risk of children attributed to PAHs inhalation was assessed by taking into account the lifetime-average daily dose (LADD) and corresponding lifetime cancer risk. Lifetime average daily dose for children in only one household were slightly higher than health-based guideline level (1.0 × 10−5), defined by WHO, whereas LADD for adults and children of other households were within acceptable limit. The cancer risks from the exposure of children to air pollutants in all households except HH-3 were found high. In the Vibrio fischeri bioluminescence inhibition assay, according to the toxic unit (TU) values of indoor PM2.5 from ten households, all samples were classified as toxic.

Detection of Polynitro Compounds at Low Concentrations by SERS Using Ni@Au Nanotubes

The identification of high-energy compounds in trace concentrations not only in the laboratory, but also in field conditions is of particular interest. The process should be clear, easy, and well-recognizable. We formed SERS-active substrates by using elongated nickel nanotubes synthesized by electrochemical deposition in the pores of ion-track membranes and coated them with gold for further application in the detection of low concentrations of analytes. The substrates were characterized using various techniques to determine the morphology of the nanotubes and modifying gold layer. The possibility of obtaining two types of gold-layer morphology was shown: in the form of a smooth film up to 20–50 nm thick and a coating with nanoneedles up to 250 nm long. The electric fields around the nanotubes were simulated at a laser wavelength of 532 nm to demonstrate the influence of the gold-layer morphology on the field distribution. The “needle” morphology was chosen to form the most effective SERS-active substrates for detection of low concentrations of aromatic polynitro compounds. The spectral peaks were identified by comparing the model and experimental Raman spectra at concentrations down to 10−5 M. Within this limit, all peaks (“fingerprints” of the substance) were clearly distinguishable.

Oxidative stability of marine phospholipids derived from large yellow croaker roe

Large yellow croaker roe phospholipids (LYCPLs) have various functions and high nutritional value, which are expected to be functional foods ingredients. The aim of this study is to investigate the oxidative stability of LYCPLs at different temperatures (100 °C, 140 °C and 180 °C) in terms of peroxide value (POV), thiobarbituric acid-reactive substances value (TBARS), acid value (AV) and fatty acids compositions of phospholipids. The volatile compounds were also identified and analyzed via headspace solid-phase microextraction-gas chromatography-mass spectroscopy (HS-SPME-GC-MS) and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS). The results showed that the highest POV was 192.92, 133.70 and 121.25 meq/kg at 100 °C, 140 °C and 180 °C within 10–20 min, respectively, then fell along with the increment of heating time, while the highest TBARS was 6.38, 7.66 and 8.19 mg/kg at 30 min, respectively. The AV was increased, but monounsaturated fatty acid and polyunsaturated fatty acid content were decreased with the increment of temperatures. A total of 94 volatile compounds were identified, and the content of alkanes, aldehydes, and heterocyclic compounds were reasonably increased, while the aromatic compound and amide compound content were decreased when LYCPLs heated at 180 °C. The present research improves the comprehensive understanding of oxidative stability of marine phospholipids.

Distribution of Molecular Weight of Humic Substances Isolated from Soils of Tallgrass Temperate Rainforests (Chernevaya Taiga)

The boreal forests of Russia are one of the largest forest areas on the planet. As a result of climate change, the rate of carbon sequestration and stabilization of organic matter are important indicators of environmental conservation. To understand mechanisms of stabilization and the structure of soil organic carbon, the molecular-weight (MW) distribution of humic acids (HAs) in soils of the central deciduous-forest zone of boreal forests (Chernevaya taiga, transitional ecotone forest, coniferous forest) was studied. Analysis of the MW distribution of HAs was conducted using size-exclusion chromatography. This approach allowed us to obtain the distribution of high-, medium-, and low-molecular fractions of HAs. It has been revealed that the content of the low-MW fraction prevails over the content of the medium- and high-MW fractions of HAs, which indicates the process of stabilization in soil organic matter. The accumulation of low-molecular-weight fraction occurs with the aromaticity increase in HAs, which indicates that HAs with a relatively high proportion of aromatic fragments have smaller hydrodynamic radius and a lower MW. It has been statistically substantiated that the low-molecular-weight fraction correlates with the content of aromatic compounds and carboxyl structural fragments of HAs, which indicates the resistance of the soil organic matter of Chernevaya taiga to biodegradation.

Investigation of the hydroisomerization of diesel fractions with different concentration of nitrogen-containing compounds on bifunctional catalysts based on ZSM-23 and non-noble metals

Bifunctional catalysts based on NiMo(W) sulfides and a ZSM-23-Al2O3 composite support have been synthesized. Their properties were studied in the transformations of diesel fractions with different nitrogen content (&lt; 1, 10 and 20 ppm). It was demonstrated that the synthesized catalysts could be used to obtain hydrogenizates with the limiting filterability temperature  –38 °C, which comply with the requirements of GOST R 55475-2013 to the content of gasoline fraction and aromatic compounds, and the derived cetane number. Properties of the developed catalysts based on NiMo and NiW sulfides and characteristics of the corresponding hydrogenizates were compared with each other. In addition, properties of the developed samples were compared with the properties of a foreign commercial platinum catalyst for isodeparaffinization. The synthesized catalysts were found to be less selective than the reference sample, but more stable to N-containing compounds in the feedstock.

Biofuel production from olive pomace via thermal and catalytic pyrolysis using an RFCC catalyst

AbstractThermal and catalytic pyrolysis of olive pomace as a second generation of biomass for the production of valuable bio‐oil has been investigated. The achieved results indicate that the maximum bio‐oil production yield through the non‐catalytic pyrolysis process is 56% at a temperature of 500°C, with a high content of oxygenated compounds. Since the main focus of this study was the catalytic upgrading of pyrolysis‐derived bio‐oil to valuable fuels, an industrial residue fluid catalytic cracking (RFCC) catalyst has been examined using different catalyst to biomass ratios. For a catalyst to biomass ratio of 0.5, the highest bio‐oil production yield was 44 wt% at 500°C and for a catalyst to biomass ratio of 5, the highest bio‐oil yield was 39 wt% at 400°C. The obtained experimental results indicate that, although the bio‐oil production yield decreases through catalytic pyrolysis, application of RFCC catalysts reduces the oxygenated compounds as undesirable products and increases aromatic and cyclic compound content in the bio‐oil, significantly. By increasing the temperature, the production of aromatic compounds as valuable products intensifies, and this compound group is identified as the main content of the derived bio‐oil. It is inferred that RFCC catalysts are appropriate candidates for use in the pyrolysis process for developing biofuel production on an industrial scale. © 2022 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Effects of LED supplemental lighting on the growth and metabolomic profile of Taxus baccata cultivated in a smart greenhouse.

Light emitting diode (LED) lamps are increasingly being studied in cultivation of horticultural, ornamental and medicinal plants as means to increase yield, quality, stress resistance, and bioactive compounds content. Enhancing the production of metabolites for medicinal or pharmaceutical use by regulating LED intensity and spectra is a challenging subject, where promising results have been achieved. Nevertheless, some species have been poorly investigated, despite their interest as a source of medicinally active substances, with particular reference to LED effects at the plant cultivation level. This study evaluates the effects of supplementary top-light LED treatments on Taxus baccata, one of the main sources of taxane precursors. Blue, red and mixed red–and-blue spectra were tested at 100 μM m-2 s-1. Moreover, 50 and 150 μM m-2 s-1 intensities were tested for the mixed spectrum. All treatments were set for 14 hours a day and were tested against natural light as control treatment, in a controlled environment, from 19 August to 9 December 2019, this latter date representing 112 days after treatment (DAT) began. A smart monitoring and control system powered by environmental and proximal sensors was implemented to assure homogeneity of temperature, humidity, and base natural light for all the treatments. It resulted in negligible deviations from expected values and reliable exclusion of confusing factors. Biometric measurements and 1H-NMR based metabolomic analysis were performed to investigate growth and phytochemical profile throughout the trial. One-way ANOVA showed that supplemental LED lighting increased plant height and number of sprouts. Considering the mixed red–and-blue spectrum, plant height increased almost proportionally from control to 100 μM m-2 s-1 (+20% at 112 DAT), with no further increase at higher intensity. The number of sprouts was strongly enhanced by LED treatments only in the early phase (48.9 vs. 7.5 sprouts in the averaged 50, 100 and 150 μM m-2 s-1 vs. the control at 28 DAT), with no differences related to intensity in the very early stage, and more persisting effects (up to 56 DAT) for higher intensities. After the very early growth stages (28 DAT), plant vigor showed a modest although significant increase over time compared to the control, with no differences related to light intensity (0.81 vs. 0.74 of NDVI in the averaged 50, 100 and 150 μM m-2 s-1 vs. the control, across 56, 84 and 112 DAT). The different spectra tested at 100 μM m-2 s-1 showed no significant differences in growth parameters, except for a slight beneficial influence of blue (alone or with red) compared to only red for sprouting. According to the metabolomic analysis, treated plants at 28 DAT were characterized by the highest content of sucrose and aromatic compounds. Signals of a putative taxane were detected in the 1H NMR profiles of plants, which were compared to the spectrum of baccatin III standard. However, the intensity of these spectral signals was not affected by the treatment, while they increased only slightly during time. Light at 150 μM m-2 s-1 induced the strongest variation in the metabolome. Conversely, light composition did not induce significant differences in the metabolome.

Effect of Deacidification Treatment on the Flavor Quality of Zaosu Pear-Kiwifruit Wine.

Conventional pear–kiwifruit wine has a bland flavor and sour taste, because of excessive l-malic acid content and, consequently, little consumer appeal. An Oenococcus oeni strain, GF-2, has good malolactic fermentation (MLF) performance and high glucosidase activity. Through a Box–Behnken design, the optimum MLF parameters for deacidification by GF-2 were determined: initial pH of 3.4, 5% v/v inoculation, and temperature of 20 °C, which reduced the malic acid content by 98.3%. The changes in the content of organic acids, polyphenols, and aromatic compounds after MLF were compared with chemical deacidification. MLF significantly decreased the total concentration of organic acids by 29.7% and promoted the accumulation of aromatic esters, higher alcohols, and terpenoids, but chemical deacidification markedly decreased aromatic compound content by 59.8%. MLF wine achieved the highest sensory scores for aroma, taste, and overall acceptability. Therefore, MLF with O. oeni GF-2 has great potential to markedly improve the quality of commercial pear–kiwifruit wine.

Pyrolysis of solid polymer waste and properties of obtained products

Pyrolysis of solid polymer waste (car tires) was investigated in the temperature range of 350–6500C for 15–105 minutes. It was established that the maximum yield of a liquid product (58%) was observed in the temperature range of 520–5400С. The obtained pyrocondensate was compared with oil and it was stated that pyrolysis condensate was quite heavy, but had low kinematic viscosity and average molecular weight. It was determined that the most part of sulfur (1.27–2.1%) remained in the solid residue during the rubber pyrolysis. Unsaturated hydrocarbons (12.9%) in pyrolysis oil were found due to the presence of double bonds in rubber and the formation of double bonds during the polymer destruction. It was found that increasing the pyrolysis temperature from 400 to 6000C led to a decrease in polycyclic naphthenes and an increase in the proportion of aromatic ring in the molecule due to the cleavage of alkyl substituents. The fractional composition of pyrolysis products obtained in the temperature range of 520–5400C was determined. The yield of the gasoline fraction, the diesel fraction and the residue was 26–28 wt.%, 18–23 wt.% and 45–47 wt.%, respectively. Comparison of the properties of fractions obtained from pyrocondensate with traditional petroleum products showed that the content of sulfur compounds for gasoline and diesel fractions was overestimated due to the presence of sulfur vulcanizing agent in rubber. The content of aromatic compounds, density and viscosity were slightly increased in those fractions. The properties of the fraction 3500C (end of boiling) were almost the same as those of fuel oil.

ИЗМЕНЕНИЕ ФИЗИКО-ХИМИЧЕСКИХ ХАРАКТЕРИСТИК БИОДИЗЕЛЬНОГО ТОПЛИВА И ЕГО КОМПОЗИЦИЙ ПРИ ХРАНЕНИИ

Alternative fuels, primarily synthesized from renewable plant materials, are becoming increasingly important. The standards that regulate the characteristics of modern environmentally friendly diesel fuel allow the addition of 6 to 20% of biodiesel fuel synthesized from renewable plant or animal feedstock to petroleum fuel. This additive allows not only to reduce the emission of harmful substances with exhaust gases, but also to increase the cetane number and lubricity of modern fuels with a low content of sulfur and aromatic compounds. The changes in physicochemical characteristics that occur during storage of biodiesel fuel have been studied on the example of biodiesel fuels synthesized from camelina and flax oils. It is shown that the density and viscosity of biodiesel fuel increase during storage in polyethylene and metal tanks, and to a greater extent during storage in a metal tank. It has been established that the viscosity (3.5-5.0 mm2 /s) and density (860-900 kg/m3 ) of biodiesel fuel is stored within the normalized limits for 7 months in a polyethylene tank; and the shelf life is reduced to 4-5 months in metal tank. The reason for the deterioration of fuel quality are oxidation and polymerization processes. Additives belong to a homologous series of sterically hindered phenols containing an azo group have been proposed for stabilization. Studies of the storage process of compositions of petroleum and biodiesel fuels containing from 10 to 70% (vol.) of the latter (B10 - B70) have been carried out. It has been established that stratification of fuel compositions occurs in addition to an increase in density and viscosity during storage. In this case, compositions with a low content of biodiesel fuel are stratified first. 50% and 40% of biodiesel fuel flaked off in compositions B10 and B20, respectively, for 5 months; the process began already after 30 and 60 days of storage. In composition B50, stratification started only after 4 months of storage; only 4% of the biodiesel fuel flaked off by the end of the fifth month. No stratification was observed for composition B70. The stratification may be due to weak intermolecular interactions between petroleum hydrocarbons and biodiesel molecules containing polar ester groups; as well as with the destruction of the colloidal structure of fuels.

Holocene and recent fires influence on soil organic matter, microbiological and physico-chemical properties of peats in the European North-East of Russia

The influence of fires on the development and chemical composition of two Rheic Hemic Histosols in the native territory of the middle taiga of the Komi Republic was estimated. The development of peat on site I (SI) located in the south boarder of the middle taiga began in the Boreal period (about nine ths. years ago14C yr BP). The growth of peat on site II (SII) located at the foothills of the Northern Urals started in the middle of the Atlantic Holocene period (about 6.7 ths. years ago14C yr BP). This work shows that during the time of development, peatlands experienced various pyrogenic events. The organic horizons were burned out and often led to a change in the dominant ground cover plants. Also, the charcoal particles formed during the fire at the forest surrounding the bogs were transported by air and accumulated in the peat. The pyrogenic history of the studied peats is different, the SI was subjected to intense fires at least twice: at the beginning of formation and in the modern period (140 years ago). The Histosol on SII experienced only low-intensity and indirect fire effect. The highest burning activity of nearest forests in both sites estimated based on charcoal content occurred at the end of the Atlantic, middle of the Subboreal periods. It was shown that an increase in the aromatic compounds occurs in horizons with pyrogenic features; in some cases, an increase in the concentration of polycyclic aromatic hydrocarbons (PAHs) was revealed. The aromatic compounds content in the SOM is determined by the content of macroscopic charcoal particles with significant correlation (CAr-H(C), R = 0.49, p < 0.05, CAr-O,N, R = 0.68, p < 0.05). It is shown that a high frequency of fires leads to an increase in carbon stocks at Histosols.

Utilization of Vertical Cordon System to Improve Source-Sink Balance and Wine Aroma under Water Shortage Conditions of Maturana Blanca

In small-clustered vine cultivars, the conditions of success for a hanging form in order to guarantee a sufficient yield and quality level could go through establishing a permanent vertical cordon to enhance vine capacity and to retain a greater number of buds without making a canopy too compact. In this case, it is also important to quantify the main source–sink relationships within the vine in terms of the vine’s general responses to water shortage. The influence of two types of spur pruned vines (head-trained (HT) vs. vertical cordon trained (VCT)) was examined in field-grown vines in the local cultivar Maturana Blanca in order to achieve an optimal yield under two irrigation regimes (non-irrigated and irrigated at 30% of ET0). For this vegetative development, yield, fruit composition, and wine volatile compounds were measured. The VCT system has demonstrated to increase yield up to 1.8-fold as compared with the HT system independently of the irrigation regime. Although clear differences were observed in the source-sink ratios between the two training systems, these differences did not affect the ripening of the grapes nor their quality. However, a reduction in berry size and the more exposed clusters in VCT vines resulted in a higher concentration of aromatic compounds in the obtained wines as compared with those of HT vines. This study indicates the improvement of the source to sink ratio of the cv. Maturana Blanca through a change in the training system, which helps to increase light interception, leading to a higher yield potential, an optimization of the leaf area to fruit ratio, and an increase in the concentration of aromatic compounds.