Optimal Ethanol Concentration Research Articles

Ethanol Purification through Distillation Method: Effect of Height and Packing Types on Ethanol Concentration

Energy demand is increasing every year along with the growing global population. Ethanol can be synthesized through the fermentation of sucrose or carbohydrates with the assistance of microorganisms. Ethanol produced from fermentation often does not have the desired concentration; hence purification such as distillation is necessary. This study aims to investigate distillation using packing materials and packing height to enhance ethanol purity. The materials used in this study are 30% ethanol, distilled water, pumice, and ginger coral. The purification process begins with understanding the characteristics of the packing through SEM characterization, followed by the distillation process. Based on the research, ginger coral exhibits complex crystal patterns and varying porosity, while pumice shows different porosity and fibrous structure. The ethanol concentration with ginger coral packing can increase by 66.27%, and with pumice packing, it can increase by 65.09%. Additionally, the optimum ethanol concentration is achieved with the highest packing fill. This is due to the surface area of the packing, enabling more efficient mass transfer.

CuNi2O4/MWCNTs nanocatalyst for methanol and ethanol electro-oxidation

The widespread use of cheap and efficient catalysts in energy storage and production in electrochemical processes led our research team to the synthesis and evaluation of CuNi2O4/MWCNTs nanocatalyst for alcohol oxidation. Nanocatalyst was characterized in terms of structure and morphology by X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDAX). The ability of CuNi2O4/MWCNTs was evaluated with cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analyses in the oxidation process of methanol and ethanol alcohols in alkaline media. The optimal concentration of methanol and ethanol for CuNi2O4/MWCNTs and CuNi2O4 was obtained to investigate the methanol oxidation reaction and ethanol oxidation reaction processes. The mechanism of these processes was also evaluated in detail. The stability of both nanocatalysts was investigated by performing several consecutive CVs and in 3600 s by chronoamperometric analysis. The results showed the good stability of this catalyst. The synergistic effect of placing CuNi2O4 on the surface of carbon nanotubes improved the oxidation process of methanol and ethanol. In general, the proposed catalyst can be an efficient, stable, and cheap option and at the same time very stable for use in alcohol fuel cells.

Narrative Review: Optimation of Ethanol as a Solvent for Flavonoid Compounds in Papaya Leaf Extraction

Ethanol is widely used as a distiller of secondary metabolite compounds. Ethanol very well dissolves secondary metabolite compounds including flavonoids group compounds including for papaya (Carica papaya L.) leaf extraction. This review was conducted to examine solvent optimization that has been used in various original studies. The method of searching scientific journal article using PubMed and MDPI using keyword “extraction and ethanol and flavonoid and carica papaya leaf” with the inclusion criteria of 2018 – 2023 article, free full text and not review articles, the number of article obtained was 3 articles. The optimal concentration of ethanol as a flavonoid extract solven is 70 % ethanol at temperatures from 30 °C – 50°C with a time range of 10 – 48 hours of immersion.

An integrated process by ultrasonic enhancement in the deep eutectic solvents system for extraction and separation of chlorogenic acid from Eucommia ulmoides leaves

This study established an integrated process for the extraction and enrichment of chlorogenic acid(CGA)from Eucommia ulmoides leaves in a deep eutectic solvent system via ultrasonic wave-enhanced adsorption and desorption practices utilizing macroporous resins. Although deep eutectic solvents (DESs) have the advantages of chemical stability, good dissolving capacity, and nonvolatilization, routine solvent recovery operations are not suitable for subsequent separation in this solvent system. Based on the above characteristics, this study integrated the extraction and enrichment processes, in which DESs extracts directly loaded onto the macroporous adsorption resin, avoiding the loss of target components in solvent recovery and redissolution processes. The screening results of solvents and resin types further showed that choline chloride-malic acid (1:1) was the optimal DES, and the NKA-II resin had high adsorption and elution performance for CGA. The viscosities of the DESs were much higher than those of water and conventional organic solvents; thus, the mass transfer resistance was large, which could also affect the adsorption behaviour of the macroporous resin. The thermal and mechanical effects of ultrasound could effectively enhance the efficiency of the mass transfer, adsorption, and desorption in the DES systems. When compared to no sonication treatment, the CGA adsorption at various ultrasonic powers (120–600 W) was examined. At optimal ethanol concentration (60%), the effect of the ultrasonic treatment on the recovery of the DESs (water eluting process) and the desorption capability of CGA were confirmed. The use of three volumes of water elution could recover the DESs without loss of CGA. The adsorption process significantly differed depending on the ultrasonic settings, and the absorption balance time and experimental adsorption capacity at equilibrium were enhanced. Additionally, the adsorption procedure of the NKA-II macroporous resin for CGA under ultrasonic treatment could be clarified by the pseudo second order kinetic equation and the Freundlich isotherm model. Thermodynamic and dynamic parameters indicated that physical adsorption was the main process of the entire procedure, and it was a spontaneous, exothermic, and entropy-reducing physical adsorption process. This study potentially indicates that the use of ultrasonication, as a high-efficiency, environmentally friendly method, can enhance the features of the macroporous resin to better purify target chemicals from a DES extract.

OBTAINING ANTIOXIDANTS FROM FOOD INDUSTRY WASTE AND THEIR USE IN FATS

The food industry generates a large amount of waste and by-products of processing, which becomes a problem for the environment. Potato and onion peel, tomato seeds and peel are agro-industrial wastes of the world's main vegetable crops. However, the potential for antioxidants from them is not yet fully known. In this work, the influence of extracts obtained from these wastes on the process of inhibition of the rate of oxidation of sunflower oil was studied. Regression equations describing the process of extraction of biologically active substances from crop production waste as a result of water-ethanol extraction at a temperature of 60°C were obtained. It was established that the optimum concentration of ethanol in the water-ethanol mixture of extractants is in the range of 70–80%. Increasing the extraction time has a positive effect on the yield of extractive substances (at an interval of 2–15 hours). The kinetics of oxidation of sunflower oil by the accelerated method was studied and the antioxidant activity of the obtained antioxidants was determined, which is: for onion peel 2.29 (ie at a concentration of antioxidant 200 mg/kg oil the induction period of sunflower oil oxidation is more than doubled). For potato peels, this figure is 3.17, and for tomato peels – 1.85. All antioxidants obtained from plant waste were no less effective than butylhydroxyanisole (antioxidant activity – 1.93). The effectiveness of antioxidants varied as follows: onion peel > potato peel > butylhydroxyanisole > tomato residues. The expediency of using ascorbic acid in the course of water-alcohol extraction of antioxidants from vegetable raw materials has been proven. It has a positive effect on increasing the output of antioxidants and on extending the induction period of sunflower oil as a result of its own antioxidant properties. The existence of a synergistic effect between ascorbic acid and substances extracted from potato, onion and tomato peel has been proven, which in numerical value is 163, 126, and 180%, respectively.

Effect of NaOH-catalyzed organosolv pretreatment on the co-production of ethanol and xylose from poplar

NaOH-catalyzed organosolv pretreatment was proposed to degrade lignin, retain cellulose and hemicellulose in poplar, and the pretreated substrates was used to produce ethanol and xylose simultaneously. After the organosolv pretreatment conducted at 205 ºC for 20 min with 1.2% NaOH, the optimal ethanol concentration and xylose yield reached 30.1 g/L and 10.3 g/100 g raw material after 48 h, respectively, and the xylose yield was positively correlated with the ethanol concentration (R2 =0.934). The alteration in chemical composition and structure enhanced the ethanol concentration and xylose yield, which was revealed by Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectrum (FT-IR), Thermogravimetric (TG), and correlation analysis. In addition, their capacity for generating ethanol and xylose during three fermentation processes was comprehensively compared. The results indicated that SSF was beneficial to improve ethanol concentration, and SHF was in favour of enhancing xylose and ethanol yields to 95.4% and 85.3% based on retained xylan after pretreatment and the fermentable glucose, respectively. The NaOH enhanced organosolv pretreatment exhibited excellent performance in converting poplar into energy and chemicals, which presented a new idea for biomass refining.

Effectiveness of anesthesia solution (2-Phenoxyethanol) in the transportation of brood stock of Perkasa Striped Catfish (Pangasianodon hypophthalmus Sauvage, 1878)

This study aimed to obtain the optimal concentration of 2-phenoxy ethanol in the transportation medium for the brood stock candidate of the Perkasa Striped catfish. To determine the optimal concentration of 2-phenoxy ethanol in the transportation medium for the Perkasa Striped catfish brood stock candidate, the study used a completely randomized design with three replications consisting of five levels of treatment with a concentration of 2-phenoxy ethanol, namely 0 (control), 100, 150, 200, and 250 ppm. The test fish were Perkasa Striped catfish brood stock candidates weighing an average of 1,000 grams. A plastic bag of 80 x 40 cm was filled with 15 liters of water, 45 liters of oxygen, and 5 fish, and the transport test was carried out in a closed and static way for 12 hours. Parameters observed included survival rate at the end of transportation and on day 7 after transportation, the quality of the media water (dissolved oxygen, pH, temperature), and cortisol level in the blood. The results showed that 100 ppm of 2-phenoxy ethanol was the best concentration for transporting Perkasa Striped catfish brood stock candidates, with a survival rate of 100.0±0.0 percent at the end of transportation and 83.3±28.9 percent on the seventh day after transportation, dissolved oxygen content of 1.47±0.99 mg/L, and blood cortisol levels of 47.85±11.85 g/dL.

Impact of Calcium and Nitrogen Addition on Bioethanol Production by S. cerevisiae Fermentation from Date By-Products: Physicochemical Characterization and Technical Design

Given crude oil prices and their environmental impacts, the use of sustainable renewable alternative energies such as biofuels is rapidly progressing in numerous countries. Among biofuels, bioethanol is a renewable and clean fuel that can be obtained from the fermentation of several raw agricultural materials, including date fruit. However, the low product yield, mainly due to the low-grade nutrient content, limits its use as a promising alternative biofuel. This current study investigated bioethanol production from date by-products in Saudi Arabia and examined the impact of calcium and nitrogen sources added at different concentrations (0 to 1 g/L) on the productivity and ethanol concentration using Saccharomyces cerevisiae. Yeast extracts and ammonium chloride (NH4Cl) were tested as nitrogen sources for bioethanol fermentation from date juice. Calcium chloride (CaCl2) and calcium carbonate (CaCO3) were evaluated as calcium sources for the same purpose mentioned above. The results showed that both calcium and nitrogen sources improved ethanol production efficiencies. The addition of calcium sources such as CaCl2 at 0.4 g/L resulted in maximum ethanol concentration (41.5 ± 0.85 g/L) and the highest productivity of 0.511 g/L/h. Thus, an increase of 31.3% compared to the control sample was acquired. Ammonium chloride was found to be the best nitrogen supplement among them. Indeed, supplementing the fermentation medium with 1 g/L NH4Cl gave an optimal ethanol concentration and productivity, reaching more than 65 g/L and 0.83 g/L/h, respectively. This is an increase of 106.6%. The functional group of ethanol (C2H5OH) for all the elaborated samples was confirmed by Fourier-transform infrared spectroscopy (FTIR) and NMR analyses. Moreover, the results confirmed the high quality and purity of the bioethanol products. Thus, the “Khodhari” date variety of low market value is a privileged substrate for industrial bioethanol production. For this reason, a proposed flow diagram of a designed plant for bioethanol industrialization is provided and detailed.

Gradient-Based Extremum Seeking Control Applied to a Dark Fermentation Process

In this paper we use an extremum seeking control strategy to maximize the produced ethanol in a dark fermenter. Such a strategy avails of a continuous estimation of the reactor’s input-output gradient to compute the dilution rate applied to the reactor. This dilution rate, however, is updated at discrete moments. We consider a scenario in which tequila vinasse is the raw material for this fermentation process; thereby reducing the concentrations of sugars in the vinasse and at the same time obtaining ethanol. Via numerical simulations we show the applicability of the strategy when the optimal concentration of ethanol varies in time as step functions.

Species-specific effects of ethanol concentration on host colonization by four common species of ambrosia beetles

Ambrosia beetles (Coleoptera; Curculionidae; Scolytinae and Platypodinae) can cause severe damage to trees growing in plant nurseries, orchards and natural forests. Ethanol is emitted by stressed trees and represents an important cue used by ambrosia beetles to locate suitable hosts to infest. Ethanol also favors the growth of ambrosia beetles’ nutritional fungal symbionts and suppresses the growth of antagonistic fungi. An optimal concentration of ethanol in host tissues might maximize fungal growth and offspring production, but it is unclear if this optimal concentration varies among ambrosia beetle species. To investigate this mechanism, we injected five different concentrations of aqueous ethanol solution (5%, 25%, 50%, 75% and 90%) into the stems of container-grown oak trees, Quercus robur L. Modified Falcon tube chambers were used to confine four species of field-collected ambrosia beetles to the injected stems, namely, Anisandrus dispar, Xyleborinus saxesenii, Xylosandrus germanus, and Xylosandrus crassiusculus. Incidence of boring, ejected sawdust, gallery development, and offspring production were then quantified. The incidence of boring generally increased with increasing ethanol concentration for all four Scolytinae species tested. Ejected sawdust and offspring production increased with increasing ethanol concentration up to 90% for A. dispar and X. saxesenii; by contrast, an increasing trend up to 75% ethanol followed by a decrease at 90% ethanol was associated with X. germanus and X. crassiusculus. Our study highlights the key role of ethanol for ambrosia beetles, and showed that the optimal concentration maximizing colonization and offspring production can vary among species.

Identification of polyphenols in white mugwort (Artemisia lactiflora Wall.) ethanolic extracts and their anti-inflammatory and anti-adipogenic activity potential

White mugwort (Artemisia lactiflora Wall.) is known as a medicinal herb containing phytochemicals with antioxidant and bio-activity. The optimal concentration of ethanol was investigated for extracting polyphenols from the fresh aerial part and dried powder of white mugwort as expressed by total phenolic content (TPC), phenolic compounds, antioxidant, anti-inflammatory, and anti-adipogenic activity. Among various ethanol concentrations (0, 25, 50 or 95%) used in the extraction process, the freeze-dried extract from fresh aerial part (FE) extracted with 95% ethanol expressed the highest antioxidant activity (DPPH radical scavenging IC50 of 0.817 ± 0.06 μl/mg dry weight (DW) and FRAP value of 11.40 ± 0.86 mmol Fe(II)/g DW) and the highest TPC (61.46 ± 3.09 mgGAE/g DW). While, the freeze-dried extract from dried powder (PE) exhibited the prominent antioxidant properties (DPPH radical scavenging IC50 of 0.975 ± 0.03 μl/mg DW and FRAP value of 07.60 ± 0.22 mmol Fe(II)/g DW), TPC (48.11 ± 1.45 mgGAE/g DW) when extracted with 50% ethanol. Seven phenolic compounds—two phenolic acids (gallic acid and tannic acid) and five flavonoids (apigenin, isoquercetin, quercetin, rutin, and catechin) were identified in FE and PE using HPLC-DAD/MS. The inflammatory genes were down-regulated in lipopolysaccharide-stimulated THP-1 monocytes treated with PE, suggesting anti-inflammatory activity. Lipid accumulation in 3T3-L1 adipocytes treated with FE at 60 μ gGAE/mL decreased to 12.8%, while the decrease of 36.8% was detected in PE. Hence, flavonoids were suggested to be responsible for the stronger bioactivity of PE over FE. Moreover, this work originally revealed the investigation of the anti-inflammatory and anti-adipogenic activity of white mugwort on THP-1 and 3T3-L1 cells.

Electrophoretic Deposition of Platinum Nanoparticles using Ethanol-Water Mixtures Significantly Reduces Neural Electrode Impedance

Platinum electrodes are critical components in many biomedical devices, an important example being implantable neural stimulation or recording electrodes. However, upon implantation, scar tissue forms around the electrode surface, causing unwanted deterioration of the electrical contact. We demonstrate that sub-monolayer coatings of platinum nanoparticles (PtNPs) applied to 3D neural electrodes by electrophoretic deposition (EPD) can enhance the electrode's active surface area and significantly lower its impedance. In this work we use ethanol-water mixtures as the EPD solvent, in contrast to our previous studies carried out in water. We show that EPD coating in 30 vol.% ethanol improves the device's electrochemical performance. Computational mesoscale multiparticle simulations were for the first time applied to PtNP-on-Pt EPD, revealing correlations between ethanol concentration, electrochemical properties, and coating homogeneity. Thereto, this optimum ethanol concentration (30 vol.%) balances two opposing trends: (i) the addition of ethanol reduces water splitting and gas bubble formation, which benefits surface coverage, and (ii) increased viscosity and reduced permittivity occur at high ethanol concentrations, which impair the coating quality and favoring clustering. A seven-fold increase in active surface area and significantly reduced in vitro impedance of the nano-modified neural stimulation electrode surfaces highlight the influence of ethanol-water mixtures in PtNP EPD.

Anti-Aging Effects of Terminalia bellirica, Phyllanthus emblica, Triphala, and Carica papaya Extracts for Sustainable Youth

As the human lifespan becomes longer, many people invest time and money in managing external beauty. However, managing external beauty has the disadvantage of causing side effects or that the effect does not last. Therefore, research and development are required to maximize effectiveness, eco-friendliness, and sustainably in beauty management. The purpose of this study was to experimentally identify the anti-aging effects, such as skin wrinkle and elasticity improvement, of extracts from Bahera, Phyllanthus emblica, Triphala, and Carica papaya, and to confirm their development as whitening and wrinkle functional cosmetic materials. In this study, a solid mixture was prepared using eco-friendly Terminalia bellirica, amla (Phyllanthus emblica), Triphala, and Carica papaya, and experimental samples were extracted. Antioxidant tests, antibacterial activity tests, polyphenol and flavonoid content, and deodorization tests were conducted to test the efficacy of experimental samples. The procedures and methods of these experiments are summarized in the following article. In this study, we found that the Bahera, Phyllanthus emblica, Triphala, and Carica papaya extracts had significant effects on whitening and wrinkle improvement, and that the effects of using ethanol-based extracts as the co-solvent were even greater. In other words, extracts of Bahera, Phyllanthus emblica, Triphala and Carica papaya showed antioxidant, whitening, and anti-wrinkle effects, and extracts that used ethanol as a co-solvent showed greater effects. In particular, we found that the optimal concentration of ethanol as a co-solvent maximizes its effectiveness at 70%.

Experimental Investigation and Optimization of Non-Catalytic In-Situ Biodiesel Production from Rice Bran Using Response Surface Methodology Historical Data Design

Rice bran oil (RBO)is claimed to be a potential feedstock for biodiesel production. Non-catalytic in-situ biodiesel production from a low-cost feedstock (rice bran) using subcritical ethanol-water mixture was investigated in this study. The influence of four independent variables, i.e., addition of co-solvent, ethanol concentration, temperature, and time of reactions, on the yield of biodiesel was examined. The results showed that the most effective co-solvent wasethyl acetate and the optimum ethanol concentration, temperature and reaction time were 80% v/v, 200 oC and 3 hours, respectively. The maximum yield of biodiesel was found to be around 80%. The optimization of operating conditions was carried out by response surface methodology (RSM) with historical data design (HDD). The statistical method also suggested similar optimum operating conditions, i.e., 78.44% (v/v) ethanol concentration, 200 oC, and 3.2 hours reaction time with ethyl acetate as a co-solvent. The predicted maximum biodiesel yield was also slightly lower, i.e., 76.98%. Therefore, this study suggests that biodiesel production from rice bran through a non-catalytic in-situ process using a subcritical ethanol-water mixture with ethyl acetate as a co-solvent is very feasible since the yield can reach 80%. The study also found that RSM with HDD can predict the optimum operating conditions with a good accuracy.

Pemurnian Bioetanol Dari Limbah Kulit Kopi Dengan Menggunakan Zeolit Alam dan Batu Gamping

In this research, zeolites were used to increase the levels of ethanol distillation process results of laboratory Department of Chemical Engineering Politeknik Negeri Lhokseumawe. Ethanol yield after distillation process only reaches 20.66%, to increase the concentration of ethanol used advanced treatment is by the adsorption method. The results were obtained optimum ethanol concentration, ie 38.67% with a contact time of 8 hours and 80 mesh size. the refractive index and density of 1.33960 and 0.798. bioethanol with 3 g of limestone can eliminate moisture content up to 29.36%; the activation treatment adsorption process of bioethanol with adsorbent zeolite, limestone, and limestone following the zeolite with Freundlich isotherm with adsorption capacity of each 4.5 mg / g; 5.7 mg / g; and 6.4 mg / g.

Optimization conditions of ultrasound‐assisted extraction of phenolic compounds from orange peels using response surface methodology

This study focused on optimizing the extraction conditions of bioactive compounds from orange peels using response surface methodology (RSM) to decrease the number of experimental trials and increase the yield of bioactive compounds. Ultrasonic extraction time, extraction temperature, and ethanol concentration have been optimized. Twenty experimental trials have been carried out to optimize the extraction conditions. The RSM results showed that the extraction temperature and ethanol concentration had a remarkable effect on the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. The optimal ultrasound-assisted extraction conditions were 44 min extraction time, 50℃ extraction temperature, and 57.7% ethanol concentration. Under these optimal conditions, TPC and TFC were 292.158 µg GAE/g and 191.144 µg catechol/g, respectively, whereas antioxidant activities were 5.199 and 2.96 µg/ml for 2,2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis(3-ethylbenzothiazoline-60-sulfonic acid) diammonium salt, respectively. RSM saves the extraction time and effective for optimizing extraction conditions with the highest efficiency and yield. Novelty impact statement The findings of the current work emphasized usefulness of ultrasound assisted extraction for elevation the extraction efficiency with decreasing the extraction time. The extraction temperature and ethanol concentration are the main effective factors of extraction efficiency. The optimal extraction time was 44 min at 50℃ extraction temperature, and the optimal ethanol concentration was 57.7%. These optimal conditions were giving the highest yield of TPC and TFC that were 292.158 µg GAE/g and 191.144 µg catechol/g. These novel optimized extraction conditions could be useful in different food and pharmaceutical applications.

Effect of ethanol concentration on methane hydrate decomposition: MD simulation insights

The controllability of mining is a key factor affecting the commercial application of methane hydrates, and the addition of chemical additives can significantly accelerate the mining process. However, the effect of additive concentration on hydrate decomposition is not yet well understood. In this study, we systematically investigate the effect of ethanol concentration on the decomposition of methane hydrate under varying thermodynamic conditions using molecular dynamics (MD) simulations. To quantitatively characterize the decomposition process and mechanism of methane hydrates, the combination of angular order parameter (AOP), radial distribution function (RDF), mean square displacement (MSD), diffusion coefficients and system energy was for the first time used. The results showed that the addition of ethanol contributed to the formation of methane bubbles and accelerated the decomposition of hydrates. The mass transfer effect of ethanol molecules and the reconstruction of the hydrogen bond network of water molecules determined the stability of hydrates. From 0 to 40 mol% ethanol concentration, the hydrate decomposition increased with increasing the concentration of ethanol. Both increasing the temperature and decreasing the pressure are beneficial to the decomposition of the hydrate system. These results provide the selection of optimal ethanol concentration for the decomposition of methane hydrate and reveal its decomposition mechanism, and shed important light for the controllable production of gas hydrates.

Study of the antimicrobial activity of the bark extracts of <i>Quercus robur</i> L.

The purpose of this study is to carry out comparative analysis of the antimicrobial activity of water-ethanolic and chloroform extractions from the bark of Quercus robur L.
 The determination of the minimum inhibitory concentration was carried out by the method of double serial dilutions in Mueller-Hinton nutrient broth (Bio-Rad, USA). Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans were used as test cultures.
 It was revealed that the greatest antimicrobial effect was exhibited by water-ethanolic extractions from Q. robur L. bark in ethanol concentrations of 60%, 70% and 96% ethanol in relation to strains of microorganisms P. aeruginosa and C. albicans. The lowest antimicrobial activity against strains of microorganisms E. coli and S. aureus was observed in 40% of water-ethanolic extractions. Chloroform extracts of Q. robur L. bark has a pronounced antimicrobial activity against C. albicans and P. aeruginosa strains. It is proposed to use 60% ethanol as the optimal concentration of ethanol for the bark of Q. robur L., since at the given concentration of ethanol, the maximum antimicrobial effect is observed, and the balance between the release of tannins and flavonoids into the dosage form also preserves.
 This study contributes to solving the issue of recycling wood waste of Q. robur L. and their rational use in pharmaceutical practice.
 The obtained results can be used in the future to create antimicrobial drugs based on the bark of Q. robur L.

The effect of ethanol concentration on the morphological and molecular preservation of insects for biodiversity studies.

Traditionally, insects collected for scientific purposes have been dried and pinned, or preserved in 70% ethanol. Both methods preserve taxonomically informative exoskeletal structures well but are suboptimal for preserving DNA for molecular biology. Highly concentrated ethanol (95–100%), preferred as a DNA preservative, has generally been assumed to make specimens brittle and prone to breaking. However, systematic studies on the correlation between ethanol concentration and specimen preservation are lacking. Here, we tested how preservative ethanol concentration in combination with different sample handling regimes affect the integrity of seven insect species representing four orders, and differing substantially in the level of sclerotization. After preservation and treatments (various levels of disturbance), we counted the number of appendages (legs, wings, antennae, or heads) that each specimen had lost. Additionally, we assessed the preservation of DNA after long-term storage by comparing the ratio of PCR amplicon copy numbers to an added artificial standard. We found that high ethanol concentrations indeed induce brittleness in insects. However, the magnitude and nature of the effect varied strikingly among species. In general, ethanol concentrations at or above 90% made the insects more brittle, but for species with robust, thicker exoskeletons, this did not translate to an increased loss of appendages. Neither freezing the samples nor drying the insects after immersion in ethanol had a negative effect on the retention of appendages. However, the morphology of the insects was severely damaged if they were allowed to dry. We also found that DNA preserves less well at lower ethanol concentrations when stored at room temperature for an extended period. However, the magnitude of the effect varies among species; the concentrations at which the number of COI amplicon copies relative to the standard was significantly decreased compared to 95% ethanol ranged from 90% to as low as 50%. While higher ethanol concentrations positively affect long-term DNA preservation, there is a clear trade-off between preserving insects for morphological examination and genetic analysis. The optimal ethanol concentration for the latter is detrimental for the former, and vice versa. These trade-offs need to be considered in large insect biodiversity surveys and other projects aiming to combine molecular work with traditional morphology-based characterization of collected specimens.

Using of brown algae Sargassum pallidum as raw materials for extraction of fucoxanthin

Fucoxanthin is a widespread carotenoid contained in tissues of brown algae, known by its antitumor activity and ability to suppress cancer cells growth. Its inclusion into diet prevents accumulation of the body fat and regulates level of glucose and insulin in the blood. Fucoxanthin can be considered as a promising nutritional supplement for suppressing obesity. Extraction of fucoxanthin from brown algae Sargassum pallidum is investigated under various conditions. The samples of algae were collected in different sites at Primorye coast in 2018–2019. Two types of the preparations were used ― frozen and dried. The frozen preparations were stored under temperature of –18 оC no more than 30 days. For the dried preparations, fresh algae were dried in a dark room by air fan under temperature of +18–+20 оC and then crushed to powder and stored in dark place under the same temperature no more than 6 months. Content of dry substance in the preparations was 16.4 ± 1.0 % for frozen algae and 93.6 ± 1.0 % for dried algae. Fucoxanthin was extracted from these preparations by method of alcohol extraction using the ethanol water solution in ratio of 1 : 10 during 24 hours in a dark place, then the solution was filtered or centrifuged. Concentration of fucoxanthin in the filtered solution was measured in spectrophotometer relative to a standard solution (ethanol 96 %) with wavelength of 350–800 nm. Yield of fucoxanthin was higher from the frozen preparations, but more ethanol was consumed for its extraction in comparison with extraction from the dried preparations. Besides, the dried preparations were processed during 1 day with the ethanol solution in concentration 96, 88, 84, 80, and 76 %, under various temperature. Yield of fucoxanthin decreased with temperature increasing: the optimal temperature was +7 оC, so the room temperature could not be recommended for extraction. The optimum concentration of ethanol for fucoxanthin extraction was 80 ± 2%.