Yield Of Phenolic Compounds Research Articles

Evaluation of Cellulase, Pectinase, and Hemicellulase Effectiveness in Extraction of Phenolic Compounds from Grape Pomace

Grape pomace, the solid residue from winemaking, is a rich source of polyphenolic compounds with significant antioxidant properties. However, the efficient extraction of these valuable compounds remains a challenge. This study focuses on optimizing the conditions for the enzyme-assisted extraction of polyphenolic compounds from red grape pomace using cellulase, hemicellulase, and pectinase. The key variables investigated in this study were enzyme concentration, extraction time, and solid/liquid ratio. The results highlight the importance of selecting enzymes based on target compounds, as different enzymes were found to be more effective for specific phenolic fractions. Hemicellulase was most effective for phenolic acids, cellulase for catechins, and pectinase for anthocyanins. Enzyme-assisted extraction significantly increased the yield of phenolic compounds and resulted in higher total phenolic content and antioxidant activity compared to control samples treated with solid/liquid extraction without enzyme addition. These findings confirm that enzyme-assisted extraction is a promising approach for enhancing the recovery of polyphenolic compounds from grape pomace.

Phytochemical Extract from Syzygium cumini Leaf: Maximization of Compound Extraction, Chemical Characterization, Antidiabetic and Antibacterial Activity, and Cell Viability

This work aimed to obtain a phytochemical extract from jambolan leaf using a hydroethanolic solvent and ultrasound-assisted extraction. For this purpose, an experimental design was applied to analyze the effect of process variables related to temperature (30–60 °C), time (10–30 min), and solvent to leaf ratio (5–15 mL g−1), on the extraction mass yield (EMY) and on the yield of phenolic compounds (PCY). The effect of extractor solvent, AE (absolute ethanol), 75E (75% v·v−1 ethanol) and 50E (50% v·v−1), on the chemical characterization of the extracts, antidiabetic and antimicrobial activity, and cell viability, were also evaluated. The application of the highest values of process variables resulted in obtaining the maximum of the response variables (EMY = 9.94 wt% and PCY = 13.01 mg GAE g−1 leaf). A higher content of phenolic compounds and flavonoids was obtained with 50E, which is mainly composed of sinapic, vanillic, trans-caffeic, and quinic acids, which were responsible for the greatest antioxidant potential, antibacterial activity (against Staphylococcus aureus and Pseudomonas aeruginosa), and inhibition of α-amylase. On the other hand, the use of AE allowed us to obtain extracts with higher concentrations of squalene, α-tocopherol, β-sitosterol, and friedelin. From cell viability tests, the extracts are not considered toxic at the concentration tested (100 µg mg−1).

Exploring the Impact of Temperature and Solvent Ratio on Phenol and Flavonoid Levels in Alpinia galangal L. Extract Using Evaporative Vacuum Cooling

The objective of this research is to determine the impact of temperature gradients and solvent ratios in the evaporative vacuum cooling method on the yield of phenol and flavonoid content in galangal extract; ascertain the impact of these factors on the yield generated by galangal extract; and ascertain the mass balance analysis of materials are the objectives of this study. Throughout the extraction of galangal. The study's findings demonstrated that the evaporative vacuum cooling technique, conducted at 49 ºC and with a 1:1 solvent ratio of 1.4432±0.7317 mg GAE/g, produced the highest total phenol concentration. The three differences in the temperature of the evaporative vacuum produced the total phenol content cooling. The overall phenol content obtained decreases with increasing solvent ratio addition. Although the evaporative vacuum cooling treatment at 45 °C yielded the highest total flavonoid content (1.2418±0.2365 mg QE/g) at a 1:2 solvent ratio, the total flavonoid content varied between the three evaporative vacuum cooling temperature variations. The yield of total phenolic and flavonoid compounds was not significantly affected by temperature gradient adjustments or the ratio of galangal extract to solvent (Sig. > 0.05) in any of the data samples pertaining to phenolic and flavonoid compounds. Keywords: Evaporative vacuum cooling, Flavonoids, Galangal, Phenol.

Hydrogenolysis of guaiacol and lignin to phenols over Ni/Nb2O5[sbnd]HZSM-5 catalyst

Selective hydrogenolysis of CAr-O bonds in lignin to produce aromatic compounds typically necessitates severe conditions. We developed a Ni/Nb2O5HZSM-5 catalyst that facilitates direct cleavage of guaiacol's aryl ether bonds at reduced temperatures (200 °C) and pressure (0.1 MPa H2), achieving a conversion of 89.5 % with the selectivity of phenol at 81.7 %, while retaining its activity after five cycles. The Ni/Nb2O5HZSM-5 exhibits a higher yield of phenol (49.1 mmolphenol·gNi−1·h−1), currently achieving the highest phenol yield among Ni-based catalysts. The addition of Nb2O5 enhances the dispersion of Ni and augments the effective surface area. In addition, the strong interaction of Nb with the HZSM-5 changed the electronic state of Nb and enhanced the resistance of the catalyst to high temperature and mechanical stress. Employing this catalyst for lignin depolymerization in an aqueous medium led to a 17.0 wt% yield of alkyl phenolic compounds. This approach represents an advancement in biomass resource conversion, circumventing the dependency on high-pressure and precious-metal catalysts, and signaling a new trajectory for sustainable biomass utilization in scientific research.

Microwave-assisted extraction of phenolic compounds from Commiphora gileadensis leaf and their characterization

Commiphora gileadensis (C. gileadensis) is a plant traditionally used in many parts of the world for medicinal purposes. However, the benefits of this plant are yet to be uncovered due to the use of conventional extraction methods during its extraction. Hence, there is a need for more efficient and environment-friendly extraction methods for optimum recovery of the bioactive components of C. gileadensis. This study aims to evaluate the impact of microwave-assisted extraction (MAE) process parameters (individually and in combination) on the recovery of phenolic compounds from C. gileadensis leaf. One-Factor-At-a-Time (OFAT) optimization method was used in this work to study the impact of varying the MAE process parameters (sample: solvent ratio, microwave power, ethanol concentration, and extraction temperature) on the optimum yield of phenolic compounds. The obtained phenolic compounds were characterized using Gas chromatography-mass spectrometry (GC–MS) for tentative identification of the component phytochemicals of the extract. The results showed that the optimal process condition of microwave power at 300 W, solvent/sample ratio of 1:10 g/mL, solvent concentration of 40 % v/v, and extraction temperature of 40 °C gave the maximum extraction yield of 33.20 ± 0.42 % w/w, total phenolic content (TPC) of 114.65 ± 3.14 mg GAE/g d.w., and total flavonoids content (TFC) of 37.56 mg QE/g d.w.). Furthermore, the GC-MS analysis identified 25 phenolic compounds with good antioxidant activities from the extracts. Therefore, MAE is considered a non-conventional green method for improved extraction of phenolic compounds from C. gileadensis leaf compared to the existing conventional extraction methods.

Extraction of phenolic compounds from Juglans regia L. leaves using aqueous solutions of eutectic solvents

The leaves of Juglans regia L. (walnut tree) are a rich source of bioactive phenolic compounds, particularly flavonoids and phenolic acids, which can be used in cosmetic applications due to their antioxidant properties. Conventionally, these compounds are extracted using volatile organic solvents. This study focuses on a more sustainable approach by designing a heat-assisted extraction process using aqueous solutions of eutectic solvents (ES) composed of cosmetic-compatible ingredients aiming for direct incorporation into cream formulations. In this context, aqueous solutions of the ES betaine + urea and betaine + 1,3-propanediol (PPD) were selected, considering their potential as cosmetic ingredients. The screening process targeted the maximum extraction yield of phenolic compounds (phenolic acids and flavonoids), quantified by HPLC-DAD. The selected variables were water content (25, 50 and 75 % in weight) and the molar proportion of the ES components. For comparison purposes, pure water was used as a reference solvent.The total phenolic content ranged between 5.5 and 14.6 mg/g of dry plant. Betaine:urea (2:1), betaine:PPD (1:2), betaine, and PPD, all with 50 % water mass percentage, were among those resulting in higher extraction yields and were further selected for bioactivity analysis. The system containing betaine presented the best antioxidant capacity, analysed through ferric reducing power, DPPH radical scavenging, and TBARS assays. The extracts obtained with PPD presented the highest antimicrobial activity against gram-positive and gram-negative bacteria, and yeast. The results show the potential of using binary aqueous mixtures of betaine, or 1,3-propanediol, which are simple ingredients in cosmetics formulations, to efficiently extract phenolic compounds from a natural matrix. Moreover, the bioactivity results, particularly in the antioxidant dimension, support using J. regia leaves as a source of natural antioxidants.

Electro-depolymerization of Kraft lignin with deep eutectic solvents

The paper production industry annually produces approximately 50 million tons of lignin, an intermediate product. While lignin has the potential for producing valuable chemicals and energy materials, an effective method for its conversion is yet to be developed. This study aims to establish a sustainable and environmentally friendly approach for electrochemically synthesizing valuable compounds from lignin with using natural deep eutectic solvents as electrolytes. The study used cyclic voltammetry (CV) for the electrochemical depolymerization of Kraft lignin, examining the effects of different scan numbers on depolymerization and the resulting lignin derivatives. Observed changes in the depolymerization peak current of lignin were reported as the number of scans increased. Choline chloride: Lactic acid (CC:LA), Choline chloride: Ethylene glycol (CC:EG), and Lactic acid:1,2-propanediol (LA:PR) were used as green electrolytes. Syringaldehyde was found to be the major compound obtained by this method. As a result of statistical analysis performed using The Grey Relations Analysis method, it was determined that the conditions that utilized Kraft lignin with the highest added value involved performing five cycles of CV scans with the CC:LA electrolyte. CV scans in DES environments increased the yield of lignin-derived phenolic compounds.

Optimizing Ultrasonic‐Assisted Extraction for Enhanced Yield of Phenolic Compounds and Antioxidant Activity in Cold Brew Coffee

ABSTRACTThis study aimed to identify the best conditions for ultrasonic‐assisted extraction (UAE) of DPPH and phenolic compounds from cold brew coffee using Box‐Behnken Design (BBD) and Response Surface Methodology (RSM). It explored the effects of solid‐liquid ratio (5%–15%), extraction time (40–50 min), and ultrasonic power (70%–80%) on these compounds, finding that all factors significantly influenced the outcomes. Statistical analysis showed the data fit a quadratic polynomial model well, with R2 values of 0.9981 for phenolic compounds and 0.9799 for DPPH radicals. Using 3D surface and contour plots from these models, the optimal extraction conditions for these compounds from cold brew coffee were determined. The highest yields of total phenolic compounds and DPPH radical were obtained when samples were extracted at a 10% solid–liquid ratio, 45 min extraction time, and 75% ultrasonic power. Under these optimal conditions, total phenolic compounds and DPPH radical were 64.10 ± 0.31 gGAE/mL and 61.90 ± 0.14%, respectively, with a maximum caffeine content of 213.13 ± 0.23 mg/L. Gamma irradiation at kGy also reduced cold brew coffee's microbial content. This research may be a new alternative for producing cold brew coffee that will save time and help extend the shelf life.

Optimization of Extraction Method of Bioactive Compounds from Elderberries (Sambucus nigra L.) and Testing Extract Stability

Phenolic compounds from elderberries (Sambucus nigra L.) have attracted attention due to their potential health benefits. This paper examines different extraction methods used to obtain phenolic compounds from these fruits and the stability of the extracts. Several extraction techniques (extraction with continuous agitation, ultrasound-assisted extraction, microwave-assisted extraction, maceration, and enzyme-assisted extraction) were tested and compared to evaluate the yield and the quality of the extracts. The stability of the extracts with various storage parameters (time and temperature) and processing conditions (concentration and lyophilization) was also investigated. The results showed that ultrasound-assisted extraction (UAE) provided the highest yield of total phenolic compounds (74.89 mg GAE/g), of which 71.23% were represented by total anthocyanins and 62.50% by monomeric anthocyanins, with total flavonoids of 8.11–9.41 mg RUE/g. The analysis of individual phenolic compounds reconfirms the efficiency of UAE, obtaining 0.42–0.09 mg/g gallic acid, 0.59–0.01 mg/g chlorogenic acid, 0.17–0.03 mg/g 4-coumaric acid, and 2.43–0.01 mg/g rutin. The optimization of the extraction conditions led to the conclusion that the best solvent is 45% ethanol (v/v), and the optimal parameters are 40 °C for 40 min. It was also found that the stability of the extracts can be high during long periods of time (even after 180 days). These findings contribute to the understanding of the optimization of extraction processes and storage conditions to obtain extracts rich in phenolic compounds from elderberries, with potential uses in pharmaceutical and food applications.

Optimization of Ultrasonic-Assisted Extraction Condition for Total Phenolic Compounds from Citrus Hystrix Peel

This study aims to optimize the extraction conditions of Ultrasonic-Assisted Extraction (UAE) on the extraction of phenolic compound and antioxidant activity of Citrus Hystrix (C. Hystrix) peel. The experimental design was carried out using Face Centered Central Composite Design. A total of 20 sets of different combination experiment designs were generated from 3 parameters; temperature (30-50°C), time (20-40 min), and raw material to the solvent ratio (1:30-1:70). The highest yield of total phenolic compounds was 4.36 mg/g with the optimize extraction condition of , 30 min extraction time and 1:50 raw material to the solvent ratio. The result of this study indicates that the phenolic compounds extracted from C. Hystrix peel could have the potential to be used for pharmaceutical and food applications.

Sustainable depolymerization of lignin into aromatic compounds using amphiphilic Anderson-type polyoxometalate catalysts

Lignin serves as a primary abundant source of renewable aromatic compounds. Achieving efficient breakdown of lignin and retaining its aromatic properties is highly desirable but remains a challenging task. To address this challenge, we synthesized Anderson-type polyoxometalate (POM) catalysts, particularly [CTAC]2[CoMo6]. We then investigated the effectiveness of the POM catalysts in the oxidative depolymerization of larch lignin. Under conditions of 160 °C, 1.0 MPa oxygen atmosphere, and a catalyst-to-substrate ratio of 1:5, we achieved a monomer yield of phenolic compounds at 12.43 wt%. The unsaturated coordination sites of Mo5+ within the catalysts were identified as active sites, facilitating enhanced O2 adsorption and activation. The enhanced O2 adsorption significantly influenced the production of aromatic monomers from lignin. We observed that the catalysts effectively cleaved CC bonds in β-O-4 dimer compounds using lignin dimer model compounds. Notably, the [CTAC]2[CoMo6] catalyst exhibited excellent stability across five cycles, maintaining its high efficiency in lignin depolymerization. This indicates that Anderson-type POM-based catalysts exhibit potential for sustainable conversion of biomass into valuable compounds and for enhancing lignin valorization processes.

Extraction of phenolic compounds from lucuma (Pouteria lucuma) seeds with natural deep eutectic solvents: modelling using response surface methodology and artificial neural networks

The present study aimed to extract polyphenolic compounds from lucuma (Pouteria lucuma) seeds using natural deep eutectic solvents (NADES) as a green, efficient, and environmentally friendly extraction. This was optimized by using the Response Surface Method (RSM) and comparing its predictive capacity with Artificial Neural Networks (ANN) and Convolutional Neural Networks (CNN). Four NADES were prepared by mixing lactic acid (LA) with each of the following reagents: sodium acetate (SA), urea (U), glucose (G), and ammonium acetate (AA), separately. The yield of total phenolic compounds (TPC) obtained from lucuma seeds with each NADES was measured as an optimization criterion with the Box-Benhken design. The following factors were evaluated: time, temperature, and the lucuma seed flour (LSF): NADES ratio. The response variables were TPC and antioxidant activity. The LA-AA extract was selected because it exhibited the highest TPC value and was analyzed by UHPLC–MS (Ultra-performance Liquid Chromatography-Mass Spectrometry). From the RSM, the optimal extraction parameters were 80 min, 52°C, and LSF: NADES ratio of 8:100 (w/v), obtaining a TPC value of 3601.51 ± 0.51 mg GAE/100 g LFS. UHPLC–MS analysis evidenced the formation of epigallocatechin isomers from epigallocatechin gallate. The predictive ability of ANNs compared to RSM was demonstrated.

Comparative Cytotoxicity Evaluation of Heat-Assisted vs Cold Water Extractions of Six Medicinal Fungi against Breast and Lung Cancer Cells.

Preparation of medicinal fungi for experimental purposes usually involves the extraction and determination of the quality and quantity of bioactive compounds prior to the biological experiment. Water, a common polar solvent, is usually used for traditional preparations for consumption. The application of high temperatures during water extraction can affect the chemical composition and functional properties of the extracts. Therefore, the aim of this study is to compare the differences in composition between extracts obtained with heat-assisted and cold water extractions of six selected species of fungi (Lignosus rhinocerus, Ophiocordyceps sinensis, Inonotus obliquus, Antrodia camphorata, Phellinus linteus and Monascus purpureus) and their cytotoxicity against human lung and breast cancer cells. The extracts obtained with heat-assisted and cold water extraction of six species of fungi were analysed to determine their protein, carbohydrate and phenolic contents. Their cytotoxicity was tested against lung (A549) and breast (MCF-7 and MDA-MB-231) cancer cell lines. The most potent extract was further separated into its protein and non-protein fractions to determine their respective cytotoxicity. The cytotoxicity of the different extracts obtained with heat-assisted and cold water extraction varied. Comparing the two extractions, the cold water extraction resulted in a significantly higher yield of proteins (except M. purpureus) and phenolic compounds (except A. camphorata), while the extracts of I. obliquus and M. purpureus obtained with heat-assisted extraction had a significantly higher carbohydrate mass fraction. Notably, the cold water extract of I. obliquus showed cytotoxicity (IC50=(701±35) µg/mL), which was one of the highest of the extracts tested against A549 cells. The cold water extract of I. obliquus was selected for further studies. Our results showed that cold water extracts generally have higher cytotoxicity against selected human cancer cell lines, with the exception of O. sinensis and A. camphorata extracts. This study reports the advantage of cold water extracts of fungi over those obtained with heat-assisted extraction in terms of cytotoxicity against human cancer cell lines and emphasises the role of extraction conditions, particularly heat, in influencing chemical composition and cytotoxic effects.

Exploring forced convective solar drying of henna (Lawsonia inermis) and its effect on the biological activities: Comparison with open sun dried product

The first focus of this study is to investigate the design and behavior of locally built solar dryer during processing henna leaves. This was performed through the determination of the most important parameters that effect drying process. Appropriately, it was found that solar radiation has a direct effect on the collector outlet air temperature and consequently the product moisture content. Accordingly, high radiations lead having high air temperature at the drying chamber and consequently, the moisture content will decrease rapidly. Similarly, lower radiations will still lead to decrease of the moisture content, however, the drying rate will be less important than at high radiations. On the other hand, air velocity has an inverse dissipative effect of the energy and its increase leads to the decrease of the outlet temperature of the solar collector. Indeed, the highest outlet temperature from the solar collector was around 32 °C at an air velocity of 2 m/s. At 5.5 m/s, this temperature dropped to around 27 °C. The second objective of this study is to present the effect of different drying methods (i.e. forced convective solar drying and open sun drying) of Lawsonia inermis on the content of secondary metabolites (phenolic and flavonoid compounds) and compare the results with fresh henna samples. The yield of phenolic compounds was determined, and the dry crude extracts were found to be richer than the fresh sample in all of the drying modes used. The best yields are obtained with convective solar dryer and open sun drying samples (28.6 and 13.93%), respectively. The total phenolic and flavonoid contents of convective solar dryer product were 25 and 10% higher than open sun dried samples. Antioxidant tests (DPPH, ABTS, and ferric reducing power) revealed the scavenging and reducing abilities of the extract dried with the solar dryer. The values of antioxidant capacities measured by the three different methods were all consistent, appropriate, and highly correlative for assessing total antioxidant capacities. The solar dryer allows the preservation or even the increase of the antioxidant activity of the tested extracts.

Sustainability‐driven optimization of microwave‐assisted extraction for enhanced corilagin and total phenolic compound yield from Dimocarpus longan

AbstractThe longan fruit, widely grown and consumed in Southeast Asia, contains an abundance of essential natural chemicals present in its flesh and seeds. The microwave‐assisted approach is used to extract these components, which include total phenolic compound and corilagin. The optimization of the extraction process included factors such as the sample ratio (0.5–1.5 g/30 mL), time (10–20 min), and microwave power (600–700 W). These variables were examined using the response surface approach. The statistical analysis revealed that the data was most accurately represented by a quadratic polynomial equation. The decision coefficients for total phenolic compounds and corilagin were found to be 0.9956 and 0.9485, respectively, indicating a high level of accuracy. The result was that the optimal conditions to obtain the highest total phenolic compound and corilagin from longan extract are 22.214 mgGAE/gDW and 55.137 mg/gDW, respectively. The sample was extracted under a ratio of 0.97 g/30 mL set at microwave power at 695.74 W, with an extraction time of 15 min. This study suggests that microwave‐assisted, water‐based extraction can produce healthful, eco‐friendly concentrated longan extracts, yielding high levels of corilagin and phenolic compounds.

Extraction of phenolic compounds from edible flowers (Phlogacanthus thyrsiflorus) using ultrasound‐microwave‐assisted extraction and its screening by HPLC

AbstractPhlogacanthus thyrsiflorus flowers have been consumed as a traditional delicacy in the north‐eastern region of India. The present investigation utilized the microwave‐assisted extraction (MAE) technique in conjunction with an ultrasound pretreatment (at 250 W for 15 min) to extract phenolic compounds from Phlogacanthus thyrsiflorus flowers. Here, independent factors for optimization of MAE were microwave power (300, 500, and 700 W) and extraction time (2, 4, and 6 min), and responses were total phenolic content (TPC), total flavonoid content (TFC) and DPPH (2,2‐dipheny‐1‐picrylhydrazyl) activity. For the experimental design, a Response surface methodology and a central composite design were followed. The optimum MAE condition was found at microwave power 700 W for 5 min resulting 30.204 mg GAE/g TPC, 81.26% DPPH and 22.50 mg QAE/g of TFC. The extraction of phenolic compounds was significantly impacted by both the microwave power and the extraction time. The high‐performance liquid chromatography (HPLC) analysis detected various phenolic compounds in both conventional and MAE extracts. However, compared to conventional extract, the majority of the identified phenolic compounds were found to be higher in quantities in MAE extract. These results highlighted that MAE‐optimized flower extract could be beneficial as a functional ingredient for food product development.Practical applicationsPhlogacanthus thyrsiflorus is a highly nutritious flower with medicinal properties. Though traditionally edible flowers have been consumed in the northeastern part of India but people are still neophobic and there is scanty awareness available regarding the benefits of consuming edible flowers. This scientific justification regarding the advantages of edible flowers makes them appealing for future novel use in food technology and also for further scientific study. High perishability of flowers makes them limited for market viability and extraction of its phenolic compounds is one of the novel solutions to utilize the flowers before spoilage. Also, using ultrasound as a pretreatment could enhance the efficiency of microwave‐assisted extraction techniques for a higher yield of phenolic compounds. Microwave‐assisted extraction technique as its novel and was proven an easy successful extraction technique on this flower. Also, the study of phenolic compounds through HPLC provides important information regarding the presence of various phenolic compounds in the Phlogacanthus thyrsiflorus flower. This research can be supportive of both food technology and the medicinal industry.

Oxygen bond cleavage and its migration mechanisms during pyrolysis of naomaohu sub-bituminous coal

Investigating the oxygen bond cleavage and its migration mechanisms during the pyrolysis process of sub-bituminous coals is essential for their classification utilization. The present study employed a fixed-bed pyrolysis technique (temperature range: 350–600 °C) to explore the cleavage of oxygen-containing bonds and subsequent behavior of oxygen migration and transformation during the pyrolysis process of Naomaohu sub-bituminous coal (NSBC). X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results reveal that the organic oxygen in NSBC predominantly exists as the form of C–O bonds, accounting for 22.81 wt% of the total composition, mainly encompassing hydroxyl, carbonyl, ester, and ether groups. The organic oxygen in the light tar is mainly in the form of phenols, reaching 1.71 wt%, of which methyl substituted phenols is predominant at a final pyrolysis temperature of 600 °C. This can be attributed to the presence of more aryl ether bonds and hydroxyl groups in NSBC, which are prone to cleavage at higher temperatures, resulting in the formation of phenoxyl radicals. Additionally, the higher temperature facilitates the weakening of hydrogen bonds between phenolic hydroxyl groups, thereby enhancing the yield of phenolic compounds. The ester compounds present a decreasing trend with increasing temperature, primarily associated with the cleavage temperature of ester linkers being 350 °C, suggesting that an increase in temperature favors the cleavage of ester bonds. In addition, the cleavage of C–O bonds begins to accelerate significantly during the pyrolysis temperature range of 450–500 °C, subsequently accounting for the pronounced proliferation of phenols within this specific thermal interval. The oxygen content in semi-coke decreased with the increase of temperature, from 85.27 wt% at 350 °C to 37.17 wt% at 600 °C, while the oxygen content in the pyrolysis gas increases from 11.63 wt% at 350 °C to 47.53 wt% at 600 °C, indicating that a significant migration of organic oxygen to the pyrolysis gas during the pyrolysis of NSBC. This study can deepen the understanding of the transformation mechanism of oxygen-containing structure in NSBC pyrolysis process, and provide a theoretical basis for high-grade utilization of low-rank coals.

Valorization of Wood Residues from Vegetation Suppression during Wind Energy Plant Implementation and Its Potential for Renewable Phenolic Compounds through Flash Pyrolysis: A Case Study in Northeast Brazil’s Semi-Arid Region

In the past few years, wind power has become a viable alternative in Brazil to diversify the energy mix and mitigate pollutant emissions from fossil fuels. Significant wind energy generation potential is inherent in the Brazilian Northeast state of Rio Grande do Norte, due to prevailing strong winds along the coastline and elevated regions. However, clean and renewable wind energy may lead to potential biodiversity impacts, including the removal of native vegetation during plant construction and operation. This case study explores the flash pyrolysis-based valorization of three commonly suppressed species, namely Cenostigma pyramidale (CP), Commiphora leptophloeos (CL), and Aspidosperma pyrifolium (AP), in a wind farm situated within the Mato Grande region of Rio Grande do Norte State. The study centers on determining their bioenergy-related properties and assessing their potential for producing phenolic-rich bio-oil. The investigation of three wood residues as potential sources of high-value chemicals, specifically phenolic compounds, was conducted using a micro-furnace type temperature programmable pyrolyzer combined with gas chromatography/mass spectrometry (Py–GC/MS setup). The range of higher heating values observed for three wood residues was 17.5–18.4 MJ kg−1, with the highest value attributed to AP wood residue. The bulk density ranged from 126.5 to 268.7 kg m−3, while ash content, volatile matter content, fixed carbon content, and lignin content were within the respective ranges of 0.8–2.9 wt.%, 78.5–89.6 wt.%, 2.6–9.5 wt.%, and 19.1–30.6 wt.%. Although the energy-related properties signifying the potential value of three wood residues as energy resources are evident, their applicability in the bioenergy sector can be expanded via pelleting or briquetting. Yields of phenolic compounds exceeding 40% from the volatile pyrolysis products of CL and AP wood residues at 500 °C make them favorable for phenolic-rich bio-oil production. The findings of this study endorse the utilization of wood residues resulting from vegetation suppression during the installation of wind energy plants as potential feedstocks for producing bioenergy and sustainable phenolic compounds. This presents a solution for addressing a regional environmental concern following the principles of green chemistry.

Optimization of Aqueous Extraction of Polyphenols from Cuminum cyminum Seeds Using Response Surface Methodology and Assessment of Biological Activity.

(1) Background: Cumin seeds, extracted from the plant Cuminum cyminum, are abundant in phenolic compounds and have been extensively researched for their chemical makeup and biological effects. The objective of this research is to enhance the water extraction of polyphenols through the water bath (WB) technique and to evaluate the antiradical, antibacterial, and anticancer effects of the extract. (2) Methods: Response Surface Methodology was used to find the best parameters to extract polyphenols. Three experimental parameters, time, temperature, and solid-liquid ratio, were tested. The disc diffusion method has been used to determine the antimicrobial activities against Salmonella Typhimurium, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Candida albicans. The antiradical activity was performed using the DPPH method, while total phenolic content was performed using Folin-Ciocalteu. High-Performance Liquid Chromatography (HPLC) was conducted to analyze the phytochemical profile of WB extracts. The anticancer activity of the lyophilized extract was assessed against three cancer cell lines (colon (HT29), lung (A549), and breast (MCF7) cancer cell lines).; (3) Results: The optimal conditions for water extraction were 130 min at 72 °C. The total phenolic compounds yield (14.7 mg GAE/g DM) and antioxidant activity (0.52 mg trolox eq./mL) were obtained using a 1:40 solid-liquid ratio. The primary polyphenols identified were the flavonoids rutin (0.1 ppm) and ellagic acid (3.78 ppm). The extract had no antibacterial or antifungal activities against the microorganisms tested. The extract showed anticancer activity of about 98% against MCF7 (breast cancer cell line), about 81% against HT29 (colon cancer cell line), and 85% against A549 (lung cancer cell line) at high doses. (4) Conclusions: Extraction time and a high solid-liquid ratio had a positive impact on polyphenol recovery and in maintaining their quantity and quality. Furthermore, the optimal aqueous extract exhibited strong antiradical activity reflected by the inhibition of free radicals in addition to a significant specificity against the tested cancer cell lines.

Ultrasonic-assisted extraction to enhance the recovery of bioactive phenolic compounds from Commiphora gileadensis leaves

The “ultrasonic-assisted extraction (UAE)” method was utilized in this work to assess how different process parameters affected the yield and recovery of phenolic compounds from the leaf of Commiphora gileadensis, which is one of the medicinal plants with a variety of biological functions. Its leaf is used for a various of therapeutic applications, such as the treatment of bacterial infections, inflammation, and wound healing. The “One-Factor-At-a-Time (OFAT)” approach was employed to examine the impacts of various UAE process parameters on the process of extraction, which include time of extraction, sample/solvent ratio, ultrasonic frequency, and solvent (ethanol) concentration. The extracts were then investigated for the presence of several phytochemicals using analytical techniques such as “Gas Chromatography-Mass Spectroscopy (GC–MS)” and “Fourier Transform Infrared Spectroscopy (FTIR)” studies. The findings showed that the maximum extraction yield, the total phenolic content (TPC), and the total flavonoids content (TFC) of the ethanolic extract of the leaves of C. gileadensis using the UAE method were at 31.80 ± 0.41 %, 96.55 ± 2.81 mg GAE/g d.w. and 31.66 ± 2.01 mg QE/g d.w. accordingly under a procedure duration of 15 min, ultrasonic frequency of 20 kHz, solvent/sample ratio of 1:20 g/mL, and solvent concentration of 40 % v/v. The leaves extract of C. gileadensis included 25 phenolic compounds that were previously unreported, and GC–MS analysis confirmed their presence. Hence, it follows that the UAE technique can successfully extract the phytochemicals from C. gileadensis for a variety of therapeutic uses.