Phenol Yield Research Articles

Dealkylation of alkylphenols in phenol oil on acid zeolites

The majority of the phenolic compounds in coal tar are alkyl-substituted phenols. To overcome the difficulty of separation, zeolites catalyzed dealkylation of alkylphenols was studied in a slurry-bed reactor. ZSM-5 displayed higher catalytic performance than other zeolites within a group of acidic zeolites with various topologies (including SAPO-34, ZSM-23, MCM-22, USY, and Mordenite). The yield of phenol gradually increased together with the zeolite acidity, but the types and yields of byproducts also increased in step with it. The pore size of the zeolites was a significant influence at similar acidity. The micropore of ZSM-5 inhibited some bimolecular processes, decreasing disproportionation/transalkylation as a result of transition state shape selection. In this study, the reaction paths of alkylphenols were investigated, based on the composition of products catalyzed by different zeolites, the distribution of products under different conditions, and the reaction process of various alkylphenols. Reaction process of alkylphenols included dealkylation, isomerization, disproportionation, transalkylation, and C-C cracking. Dealkylation took the place of isomerization as the primary reaction when the reaction temperature exceeded 350 °C. Disproportionation, transalkylation, and C-C cracking were exacerbated by excessive temperature. In addition, excessive reaction time and pressure can exacerbate side reactions, alkylphenols yields and coke deposition.

Holistic investigation of structural evolution in corn stover lignin under pretreatment with varying γ-valerolactone concentrations

Until now, research on green and sustainable γ-valerolactone (GVL) pretreatment has predominantly centered on component separation efficiency, with limited attention given to the lignin structure. Nonetheless, the lignin's structure is considerably affected by the fractionation, consequently influencing its potential valorization. Herein, we conducted a holistic investigation of the structural evolution of two fractions of lignin in corn stover, obtained under pretreatment with varying GVL concentrations: GVL lignin (GVLL) originated from pretreatment liquor and cellulolytic enzyme lignin (CEL) separated from pretreated residue. Our findings indicated a general positive correlation between the molecular weight and polydispersity index of both GVLL and CEL with the increasing GVL concentration. This phenomenon is attributed to the enhanced lignin dissolution and relocation as the GVL concentration increases. Moreover, higher GVL concentrations also increased the acidity of reaction system, leading to degradation of β-O-4 linkages from 45.2 to 34.9 and 57.6 to 37.9 per 100 aromatic units in GVLL and CEL, respectively. Compared to CEL, GVLL exhibited a more remarkable phenolics yield (33.7% vs. 22.2%) during hydrodeoxygenation due to its superior purity and lower degree of polymerization. Recycling studies demonstrated the stability of GVL at lower concentrations. These findings provide valuable insights for optimizing GVL pretreatment systems.

Variability Study and DUS Characterization in Kodo Millet (Paspalum scrobiculatum L.)

Variability Study and DUS Characterization in Kodo Millet (Paspalum scrobiculatum L.)

Effects of mild acid pre-treatment on the co-pyrolysis behaviour of biosolids and wheat straw

Co-pyrolysis of biosolids (BS) and wheat straw (WS), as well as their treated variants, was performed in a fluidised bed reactor at 500 ℃. Under mild acid pre-treatment conditions (3% H2SO4 and 25 ℃), demineralisation was the dominating effect of pre-treatment on BS, while it was hemicellulose hydrolysis for WS. Consequently, the co-pyrolysis of raw biosolids (RBS) or treated biosolids (TBS) with raw wheat straw (RWS) or treated wheat straw (TWS) had varying effects on product distribution and product compositions. The co-pyrolysis of RBS+RWS gave the lowest bio-oil yield (36.3 wt%) and highest gas yield (23.1 wt%). In contrast, the highest bio-oil yield (45.8 wt%) and lowest gas yield (14.4 wt%) occurred during the co-pyrolysis of TBS+TWS. The degree of synergy in product distribution was strongest in TBS+RWS followed by RBS+RWS and was weakest in TBS+TWS, demonstrating the catalytic effect of inherent minerals on organic matter devolatilisation and char cracking reactions during co-pyrolysis. Biosolids pre-treatment alone performed competitively with BS co-pyrolysis alone with respect to enhancement in biochar properties producing biochar having 15–18 MJ/kg calorific value, 43–51 wt% carbon content, 0.7–1.0 fuel ratio, ⁓30% organic matter retention, and 27–41 wt% ash content. However, combining BS co-pyrolysis and pre-treatment gave the lowest reduction in biochar total heavy metal concentration. Furthermore, bio-oil compositions were influenced by pre-treatment and/or co-pyrolysis, increasing the yield (area%) of phenols to 25.4%, furans to 24.8%, anhydrosugars to 7.8%, and aromatic hydrocarbons to 20.6%. Lastly, pre-treatment alone weakened gas production while co-pyrolysis combined with pre-treatment impacted the pyrolysis gas profile, switching between light hydrocarbons and carbon oxides (CO and CO2). Overall, co-pyrolysis and pre-treatment can each be a standalone strategy for enhancing BS pyrolysis; however, their combination produced greater synergy for generating high value products.

Enhancing bio-based chemical production and reducing pollutants emission through the synergistic effect of ZSM-5/CaO during hydrogen-deficient biomass pyrolysis

The study proposed the use of ZSM-5/CaO as a catalyst to simultaneously improve the quality of pyrolytic products and reduce pollutants emission during the pyrolysis of hydrogen-deficient biomass, specifically cabbage waste (CW). Variables such as pyrolysis temperature and catalysts, including 5% ZSM-5, 5% CaO and 10% ZSM-5/CaO, significantly affected biomass conversion, yield, and products composition. Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) analysis shows that the catalysts (5% ZSM-5, 5% CaO and 10% ZSM-5/CaO) reduced pollutants emission and increased value-added chemicals production by 24.96%, 28.5%, 17.39% and 75.04%, 71.5%, 82.1%, respectively compared to non-catalytic process as 34.18% and 65.82%. Moreover, these catalysts enhanced the relative yield of olefins, aromatics, and phenols to 23.5, 21.6, 27.6% for 5wt.%ZSM-5; 20.8, 18.7, 23.3% for 5wt.%CaO; 30.7, 38.6, 41.3% for 10wt.%ZSM-5/CaO, compared to the non-catalytic process' yield of 15.7, 10.7, 19.3%. Py/GC–MS analysis confirms that these catalysts also decreased PAH and oxygenates production to 13.5, 15.3% for 5wt.%ZSM-5; 11.8, 9.1% for 5wt.%CaO; 5.2, 4.7% for 10wt.%ZSM-5/CaO, in contrast to the non-catalytic process' 26.2, 28.7%. This confirms the synergistic effect of ZSM-5/CaO for upgrading bio-based chemicals and reducing pollutants emission.

Process optimization, multi-gene genetic programming modeling and reliability assessment of bioactive extracts recovery from Phyllantus emblica

This study investigates the feasibility of extracting bioactive antioxidants from Phyllantus emblica leaves using a combination of ethanol-water mixture (0-100%) and heat-assisted extraction technology (HAE-T). Operating temperature (30-50°C), solid-to-liquid ratio (1:20-1:60 g/mL), and extraction time (45-180 min) were varied to determine their effects on extract total phenolic content (TPC), yield (EY), and antioxidant activity (AA). The Box-Behnken experimental design (BBD) within response surface methodology (RSM) was employed, with multi-objective process optimization using the desirability function algorithm to find the optimal process variables for maximizing TPC, EY, and AA simultaneously. The extraction process was modeled using BBD-RSM and multi-gene genetic programming (MGGP) algorithm, with model reliability assessed via Monte Carlo simulation. HPLC characterization identified betulinic acid, gallic acid, chlorogenic acid, caffeic acid, ellagic acid, and ferulic acid as bioactive constituents in the extract. The study found that a 50% ethanol solution yielded the best extraction efficiency. The optimal process parameters for maximum EY (21.6565%), TPC (67.116 mg GAE/g), and AA (3.68583 µM AAE/g) were determined as OT of 41.61°C, S:L of 1:60 g/mL, and ET of 180 min. Both BBD-RSM and MGGP-based models satisfactorily predicted the observed process responses, with BBD-RSM models showing slightly better performance. Reliability analysis indicated high certainty in the predictions, with BBD-RSM models achieving 99.985% certainty for TPC, 97.569% for EY, and 98.661% for AA values.

Green Extraction of Oleoresin from Pink Pepper Fruits: Effect of Experimental Conditions and Characterization

This work evaluated the green extraction of oleoresin from pink pepper fruits (ORPPF) using ultrasound-assisted extraction (UAE) and ethanol as a solvent. The effects of temperature, ultrasound power intensity, sample to solvent ratio and time on the global extraction yield (YGE) and phenolic compounds yield (YPC) were evaluated. The oleoresin samples were characterized and its antimicrobial activity determined, and the obtained results were compared to conventional extraction in Soxhlet. From the results it was found that the application of the highest levels of the independent variables favored the extraction process. The maximum values of YGE and YPC were 28.60 wt% and 6.37 mg GAE per g fruit, respectively, obtained at 60 °C, 100% of ultrasound power (165 W), 1:20 g mL−1 (sample:solvent) and 45 min. Under maximized conditions, the ORPPF obtained by UAE showed a content of phenolic compounds and antioxidant activity inferior to soxhlet–ethanol extraction. However, the time and solvent consumption were reduced. Oleic and linoleic acids predominated in the fatty acid composition of ORPPF, in addition to sesquiterpenes and gallic and syringic acids. The ORPPF presented weak antibacterial activity, with minimum inhibitory concentration ranging from 31.25 to 125 mg mL−1.

Carbocation Mechanism Revelation of Molecular Iodine-Mediated Dehydrogenative Aromatization of Substituted Cyclic Ketones to Phenols.

Dehydrogenative aromatization (DA) of cyclic ketones is central to the development of functionalized aromatic precursors and hydrogen transfer-related technologies. Traditional DA strategies require precious metals with oxidants and are typically performed at high temperatures (100-150 °C) to overcome the high energy barrier of aliphatic C-H bond activation. Recently, a mild alternative approach based on I2 has been proposed to realize DA on substituted unsaturated cyclic ketones under ambient conditions. However, depending on the solvent, the product selectivity may vary between phenol ether and phenol, and the reaction mechanisms remain unclear. Herein, based on time-resolved proton nuclear magnetic resonance, DFT calculation, and mass spectrometric analyses, we established a unified mechanism to account for the product distribution. Through substrate scope and desorption electrospray ionization-mass spectrometry, we discovered the formation of a carbocation, which has been overlooked in previous studies. An expanded substrate scope study coupled with spectroscopic observation provided strong evidence to elucidate the formation mechanism and the location of the carbocation. With a renewed understanding of the mechanism, we achieved a phenolic product yield of 17-96% while controlling the selectivity. Moreover, some reactants could undergo DA in H2O, achieving 95-96% yield at below water-boiling temperature.

Bioactivity, phytochemistry studies and subacute in vivo toxicity of ethanolic leaf extract of white mulberry (Morus alba linn.) in female mice

Ethnopharmacological relevanceTraditional uses of Morus alba L. leaf extracts (MLE) have been reported for treating hyperglycaemia and diabetes. Phytochemical compounds in the leaves demonstrated the ability to enhance insulin sensitivity and β-cell secretory function, suggesting their potential value in reducing blood glucose and treating diabetes. However, the phytochemical constituents and safety of the herbal medicines need to be verified in each experimental field from different growing areas. Studies on the phytochemistry and toxicity of Morus alba leaves in Southeast Asia, especially in Brunei, have never been investigated. Aim of the studyThis study aimed to investigate the bioactivity and phytochemistry of Morus alba ethanolic leaf extract from Brunei Darussalam and its subacute toxic effects in the Institute of Cancer Research (ICR) female mice. Materials and methodsThe phenolic yield and antioxidant of the extract were analysed. Meanwhile, liquid chromatography-mass spectrometry and high-performance liquid chromatography were utilised to determine the phenolic compound of the MLE. In the subacute toxicity study, twenty-five female mice were randomly divided into five groups: the control group, which received oral gavage of 5% dimethyl sulfoxide solvent (DMSO), and the MLE treatment group, which received the extract at a dose of 125, 250, 500 and 1000 mg/kg. Physiology, haematology, biochemistry, and histology were evaluated during the study. ResultsMorus alba leaf depicted total phenolic 10.93 mg gallic acid equivalents (GAE)/g dry weight (DW), flavonoid 256.67 mg quercetin equivalents (QE)/g DW, and antioxidant bioactivity content of 602.03 IC50 μg/mL and 13.21 mg Fe2+/g DW. Twenty compounds in the Morus alba ethanolic leaf extract were identified, with chlorogenic acid (305.60 mg/100 g DW) as the primary compound. As for subacute toxicity in this study, neither mortality nor haematological changes were observed. On the other hand, administration of 500 and 1000 mg/kg MLE resulted in mild hepatocellular injury, as indicated by a significant (p < 0.05) increase in liver enzyme activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The histopathological score showed mild hepatocellular necrosis in administering 250, 500, and 1000 mg/kg of MLE. The parameters of renal injury were within normal limits, with the increase in eosinophilic cytoplasm observed in the histological scoring at 1000 mg/kg of MLE. ConclusionsMorus alba leaf extract showed abundant polyphenols. In a study on subacute toxicity, MLE caused mild hepatotoxicity in mice. The toxic effect of the extract may be due to kaempferol and chlorogenic acid compounds. The 125 mg/kg MLE dose was safe with no adverse effects.

Polyphenol recovery from sorghum bran waste by microwave assisted extraction: Structural transformations as affected by grain phenolic profile

Sorghum milling waste stream (bran), contains diverse phenolic compounds with bioactive properties. The study determined the potential of microwave assisted extraction (MAE) to recover the bran phenolic compounds. Red, white, and lemon-yellow pericarp sorghum brans were subjected to MAE and phenolic yield and structural transformation vs conventional extraction (control) assessed by UPLC-MS/MS, Folin-Ciocalteu and Trolox equivalent antioxidant capacity methods. Phenols yield increased from 3.7–20.3 to 12.6–75.5 mg/g, while antioxidants capacity increased average 3.3X in MAE extracts vs controls. Hydroxycinnamic acids increased most dramatically (3.0–32X) in MAE extracts (0.08–2.64 to 2.57–8.01 mg/g), largely driven by release of cell-wall derived feruloyl- and coumaroyl-arabinose. MAE hydrolyzed flavonoid glycosides into aglycones, and depolymerized condensed flavonoid heteropolymers into flavanones, flavanols and (deoxy)anthocyanidins. Thus, MAE dramatically enhances yield of valuable phenolics from sorghum bran waste, but also alters the phenolic profile in ways that may influence their chemical and biological properties.

Innovative flow-through reaction system for the sustainable production of phenolic monomers from lignocellulose catalyzed by supported Mo2C.

Molybdenum carbide supported on activated carbon (β-Mo2C/AC) has been tested as catalyst in the reductive catalytic fractionation (RCF) of lignocellulosic biomass both in batch and in Flow-Through (FT) reaction systems. High phenolic monomer yields (34 wt.%) and selectivity to monomers with reduced side alkyl chains (up to 80 wt.%) could be achieved in batch in the presence of hydrogen. FT-RCF were made with no hydrogen feed, thus via transfer hydrogenation from ethanol. Similar selectivity could be attained in FT-RCF using high catalyst/biomass ratios (0.6) and high molybdenum loading (35 wt.%) in the catalyst, although selectivity decreased with lower catalyst/biomass ratios or molybdenum contents. Regardless of these parameters, high delignification of the lignocellulosic biomass and similar monomer yields were observed in the FT mode (13-15 wt.%) while preserving the holocellulose fractions in the delignified pulp. FT-RCF system outperforms the batch reaction mode in the absence of hydrogen, both in terms of activity and selectivity to reduced monomers that is attributed to the two-step non-equilibrium processes and the removal of diffusional limitations that occur in the FT mode. Even though some molybdenum leaching was detected, the catalytic performance could be maintained with negligible loss of activity or selectivity for 15 consecutive runs.

Effect of Nickel-Aluminum Trioxide/Titanium Dioxide Nanocomposites on Photo-oxidation of Olive Mill Wastewater

In this study, the magnetic nickel (Ni) doped aluminium trioxide (aluminium oxide or alumina, Al2 O3 ) based titanium dioxide (TiO2 ) [Ni-Al2 O3 /TiO2 ] nanocomposites (NCs) was used for the photocatalytic oxidation (photo-oxidation) of pollutant parameters {chemical oxygen demand (COD) components [CODtotal, CODdis, CODinert]}, toxic polyphenols [catechol, 3-hydroxybenzoic acid, tyrosol, 4-hydroxybenzoic acid, 4-hydroxyphenylacetic acid, 3-hydroxyphenylpropionic acid, 4-hydroxyphenylpropionic acid, 3,4-dihydroxyphenylethanol, 3,4-dihydroxyphenylacetic acid], and toxic polyaromatics [aniline, 4–nitroaniline, o–toluidine, o-anisidine, benzene, nitrobenzene, ethylbenzene, 3,6-bis(dimethylamino)durene, benzidine, dimethylaniline, 3,3–dichlorobenzidine]} from the olive mill effluent wastewaters (OMW), at different mass ratios of Al2 O3 , TiO2 and Ni (1%/5%/10%; 10%/1%/5% and 1%/10%/5%), at increasing photooxidation times (10, 30, 60, 100 and 120 min), at different Ni/Al2 O3 /TiO2 photocatalyst concentrations (50, 250, 500 and 1000 mg/l), pH values (4.0-7.0-9.0 and 10.0) and temperatures (15°C, 25°C, 50°C and 80°C), under 500 W ultraviolet visible (UV-vis) and 50 W sun lights irradiations, respectively. The acute toxicity assays were operated with Microtox (Aliivibrio fischeri also called Vibrio fischeri) and Daphnia magna acute toxicity tests. The significance of the correlations between data of all experimental samples were determined using the Analysis of Variance (ANOVA) test statistics. Under the optimized conditions, the maximum CODdis, total phenol and total aromatic amines (TAAs) photooxidation yields were 98%, 88%, 94%, respectively, at pH=9.0, at 500 mg/l Ni/Al2 O3 / TiO2 NCs, under 500 W UV-vis light, after 100 min photooxidation time, at 50°C, respectively. The photooxidation yields in OMW under sun light was lower than the photooxidation yields in the OMW under UV-vis light. 94.44% maximum Microtox acute toxicity yield was found in Ni/Al2 O3 /TiO2 NCs=500 mg/l after 150 min photooxidation time, at 60°C. 90% maximum Daphnia magna acute toxicity removal was obtained in Ni/Al2 O3 /TiO2 NCs=500 mg/l after 150 min photooxidation time, at 60o C. Microtox acute toxicity test was more sensitive than Daphnia magna acute toxicity assay

An iron-containing POM-based hybrid compound as a heterogeneous catalyst for one-step hydroxylation of benzene to phenol.

It is a major challenge to perform one-pot hydroxylation of benzene to phenol under mild conditions, which replaces the environmentally harmful cumene method. Thus, finding highly efficient heterogeneous catalysts that can be recycled is extremely significant. Herein, a (POM)-based hybrid compound {[FeII(pyim)2(C2H5O)][FeII(pyim)2(H2O)][PMoV2MoVI9VIV3O42]}·H2O (pyim = 2-(2-pyridyl)benzimidazole) (Fe2-PMo11V3) was successfully prepared by hydrothermal synthesis using typical Keggin POMs, iron ions and pyim ligands. Single-crystal diffraction shows that the Fe-pyim unit in Fe2-PMo11V3 forms a stable double-supported skeleton by Fe-O bonding to the polyacid anion. Remarkably, due to the introduction of vanadium, Fe2-PMo11V3 forms a divanadium-capped conformation. Benzene oxidation experiments indicated that Fe2-PMo11V3 can catalyze the benzene hydroxylation reaction to phenol in a mixed solution of acetonitrile and acetic acid containing H2O2 at 60 °C, affording a phenol yield of about 16.2% and a selectivity of about 94%.

EXTRACTION OF FREE AND BOUND PHENOLICS FROM GLABROUS CANARY SEED (Phalaris canariensis L.) HULLS

The aim was to extract free phenolics using a green solvent (ethanol), and bound phenolics from glabrous canary seed hulls. The efficiency of ethanol 75% was compared with that of other solvents used in the literature (acetone 70%; methanol 80%) in terms of phenolic yield and antioxidant activity. Bound phenolics were extracted with ethyl acetate, prior to hydrolysis with NaOH 2 M. The phenolic extracts obtained were characterized according to extraction yield, total phenols, flavonoides, antioxidant activity, radical DPPH; and phenolic profile, HPLC. Methanol 80% had lower extraction yield, and acetone 70% had lower antioxidant activity; whereas ethanol 75% was the most efficient solvent to obtain free phenolics. Extraction yield of bound phenolics (6411.13 mg/100g hulls d.b.) doubled the value of free phenolics. Thus, antioxidant activity was four times higher (78.67% inhibition of radical DPPH). On the other hand, phenolic acids predominated over flavonoids compounds in a rate 26/1. Ferulic acid was the dominant (42.48 mg/100g hulls), followed by p-coumaric (39.07 mg/100g hulls). Although the use of glabrous canary seed is new, interest in its processing at industrial level makes canary seed hulls a potential waste material that could be leveraged as a source of bioactive compounds with several applications.

Green extraction of phenolics and terpenoids from passion fruit peels using natural deep eutectic solvents

AbstractThis work aimed to optimize the ultrasonic‐assisted extraction (UAE) and microwave‐assisted extraction (MAE) of phenolics and terpenoids from passion fruit peels using natural deep eutectic solvents (NADES). NADES formulated with choline chloride and polyols with organic acids were used to investigate the solubility of phenolics and flavonoids in the solvent. Among these formulations, those derived from lactic acid‐glycerine (LGLY) and citric acid‐glucose (CGLU) exhibited the highest efficiency in extracting phenolics and terpenoids, respectively, when combined with UAE. Then one‐factor experiments were conducted to examine the influence of the UAE conditions (liquid‐to‐solid ratios [LSR], water content in NADES, ultrasonic power, time, and temperature) and MAE conditions (LSR, water content in NADES, ultrasonic power, and time) on the extraction yield of phenolics and terpenoids. The Box‐Behnken design (BBD) model was employed to optimize the extraction conditions with conditional ranges determined based on the results of the one‐factor experiments. The optimal conditions for the CGLU‐based MAE of terpenoids were 387 W of microwave power, 30% water content, 2.4 min, and 20 mL/g of LSR. The optimized conditions for LGLY‐based MAE of phenolics were 299 W, 18.7%, 1.3 min, and 10 mL/g. Total terpenoid content acquired from NADES‐based UAE was higher than NADES‐based MAE, while total phenolic content obtained at the optimal conditions of NADES‐based UAE and MAE was statistically insignificant. The efficiency of the two extraction ways was compared to selecting the favorable extraction method for acquiring phenolics and flavonoids from passion fruit peels. The research proposed that NADES‐based UAE was a green and effective method for attaining phenolics and terpenoids from passion fruit peel.Practical applicationPassion fruit peels are a by‐product of beverage production, which causes environmental pollution and increases treatment costs in the factory. These peels contain various bioactive compounds which benefit human health. The traditional extraction method shows low efficiency and high energy consumption. Thus, the appropriate extraction method and green solvents are needed to improve the extraction efficiency of bioactive compounds and can be directly applied to food products. Ultrasonic‐assisted extraction (UAE) and microwave‐assisted extraction (MAE) combined with natural deep eutectic solvents can enhance the extraction efficiency of bioactive compounds. However, the detailed conditions of UAE and MAE are necessary to compare the performance of the two methods. In addition to showing the significant superiority of UAE with MAE, the research showed the optimized conditions of the UAE process, which can be applied on the industrial scale to extract bioactive compounds and directly add them to food products.

Novel insights into mass transfer-controlled radical-mediated co-pyrolysis of lignin with typical plastics

Co-pyrolysis of lignin with representative waste plastics, including polypropylene (PP), acrylonitrile butadiene styrene (ABS), polystyrene (PS), and polyethylene terephthalate (PET), was investigated, focusing on radical-mediated reactions, with radical detection via electron paramagnetic resonance (EPR). During the co-pyrolysis of lignin with PP, favorable synergistic effects were observed, resulting in a significant 17 % enhancement in phenolic compound yields within the fixed-bed reactor, whereas the presence of other plastics led to exacerbated cross-linking carbonization in contrast. Furthermore, TOF-MS and FT-ICR-MS analyses corroborated that the bio-oil derived from lignin/PP exhibited a higher phenolic content and lower carbon number distribution. Additionally, the radical concentrations in bio-oil of lignin/PP were determined to be the lowest (1.07 × 1013 spins/µL), providing compelling evidence of the strong interaction between lignin and PP. Interestingly, EPR spectroscopy detected the resultant lowest spin concentrations (1.28 × 1019 spins/g) in lignin/PP char, in contrast to lignin in isolation or within other plastics, which strongly indicating that hydrogen-rich radicals originating from PP were responsible for inducing more effective quenching reactions with lignin intermediates. Moreover, the lignin/PP char demonstrated the highest carbon content (80.30 %) and the lowest ID/IG ratio (1.98), further affirming a highly effective interaction between lignin and PP. The perspective drawn from this study is that the abundant hydrogen source of PP can provide hydrogen-rich radicals to quench lignin intermediates and improve phenolic yield. This intriguing work provides a fresh perspective to evaluate the effect of plastic origin on lignin co-pyrolysis based on radical theory.

Impact of atmospheric cold plasma pretreatment on morphology, structure, and chemical properties of clove (Syzygium aromaticum)

This study evaluates the impact of dielectric barrier discharge (DBD) plasma pretreatment (5,10, and 15 min) on morphological characteristics, chemical structure, color, total phenolic content, and antioxidant activity of clove. Scanning electron microscopy analysis displayed that cold plasma caused substantial rupturing in the microstructure of the samples, which may facilitate the release of phenolic compounds. FT-IR results showed that cold plasma did not produce new functional groups. 10 min-DBD plasma groups exhibited significantly higher phenolic extraction yields and organic radical scavenging capacity (DPPH) than the untreated sample. The color parameters change after DBD plasma pretreatment is probably related to the oxidation reactions initiated by the reactive species. The results suggest that free radicals and reactive species generated during the plasma process could disrupt the cell wall structure of clove and promote extraction yield. Cold plasma possesses great potential as an effective processing technology for the extraction of bioactive compounds.

Structural changes and product distribution of typical Xinjiang coals and chars during pyrolysis

AbstractThis study used micro‐Raman spectroscopy, gas chromatography–mass spectrometry (GC–MS), and gas chromatography–flame ionization detector/thermal conductivity detector (GC–FID/TCD) to analyze the structure and pyrolysis reactions of nine typical coals and chars from Xinjiang. The study fitted 10 Gaussian bands of typical Xinjiang coal and investigated the changes in coal structure during coalification and pyrolysis. The results indicated that the reduction degree of CO structures in coal during coalification had a rough linear relationship with the Vdaf (dry ash‐free volatile matter) content. During coalification, the condensation of aromatic rings is accompanied by a continuous decrease of CO structures, while the contents of cross‐linking and substitution structures decrease persistently relative to the large aromatic ring structures. The influence of coal type on char yield for typical Xinjiang coal is within 15 wt.%; the influence on tar yield is within 8.5%, with a greater impact on the yield of alkanes and phenols in tar; the influence on CO yield in pyrolysis gas is within 6.3%. The relative content of large aromatic ring structures in coal is relatively stable during pyrolysis, while the relative content of small aromatic ring structures declines as coal transforms into char. The study inferred that small aromatic rings might decompose and transform into tar after pyrolysis reaction, which also resulted in a high selectivity of phenolic products in tar from most coal pyrolysis above 40%. This study revealed the structural changes and pyrolysis product distribution of nine typical coals and chars from Xinjiang, providing useful information for their utilization.

Qualitative And Quantitative Analysis of Cinnamomum Tamala Leaf Extract

Objective: The purpose of the study is to assess the properties and bioactive components of Cinnamomum tamala leaves. Methods: The leaves of Cinnamomum tamala were extracted. Different experimental methods have been used to study the phytochemicals (qualitative and quantitative). The phytochemical screening was evaluated in different extractions such as aqueous, hexane, ethanol, petroleum ether and hydroethanolic to compare the solubility of various bioactive components. Further, high performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC-MS) were also performed to study the presence of flavonoids and secondary metabolites respectively. Results: The Qualitative analysis showed the presence of phytochemical compounds in higher concentration in hydroethanolic extract of the leaves of Cinnamomum tamala. In comparison with other extracts, hydroethanolic extract had larger yields of flavonoids (186.42 ± 13.04 mg/g QE), phenols (226.34 ± 15.84 mg/g GAE), saponins (112.10 ± 7.84 mg/g) and steroids (161.30 ± 11.29 mg/g CL). HPLC analysis revealed the presence of flavonoids in hydroethanolic extracts of the leaves of Cinnamomum tamala. GC-MS analysis proved the presence of various bioactive compounds in the hydroethanolic extract of the leaves of Cinnamomum tamala. Conclusion: The results of this study demonstrated the significance of the leaves of Cinnamomum tamala. We concluded that Cinnamomum tamala leaves have various biological activities which can treat diseases..

Optimization of ultrasound-assisted extraction of sorghum phenolics and effect on the stability of 3-deoxyanthocyanins.

Sorghum 3-deoxyanthocyanins (3-DXAs) have greater stability when compared to other anthocyanins. However, the efficiency in extracting these phenolic compounds from cereals, using conventional methods, is low, because most of them are bound to the cell wall. Thus, the aim of this study was to optimize the ultrasound-assisted extraction (UAE) of anthocyanins and total phenolics from sorghum flour, and evaluate the stability of the 3-DXAs. Two frequencies (25 and 45kHz) were applied in a Central Composite Rotational design to investigate the effect of the variables time (5-75min) and temperature (30-65°C) using the UAE, with amplitude of the ultrasonic power set at 400W. In addition, the stability of the 3-DXAs present in the extracts was evaluated. It was possible to successfully optimize the extraction of total anthocyanins (both frequencies) and phenolics (at 45kHz), and then to obtain equations, to predict their concentrations, with high R2 . The efficiency of UAE was observed, increasing the yield of total anthocyanins, phenolics, and antioxidant capacity at the frequencies of 25 and 45kHz by 30% and 27%, 10% and 5%, and 30% and 15%, respectively. The apigeninidin was the major 3-DXA found in the extracts, and the luteolinidin was the most stable over storage time. Overall, there was no difference in the 3-DXAs stability obtained by the UAE compared to the conventional method. Thus, ultrasound is an alternative to obtaining sorghum extracts rich in 3-DXAs and other phenolic compounds. PRACTICAL APPLICATION: The health benefits of sorghum 3-deoxyanthocyanins coupled with the growing interest of the food industry in producing healthier food products have motivated this study, because it is important to find ways to optimize 3-deoxyanthocyanins extraction. We have demonstrated that ultrasound-assisted extraction was efficient in extracting high amounts of 3-deoxyanthocyanins and other phenolics from sorghum flour. Moreover, some 3-deoxyanthocyanins have shown to be more stable than others after extraction. Thus, the ultrasound has great potential to produce sorghum phenolic extracts rich in 3-deoxyanthocyanins, which can be used as natural colorants and functional ingredients in foods.