Total Phenolic Yield Research Articles

Optimization of the production of grade A liquid smoke from Patchouli solid residue using a distillation-adsorption process

<p>Patchouli cultivation in Lhokseumawe, Aceh Province, produces a significant amount of biomass, with approximately 96%–98.5% of the raw material ending up as solid residue after the oil distillation process. This waste is often discarded or burned, leading to environmental problems. However, this residue is rich in compounds derived from the breakdown of lignocellulose and can be pyrolyzed to produce liquid smoke. Liquid smoke contains valuable phenols, acids, and carbonyls but may also generate harmful byproducts such as polycyclic aromatic hydrocarbons (PAHs). This study aimed to optimize the production of grade A liquid smoke through purification using a distillation and adsorption process. Pyrolysis of patchouli residue was conducted at 400 ℃ to produce liquid smoke. Furthermore, the raw liquid smoke was purified by distillation and adsorption. The distillation process was conducted at a temperature range (X<sub>1</sub>) of 150–200 ℃ for 30–90 min (X<sub>2</sub>). The weight of activated biochar used during the adsorption process varied between 5 and 15 g (X<sub>3</sub>). The experimental design was carried out using Design Expert version 13. Research findings indicate that the optimal condition for liquid smoke was achieved with the equation Y = 1.26 + 0.53X<sub>1</sub> + 0.0319X<sub>2</sub> + 0.8023X<sub>3</sub> – (4.91X<sub>1</sub>)<sup>2</sup> – (0.0015X<sub>2</sub>)<sup>2</sup> – (0.2147X<sub>3</sub>)<sup>2</sup> – 0. 0644 X<sub>1</sub>X<sub>2</sub> – 0.0327X<sub>1</sub>X<sub>3</sub> + 2.15X<sub>2</sub>X<sub>3</sub>. The best results were obtained at a distillation temperature of 175 ℃, a duration of 90 minutes, and using 13.4 g of activated carbon, which resulted in a high total phenol yield of 8.06%. The produced liquid smoke was classified as grade A, with a yield of 74.33%, a density of 0.9928 g/m³, a viscosity of 1.6203 cP, and a pH of 3.32. This research highlights an eco-friendly solution for valorizing patchouli waste, transforming it into a product with a wide range of applications as a food preservative, flavor enhancer, and medicinal agent.</p>

Extraction of Bioactive Compounds from Coffee Husk with Acetone Using Microwave Assisted Extraction Method and Analysis of Phenolic Compounds

Nowadays, the use of coffee husk is limited to animal feed and fertilizer. Therefore, a study was conducted using Robusta coffee husk waste as a raw material for research. The purpose of this study was to determine the effect of several variables and to determine the optimum conditions in the process of extracting bioactive compounds from coffee husk waste. Coffee husk waste will be extracted using the Microwave-Assisted Extraction (MAE) method with acetone solvent, with several variables, namely the ratio of material to solvent, microwave power, and extraction time. Analysis of the identification of phenolic compound content was then also carried out using UV-Vis spectrophotometry. The variables of material ratio, extraction time, and microwave power were proven to be interrelated so that they could produce total phenol at optimum conditions. The optimum conditions for extracting bioactive compounds from coffee husk waste were obtained at a material ratio of 0.04 g/ml; time of 9 minutes; and power of 300 watts, with a total phenol yield of 8.65 GAE/g sample.

In vitro strategy to enhance the production of bioactive polyphenols and caffeoylputrescine in the hairy roots of Physalis peruviana L.

The Rhizobium rhizogene-transformed root culture from Physalis peruviana L. (P. peruviana) may be a promising and novel source of valuable phenolics, including caffeoylputrescine (CP), which is known for antioxidant, antidiabetic, insect-resistant, disease-resistant, and neuroprotective properties. In this study, to improve the production efficiency of phytochemical components in P. peruviana hairy root cultures, we optimized various culture conditions, including the inoculum size, liquid volume, culture media type, carbon source, sucrose concentration, initial pH, and application of elicitors, to enhance the total phenolic content and CP yield in these hairy root cultures. The findings indicate that the use of sucrose as carbon source resulted in the highest biomass (13.28 g DW/L), total phenolic content (6.26 mg/g), and CP yield (2.40 mg/L). The White medium excelled in enhancing the total phenolic content (9.35 mg/g), whereas the B5 medium was most effective for the biomass (13.38 g DW/L) and CP yield (6.30 mg/L). A sucrose concentration of 5% was best for the biomass (18.40 g DW/L), whereas a sucrose concentration of 4% was ideal for the CP yield. Optimal culture conditions were as follows: an inoculum size of 0.5 g/100 mL, a liquid volume of 100 mL in a 250-mL flask, B5 medium, 4% sucrose, and a pH of 5.5. Among the tested elicitors, methyl jasmonate (MeJA) at 100 µM significantly increased the biomass (21.3 g/L), total phenolic content (23.34 mg/g), and CP yield (141.10 mg/L), which represent 0.96-, 2.12-, and 13.04-fold increases, respectively, over the control after 8 days. The optimized HR culture of P. peruviana provides a promising system to enhance the production of CP for pharmaceutical applications.

Effect of supercritical CO2 modified with ethanol on the extraction yield and antimicrobial activity of bioactive compounds from aerial parts of Berberis microphylla G. Fort

Calafate (Berberis microphylla G. Forts) is an endemic plant from the Patagonian area of Chile and Argentina, with a high content of bioactive compounds. In this study the effect of ethanol-modified supercritical extraction at temperatures of 40 and 60 °C, pressures of 30 and 35 MPa, and azeotropic ethanol contents in CO2 of 5 and 10% on the yield of total solids (gravimetric method), alkaloids (spectrophotometric analysis), berberine (HPLC-DAD analysis), phenolics (spectrophotometric analysis), and antimicrobial activity (disc diffusion method) of calafate aerial parts, was evaluated. The yield of total solids increased with extraction temperature, pressure, and the percentage of ethanol in CO2. Berberine yield reached a maximum of 0.0211 ± 0.46 g/kg substrate at 60 °C, 35 MPa, and using 10% ethanol. Extraction at 40 °C resulted in a higher phenolic content (1.69 ± 0.02 g GAE/kg substrate) than at 60 °C. Limited antibacterial activity was observed in all obtained extracts with ethanol-modified supercritical CO2 against Staphylococcus aureus, with no significant difference between treatments. Ethanol-modified CO2 demonstrated moderate efficiency for extracting bioactive compounds from calafate aerial parts compared with Soxhlet extraction with azeotropic ethanol.

Synergistic antimicrobial activities of aqueous extract derived from olive byproduct and their modes of action

BackgroundPlant-derived antimicrobials (PDAs) are considered a viable alternative to synthetic antimicrobial agents. Diverse antimicrobial mechanisms of PDAs significantly reduce the risk of developing antimicrobial resistance. Utilization of PDAs also offers economic and environmental advantages, as they can be derived from agricultural byproducts, such as olive pomace.ResultsIn this study, a green, water-based, ultrasound-assisted extraction (UAE) was deployed to obtain aqueous olive pomace extract (OPE) from dry olive pomace. Total phenolic content, extraction yield, chemical compositions, and antimicrobial activities of OPE were evaluated. In addition, the potential synergistic interaction between the phenolic components in OPE and the antimicrobial mechanisms underlying the synergistic interaction were characterized. The results show that ca. 25 mg GAE/g of extraction yields were achieved by the UAE of dry olive pomace. Based on the high-performance liquid chromatography (HPLC) analysis, diverse phenolic compounds such as gallic acid (GA), hydroxytyrosol (HT), and 4-hydroxyphenylacetic acid (4-HPA) were identified in OPE. OPE exhibited strong antimicrobial activities, and 0.2 mg GAE/mL of OPE achieved > 5 log reductions of Escherichia coli O157:H7 and Listeria innocua cells within 30 min of treatment. A 3D isobologram analysis demonstrated that OPE exhibited strong synergistic antimicrobial activities, compared to those of individual phenolic components (GA, HT, or 4-HPA), showing interaction index (γ) of 0.092 and 0.014 against E. coli O157:H7 and L. innocua, respectively (γ < 1: synergistic activity). Antimicrobial mechanism analyses revealed that phenolic components in OPE exerted strong synergistic activities through diverse modes of action, and increased levels of oxidative stress, membrane damage, and decreased levels of metabolic activities were observed in the OPE-treated bacterial cells.ConclusionsThese findings demonstrate an approach for valorizing agricultural byproducts to develop plant byproduct-based antimicrobials with strong synergistic activities. Multiple modes of action of this byproduct extract may enable the control of diverse microbes in food and agriculture systems.Graphical abstract

Application of Different Aqueous Ultrasound-assisted Extraction Process Parameters on the Quality of Pandan (Pandanus amaryllifolius Roxb) Leaves Extract

Pandan of Pandanaceae family, known for its aromatic foliage, vibrant green color, and rich in bioactive compounds, requires green extraction technology to stabilise compounds. Hence, this study aims to optimise process parameters of aqueous ultrasound-assisted extraction (UAE) on the color, yield, and antioxidant content of pandan extract using the Response Surface Method (RSM), and compare the volatile compounds present in optimised ultrasonicated pandan extract with macerated extract (control). The analysis includes DPPH and FRAP assays, total phenolic content (TPC), color, and yield. Optimally validated parameters (R2 ≥ 0.90, p-value lack-of-fit ≥ 0.05) were: 80°C extraction temperature, 90 min ultrasonic time, 2.60 % of solid in 20 mL distilled water yielded promising antioxidant activities: 277.64 mg/g AAE, 19.90 mg/g GAE, and 1.48 g/g AAE for DPPH, TPC, and FRAP assays, respectively). UAE technique has significantly (p&lt;0.05) higher yield of extract (86.24%) and DPPH scavenging activity (277.64 mg/g AAE) compared with control. The 3-methyl-2(5H)-furanone is the most abundant volatile compound found in both extracts. The cavitation in ultrasonication generates currents, increasing pandan's mass transfer rate into the solvent medium. The optimised ultrasonication condition contributes to the increased quality of the pandan extract.

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.

Valorization of Wine Lees: Assessment of Antioxidant, Antimicrobial and Enzyme Inhibitory Activity of Wine Lees Extract and Incorporation in Chitosan Films

Wine lees, as one of the main by-products of winery wastes, is considered a rich source of bioactive compounds such as polyphenols. Recovery of such bioactive compounds would amplify the valorization of winery by-products, as well as promote their use in cosmetics and health applications. Towards this aim, the objective of this work is the recovery of phenolic compounds from wine lees by ultrasound-assisted extraction. The effect of extraction time, and ethanol content on the extraction yield of total phenolics was investigated, while the phenolic profile of the extract was monitored by GC-MS. Under the optimized conditions, the total phenolic content was calculated at 302.6 mg gallic acid equivalents g− 1 dry extract; the dry extract was investigated for its biological activities, exhibiting excellent antioxidant and antimicrobial activity. Moreover, the extract was found to be a potent inhibitor of tyrosinase, elastase, collagenase, α-glucosidase, and α-amylase with IC50 values of 53.3, 83.5, 82.7, 19.0, and 31.3 µg mL− 1, respectively. Finally, the wine lees dry extract was incorporated into chitosan films, reinforcing the properties of the films, and providing them with excellent antioxidant activity. The results support that wine lees extract exhibits high antioxidant activity and can be used as a highly efficient inhibitor of enzymes with pharmaceutical and health interest. Moreover, the chitosan film enriched with wine lees extract is a promising material with high antioxidant potential and can lead to the development of novel food packaging films in the food industry.Graphical

Optimization of Ultrasonic-Assisted Extraction of Antioxidants in Apple Pomace (var. Belorusskoje malinovoje) Using Response Surface Methodology: Scope and Opportunity to Develop as a Potential Feed Supplement or Feed Ingredient

Apple pomace represents an underexploited source of bioactive compounds. This study examines the optimization of total phenolic content (TPC) and antioxidant extraction yield of apple pomace (variety: Belorusskoje malinovoje) using response surface methodology. The green extraction technique used was ultrasound-assisted extraction, and it was compared with conventional solvent extraction. The impact of extraction time and amplitude of ultrasound-assisted extraction on the yield of polyphenols and antioxidants has been evaluated. Total phenolic content was determined using an established TPC assay. The antioxidant activity of the apple pomace was determined using established assays 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+). Furthermore, the potential of apple pomace as a feed material was explored by assessing its nutritional composition, vitamins, minerals, fatty acids, and amino acid content. The extraction of antioxidants and phenolic compounds was efficiently optimized using RSM. The optimal conditions for TPC and DPPH• analyses were achieved with an extraction time of 17.5 min and an ultrasound-assisted extraction amplitude of 20%. Optimal conditions for ABTS•+ were 5 min extraction time and 20% amplitude. Conventional and ultrasound-assisted extraction methods yielded comparable results. Moreover, apple pomace exhibits potential as a feed ingredient despite its modest protein content. This study contributes to the utilization of apple pomace by providing additional information on its antioxidant content and nutritional composition, thus contributing to its sustainable utilization in various industries, especially the livestock feed sector.

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.

The Effect of Green Extraction Technologies on the Chemical Composition of Medicinal Chaga Mushroom Extracts.

The mushroom industry should implement green extraction technologies; however, there is not enough information on the differences between these techniques expressed as the chemical composition of the resulting extract. In this study, selected types of green extraction techniques (GETs) were used on Chaga (Inonotus obliquus) (Fr.) Pilát from Serbia (IS) and Mongolia (IM) to examine the differences that would enable the composition-based technology choices in the mushroom supplement industry. Subcritical water extraction (SWE), microwave-assisted (MW) extraction, and ultrasonic-assisted extraction (VAE) were used to prepare the extracts. SWE was performed at two different temperatures (120 and 200 °C), while 96% ethanol, 50% ethanol, and water were used for MW and VAE. The yield, the content of total phenols, total proteins, and carbohydrates, qualitative and quantitative analysis of phenolic compounds, carbohydrates, including α- and β- and total glucans, and fatty acids, were determined in the obtained extracts. SWE resulted in a significantly higher yield, total polysaccharide, and glucan content than any other technique. Glucose was the most dominant monosaccharide in the SWE samples, especially those extracted at 200 °C. The MW 50% EtOH extracts showed the highest yield of total phenols. Among the tested phenolic compounds, chlorogenic acid was the most dominant. SWE can be recommended as the most efficient method for extracting commercially important compounds, especially glucans and phenols.

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

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

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.

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

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.

From waste to wonder: Unleashing the antimicrobial and antioxidant potential of acerola residue using a central composite rotatable design

This study aimed to optimize the extraction conditions of the antioxidant and antimicrobial compounds from acerola residue and evaluate the optimized extract's bioactivity. A central composite rotatable design (CCRD) was used to evaluate the effect of three independent variables (time, temperature, and ethanol concentration) on the total phenolic content, antioxidant activity, and extraction yield. The optimized extract was evaluated for phenolic profile, yellow flavonoid, total anthocyanins, total and condensed tannins, and antimicrobial activity. Optimum conditions were achieved at 110 min, 20 °C, and 34% ethanol. The optimized extract showed high content of total phenolic compounds (903.64 mg GAE .100 g−1 d.m) and the phenolic profile revealed the presence of 16 substances, especially gentisic acid (60.46 ± 4.94 mg .100 g−1). The optimized extract showed high antioxidant activity (3510.64 mgTE .100 g−1), and antimicrobial action against Salmonella Typhimurium and Listeria monocytogenes strains, making it a promising alternative in the food, chemical, and pharmaceutical industries.

New coupling technology of phenols extraction in coal tar and carbon dioxide capture: Modeling, optimization and techno-economic analysis

A new coupling process for highly efficient extracting phenols from coal tar and capturing carbon dioxide in exhaust gas employing aqueous amine was developed, which improved the shortcomings of high cost and environment pollution of single industrial process by process coupling and strengthening. The cyclic experiment of this process with monoethanolamine solution as extractant reached a stable state after 4 cycles. Under the steady-state, the total extraction yield of phenols and the total recovery yield of monoethanolamine and water were 100%, 98.8% and 90.9%, respectively. In addition, the empirical and semi-empirical models based on the experimental and literature data were constructed, and the models were linked to Aspen Plus software to simulate and optimize the coupling process. The optimization results showed that the unit production cost of present green process was 274.79 CNY·t−1, which only 25.4% and 65.6% of the cost for the traditional and improved industrial processes, respectively. Especially, the consumption of mineral resources and pollutant emissions in this process were reduced compared to the industrial processes. This work provides an industrially promising method for extracting phenolic compounds from coal tar and synergistically capturing carbon dioxide in industrial exhaust gas, and lays an engineering foundation.

Exploring the potential of advanced eco-friendly extraction techniques for a rapid recovery of oleuropein-rich extracts from “Picholine Marocaine” olive tree leaves

This study aimed to explore the use of different advanced extraction methods to obtain oleuropein-rich extracts from leaves of the predominant olive variety in Morocco: “Picholine Marocaine”, and compare them with the conventional maceration method. Initially, the solubility of oleuropein in various ethanol-water ratios was predicted using COSMO-RS software. Subsequently, a kinetic study was conducted to extract phenolic compounds using maceration for 3 h, based on the total phenolic and oleuropein contents. Advanced extraction methods, including ultrasound extraction systems (based on both bath and probe systems), bead milling, microwave-based extraction, and accelerated solvent extraction, were then applied for 5 min. The obtained results from COSMO-RS prediction indicated that ethanol-water 60:40 (v:v) was the most efficient ratio. The kinetic study revealed that the highest total phenolic and oleuropein contents were achieved after 1 h of maceration. Ultrasonic extraction, using both bath and probe systems, resulted in extraction within only 5 min, of over 92% (19.61 mg of gallic acid equivalent (GAE)/g of dry weight (DW)) and 83% (17.55 mg of GAE/g DW), respectively, of the total phenolic compound yield achieved in 1 h of maceration (21.14 mg of GAE/g DW). Moreover, the extracted amount of oleuropein using ultrasonic systems (fluctuating between 15.90 and 15.10 mg/g DW for the ultrasonic bath and probe extracts, respectively) was higher than that obtained with the conventional method during 1 h (14.31 mg/g DW). Therefore, ultrasonic assisted extraction appears to be the most efficient and rapid method for obtaining oleuropein-rich extracts from Moroccan olive leaves.

Valorization of apple pomace by-products from the juice processing industry using pressurized liquid technology

Bagasse is a by-product of the juice processing industry with a high water content, high acidity, and rapid deterioration. Considering apple pomace, approximately 21 million tons are produced annually, rich in dietary fiber, vitamins, reducing sugars, and phenolic compounds. In this sense, conventional extraction (CE) and pressurized liquid extraction (PLE) were compared in terms of pectin yield, total phenolic compounds, and Ferric ion Reducing Antioxidant Power (FRAP) using a Box-Behnken factorial design considering the variables temperature, pressure, and Solvent/Feed (S/F) ratio. CE occurred with citric acid solution 6.5% (w/v) under stirring for 2 h. PLE occurred continuously with a flow rate of 5 mL min−1 with citric acid solution 6.5% (w/v) for 40 min. The highest pectin yield was 20.05% at 110 °C, 20 MPa, and S/F 10. Further optimized conditions led to a total phenolic compounds yield of 16.3 ± 0.3 mg GAE g−1 and FRAP of 137 ± 5 µmol TE g−1. Although pectin yield was higher for EC (25.27 ± 1.78%), total phenolic compounds content and FRAP were higher for PLE. High contents of glucose and fructose were found in all extracts. However, only high temperatures facilitated the hydrolysis and release of ellagic acid. Furthermore, a kinetic study demonstrated that 91.94% of total pectin was extracted with 11.30 min by PLE. Statistical analysis indicated that the effect of the linear and quadratic terms of the variable S/F ratio was significant for all responses evaluated. Therefore, the design approach efficiently obtained high pectin yields, providing information that allows expansion to pilot and industrial scales.

Ultrasound, microwave and enzyme-assisted multiproduct biorefinery of Ascophyllum nodosum

This study investigated the multiproduct (fucoidans, β-glucans, proteins, carotenoids, fatty acids, amino acids and polyphenols) valorization of the invasive macroalgae Ascophyllum nodosum within a green biorefinery concept using ultrasound (US), microwave (MW) treatment followed by supercritical CO2 (SC-CO2) with co-solvent and enzymatic extraction. Water and 50% aqueous ethanol were used as green extraction solvents. The extraction methods using 50% ethanol as extraction solvent improved the yields of phenolic compounds and glucan and enhanced in vitro antioxidant activity. The characterization of SC-CO2 extracts revealed that pretreatment with US and MW improved the 2-fold yield of carotenoids, total phenolics and fatty acids. However, US/MW pretreatment and enzymatic extraction did not improve the yields of proteins and free amino acids. Overall, using concurrent green US/MW-assisted extraction methods enhanced the yields of the bioactive compounds in a short duration and provided extracts with a better antioxidant capacity in the field of food applications.