scholarly journals Batch Stirred-Tank Green Extraction of Salvia fruticosa Mill. Polyphenols Using Newly Designed Citrate-Based Deep Eutectic Solvents and Ultrasonication Pretreatment

2020 ◽  
Vol 10 (14) ◽  
pp. 4774
Author(s):  
Spyros Grigorakis ◽  
Abedalghani Halahlah ◽  
Dimitris P. Makris
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Deep Eutectic Solvents ◽  
Extraction Process ◽  
Dry Mass ◽  
Stirred Tank ◽  
Molar Ratio ◽  
Salvia Fruticosa ◽  
The One ◽  
Optimal Settings

A series of citrate salts were tested as hydrogen bond acceptors to synthesize deep eutectic solvents (DES) based on lactic acid and glycerol, used as hydrogen bond donors. The DES produced were then screened to identify the highest performing system for the effective extraction of polyphenolic phytochemicals from the medicinal plant Salvia fruticosa Mill. (Greek sage). The most efficacious DES was the one composed of lactic acid and sodium citrate dibasic, at a molar ratio of 15:1 (LA-SCDB15). Furthermore, for the first time there has been evidence concerning DES pH and extraction efficiency. Using this solvent, a batch, stirred-tank extraction process was developed, by employing ultrasonication pretreatment and response surface methodology. The optimal settings determined were stirring speed 900 rpm, proportion of DES/water 77% (w/v), and ultrasonication pretreatment time 15 min. By adjusting these optimal settings, the predicted maximum total polyphenol yield was calculated to be 79.93 ± 1.92 mg gallic acid equivalents g−1 dry mass. The examination of temperature effects demonstrated that the batch, stirred-tank extraction stage was very energy-efficient, with a barrier of 7.64 kJ mol−1. Comparison of the extraction of Salvia fruticosa polyphenols with other green processes previously developed, illustrated the high extraction capacity of LA-SCDB15. The major polyphenols identified in the extracts produced under optimized settings were chlorogenic acid, luteolin 7-O-glucuronide and rosmarinic acid.

scholarly journals Hydroglycerolic Solvent and Ultrasonication Pretreatment: A Green Blend for High-Efficiency Extraction of Salvia fruticosa Polyphenols

2020 ◽  
Vol 12 (12) ◽  
pp. 4840 ◽  
Author(s):  
Spyros Grigorakis ◽  
Abedalghani Halahlah ◽  
Dimitris P. Makris
Keyword(s):  
High Efficiency ◽  
Extraction Process ◽  
Dry Mass ◽  
Biological Properties ◽  
Stirred Tank ◽  
Total Polyphenol ◽  
Salvia Fruticosa ◽  
Polyphenolic Composition ◽  
Mass Comparison ◽  
Favorable Temperature

Salvia fruticosa Miller, also known as Cretan or Greek sage, is a medicinal plant with significant biological properties, which are largely ascribed to its polyphenolic composition, but there is to-date a scarcity of green and sustainable processes for efficient polyphenol extraction from this plant. The objective of this study was the implementation of an extraction process that would combine a green solvent based on glycerol, a biodiesel industry by-product, and ultrasonication pretreatment. Ultrasonication for 40 min followed by stirred-tank extraction was shown to provide significantly higher total polyphenol yield than mere stirred-tank extraction, while kinetics indicated 50 °C as the most favorable temperature, with the yield being 92 mg gallic acid equivalents (GAE) per g dry mass. Comparison of this method with a previously developed one that used methyl β-cyclodextrin revealed that the extracts obtained had similar antioxidant activity, and yield in major polyphenols including luteolin 7-O-glucuronide and rosmarinic acid was virtually equal. The current process is proposed as a sustainable and effective methodology for the generation of polyphenol-enriched extracts from S. fruticosa, which could be used as effective food antioxidants/antimicrobials and/or cosmetic constituents.

scholarly journals Effect of Four Novel Bio-Based DES (Deep Eutectic Solvents) on Hardwood Fractionation

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2157 ◽  
Author(s):  
Paulo Torres ◽  
Mercè Balcells ◽  
Enrique Cequier ◽  
Ramon Canela-Garayoa
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Scale Up ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Olive Pomace ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Raw Glycerol ◽  
Lignin Recovery

Using the basic principle of construction between a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), four bio-based deep eutectic solvents (DESs) were prepared in a 1:2 molar ratio of HBA:HBD. 2,3-Dihydroxypropyl-1-triethylammonium chloride ([C9H22N+O2]Cl−) was synthesized from raw glycerol and used as an HBA. Lactic acid, urea, pure glycerol, and ethylene glycol were selected as HBD. Attempts to prepare DESs, using citric acid and benzoic acid as HBDs, were unsuccessful. All these DESs were characterized using FTIR and NMR techniques. Besides, physicochemical parameters such as pH, viscosity, density, and melting point were determined. The behavior of these DES to fractionate olive pomace was studied. Lignin recovery yields spanned between 27% and 39% (w/w) of the available lignin in olive pomace. The best DES, in terms of lignin yield ([C9H22N+O2]Cl− -lactic acid), was selected to perform a scale-up lignin extraction using 40 g of olive pomace. Lignin recovery on the multigram scale was similar to the mg scale (38% w/w). Similarly, for the holocellulose-rich fractions, recovery yields were 34% and 45% for mg and multi-gram scale, respectively. Finally, this DES was used to fractionate four fruit pruning samples. These results show that our novel DESs are alternative approaches to the ionic liquid:triethylammonium hydrogen sulfate and the widely used DES: choline chloride:lactic acid (1:10 molar ratio) for biomass processing.

scholarly journals Silica Gel Impregnated by Deep Eutectic Solvents for Adsorptive Removal of BTEX from Gas Streams

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1894 ◽  
Author(s):  
Patrycja Makoś ◽  
Edyta Słupek ◽  
Aleksandra Małachowska
Keyword(s):  
Lactic Acid ◽  
Silica Gel ◽  
Choline Chloride ◽  
Specific Interaction ◽  
Chemical Properties ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Gas Streams ◽  
Tetrapropylammonium Bromide ◽  
Sorbent Materials

The paper presents the preparation of new adsorbents based on silica gel (SiO2) impregnated with deep eutectic solvents (DESs) to increase benzene, toluene, ethylbenzene, and p-xylene (BTEX) adsorption efficiency from gas streams. The DESs were synthesized by means of choline chloride, tetrapropylammonium bromide, levulinic acid, lactic acid, and phenol. The physico-chemical properties of new sorbent materials, including surface morphology and structures, as well as porosity, were studied by means of thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer–Emmett–Teller analysis. The effect of DESs type, flow rate, and initial concentration of BTEX were also investigated followed by regeneration and reusability of adsorbents. The results indicate that SiO2 impregnated with tetrapropylammonium bromide and lactic acid in a 1:2 molar ratio have great potential for the removal of BTEX from gas streams. Its adsorption capacity was higher than the pure SiO2 and other developed SiO2-DES adsorbents. This result can be explained by the specific interaction between DESs and BTEX, i.e., hydrogen bonds interaction.

scholarly journals Facilely reducing recalcitrance of lignocellulosic biomass by a newly developed ethylamine-based deep eutectic solvent for biobutanol fermentation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Lignocellulosic Biomass ◽  
Fossil Fuels ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Specific Yield ◽  
Green Solvents ◽  
Hydrogen Bond Donor ◽  
Total Sugars

Abstract Background Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation. Results Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars as high as 53.5 g L−1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU g−1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g L−1 and 706 g kg−1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g L−1 was achieved with butanol yield of 137 g kg−1 pretreated corncob by Clostridium saccharobutylicum DSM13864. Conclusions Ethylamine and lactic acid-based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.

scholarly journals Saffron Processing Wastes as a Bioresource of High-Value Added Compounds: Development of a Green Extraction Process for Polyphenol Recovery Using a Natural Deep Eutectic Solvent

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 586 ◽  
Author(s):  
Achillia Lakka ◽  
Spyros Grigorakis ◽  
Ioanna Karageorgou ◽  
Georgia Batra ◽  
Olga Kaltsa ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Maximum Yield ◽  
Deep Eutectic Solvent ◽  
Value Added ◽  
Extraction Process ◽  
Mass Spectrometry Analysis ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Hydrogen Bond Acceptor ◽  
Natural Deep Eutectic Solvent

The current investigation was undertaken to examine saffron processing waste (SPW) as a bioresource, which could be valorized to produce extracts rich in antioxidant polyphenols, using a green, natural deep eutectic solvent (DES). Initially, there was an appraisal of the molar ratio of hydrogen bond donor/hydrogen bond acceptor in order to come up with the most efficient DES composed of L-lactic acid/glycine (5:1). The following step was the optimization of the extraction process using response surface methodology. The optimal conditions thus determined were a DES concentration of 55% (w/v), a liquid-to-solid ratio of 60 mL g−1, and a stirring speed of 800 rounds per minute. Under these conditions, the extraction yield in total polyphenols achieved was 132.43 ± 10.63 mg gallic acid equivalents per g of dry mass. The temperature assay performed within a range of 23 to 80 °C, suggested that extracts displayed maximum yield and antioxidant activity at 50–60 °C. Liquid chromatography-mass spectrometry analysis of the SPW extract obtained under optimal conditions showed that the predominant flavonol was kaempferol 3-O-sophoroside and the major anthocyanin delphinidin 3,5-di-O-glucoside. The results indicated that SPW extraction with the DES used is a green and efficient methodology and may afford extracts rich flavonols and anthocyanins, which are considered to be powerful antioxidants.

scholarly journals Tetraethylammonium Acetate and Tetraethylammonium Bromide-Based Deep Eutectic Solvents as Thermodynamic CO2 Gas Hydrate Inhibitors

2020 ◽  
Vol 10 (19) ◽  
pp. 6794
Author(s):  
Vinayagam Sivabalan ◽  
Nurasyikin Hasnor ◽  
Bhajan Lal ◽  
Zamzila Kassim ◽  
Abdulhalim Shah Maulud
Keyword(s):  
Hydrogen Bond ◽  
Ethylene Glycol ◽  
Gas Hydrate ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Tetraethylammonium Bromide ◽  
Hydrate Dissociation ◽  
Co2 Gas ◽  
Vapor Equilibrium ◽  
Liquid Vapor

The thermodynamic gas hydrate suppression behavior of four Deep Eutectic Solvents (DESs) was evaluated in this paper. The mixtures of Hydrogen Bond Acceptors (HBA), Tetraethylammonium Acetate (TEAAC), and Tetraethylammonium Bromide (TEAB) with Hydrogen Bond Donors (HBD), Mono-Ethylene Glycol (MEG), and Glycerol were used to make the DES. The DESs were made at a 1:7 molar ratio for the combinations of TEAAC:MEG, TEAAC:Glycerol, TEAB:MEG, and TEAB:Glycerol. The Hydrate Liquid-Vapor Equilibrium (HLVE) data for CO2 were evaluated through the T-cycle method at different temperature (273.15–283.15 K) and pressure (2–4 MPa) conditions in the presence and absence of 5 wt % aqueous DES solutions. The inhibition effects showed by the DESs, including average suppression temperature (ΔŦ) and gas hydrate dissociation enthalpies (ΔHdiss), were also calculated. The average suppression temperature values of the DESs ranged between 0.4 and 2.4, with the highest inhibition to lowest inhibition order being TEAB:Glycerol > TEAB:MEG > TEAAC:Glycerol > TEAAC:MEG. A comparison of the DES with conventional Thermodynamic Hydrate Inhibitors (THIs) showed that studied Deep Eutectic Solvents had better gas hydrate inhibition. The results proved that DES has the potential to be one of the promising alternatives in gas hydrate inhibition.

scholarly journals Delignification of unbleached pulp by ternary deep eutectic solvents

2021 ◽  
Vol 10 (1) ◽  
pp. 666-676
Author(s):  
Veronika Majová ◽  
Michal Jablonský ◽  
Marek Lelovský
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Molar Ratios ◽  
The Individual ◽  
Low Solubility ◽  
Unbleached Pulp

Abstract The processing of lignocellulosic materials is very limited because of their low solubility in water and some organic solvents. Fifteen ternary deep eutectic solvents (DESs) were prepared and tested as solvents suitable for delignification of unbleached pulp. The selected ternary DESs are composed of quaternary ammonium salts and amino acids as hydrogen-bond acceptors, and organic acids and polyvalent alcohols as hydrogen bond donors, with molar ratios varying for the individual components. The delignification efficiency is significantly influenced by the degree of penetration of the solvent into the pulp fibre structure. Therefore, the density and viscosity analysis of individual solvents was performed. Unbleached beech pulp with initial kappa number 13.9 was treated with the prepared DESs. The kappa number indicates the residual lignin content or the bleachability of pulp. The efficiency of the solvents ranged from 1.4% to 28.1%. The most suitable for the pretreatment of fibres, based on lignin removal efficiency, were found to be three DESs, in the following order: malonic acid/choline chloride/1,3-propanediol (1:1:3) > choline chloride/acetamide/lactic acid (1:2:3) > choline chloride/urea/lactic acid (1:2:3).

scholarly journals Facilely Reducing Recalcitrance of Lignocellulosic Biomass by a Newly Developed Ethylamine Based Deep Eutectic Solvent for Biobutanol Fermentation

2020 ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Lignocellulosic Biomass ◽  
Fossil Fuels ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Specific Yield ◽  
Green Solvents ◽  
Hydrogen Bond Donor ◽  
Total Sugars

Abstract Background: Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation.Results: Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars of as high as 53.5 g·L–1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU·g–1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g·L–1 and 706 g·kg–1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g·L–1 was achieved with butanol yield of 137 g·kg–1 pretreated corncob by Clostridium saccharobutylicum DSM13864.Conclusions: Ethylamine and lactic acid based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.

Deacidification of Crude Rice Bran Oil (CRBO) to Remove FFA and Preserve γ-Oryzanol Using Deep Eutectic Solvents (DES)

2019 ◽  
Vol 964 ◽  
pp. 109-114 ◽  
Author(s):  
Siti Zullaikah ◽  
Nizar Dwi Wibowo ◽  
I Made Gede Eris Dwi Wahyudi ◽  
M. Rachimoellah
Keyword(s):  
Hydrogen Bond ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Extraction Temperature ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
C 50

High content of free fatty acids (FFA) in crude rice bran oil (CRBO) needs to be separated through deacidification. Generally, deacidification process that is widely used are chemical and physical processes which causes the loss of bioactive compounds (γ-oryzanol) and un-environmentally friendly. The liquid-liquid extraction (LLE) using deep eutectic solvents (DES) to remove FFA and preserve g-oryzanol would be implemented in this study. DES with different hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) with certain molar ratio such as Choline Chloride (ChCl)-Ethylene glycol 1:2 (DES I), ChCl-Glycerol 1:1 (DES II), ChCl-Urea 1:2 (DES III), ChCl-Oxalic acid 1:2 (DES IV), and Betaine Monohydrate-Glycerol 1:8 (NADES) were used as solvent to extract FFA from dewaxed/degummed RBO (DDRBO) for certain extraction time (30, 60, 120, 180, and 240 min) and extraction temperature (30°C, 40°C, 50°C, 60°C, and 70°C) under stirring (200 rpm). Deacidification using DES I for 240 min. and temperature of 50 °C was the optimum solvent to remove FFA (19.03 ± 2.33 %) and preserve g-oryzanol (recovery of g-oryzanol was 51.30 ± 1.77 %). The results also revealed that the longer time of extraction would be increased removal of FFA and decreased recovery of g-oryzanol. The higher temperature of extraction would be increased removal of FFA. In this work, temperature of 50 °C was the best extraction temperature of FFA since DES has highest solubility at this temperature.

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