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 ◽  
...  

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.

2020 ◽  
Vol 11 (3) ◽  
pp. 3017-3023
Author(s):  
Balakrishnan I ◽  
Jawahar N ◽  
Senthil Venkatachalam ◽  
Debosmita Datta

Eutectic mixture (EM) is as a mixture of more than one substance that does not interact individually to create a new entity but in a particular ratio that exhibits a lower range of melting point than it had in individual. EM should be formulated in such a way that it should have major advantages in pharmaceutical industries. EM can be a mixture of Active Pharmaceutical Ingredients (APIs), or different ratios of APIs and excipients, or various excipients. Deep eutectic solvents containing APIs (API-DES) considered as an innovative approach to form different APIs in the liquid state. This new approach of liquid form is versatile and plays an important role in drug delivery. The selection of ideal hydrogen bond-donor (HBD) and hydrogen bond-acceptor (HBA) is an essential parameter. Ionic liquids (IL), derivatives of deep eutectic solvents (DES) have got much attention since it can replace harmful organic solvent by their extraordinary properties. Therapeutic deep eutectic solvents (THEDESs) are considered to be an exceptional option in the advancement of biomedicine. This can be utilized for improvising drug solubility, bioavailability as well as drug permeation through the skin. Natural deep eutectic solvent (NADES) can be considered as an alternate option, replacing harsh solvents. It has special characteristics of better biodegradability and biocompatibility. These NADES mainly used to separate and purification of natural compounds. This review focuses on the eutectic mixture and its application in the area of drug delivery systems, and pharmaceutical and pharmacological fields.


Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 921 ◽  
Author(s):  
Olga Kaltsa ◽  
Achillia Lakka ◽  
Spyros Grigorakis ◽  
Ioanna Karageorgou ◽  
Georgia Batra ◽  
...  

Sambucus nigra flowers, known as elderberry flowers (EBF), are a plant tissue rich in polyphenolic phytochemicals with important bioactivities. However, there are few studies dealing with the production of polyphenol-containing EBF extracts. The objective of the investigation presented herein was the development of a high-performance green extraction methodology, to generate EBF extracts enriched in polyphenolic substances, using an efficient deep eutectic solvent, combined with ultrasonication pretreatment. The DES was composed of L-lactic acid (hydrogen bond donor—HBD) and glycine (hydrogen bond acceptor—HBA) and, after an initial screening to properly regulate HBD/HBA ratio, the extraction was optimized by deploying response surface methodology. Under the optimized conditions, which were DES/water (85% w/v), liquid-to-solid ratio 60 mL g−1, and stirring speed 200 rounds per minute, the extraction yield in total polyphenols amounted to 121.24 ± 8.77 mg gallic acid equivalents per g dry matter. The integration of ultrasonication prior to the batch stirred-tank extraction boosted polyphenol recovery of up to 174.73 ± 2.62 mg gallic acid equivalents per g dry matter. Liquid chromatography–mass spectrometry analysis showed that the richest EBF extract obtained was dominated by rutin, a di-p-coumaroylquic acid and chlorogenic acid.


2021 ◽  
Vol 11 (6) ◽  
pp. 14620-14633

Turmeric contains curcumin as one of the active constituents, which gives yellow color and possesses lots of pharmacological actions. Even though curcumin has lots of pharmacological actions till now, it has not been approved as a medicine due to its low water solubility, permeability, and poor bioavailability. Deep eutectic solvent (DES) can be prepared by simply mixing two or more solid components, [among the two one is hydrogen bond donor (HBD) and another is hydrogen bond acceptor (HBA)] at a definite molar ratio where the solid components by self-association converted into a liquid at room temperature (RT). Natural deep eutectic solvents (NADES) are a specific subgroup of DES containing primary plant-based metabolites such as organic acids, alcohols, amino acids, or sugars. In this work, natural hydrophobic DESs were prepared with Camphor, Menthol, and Thymol. This was prepared from different ratios of Menthol:Thymol 1:1 to 1:5 and 1:1 to 5:1 (MT-DES); Camphor:Thymol 1:1 to 1:5 and 1:1 to 5:1 (CT-NADES); Camphor:Menthol 1:1 to 1:5 and 1:1 to 2:1 (CM-NADES). The pH and viscosity of prepared DESs were determined with the help of a digital pH meter and Brookfield viscometer. The solubility of curcumin in different NADESs was determined at room temperature (RT) to higher temperatures. The formation of different clear DES was obtained with slight heat. There was no difference in pH for the NADESs prepared without and with heat. Regarding the viscosity CM-DES (1:1) showed less viscosity when compared to other NADESs. The solubility of curcumin was found to be nearly double when it was dissolved in NADES for 1 hr at 35-40°C compared to 48 h stirring at 500 rotations per minute (rpm) at RT. Among different NADESs, curcumin solubility was found to be more in CM (1:1) ratio when compared to other NADESs.


Author(s):  
Hosein Ghaedi ◽  
Muhammad Ayoub ◽  
Suriati Sufian ◽  
Azmi Mohd Shariff ◽  
Bhajan Lal

Deep eutectic solvents (DESs) are known as tunable solvents. It is possible to prepare ternary deep eutectic solvent (TDES) are used for desired purpose by selecting the suitable molar ratio and components of mixture. Therefore, four DESs and two TDESs were prepared in this work. DESs and TDESs were prepared with potassium carbonate (PC) as a hydrogen bond acceptor (HBA) and three hydrogen bond donors (HBDs) such as glycerol (GL), ethylene glycol (EG) and 2-amino-2methyl-1-3-propanediol (AMPD) known as a hindered amine (HA). Binary DESs were PC-GL with molar ratios 1:10 and 1:16 and PC-EG with the same molar ratios. TDES were prepared by adding AMPD in binary DESs such as PC-GL-AMPD 1:16:1 and PC-EG-AMPD 1:10:1. The experimental density and refractive index of all DESs and TDESs were measured at the temperature of 293.15 to 343.15 K with an interval of 5 K. The effect of temperature, molar ratio and alkyl chain length on the properties was investigated. The molar volumes and isobaric thermal expansion were calculated using experimental density data. The experimental refractive index data was used to derive the specific refraction, molar refraction, free molar volume, electronic polarization, polarizability constant and internal pressure at several temperatures.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Hui Wang ◽  
Xiaodi Ma ◽  
Qibin Cheng ◽  
Xiaoli Xi ◽  
Liwei Zhang

Deep eutectic solvents (DESs) have attracted significant attention as green media for the extraction and separation of natural compounds from Chinese medicine. In this study, a hydrophobic DESs-based microwave-assisted extraction (MAE) was successfully used to efficiently extract baicalin from Scutellaria baicalensis Georgi. Firstly, DecA: N4444-Cl (DES-1 , molar ratio 1 : 2) was screened and selected as the most appropriate DES by comparing the extraction yield in different hydrophobic DESs. Based on the extraction yield of baicalin, response surface methodology (RSM) was employed to model and optimize the parameters (extraction temperature, liquid-solid ratio, and extraction time). Furthermore, the maximum yield of 106.96 mg·g−1 was achieved under optimum conditions in DES-containing aqueous solutions (33 vol% water content), which reached a similar level that was conducted using the pharmacopoeia procedure (104.94 mg·g−1). These results indicated that the proposed method is an excellent alternative for the extraction of baicalin.


2019 ◽  
Vol 102 (2) ◽  
pp. 451-456 ◽  
Author(s):  
Weifang Wang ◽  
Sai Han ◽  
Xianjun Zha ◽  
Jiangrui Cheng ◽  
Junying Song ◽  
...  

Abstract Background: The green tea scraps are the waste materials during the process of green tea production, and it is significant to extractvaluable tea polyphenols (TP) for reuse. Objective: The objective of this study was to extract valuable TP from green tea scraps, and the extraction conditions were optimized to obtain maximum yield of TP. Methods: The TPwere extracted by supercritical carbon dioxide (SC-CO2) with 65% (v/v) aqueous ethanol solution as cosolvent. The content of TP was determinedwith the Folin-Ciocalteu method. The key factors ofthe extraction process, including temperature (313.15–323.15 K), pressure (20–30 Mpa), and amount of cosolvent (50–150 mL) were optimized by response surface methodology (RSM). Results: These key factors showed the extremely complex effects on the extraction yield of TP. A second-order polynomial mathematical modelwasdeveloped for the response with high R-squared value (R2 = 0.9946) and used to predict the optimal conditions (i.e., temperature of 322.15 K, pressure of 23.60MPa, and amount of cosolvent of 150 mL). The verification experiments showed that the maximum yield ofTP was 23.07 ± 0.82% under the optimal conditions, which was in good agreement with the predicted value. Conclusions: TP can be successfully extracted from green tea scraps by SC-CO2, and RSM could be used to optimize the extraction process. Highlights: SC-CO2 extraction of TP from green tea scraps was developed. The operating conditions, including pressure, temperature, and amount of cosolvent, were optimized. RSM could successfully predict the optimal operating conditions.


2019 ◽  
Vol 8 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Emine Kaya Ekinci ◽  
Nuray Oktar

Abstract A series of active and selective MCM-41 supported catalysts have been successfully prepared and used for bioderived glycerol esterification with acetic acid to produce fuel additives. In the synthesis of MCM-41, an acidic hydrothermal synthesis route was used, and silicotungstic acid (STA) and zirconia (ZrO2) were added to the catalyst structure by wet impregnation. X-ray diffraction, nitrogen adsorption-desorption methods, scanning electron microscopy with energy-dispersive spectroscopy, and inductively coupled plasma-mass spectrometry analysis were used for characterizations of the catalysts. Diffuse reflectance infrared Fourier transform spectroscopy analyses of pyridine-adsorbed catalysts owns Lewis and Brønsted acidity hosting in one, which promotes the esterification reaction of glycerol into glycerol esters with high selectivity. Esterification of glycerol reactions were performed at temperature intervals of 105°C–200°C, with an amount of catalyst equal to 0.5 g, and glycerol/acetic acid molar ratio of 1:6 in a stirred autoclave reactor operated batchwise. STA and ZrO2-impregnated MCM-41 catalysts showed better performance with a complete glycerol conversion and high selectivity to triacetin.


2020 ◽  
Vol 58 (9) ◽  
pp. 880-886
Author(s):  
Xiao Li ◽  
Tao Yuan ◽  
Ting Zhao ◽  
Xiaomei Wu ◽  
Yaling Yang

Abstract An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.


2019 ◽  
Vol 964 ◽  
pp. 109-114 ◽  
Author(s):  
Siti Zullaikah ◽  
Nizar Dwi Wibowo ◽  
I Made Gede Eris Dwi Wahyudi ◽  
M. Rachimoellah

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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