Comparison of Extraction Methods for Recovery of Astaxanthin from Haematococcus pluvialis

Solvent extraction, ultrasound assisted extraction (UAE), and microwave assisted extraction (MAE) were examined for the extraction of astaxanthin from Haematococcus pluvialis. In all cases, acetone was found to give the highest astaxanthin recovery compared with other selected solvents, i.e., methanol, ethanol, and acetonitrile. Among the various methods, MAE at 75°C for 5 min resulted in the highest astaxanthin recovery (74 ± 4%).     

A Review on Extraction Techniques and Its Future Applications in Industry

Extraction is a mandatory process for most of the industries, especially in the food processing industry to obtain the targeted compounds from various sources such as plant or seed samples. This review paper provides information about various extraction techniques that are normally used in the edible oil extraction industry. Five extraction techniques are presented in this paper. Among all the techniques presented in this paper, pressing and solvent extraction methods are considered as traditional techniques while supercritical fluid extraction, microwave assisted extraction, and ultrasound assisted extractions are considered as advanced techniques. Both advantages and disadvantages of supercritical fluid extraction, microwave assisted and ultrasound assisted extractions are discussed. Furthermore, the parameters that would affect the output of each technique are included in each section. Nowadays, research is going on to further enhance the extraction method to obtain a higher extraction yield or increase the quality of the extraction product. The enhancement can be either combining two or more extraction techniques into one complete process or modifying the available technique alone. Therefore, the theoretical knowledge provided in this review will be useful for future researchers who are interested in enhancing the extraction techniques. Practical Applications : Extraction is a mandatory process in edible oil extraction industry. Extraction industry is always looking for a process which is high efficiency and low extraction cost. Therefore, various advanced techniques or treatments are applied to optimize the oil yield and shorten the extraction time. This paper provides a review on various techniques by summarizing both advantages and disadvantages of each technique. The information can be very useful for improving the current extraction technique to further optimize the oil yield or enhance the quality of oil.     

Microwave assisted water extraction of plant compounds

The development of environmentally friendly processes with limited generation of polluting streams to attain sustainable utilization of raw materials is encouraged. The implementation of novel extraction technologies more efficient, selective and with lower energy consumption than conventional ones, can help in achieving this objective. Particularly promising are aqueous based methods, since water is a cheap, safe and abundant solvent and the limited use of toxic organic solvents is a consumer's, ecological and processing demand. The benefits and the limiting aspects of microwave assisted water extraction, either adding water as the only solvent or in solvent free processes, using the naturally present water in vegetal materials for the extraction of valuable components from renewable vegetal sources are highlighted and the potential of this technique for industrial applications is discussed. © 2014 Society of Chemical Industry     

An effective separation and purification of rutin and scoparone from Herba Artemisiae Scopariae by solid-phase extraction cartridges packed with an ionic liquid-based silica

Five types of ionic liquid-based silica were synthesized as solid-phase extraction (SPE) sorbents for separation and purification of bioactive compounds, that is, rutin and scoparone extracted from Herba Artemisiae Scopariae. The SilprBImCl material with the highest adsorption capacity was selected as the sorbent for SPE packing. Ethyl acetate and water were found to be suitable washing and eluting solvents, respectively. SilprBImCl was then applied to multi-phase extraction, and its superiority as a sorbent over the commercial cartridge was proven with high rutin and scoparone recoveries of 90.5% and 83.9%, respectively. This highlights the potential of ionic liquid-based silica materials applied to SPE and MPE.     

Optimization of Microwave‐Assisted Extraction of Flavonoid from Radix Astragali using Response Surface Methodology

Abstract

Response surface methodology (RSM) was applied to predict optimum conditions for microwave‐assisted extraction (MAE) of flavonoid from Radix Astragali. A central composite design was used to monitor the effect of temperature, extraction time, solvent‐to‐material ratio, and the ethanol concentration on yield of total flavanoid (TFA). Optimum extraction conditions were predicted as 108.2°C, 26.7 min, 23.1 ml/g solvent‐to‐material ratio and 86.2% ethanol. The maximum yield 1.234±0.031 mg/g was close to the yield of Soxhlet and higher than that of ultrasound assisted extraction and heat reflux extraction. MAE was an effective alternative to conventional extraction methods.     

Kinetic study of nordihydroguaiaretic acid recovery from Larrea tridentata by microwave‐assisted extraction

BACKGROUND: Nordihydroguaiaretic acid (NDGA) is a powerful antioxidant with biological activities of great interest in several health areas, including antiviral, cancer chemopreventive, and antitumorgenic. Little information is available on extraction methods of NDGA from Larrea tridentata. Hence, the aim of this study was to develop a rapid and effective microwave‐assisted extraction (MAE) method for NDGA recovery from Larrea tridentata leaves, and to compare the results obtained with those found using conventional heat‐reflux extraction (HRE). RESULTS: Extraction time for similar NDGA yields was significantly reduced from 18 to 1 min when MAE was used instead of HRE. Optimum conditions for NDGA extraction (3.79 ± 0.65%) consisted in using 50% methanol as extraction solvent in a solid/liquid ratio of 1/10 g mL^?1. Micrographs demonstrated that the improvement in NDGA extraction by MAE might be related to a greater extent of cell rupture of the plant material. Extracts obtained by MAE exhibited antiradical activity only slightly lower than those obtained by HRE. CONCLUSIONS: MAE proved to be a faster and more efficient method for NDGA extraction from Larrea tridentata leaves than HRE. The better results for NDGA extraction by MAE might be explained by the greater extent of cell rupture of plant material during the extraction process. Copyright © 2010 Society of Chemical Industry     

Deep Eutectic Solvent as Green Solvent in Extraction of Biological Macromolecules: A Review

Greater awareness of environmental sustainability has driven many industries to transition from using synthetic organic solvents to greener solvents in their manufacturing. Deep eutectic solvents (DESs) have emerged as a highly promising category of green solvents with well-demonstrated and wide-ranging applications, including their use as a solvent in extraction of small-molecule bioactive compounds for food and pharmaceutical applications. The use of DES as an extraction solvent of biological macromolecules, on the other hand, has not been as extensively studied. Thereby, the feasibility of employing DES for biomacromolecule extraction has not been well elucidated. To bridge this gap, this review provides an overview of DES with an emphasis on its unique physicochemical properties that make it an attractive green solvent (e.g., non-toxicity, biodegradability, ease of preparation, renewable, tailorable properties). Recent advances in DES extraction of three classes of biomacromolecules—i.e., proteins, carbohydrates, and lipids—were discussed and future research needs were identified. The importance of DES’s properties—particularly its viscosity, polarity, molar ratio of DES components, and water addition—on the DES extraction’s performance were discussed. Not unlike the findings from DES extraction of bioactive small molecules, DES extraction of biomacromolecules was concluded to be generally superior to extraction using synthetic organic solvents.     

A comparative study of lupeol extraction from a by-product of lupin processing by hydrophobic natural deep eutectic solvents and their precursor components

A series of hydrophobic natural deep eutectic solvents (HNADESs) have been employed to extract lupeol from lupin seed coat at 30 and 70°C. The extraction yields have been compared with those obtained with conventional organic solvents. In general, lupeol extraction yields (LEYs) obtained when using HNADES are somewhat smaller than those obtained if organic solvents are used. However, the nature of the HNADES mixtures as green solvents represents a superior performance in terms of sustainability of the extraction process. Additionally, an investigation has been carried out in order to compare the LEYs obtained when using the HNADES mixtures with those obtained if the isolated precursor compounds are employed at a temperature (70°C) where both HNADES and the corresponding precursor compounds are liquids. Surprisingly, LEYs for lupeol at 70°C were found to be, in some cases, slightly higher if the precursor compounds are used in comparison with the proper HNADES mixtures. It seems that the unique properties of the HNADES mixtures are not enough to perform better as extractants in comparison with the isolated precursor compounds at moderate temperatures, at least for the case of lupeol from lupin seed coat. Some hints are presented to explain these results. Practical Applications: The demand to use by-products, such as raw materials, to obtain potential bioactive compounds is gaining strong attention in the last years. The use of green solvents to extract these compounds is also envisaged to obtain substances in an environment-friendly way and with high sustainability for the economy and end-consumers. The main aim of this work is the extraction of lupeol from lupin seed coat by using on one side different hydrophobic natural deep eutectic solvent (HNADES) mixtures, and on the other side by using the precursor compounds of the mixtures, in order to evaluate the efficiency of these green extraction solvents in the recovery of bioactive compounds with health benefits from waste material. Our results show that lupeol can be extracted both with the HNADES mixtures and with their precursor components at moderate temperatures with similar efficiency. This work questions the need of using HNADES as clean extraction solvents as the precursor compounds have themselves interesting extracting capacities.     

Rapid Salt‐Assisted Microwave Demulsification of Oil‐Rich Emulsion Obtained by Aqueous Enzymatic Extraction of Peanut Seeds

Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process that can also provide edible protein. However, the AEE process may form a stable emulsion in most cases, which seriously limits the large‐scale industry applications for producing vegetable oils. In this study, the salt‐assisted microwave radiation demulsification of the oil‐rich emulsion prepared with AEE from peanuts is investigated. The microwave demulsification method is compared with other conventional demulsification methods, including heating, and freezing–thawing. The salt‐assisted microwave demulsification of the emulsions shows a greater free oil yield than conventional heating demulsification. Moreover, the microwave demulsification shows a similar free oil yield in less time than freezing–thawing method. Under the optimal operating conditions of demulsification, the free oil yield can reach 92.3% with CaCl₂‐assisted microwave demulsification for only 2 min. In addition, the oxidative properties and the fatty acid compositions of the demulsified peanut oil are investigated. No significant difference in the fatty acid composition is observed among salt‐assisted microwave, freezing–thawing, and heating demulsified oil. The oxidative properties of the salt‐assisted microwave demulsified peanut oil is better than the conventional heating demulsified oil. Thus, salt‐assisted microwave demulsification provides a quick and effective demulsification method to obtain vegetable oils with high quality. Practical Applications: Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process. To solve the problem of stable emulsion formed during AEE process, the salt‐assisted microwave demulsification of the oil‐rich emulsion prepared with AEE is developed with high efficiency (demulsification for 2 min). In addition, the oxidative properties of the microwave demulsified oil is better than the conventional heating demulsified oil.     

Solvent extraction and purification of rosmarinic acid from supercritical fluid extraction fractionation waste: Economic evaluation and scale-up

Industry is increasingly interested in natural food preservatives, antimicrobial, and antioxidants due to their beneficial effects. The use of plant waste also presented itself to be a great opportunity in recovered bioactive compounds remaining in the residue. In this work, bioactive compounds were obtained from Rosmarinus officinalis in two different ways: firstly the supercritical fractionated rosemary extract with different composition was obtained from the plant material, and secondly a potent antioxidant-rosmarinic acid (RA) – was successfully extracted from the plant waste. A purification process scale-up of RA was proposed using GRAS solvent, and an economic evaluation was made for the overall process. A complete process to obtain bioactive compounds, antimicrobial (supercritical fluid extraction and fractionation extraction) and antioxidant (solvent extraction) was developed.     

The use of environmentally sustainable bio-derived solvents in solvent extraction applications——A review

Replacement of volatile organic compounds (VOCs) by greener or more environmental y sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as wel as economic pressures associated with VOCs. Solvents that are derived from biomass, namely bio-derived solvents, are a type of green solvent that have attracted intensive investigations in recent years because of their advantages over con-ventional VOCs, such as low toxicity, biodegradability and renewability. This review aims to summarize the use of bio-derived solvents in solvent extraction applications, with special emphasis given to utilization of biodiesels and terpenes. Compared with the conventional VOCs, the overall performance of these bio-derived solvents is comparable in terms of extraction yields and selectivity for natural product extraction and no difference was found for metal extraction. To date most researchers have focused on laboratory scale thermodynamics studies. Future work is required to develop and test new bio-derived solvents and understand the kinetic performance as well as solvent extraction pilot plant studies.     

Deep eutectic solvents aqueous two-phase system based ultrasonically assisted extraction of ursolic acid (UA) from Cynomorium songaricum Rupr.

Deep eutectic solvents (DESs) are new green solvents that have attracted the attention of the scientific community mainly due to their unique properties and special characteristics, which are different from those of traditional solvents. A method based on ultrasonically assisted deep eutectic solvent aqueous two-phase systems (UAE-DES-ATPS) was developed for extracting ursolic acid (UA) from Cynomorium songaricum Rupr. Four different types of choline chloride-based DESs were prepared. Choline chloride-glucose (ChCl-Glu) exhibited good selective extraction ability. An optimum DES-ATPS of 36% (w/w) ChCl-Glu and 25% (w/w) K₂HPO₄ was considered to be a satisfactory system for extracting UA. Response surface methodology (RSM) method was utilized to optimize the extraction of UA using UAE-DES-ATPS. The quadratic models were extremely significant (p?<?0.01) for all the parameters studied with high correlation coefficients (R²) of 0.9593. The optimum ultrasound-assisted conditions were as follows: solvent to solid ratio of 15:1 (g/g), ultrasound power density of 4.7?W·mL^?1, and extraction time of 54?min. Compared with the conventional UAE method, the yields were basically the same, but the presented method had higher purity. The structure of UA did not change between pure UA and UA in the upper phase using UV–vis and FT-IR. This approach using ChCl-based DES-ATPS as a novel extraction system and ultrasound as a source of energy provided a better choice for the separation of active components from other natural products.     

Non‐aqueous dyeing of cotton fibre with reactive dyes: A review

This study reviews the evolution of and recent developments in non‐aqueous reactive dyeing systems for cotton fibre. As conventional water‐based reactive dyeing causes adverse effects to the environment because of the need for huge quantities of water and chemicals, as well as generating a substantial amount of effluents, one of the alternative ways to alleviate pressure on the environment is to switch the dyeing medium from an aqueous water‐based approach to a non‐aqueous solvent‐assisted approach. Among a wide variety of non‐aqueous dyeing methods, this review focuses on several non‐aqueous dyeing systems, including dyeing textile fibres with chlorinated solvents, dyeing cotton with the use of reverse micellar systems, a dye/solvent suspension system and a non‐nucleophilic solvent‐assisted dyeing system.     

Extraction and HPLC Characterization of Chlorogenic Acid from Tobacco Residuals

Abstract

Chlorogenic acid is a highly valuable natural polyphenol compound used in medicine and industries. Its current commercial sources are from plant extracts of Lonicera japonica Thunb and Eucommia ulmoides Oliver. These sources are limited and expensive. On the other hand, tobacco residuals contain chlorogenic acid and other natural polyphenol compounds. Large quantities of tobacco residuals are produced each year as waste materials from tobacco manufacturing, potentially providing an alternative commercial source of chlorogenic acid and other valuable compounds. In this paper, microwave and ultrasound extractions of chlorogenic acid with mixed solvent were studied. Total polyphenol concentrations in extract solutions obtained with different extraction methods were analyzed with the method of ferrous tartrate and UV‐Vis spectrophotometry and compared. The extraction solutions were also characterized for polyphenol compositions with the method of HPLC. Experimental results indicated that high extract concentrations of chlorogenic acid were obtained with a mixed solvent of acetone and water (1:2 v/v). A total polyphenol concentration of up to 4.87 mg/ml and a chlorogenic acid concentration of up to 2.12 mg/ml were achieved. The application of microwave and ultrasound significantly increased the extract concentrations. The extraction time needed was also much reduced. HPLC analysis indicated that acetone water mixed solvent extraction achieved much higher relative concentrations of chlorogenic acid to other compounds in the extract solutions. These results indicted that fast and effective extraction of chlorogenic acid from tobacco residuals were achieved.     

Supercritical Carbon Dioxide Extraction of Carotenoids from Pumpkin (Cucurbita spp.): A Review

Carotenoids are well known for their nutritional properties and health promoting effects representing attractive ingredients to develop innovative functional foods, nutraceutical and pharmaceutical preparations. Pumpkin (Cucurbita spp.) flesh has an intense yellow/orange color owing to the high level of carotenoids, mainly α-carotene, β-carotene, β-cryptoxanthin, lutein and zeaxanthin. There is considerable interest in extracting carotenoids and other bioactives from pumpkin flesh. Extraction procedures able to preserve nutritional and pharmacological properties of carotenoids are essential. Conventional extraction methods, such as organic solvent extraction (CSE), have been used to extract carotenoids from plant material for a long time. In recent years, supercritical carbon dioxide (SC-CO₂) extraction has received a great deal of attention because it is a green technology suitable for the extraction of lipophylic molecules and is able to give extracts of high quality and totally free from potentially toxic chemical solvents. Here, we review the results obtained so far on SC-CO₂ extraction efficiency and quali-quantitative composition of carotenoids from pumpkin flesh. In particular, we consider the effects of (1) dehydration pre-treatments; (2) extraction parameters (temperature and pressure); the use of water, ethanol and olive oil singularly or in combination as entrainers or pumpkin seeds as co-matrix.     

Complexation chemistry in liquid–liquid extraction of rhenium

This review addresses the dearth of knowledge about the interaction of rhenium species with organic solvents during the liquid–liquid extraction of rhenium. To describe such interactions, the aqueous chemistry of rhenium in unlike media, the extraction mechanism and the salient role of thermodynamic properties are also discussed. Formation of a rhenium‐complexed species inorganic phase and competition between the extracted species during extraction is described by inner and outer sphere coordination. Emergence of a stabilized complex in a hydrophobic environment is greatly affected by the interaction of electrostatic and/or H‐bonding. The chemistry of liquid–liquid extraction of rhenium that can further assist future studies in this area is also relevant to other metal ion systems. © 2015 Society of Chemical Industry     

Extraction of phytochemicals using hydrotropic solvents

Every plant synthesizes phytochemicals with different properties to supply a pool of molecules for food, chemical and pharmaceutical applications. Concurrent with “green technology” development, use of green solvents to extract phytochemicals instead of conventional non-eco-friendly solvents is crucial. Hydrotrope is a one of the green solvents that enhances solubility of poorly water-soluble or hydrophobic compounds in aqueous solutions. This article critically reviews the extraction of phytochemicals using various hydrotropic solvents. Hydrotropy mechanisms, factors influencing extraction and recovery methods of phytochemicals were also evaluated in this review.     

Advances in Lipid Extraction Methods—A Review

Extraction of lipids from biological tissues is a crucial step in lipid analysis. The selection of appropriate solvent is the most critical factor in the efficient extraction of lipids. A mixture of polar (to disrupt the protein-lipid complexes) and nonpolar (to dissolve the neutral lipids) solvents are precisely selected to extract lipids efficiently. In addition, the disintegration of complex and rigid cell-wall of plants, fungi, and microalgal cells by various mechanical, chemical, and enzymatic treatments facilitate the solvent penetration and extraction of lipids. This review discusses the chloroform/methanol-based classical lipid extraction methods and modern modifications of these methods in terms of using healthy and environmentally safe solvents and rapid single-step extraction. At the same time, some adaptations were made to recover the specific lipids. In addition, the high throughput lipid extraction methodologies used for liquid chromatography-mass spectrometry (LC-MS)-based plant and animal lipidomics were discussed. The advantages and disadvantages of various pretreatments and extraction methods were also illustrated. Moreover, the emerging green solvents-based lipid extraction method, including supercritical CO₂ extraction (SCE), is also discussed.     

Reactive extraction of oilseeds with dialkyl carbonates

Using dialkyl carbonates as reagents for lipase‐catalyzed transesterification, the reaction is driven by the evolvement of carbon dioxide as the co‐product and thus no longer an equilibrium reaction. Therefore this transesterification method is faster and quantitative conversions can be obtained. Short‐chain dialkyl carbonates, like other short‐chain esters, are also suitable solvents for seed oil extraction. Thus, extraction and transesterification can be combined in a single reaction. This reaction, called reactive extraction, was carried out in a standard Soxhlet apparatus with rapeseed, linseed and calendula seed as the raw materials and with dimethyl and diethyl carbonate as extraction solvent and transesterification reagent at the same time. Fatty acid methyl esters and ethyl esters respectively were obtained with higher yields than those achieved by conventional two step extraction / transesterification. In the case of linseed fatty acid esters and especially calendula seed fatty acid esters, the iodine values of the products obtained by one‐pot‐two‐step reactive extraction were significantly higher.     

Focused Microwave (FMW) Extraction of Polycyclic Aromatic Hydrocarbons (PAHs) from Plant Bioindicators,Comparison with Classical Techniques

Extraction efficiencies of polycyclic aromatic compounds (PAHs) from spruce needles (Picea abies) obtained by recently introduced “focused microwave assisted (FMW) extraction” (i) and conventional methods represented by extraction enhanced by sonication (ii) and Soxhlet extraction (iii) were compared. n-Hexane:acetone (azeotropic ratio, 53.5 wt % of acetone) extraction mixture was used in all experiments. The influence of various parameters (extraction time, intensity of irradiation, moisture content) both on the recoveries of PAHs from spruce needles (Picea abies) and the amount of co-isolated matrix components potentially interfering within the determinative step was examined. The mean extraction efficiencies of PAHs obtained by FMW extraction and sonication were found to be lower (82 % and 75 %, respectively) compared the extraction in Soxhlet apparatus (equal 100 %).