Naturally active compounds are usually contained inside plants and materials thereof. Thus, the extraction of the active compounds from plants needs appropriate extraction methods. The commonly ...employed extraction methods are mostly based on solid-liquid extraction. Frequently used conventional extraction methods such as maceration, heat-assisted extraction, Soxhlet extraction, and hydrodistillation are often criticized for large solvent consumption and long extraction times. Therefore, many advanced extraction methods incorporating various technologies such as ultrasound, microwaves, high pressure, high voltage, enzyme hydrolysis, innovative solvent systems, adsorption, and mechanical forces have been studied. These advanced extraction methods are often better than conventional methods in terms of higher yields, higher selectivity, lower solvent consumption, shorter processing time, better energy efficiency, and potential to avoid organic solvents. They are usually designed to be greener, more sustainable, and environment friendly. In this review, we have critically described recently developed extraction methods pertaining to obtaining active compounds from plants and materials thereof. Main factors that affect the extraction performances are tuned, and extraction methods are chosen in line with the properties of targeted active compounds or the objectives of extraction. The review also highlights the advancements in extraction procedures by using combinations of extraction methods to obtain high overall yields or high purity extracts.
An interest in the development of extraction techniques of biomolecules from various natural sources has increased in recent years due to their potential applications particularly for food and ...nutraceutical purposes. The presence of polysaccharides such as hemicelluloses, starch, pectin inside the cell wall, reduces the extraction efficiency of conventional extraction techniques. Conventional techniques also suffer from low extraction yields, time inefficiency and inferior extract quality due to traces of organic solvents present in them. Hence, there is a need of the green and novel extraction methods to recover biomolecules. The present review provides a holistic insight to various aspects related to enzyme aided extraction. Applications of enzymes in the recovery of various biomolecules such as polyphenols, oils, polysaccharides, flavours and colorants have been highlighted. Additionally, the employment of hyphenated extraction technologies can overcome some of the major drawbacks of enzyme based extraction such as longer extraction time and immoderate use of solvents. This review also includes hyphenated intensification techniques by coupling conventional methods with ultrasound, microwave, high pressure and supercritical carbon dioxide. The last section gives an insight on application of enzyme immobilization as a strategy for large scale extraction. Immobilization of enzymes on magnetic nanoparticles can be employed to enhance the operational performance of the system by multiple use of expensive enzymes making them industrially and economically feasible.
Extraction of various biomolecules by using enzyme assisted extraction. Display omitted
•Application of enzyme assisted extraction in the recovery of various biomolecules.•Enzymes disrupt the complex cell wall structure to release the active constituents.•Novel extraction methods coupled with enzyme assisted extraction is reviewed.•Enzyme immobilization as a strategy for large scale application is explored.•Magnetic nanoparticles are considered as potential carriers for enzyme immobilization.
► Compressed fluids show important advantages for extraction of bioactives. ► SFE, PLE and SWE are fast, reliable and clean methods for extracting bioactives. ► Principles, instrumentation and ...applications of SFE, PLE and SWE are presented.
The improvement of sample-preparation and extraction techniques for determinations of natural bioactive compounds is very important. New concepts relate to not only enhancement of extraction efficiencies but also environmental impact. This evolution towards Green Analytical Chemistry is to new extraction and sample-preparation processes that should be faster, more reproducible and more environmentally friendly.
Compressed fluid-based sample-preparation techniques (e.g., supercritical fluid extraction and pressurized liquid extraction) demonstrate good capabilities. In this review, we update knowledge on the techniques together with the main technical developments and the most notable recent applications for the extraction of bioactive compounds.
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•Efficient cannabinoid extraction from raw and decarboxylated hemp with CO2 and propane.•High CBD extracts (up to 449 mg/g) obtained from hemp by means of supercritical CO2.•Addition ...of 5 % ethanol co-solvent enhances the extraction of cannabinoid acid forms.•Propane more effective than CO2 for extraction of cannabinoid acid forms.•Apparent solubility at 300 bar was 11 g/kg CO2 for raw hemp (dry basis).
Hemp varieties of Cannabis Sativa L. contain low levels of Δ9-tetrahydrocannabinol (THC) and can be used to produce therapeutic extracts rich in cannabidiol (CBD). In this work, extracts containing up to 449 mg/g CBD were obtained from New Zealand industrial hemp varieties by extraction of flower buds with supercritical CO2. The composition of the extracts and the influence of different processing parameters (extraction pressure up to 1300 bar, use of ethanol co-solvent, decarboxylation of feed) were determined. The apparent solubility of the extract in CO2 at different pressures was measured. Extractions using near-critical propane and dimethyl-ether were also performed. Total extraction yields reached 12.0 wt% with CO2 and 8.2 wt% with propane, whereas total cannabinoid yield ranged from 51 to 100 % with CO2 and from 74 to 99 wt% with propane. Addition of 5 % ethanol co-solvent enhances the extraction of cannabinoid acid forms, as does an increase in extraction pressure.
Supercritical fluid extraction of bioactive compounds da Silva, Rui P.F.F.; Rocha-Santos, Teresa A.P.; Duarte, Armando C.
TrAC, Trends in analytical chemistry (Regular ed.),
February 2016, 2016-02-00, 2016-02-01, Volume:
76, Issue:
C
Journal Article
Peer reviewed
Open access
•SFE as a green alternative to conventional extraction of bioactive compounds.•Techniques and methodologies for SFE improvement.•Experimental design for optimization of SFE operational ...conditions.•Structural characterization of bioactive compounds obtained by SFE.
An ideal extraction method should be swift, yield quantitative recovery without degradation, and the extracts should be easily separated from the solvent. The development and application of alternative green technology to replace conventional extraction methods with improved extraction efficiency and low environmental impact for the determination of natural bioactive compounds is therefore, highly important. Supercritical fluid technology offers features that overcome many limitations of conventional extraction methods.
This review presents an analytical overview regarding the application of supercritical fluids in the extraction of bioactive compounds and their operative extraction conditions, along with the investigation of further improvements on the extraction efficiency and the applied techniques for the structural characterization and identification of such bioactive compounds.
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•Exhaustive techniques provide higher sensitivities for targeted analysis.•Solventless microextractions are more suitable for on-site determinations.•Microextractions provide ...convenient lab automation.•Microexractions are suitable for non-targeted determinations with minimum matrix effects.
In chemical analysis, sample preparation is frequently considered the bottleneck of the entire analytical method. The success of the final method strongly depends on understanding the entire process of analysis of a particular type of analyte in a sample, namely: the physicochemical properties of the analytes (solubility, volatility, polarity etc.), the environmental conditions, and the matrix components of the sample. Various sample preparation strategies have been developed based on exhaustive or non-exhaustive extraction of analytes from matrices. Undoubtedly, amongst all sample preparation approaches, liquid extraction, including liquid–liquid (LLE) and solid phase extraction (SPE), are the most well-known, widely used, and commonly accepted methods by many international organizations and accredited laboratories. Both methods are well documented and there are many well defined procedures, which make them, at first sight, the methods of choice. However, many challenging tasks, such as complex matrix applications, on-site and in vivo applications, and determination of matrix-bound and free concentrations of analytes, are not easily attainable with these classical approaches for sample preparation.
In the last two decades, the introduction of solid phase microextraction (SPME) has brought significant progress in the sample preparation area by facilitating on-site and in vivo applications, time weighted average (TWA) and instantaneous concentration determinations. Recently introduced matrix compatible coatings for SPME facilitate direct extraction from complex matrices and fill the gap in direct sampling from challenging matrices. Following introduction of SPME, numerous other microextraction approaches evolved to address limitations of the above mentioned techniques. There is not a single method that can be considered as a universal solution for sample preparation. This review aims to show the main advantages and limitations of the above mentioned sample preparation approaches and the applicability and capability of each technique for challenging cases such as complex matrices, on-site applications and automation.
The unfavourable impacts of organic solvents on the environmental and human health have increasingly drawn the attention of scientists and technologists for a long run solution. Recently, ionic ...liquids (ILs) have emerged as an environmentally friendly alternative of choice to reduce the use of organic solvents. This review covers the data of literature published from 2011 to 2021. Literature search was performed for the relevant journal articles including books, and book chapters using the keywords of ‘ionic liquid’, ‘extraction’, ‘medicinal plants’, ‘essential oil’, ‘waste water treatment’, ‘green extraction technology’ and combination of them. ILs are designer solvents due to their modifiable properties according to the application conditions. Therefore, this review highlights the application of ILs in the extraction and purification of bioactive compounds (glycosides, phenolic compounds, flavonoids, alkaloids and others) and essential oils from plant materials. This includes the use of ILs in the microwave and ultrasound assisted extractions, as well as solid phase extraction. Previous studies reported about 20–35 % of increment in the yield of bioactive compounds with the use of ILs.
•Literature review on articles reporting ionic liquids and their applications.•The applications of ionic liquids in the extraction of bioactive compounds and essential oils.•Ionic liquids as green solvent in various conventional and advanced extraction techniques.
Green extraction techniques in green analytical chemistry Armenta, Sergio; Garrigues, Salvador; Esteve-Turrillas, Francesc A. ...
TrAC, Trends in analytical chemistry (Regular ed.),
July 2019, 2019-07-00, Volume:
116
Journal Article
Peer reviewed
Green analytical chemistry concept, involving the development of analytical methodologies with an environmental concern, encourages the use of direct analysis to avoid any sample treatment that ...involves energy and reagent consumption and generation of wastes. However, the determination of target analytes at trace concentration levels or in complex matrices frequently requires previous extraction, pre-concentration, or clean-up steps offering thus, additional possibilities for greening classical methods. So, a green evaluation of alternative extraction techniques to currently used ones for the extraction of solid, liquid, and gaseous samples has been carried out in this study. Moreover, the incidence of the continuous increase of laboratory plastic ware consumption, employed for sample treatment, has been highlighted and discussed as a new challenge to enhance the sustainability of analytical methods.
•Green extraction placed in the frame of green analytical chemistry.•Miniaturization, automation, energy and consumables saving and on-line waste treatment, as greening strategies.•The problem of single use of plastic consumables enlightened.
One of the most cited limitations of capillary (and microchip) electrophoresis is the poor sensitivity. This review continues to update this series of biannual reviews, first published in ...Electrophoresis in 2007, on developments in the field of on‐line/in‐line concentration methods, covering the period July 2012–July 2014. It includes developments in the field of stacking, covering all methods from field‐amplified sample stacking and large‐volume sample stacking, through to ITP, dynamic pH junction, and sweeping. Attention is also given to on‐line or in‐line extraction methods that have been used for electrophoresis.
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