Microwave-assisted Extraction Conditions Research Articles

Optimization of Microwave-Assisted Polyphenol Extraction and Antioxidant Activity from Papaya Peel Using Response Surface Methodology and Artificial Neural Network

The objective of the present study is to determine the optimal conditions of microwave-assisted extraction (MAE) such as microwave power (MWP), irradiation time (I-time), ethanol concentration (EtOH%), and solvent-to-solid ratio (S/S) for maximizing total polyphenol content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity from papaya peel. Box-Behnken design (BBD) was used considering MWP 300–600 W, I-time 60-120 s, EtOH% 30-70%, and S/S 30-70 mL/g. Additionally, response surface methodology (RSM) and artificial neural networks (ANN) were employed for modelling, with cross-validation to enhance reliability. These models were combined with the desirability function (DF) and/or genetic algorithm (GA) optimization approaches. Maximizing TPC and DPPH activity while maintaining MWP, I-time, EtOH%, and S/S within their respective ranges using hybrid optimization approaches (RSM-DF: TPC = 1058 mgGAE/100g, and DPPH = 83%, RSM-GA: TPC = 1064 mgGAE/100g and DPPH = 79%, and ANN-GA: TPC = 1086 mgGAE/100g, and DPPH = 83%,) yielded consistent optimal results. An additional optimization approach (RSM-DF: TPC = 955 mgGAE/100g, and DPPH = 90%), aimed at minimizing MWP, I-time, EtOH%, and S/S while maximizing TPC and DPPH activity, showed a significant reduction of approximately 3 L in ethanol consumption for each 100 g of dry samples. The maximized TPC and DPPH activity in all four approaches showed a significant (p < 0.05) alignment with their corresponding validation tests, demonstrating the better performance of these modelling and optimization processes. In terms of assessing the effectiveness of microwave assistance, conventional solvent extraction was also performed, maintaining a 70 mL/g S/S ratio of 55% ethanol at 60°C for 2 h. This method resulted in lower values of TPC (857 ± 23 g GAE/100g) yield and DPPH activity (72 ± 5%) compared to the optimized condition of MAE.

Optimization of the Microwave-Assisted Extraction Conditions for Phenolic Compounds from Date Seeds.

Date seeds, often discarded during industrial processing, are an underexploited by-product rich in polyphenols with significant antioxidant potential. This study explores the extraction of polyphenols from date seeds using microwave-assisted extraction (MAE) with an organic solvent. The extraction process was optimized using response surface methodology (RSM), focusing on extraction time, ethanol concentration, and temperature. The optimal extraction conditions were 46% (v/v) of ethanol, at 62 °C and for 27.3 min. Under these optimized conditions, the extraction yield and total phenolic content of the extract are 12.5% and 59 mg gallic acid equivalent g-1 of date seed, respectively, as confirmed by the experimental tests. The extract's antioxidant activity was confirmed through DPPH, ABTS, and FRAP assays. High-performance liquid chromatography with diode-array detection (HPLC-DAD) identified major phenolic compounds, including procyanidin B1, catechin, quercetin-3,5'-di-O-glucoside, epicatechin, procyanidin B, and syringic acid, alongside eight other tentatively identified compounds. These findings underscore the potential of MAE as an environmentally friendly technique for producing polyphenol-rich extracts from date seeds, adding value to this by-product and opening avenues for its application in food and nutritional products.

Enhancement of antioxidant properties of Eisenia bicyclis extracts through combination of green extractions: Parameter optimization and comparison

We compared and optimized combined green extraction (CGE) technologies to maximize the antioxidant activity of Eisenia bicyclis through response surface methodology (RSM). Firstly, conventional extraction (CE), microwave assisted extraction (MAE), and supercritical fluid extraction by carbon dioxide (SFE-CO2) were applied to extract and compare antioxidant activities of E. bicyclis. The antioxidant activity results indicated that MAE and SFE-CO2 were superior to CE alone. Based on the optimum conditions for MAE and SFE-CO2, ultrasound-assisted extraction (UAE) and high-pressure processing (HPP) were combining to increase antioxidant activity. SFE-CO2+UAE was selected as the optimum CGE technology. The DPPH-radical scavenging activity and the total phenolic content of E. bicyclis extracts using SFE-CO2+UAE were approximately 2 and 5-fold higher than those of extracts using CE with almost 9-fold higher dieckol content. We demonstrated that E. bicyclis has substantial potential as a natural antioxidant and that CGE is more effective than CE and GE in enhancing antioxidant yields.

Extraction, Characterisation and Utilisation of Bioactive Compounds from Date Fruit

Date fruit (Phoenix dactylifera L.), known for its rich bioactive compounds, was the focus of this study, which aimed to optimize microwave-assisted extraction (MAE) methods for isolating these compounds and developing fortified milk with added date syrup. The research evaluated total phenolic content (TPC) and total flavonoid content (TFC) under varying microwave frequencies, extraction times, and plant-to-solvent ratios. Date fruits were procured, cleaned, processed into powder, and subjected to various MAE conditions, with standard spectrophotometric methods used to quantify TPC and TFC. Optimal extraction conditions for maximum TPC (37±1.1 mg GAE/g) and TFC (460±0.6 mg QE/g) were identified at a microwave frequency of 720 W, an extraction time of 5 minutes, and a plant-to-solvent ratio of 1:15, highlighting the significant influence of microwave power and extraction time on phenolic and flavonoid contents. Furthermore, the research explored the nutritional enhancement of milk through fortification with date syrup, assessing the fortified milk for total soluble solids (TSS), pH, TPC, and TFC, which demonstrated an improved nutritional profile. This research provides valuable insights into the MAE of date fruits and the potential of date syrup in developing functional food products, guiding future studies and industrial applications aimed at enhancing the nutritional and functional properties of food products.

Unlocking the nutraceutical potential of Corylus avellana L. shells: microwave-assisted extraction of phytochemicals with antiradical and anti-diabetic properties.

In recent years, the demand for high-quality natural extracts to be included in nutraceutical formulations has increased sharply. Hazelnut (Corylus avellana L.) shells (HZS) are underrated agricultural by-products that could be exploited as a source of active ingredients with pro-healthy properties. In the present study, a fully green microwave-assisted extraction (MAE) method was established for the first time aiming to recover bioactive constituents from HZS with significant nutraceutical value. Key MAE parameters, including ethanol in water concentration, microwave power, irradiation time and solvent-to-powder ratio, were optimized through response surface methodology utilizing a Box-Behnken design to achieve the highest total phenolic content and antioxidant/antiradical activities in the final extract. The optimal MAE conditions (28% v/v ethanol/water, 270 s, 670 W, and 37 mL g-1) yielded an extract with significant scavenging capacity against reactive oxygen species and remarkable inhibitory activity towards both α-amylase (IC50 = 7.73 μg mL-1) and α-glucosidase (IC50 = 49.44 μg mL-1), demonstrating stronger hypoglycaemic properties than the anti-diabetic drug acarbose. Additionally, fluorescence spectroscopy results highlighted the ability of the optimized extract from HZS (OHS-E) to counteract advanced glycation end-product formation throughout the glycation cascade in a dose-dependent manner. Liquid chromatography/electrospray ionization-tandem mass spectrometry profiling unveiled the presence of fatty acids and phenolic compounds, including lignans, flavonoids, gallic acid derivatives and diarylheptanoids. Lastly, the biocompatibility of OHS-E was attested on HT29-MTX and Caco-2 intestinal cells. Altogether, these findings encourage the potential application of OHS-E as an effective nutraceutical component against type 2 diabetes mellitus and oxidative stress. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Optimization of the conditions for microwave-assisted hot-water extraction of polysaccharides from Cordyceps militaris and analysis of their hypoglycemic activity

Optimization of the conditions for microwave-assisted hot-water extraction of polysaccharides from Cordyceps militaris and analysis of their hypoglycemic activity

Optimization of Sulfated Polysaccharides Extraction from Gracilaria fisheri Obtained Through Microwave-Assisted Extraction

Gracilaria fisheri is a red seaweed that possesses several biological activities. The major important compounds comprising this seaweed are sulfated polysaccharides. However, limited data exists on the optimal extraction conditions for this seaweed using eco-friendly techniques like microwave-assisted extraction (MAE). This work aimed to optimize the MAE conditions for extracting sulfated polysaccharides from G. fisheri. Three factors influencing MAE were investigated: microwave time, solvent-to-solid ratio, and microwave power. These factors were initially screened by varying one factor at a time to identify levels leading to high extraction yields. These levels were then included in a Box-Behnken design. Microwave time was varied from 20 to 40 s, solvent-to-solid ratio from 8:1 to 10:1 mL/g, and microwave power from 300 to 600 W. Two responses were monitored: extraction yield and sulfate content. The optimal condition for both high extraction yield and sulfate content was found to be 30 s of microwave time, a solvent-to-solid ratio of 9.5:1 mL/g, and 450 W of microwave power. This condition yielded 20.32-20.93% extraction yield and 48.28-49.95% sulfate content. The computer program's predictions were accurate and reliable, with a very low percentage error of less than 3%. Therefore, the Box-Behnken design proved to be an effective tool for optimizing the extraction of sulfated polysaccharides from G. fisheri using the MAE method.

Valorization of avocado (Persea americana) residual paste: Microwave-assisted extraction, optimization and addition to an artisanal pork ham

ABSTRACT Recovering biocompounds from industrial by-products is crucial to avoid food waste. Microwave-assisted extraction (MAE) has been employed to recover some biocompounds from vegetal matrices using ethanol and his solutions as solvent. Optimization of MAE conditions over total soluble polyphenols (TSP) and antioxidant capacity (DPPH and FRAP) from avocado residual paste (ARP) from oil industry was carried out. Optimal extract was used to elaborate an artisanal ham. Using response surface methodology (RSM), optimal conditions for MAE were 480 W of power, absolute ethanol as solvent, and extraction time of 180 s. The extract contained TSP of 31.24 mg GAE/g DW, DPPH inhibition of 24.51 mg TE/g DW and FRAP inhibition of 21.58 mg TE/g DW. The extract was added in the ham formulation at 0, 0.5, 1, and 1.5% w/w. Ham with 1% extract had the highest scores for acceptance. Extracts from ARP may be used in ham with adequate sensory attributes.

Optimization of pectin extraction from crab apple peel and usage in a model meat emulsion system

The aim of this study was to optimize conditions of microwave-assisted pectin extraction from crab apple peels using the Box–Behnken experimental design. For this purpose, microwave-assisted pectin extraction was performed at different extraction time (3, 6, and 9 min), liquid/solid ratio (75, 100, and 125), and pH (1.5, 2.0, 2.5). The optimum conditions were selected as extraction time (7.77 min), liquid/solid ratio (77.53 mL/g), and pH/1.79). The response, obtained under optimum conditions was determined as 0.1128 ± 0.0137 g pectin/g crab apple peel. In addition, it was determined that the obtained pectin sample had an esterification degree of 79.14% and oil and water binding capacities of 8.5 ± 0.7 g oil/g pectin and 8.1 ± 1.5 g water/g pectin, respectively. It was determined that pectin emulsions showed higher stability at 1% pectin level. The possibilities of using pectin obtained under optimized conditions as a fat replacer in a model sausage system were investigated. Pectin was evaluated in the model sausage system at two different concentrations. With the increasing pectin concentration, the cooking loss value increased from 14 to 18%, while leakage decreased from 0.31% to 0.18%, showing a negative effect on cooking loss and a positive impact on the amount of leakage into the packaging. Pectin obtained from crab apple peel has the potential to be used for reducing fat content in sausage environment.

Extracting bioactive compounds and proteins from Bacopa monnieri using natural deep eutectic solvents.

This study employed novel extraction methods with natural deep eutectic solvents (NADES) to extract bioactive compounds and proteins from Bacopa monnieri leaves. The conditional influence of ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), and enzymatic-assisted extraction (EAE) on the recovery efficiency of phenolics, proteins, flavonoids, and terpenoids was evaluated. The conditions of UAE were 50 mL/g LSR, 600W of ultrasonic power, and 30% water content with 40°C for 1 min to obtain the highest bioactive compounds and protein contents. The conditions of MAE were 40 mL/g LSR, 400W of microwave power with 30% water content for 3 min to reach the highest contents of biological compounds. The conditions of EAE were 30 mL/g of LSR, 20 U/g of enzyme concentration with L-Gly-Na molar ratio at 2:4:1, and 40% water content for 60 min to acquire the highest bioactive compound contents. Scanning electron microscopy (SEM) is employed to analyze the surface of Bacopa monnieri leaves before and after extraction. Comparing seven extraction methods was conducted to find the most favorable ones. The result showed that the UMEAE method was the most effective way to exploit the compounds. The study suggested that UMEAE effectively extracts phenolics, flavonoids, terpenoids, and protein from DBMP.

Microwave-Assisted Extraction/UHPLC-Q-Orbitrap-MS-Based Lipidomic Workflow for Comprehensive Study of Lipids in Soft Cheese.

In this work, Microwave-Assisted Extraction (MAE) was proposed as an alternative and environmentally friendly technique in lipidomics to study the lipid fingerprint of soft cheeses, such as mozzarella. For method development, a first step concerning an evaluation of extraction solvents was carried out via testing three different mixtures, including methanol/ethyl acetate, isopropanol/ethyl acetate, and ethanol/ethyl acetate, at a 1:2 v/v ratio. The latter was chosen as a solvent mixture for subsequent method optimization. MAE conditions, in terms of solvent volume, time, and temperature, were explored to define their effects on extraction capability through a full factorial experimental design. The best compromise to extract more lipids at the same time was obtained with 24 mL g-1 for solvent-to-solid ratio, 65 °C for temperature, and 18 min for time. Lipid analyses were conducted by UHPLC-Q-Orbitrap-MS associated with multivariate statistics. The developed lipidomic workflow allowed for the extraction of over 400 lipids grouped into 18 different subclasses. The results confirmed that MAE is a suitable technique for lipid extraction in the omics approach with high efficiency, even using low-cost and less toxic solvents. Moreover, a comprehensive structure characterization of extracted lipids, in terms of fatty acid composition and regiochemistry, was carried out.

Optimized microwave-assisted extraction of total phenolic and flavonoid contents from defatted seeds and press residue of Opuntia ficus-indica (l.) mill

Phenolic content of Opuntia ficus indica (OFI) was estimated in samples of seeds and press residue (cake) generated through mechanical oil extraction process. A microwave-assisted extraction (MAE) method was investigated for the optimization of the extracted total phenolic (TPC) and total flavonoid contents (TFC). The influence of extraction parameters on the yields of TPC, TFC were modelled using a second-order regression equation. The optimal MAE conditions were: 61.65 % ethanol concentration, 633.42 W microwave power, 3.59 min irradiation time and 46.28 mL/g solid-to-liquid ratio (SLR) for phenolics extraction, and 54.97 %, 580.04 W, 3.20 min and 47.40 mL/g for flavonoids extraction from defatted seeds powder. The extracts obtained under these conditions showed a TPC and TFC of 416.311±1.154 mg gallic acid equivalent (GAE) per100 g dry weight (DW) and 52.67±0.72 mg quercetin equivalent (QE)/100 g DW, respectively. Regarding press residue, the optimal conditions were 60.26%, 643.89 W, 3.85 min and 47.28 mL/g for phenolics extraction, and 67.96 %, 464.41 W, 2.46 min and 41.04 mL/g for flavonoids extraction; with a TPC and TFC of 400.11±3.14 mg GAE/100 g DW and 38.75±0.16 mg QE/100g DW, respectively. The results of the present study confirmed that OFI seeds and press residues could be considered as a non-negligible source of phenolics with a good antioxidant activity and revealed that MAE is a reliable method for optimizing yields of recovered phytochemicals from such agricultural products derivatives and by-products, with an intent to be scaled-up for industrial, nutraceutical or pharmaceutical applications.

Microwave and ultrasound extraction of antioxidant phenolic compounds from Lantana camara Linn. leaves: Optimization, comparative study, and FT-Orbitrap MS analysis.

The species Lantana camara is used in folk medicine. The biological activities of this medicinal plant are attributable to the presence of various derivatives of triterpenoids and phenolic compounds present in its preparations, indicating excellent economic potential. In this study, the operational conditions of ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) were optimized using Box-Behnken design to improve the total phenolic content (TPC) recovered in hydroethanolic extracts of L. camara leaves. The TPC, total flavonoid content (TFC), and antioxidant activities of the hydroalcoholic extracts of L. camara, prepared by UAE and MAE under the optimized extraction conditions, were compared with those of the extracts obtained by conventional extraction methods. Under the optimal conditions, the extracts obtained by UAE (35% ethanol, 25 min, and a solvent-to-solid ratio of 60:1mL/g) and by MAE (53% ethanol, 15 min, and 300 W) provided high yields of 32.50% and 38.61% and TPC values of 102.89 and 109.83 mg GAE/g DW, respectively. The MAE extract showed the best results with respect to TPC, TFC, and antioxidant activities, followed by extracts obtained by UAE, Soxhlet extraction, decoction, maceration, and infusion, in that order. The results obtained indicate that L. camara may be used as an important source of antioxidant phenolic compounds to obtain products with high biological and economic potential, especially when the extraction process is performed under appropriate conditions using MAE and/or UAE, employing environmentally friendly solvents such as water and ethanol.

Evaluation of Polyphenolic Profile and Antioxidant Activity of Sea Buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) Leaf and Berry Extracts Obtained via Optimized Microwave-Assisted and Accelerated Solvent Extraction

The aim of this study was to optimize parameters of microwave-assisted extraction (MAE) and accelerated solvent extraction (ASE) in terms of extraction temperature and time, microwave power and cycle numbers on the phenolic content of sea buckthorn leaves and berries, using 70% ethanol (v/v) as an extraction solvent. The characterization of phenolic composition in leaf and berry extracts obtained at optimal MAE and ASE conditions was performed with UPLC/ESI-MS2, while antioxidant activity was determined using the ORAC method. The optimal extraction conditions for MAE were 60 °C, 500 W and 15 min for leaves and 60 °C, 300 W, and 10 min for berries. The optimal extraction conditions for ASE from both leaves and berries were 120 °C, 15 min, and 3 cycles. Total phenolic content (TPC) in MAE and ASE extracts from leaves was similar to the TPC determined in extracts obtained by conventional extraction (60 °C/30 min); however, ASE contributed to the higher TPC of the berry extracts. The flavonols kaempferol-3-rutinoside in the leaves and kaempferol in the berries were the most abundant phenols of sea buckthorn. A higher antioxidant activity was found in the leaf extracts obtained by ASE and it correlated with the phenolic content. In general, ASE favored the extraction of all polyphenols from leaves, while MAE was more suitable for the extraction of flavonols from berries, suggesting that the choice of the optimal extraction method is crucial with regard to the target molecules and future applications.

Green3: A green extraction of green additives for green plastics

PLA/PBAT bioplastic is a commercial biodegradable plastic employed for packaging and several food and agriculture applications. In this regard, properties such as the antioxidant ability to extend food shelf life and light resistance, are of great interest in the production of packaging and mulching films, respectively. These features are obtained by developing blends with pure chemicals and/or natural products as additives. In the present work blend formulations of PLA/PBAT with a walnut shell extract rich in antioxidants were developed and evaluated for their properties in comparison with classic PLA/PBAT. Specifically, natural additives, and most importantly the production process were purposely selected to i) be green and cost-effective; ii) confer antioxidant properties; and iii) improve material performance.To this aim, a walnut shell extract (EWS) with high antioxidant activity was obtained thanks to a novel green and cost-effective microwave-assisted extraction (MAE) procedure. A response surface methodology was utilized to explore how the total phenolic content (TPC) and antioxidant activity are influenced by varying aqueous ethanol concentration, extraction time, and microwave power. The highest predicted TPC and antioxidant activity were achieved when employing the ideal conditions for Microwave-Assisted Extraction (MAE): using a mixture of 30 % ethanol in water, an irradiation time of 120 s, and a microwave power of 670 W. The optimized EWS was characterized by HPLC-MS determining qualitative and quantitative data with the identification of flavonoids, fatty acids, and anacardic acids among the main components, responsible for antioxidant activity. The resulting EWS powder was melt-mixed at 140C° and 20 RPM with the bio-based PLA/PBAT bioplastic at two different concentrations (0.5 and 1.5 w/w) by forming film specimens. All EWS-based bioplastic films showed increased antioxidant features determined by the DPPH bleaching test, TEAC, and ORAC assays. The films keep the antioxidant capacity even after 7 days of UV-accelerated aging. Remarkably, adding 1.5 % EWS boosted the bioplastic UV light resistance, reducing the abatement of molecular masses by more than 60 % without affecting mechanical properties.

Green extraction of phenolics and terpenoids from passion fruit peels using natural deep eutectic solvents

AbstractThis work aimed to optimize the ultrasonic‐assisted extraction (UAE) and microwave‐assisted extraction (MAE) of phenolics and terpenoids from passion fruit peels using natural deep eutectic solvents (NADES). NADES formulated with choline chloride and polyols with organic acids were used to investigate the solubility of phenolics and flavonoids in the solvent. Among these formulations, those derived from lactic acid‐glycerine (LGLY) and citric acid‐glucose (CGLU) exhibited the highest efficiency in extracting phenolics and terpenoids, respectively, when combined with UAE. Then one‐factor experiments were conducted to examine the influence of the UAE conditions (liquid‐to‐solid ratios [LSR], water content in NADES, ultrasonic power, time, and temperature) and MAE conditions (LSR, water content in NADES, ultrasonic power, and time) on the extraction yield of phenolics and terpenoids. The Box‐Behnken design (BBD) model was employed to optimize the extraction conditions with conditional ranges determined based on the results of the one‐factor experiments. The optimal conditions for the CGLU‐based MAE of terpenoids were 387 W of microwave power, 30% water content, 2.4 min, and 20 mL/g of LSR. The optimized conditions for LGLY‐based MAE of phenolics were 299 W, 18.7%, 1.3 min, and 10 mL/g. Total terpenoid content acquired from NADES‐based UAE was higher than NADES‐based MAE, while total phenolic content obtained at the optimal conditions of NADES‐based UAE and MAE was statistically insignificant. The efficiency of the two extraction ways was compared to selecting the favorable extraction method for acquiring phenolics and flavonoids from passion fruit peels. The research proposed that NADES‐based UAE was a green and effective method for attaining phenolics and terpenoids from passion fruit peel.Practical applicationPassion fruit peels are a by‐product of beverage production, which causes environmental pollution and increases treatment costs in the factory. These peels contain various bioactive compounds which benefit human health. The traditional extraction method shows low efficiency and high energy consumption. Thus, the appropriate extraction method and green solvents are needed to improve the extraction efficiency of bioactive compounds and can be directly applied to food products. Ultrasonic‐assisted extraction (UAE) and microwave‐assisted extraction (MAE) combined with natural deep eutectic solvents can enhance the extraction efficiency of bioactive compounds. However, the detailed conditions of UAE and MAE are necessary to compare the performance of the two methods. In addition to showing the significant superiority of UAE with MAE, the research showed the optimized conditions of the UAE process, which can be applied on the industrial scale to extract bioactive compounds and directly add them to food products.

Phytochemical compounds with promising biological activities from Ascophyllum nodosum extracts using microwave-assisted extraction

Phytochemical-rich antioxidant extracts were obtained from Ascophyllum nodosum (AN) using microwave-assisted extraction (MAE). Critical extraction factors such as time, pressure, and ethanol concentration were optimized by response surface methodology with a circumscribed central composite design. Under the optimal MAE conditions (3 min, 10.4 bar, 46.8 % ethanol), the maximum recovery of phytochemical compounds (polyphenols and fucoxanthin) with improved antioxidant activity from AN was obtained. In addition, the optimized AN extract showed significant biological activities as it was able to scavenge reactive oxygen and nitrogen species, inhibit central nervous system-related enzymes, and exhibit cytotoxic activity against different cancer cell lines. In addition, the optimized AN extract showed antimicrobial, and anti-quorum sensing activities, indicating that this extract could offer direct and indirect protection against infection by pathogenic microorganisms. This work demonstrated that the sustainably obtained AN extract could be an emerging, non-toxic, and natural ingredient with potential to be included in different applications.

Efficient extraction of quassinoids and alkaloids from Eurycoma longifolia Jack roots using natural deep eutectic solvents and microwave-assisted extraction

Eurycoma longifolia Jack (EL) extracts have immunomodulatory and anti-inflammatory effects and are utilized in the treatment of male sexual dysfunctions. Water-based extraction methods for hydrophobic and bioactive components of EL are often inefficient and energy-intensive. Therefore, this study aimed to develop an efficient and environmentally friendly method for extracting EL quassinoids and alkaloids using natural deep eutectic solvents (NADESs) and microwave-assisted extraction (MAE). The NADES-based MAE method employed an optimized NADES comprising choline chloride, citric acid, glucose, and water (CCGW). CCGW provided higher extraction yields of eurycomanone (EU, 1.608 ± 0.004 mg/g) and 9-methoxy-canthin-6-one (9MCO, 0.3022 ± 0.0007 mg/g) than water-based extraction under optimal MAE conditions, as determined using Box–Behnken Design of Response Surface Methodology. CCGW effectively extracted both polar quassinoids and less-polar alkaloids from EL roots. While concentrated NADES had an impact on RAW264.7 cell viability, the use of diluted CCGW did not enhance the cytotoxicity of both EU and 9MCO compared to their preparation in water. The anti-inflammatory activity of 9MCO, prepared in diluted CCGW, was equivalent to that of the compound prepared in water. The cytotoxicity of both compounds in Vero cells was higher when coupled with CCGW than their preparation in water. The NADES-based MAE method is an efficient approach for extracting bioactive components from EL.

Process optimization of microwave-assisted aqueous extraction of tannins and saponins from Malabar Spinach (Basella alba) leaves using ANN-GA and RSM methodology

The effect of microwave-assisted aqueous extraction (MAE) conditions on the recovery and quantification of tannins and saponins from Basella alba leaves has been explored. The experiment was carried out according to the Box-Behnken experimental design of response surface methodology (RSM) with 17 runs. The independent variables of the study were microwave power (100 to 300 W), treatment time (5 to 15 min), and feed/solvent ratio (0.025 to 0.05). The effect of extraction conditions on the response variables, total condensed tannin, total hydrolyzed tannin, and total saponin content, were predicted using RSM and artificial neural network-genetic algorithm (ANN-GA) methodology. The extracted values of total condensed tannin, total hydrolyzed tannin, and total saponin content, using RSM and ANN-GA were compared and evaluated for goodness of fit. The predicted values using RSM and ANN-GA models for total condensed tannin were found to be 0.18 and 0.26 mg TAE g−1, total hydrolyzed tannin were 0.14 and 0.15 mg TAE g−1, and total saponin content were 1.66 and 1.49 mg DE g−1, respectively. When compared to RSM, ANN-GA demonstrated higher value of R2 and lower values of other statistical parameters. Additionally, the predicted value of ANN-GA was more closely aligned with the experimental value.

Microwave-assisted extraction optimization of sesquiterpene lactones from Inula helenium roots: A sustainable approach to reduce energy consumption and carbon footprint.

Inula helenium roots are consumed as natural flavor components and raw or cooked as food, and their extracts are rich in sesquiterpene lactones such as alantolactone (AL) and isoalantolactone (IAL), which have recently attracted great attention due to their pharmacological properties. The industrial utilization of these compounds requires the development of green, efficient, cost-effective, and sustainable extraction protocols. Therefore, this study focused on the optimization of microwave-assisted extraction (MAE) process variables using Face-Centered Central Composite Design (FC-CCD). Then, maceration was applied as a conventional technique, and these techniques were compared in terms of extraction efficiency, morphological changes, antimicrobial activities, carbon emissions, and energy consumption. As a result, optimal MAE conditions, i.e., EtOH: water ratio (X 1) = 100:0, liquid/sample ratio (X 2) = 30:1 mL/g, microwave power (X 3) = 300 W, and irradiation time (X 4) = 5 min, were obtained with AL and IAL yields of 54.99 ± 0.11 (mg/g) and 48.40 ± 0.19 (mg/g), respectively. The extract obtained by MAE had similar or better activity than positive controls in most cases and formed the largest inhibition zones against E. coli (29.5 ± 0.71 mm) and A. niger (34.75 ± 1.06 mm). Morphological changes of I. helenium roots after extraction were observed by scanning electron microscopy. Additionally, MAE was 43.4 times faster than maceration, resulting in 228.6 times less energy consumption and carbon emissions. Based on these findings, it is recommended to use MAE as an industrial green technique for the extraction of sesquiterpene lactones with potential applications in nutraceuticals and food products in terms of sustainable economy and environmental protection.