Accelerated solvent extraction for natural products isolation

Accelerated solvent extraction of dioxins sequestered in activated carbon: A response surface methodology-based optimization

Activated carbon (AC) is an effective sorbent for sequestering dioxin-like compounds, thereby reducing their bioavailability. Consequently, AC amendment is a promising tool for remediating dioxin-polluted soils, but tracking remediation results requires quantification of the dioxins sequestered within ACs. Standard methods for quantifying dioxins in soils are often unable to extract dioxins from AC, so the present study addresses this gap by optimizing an accelerated solvent extraction (ASE) method. The incipient wetness method, based on AC pore volume, was found effective for preparing reproducible, homogeneous, and strong dioxin-AC complexes to test extraction processes, and was validated using 14C-2378-TCDD. Preliminary extractions were conducted with AC-sequestered 2378-TCDD, and identified AC surface area, extraction temperature, and solvent system composition as key independent variables. Extraction trials using ASE were performed according to the Box-Behnken response surface methodology, and the resulting data were statistically analyzed to understand the interaction of these variables and model extraction efficiency. This model, derived using 2378-TCDD in AC, was also effective for predicting the extraction efficiencies for all 17 of the most toxic dioxin/furan congeners from three AC materials with specific surface areas from 100 to 1100 m2/g. The optimized extraction methodology achieved an average extraction efficiency of 70-90% for dioxin congeners, depending on the surface area of the AC. This study improves the quantification of dioxins in carbonaceous materials, shows that extraction temperatures above 200 °C are required for higher efficiencies, and paves the way for more reliable assessment and remediation of dioxin-like compounds.

Infrared Laser-Assisted Extraction of Bioactive Compounds from Rosa canina L

The extraction of bio-compounds from medicinal plants provides opportunities for using the plant extract for health benefits. Rosa canina L. is considered a "natural superfood", and the valorization of its active compounds requires an extraction technique that ensures a suitable extraction yield while preserving the compounds' activity. In our study, infrared laser irradiation (IRLIR) technology was used for the first time in the bioactive compound's extraction from Rosa canina L. Different solvents (water-ethanol, hexane-ethanol) and different extraction times were tested to obtain a high extraction yield. Chromatographic and spectrophotometry methods were used to monitor the profile of bioactive compounds and the antioxidant activity of the extracts. The results obtained for IRLIR were compared with those obtained by accelerated solvent extraction (ASE), an advanced extraction method. The IRLIR technology proved to be a more reliable analytical tool for the extraction of (+)-catechin, gallic acid, and lutein. In addition, a richer extract formula was obtained by IRLIR extraction with respect to ASE, with the IRLIR process ensuring a short extraction time, low volume of the extraction solvent, low energy consumption, and a less expensive device.

Bioactive and Biological Potential of Black Chokeberry Leaves Under the Influence of Pressurized Liquid Extraction and Microwave-Assisted Extraction

To determine the optimal conditions of pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE) of polyphenols from black chokeberry leaves (BCL), temperature, time and sample-to-solvent ratio (SSR) were varied to obtain maximum polyphenols yield. The extracts were analyzed for total polyphenols (TP) as well as individual ones (UPLC ESI MS2) and antioxidant capacity (FRAP, DPPH and ORAC). Moreover, the biological activity of the selected extracts was additionally determined. The optimal PLE and MAE conditions were 150 °C, 5 min extraction time and SSR 1:30 g/mL (TP 80.0 mg GAE/g dm), and 70 °C, extraction time 5 min and SSR 1:30 g/mL (TP 36.4 mg GAE/g dm), respectively. Both methods yielded similar polyphenol profiles (43 compounds) but differed quantitatively. MAE extracts contained more flavonols and phenolic acids, while PLE extracts had higher procyanidins and flavan-3-ols. Furthermore, the PLE extract exhibited a superior antioxidant capacity. This BCL extract also showed that it can protect against oxidative and DNA damage and can induce free radical formation and DNA damage, albeit at different doses. Moreover, it had a moderate antimicrobial activity against S. aureus and B. subtilis, while no antimicrobial activity was observed against Gram-negative bacteria as well as yeasts, lactic acid bacteria and molds.

Advanced Extraction Techniques for Bioactive Compounds from Berry Fruits: Enhancing Functional Food Applications

The modern functional food market is developing dynamically, responding to the growing demand for products combining nutritional and health-promoting values. At the center of this evolution are natural bio-organic extracts, rich in bioactive compounds such as antioxidants, polyphenols, flavonoids, carotenoids, and vitamins, which can enrich traditional food products, including fruit juices, increasing their health-promoting values. The aim of the research was to compare the efficiency of extraction of bioactive compounds from various forms of plant raw material (dried, freeze-dried, frozen material) using innovative techniques: supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE). The research showed that the ASE method demonstrated higher extraction efficiency, in some cases exceeding 40%, whereas SFE exhibited superior selectivity, achieving higher carotenoid contents (105.59 mg/100 g in sea buckthorn powder) and antioxidant activity (234.67 µmol TEAC/g in black elderberry fruit). The use of advanced extraction techniques is a modern approach to juice production, in line with current trends in functional food and healthy eating, which can contribute to the prevention of lifestyle diseases.

Valorization of grape (Vitis vinifera) leaves for bioactive compounds: novel green extraction technologies and food-pharma applications

Grape leaves, scientifically known as Vitis vinifera, the primary by-product obtained after the processing of grapes, are gathered in enormous amounts and disposed of as agricultural waste. For more sustainable agriculture and better food systems, it is crucial to investigate these byproducts' nutritional values. The primary bioactive compounds present in grape leaves are quercetin, resveratrol, caffeic acid, kaempferol, and gallic acid, which favour pharmacological effects on human health such as antioxidant, anti-inflammatory, anti-obesity, anti-diabetic, and hepatoprotective. Furthermore, grape leaves extract has been used as a functional ingredient for creating both food and non-food products. The aim of the current review is to review the nutritional and phytochemical composition of various varieties of grape leaves, their health-promoting characteristics and their applications. The study also highlights the various extraction techniques including conventional and non-conventional methods for extracting the various bioactive compounds present in grape leaves. Grape leaves bioactives can be extracted using environmentally safe and sustainable processes, which are in line with the rising demand for eco-friendly and healthful products worldwide. These methods are perfectly suited to the changing needs of both customers and industries since they lessen environmental effect, enhance product quality, and offer financial advantages.

Sterols and pentacyclic triterpenoids from nettle root: content and composition as affected by pressurized liquid extraction

BACKGROUND

Nettle is a medicinal plant rich in bioactive molecules. The composition of nettle leaves and stems has been extensively studied, whereas the root has been insufficiently investigated. Therefore, the present study aimed to optimize the parameters of advanced extraction technique, pressurized liquid extraction (PLE), for the lipid fraction of nettle root rich in triterpenoid derivatives and to compare the efficiency of isolation under optimal conditions with conventional Soxhlet extraction (SE).

RESULTS

The PLE yields ranged from 0.39-1.63%, whereas the total content of triterpenoid derivatives ranged from 43.50-78.26 mg 100 g^-1 , with nine sterols and three pentacyclic triterpenoids identified and quantified within a total range of 42.81-76.57 mg 100 g^-1 and 0.69-1.68 mg 100 g^-1 dried root, respectively. The most abundant sterol and pentacyclic triterpenoid were β-sitosterol and β-amyrin acetate, with mean values of 50.21 mg 100 g^-1 and 0.56 mg 100 g^-1 dried root.

CONCLUSION

The optimal PLE conditions were 150 °C/5 min/four cycles and showed significantly better performance compared to SE (68 °C, 8 h), establishing an excellent technique for the isolation of the nettle root lipid fraction. Also, triterpenoid derivatives from nettle could be used as functional ingredients for the development of new foods and dietary supplements. © 2022 Society of Chemical Industry.

Tuning water chemistry for the recovery of greener products: pragmatic and sustainable approaches

The environmental impact and denaturing propensity of organic solvents in the extraction of plant bioactives pose great challenges in extraction systems. As a result, proactive consideration of procedures and evidence for tuning water properties for better recovery and positive influence on the green synthesis of products become pivotal. The conventional maceration approach takes a longer duration (1-72 h) for product recovery while percolation, distillation, and Soxhlet extractions take about 1 to 6 h. An intensified modern hydro-extraction process was identified for tuning water properties with an appreciable yield similar to organic solvents within 10-15 min. The percentage yield of tuned hydro-solvents achieved close to 90% recovery of active metabolites. The additional advantage of using tuned water over organic solvents is in the preservation of the bio-activities and forestalling the possibility of contamination of the bio-matrices during extractions with an organic solvent. This advantage is based on the fast extraction rate and selectivity of the tuned solvent when compared to the traditional approach. This review uniquely approaches the study of biometabolite recovery through insights from the chemistry of water under different extraction techniques for the very first time. Current challenges and prospects from the study are further presented.

Extraction and utilization of active substances from edible fungi substrate and residue: A review

The expansion of the edible fungi industry has resulted in the production of large amounts of edible fungus residues, causing great pressure on environmental protection.Therefore, research on edible fungus residue utilization has become a controversial issue. Thus far, numerous efforts have been devoted to separate active substances from edible fungus substrates and residues for high application value utilization. Building upon this, the main methods for extracting active substances from edible mushroom residues are reviewed, and the mechanisms, influencing factors, and trade-offs of the various methods are analysed. Furthermore, the existing and possible directions of utilization of the extracted active substances are reviewed and discussed. Finally, challenges and prospects for the extraction and utilization of different substances in edible fungus residues are proposed. This review provides an effective strategy for protecting the ecological environment and promoting the sustainable development of human society.

Spent Coffee Grounds’ Valorization towards the Recovery of Caffeine and Chlorogenic Acid: A Response Surface Methodology Approach

The amount of spent coffee grounds (SCGs) created, represents an environmental challenge worldwide. In this context, the aim of the present study was to exploit the potential of SCGs as a source of bioactive compounds that can be utilized in high value-added products. Thus, a cost-effective and environmentally friendly extraction technique was developed to ensure extracts with high total phenolic content and antioxidant activity, as well as significant amounts of caffeine and chlorogenic acid. Response surface methodology was implemented to evaluate the effects of the main extraction parameters (i.e., time, temperature, and ethanol-to-water ratio) and their interactions on the defined responses. The ethanol ratio was found to be the most significant variable. Then, a set of optimum values was determined (i.e., 7 min, 75 °C, and ethanol:water ratio 5:95), where the predicted values for responses were found to be 5.65% for the yield (Y1), 152.68 mg gallic acid equivalents per L for total phenolic content (Y2), 0.797 μmol Trolox equivalent per mL for the antioxidant activity (Y3), 30.5 ppm for caffeine concentration (Y4), and 17.4 ppm for chlorogenic acid concentration (Y5). Furthermore, the corresponding high experimental values from the validation experiment fitted well to these predictions, clearly clarifying the high potential of SCG extracts for use in high value-added applications.

Extraction of naturally occurring cannabinoids: an update

INTRODUCTION

Organic molecules that interact with the cannabinoid receptors are called cannabinoids, which can be endogenous, natural or synthetic compounds. They possess similar pharmacological properties as produced by the plant, Cannabis sativa L. Before cannabinoids can be analysed, they need to be extracted from the matrices.

OBJECTIVE

To review literature on the methods and protocols for the extraction of naturally occurring cannabinoids.

METHODOLOGY

An extensive literature search was performed incorporating several databases, notably, Web of Knowledge, PubMed and Google Scholar, and other relevant published materials. The keywords used in the search, in various combinations, with cannabinoids and extraction being present in all combinations, were Cannabis, hemp, cannabinoids, Cannabis sativa, marijuana, and extraction.

RESULTS

In addition to classical maceration with organic solvents, e.g. ethanol, pressurised solvent extraction, solvent heat reflux, Soxhlet extraction, supercritical fluid extraction, ultrasound-assisted extraction and microwave-assisted extraction, are routinely used nowadays for the extraction of cannabinoids from plant materials and cannabis consumer products. For the extraction of cannabinoids from biological samples, e.g. human blood, and also from food and beverages, and wastewater, solid-phase extraction and its variants, as well as liquid-liquid extraction are commonly used. Parameters for extraction can be optimised by response surface methodology or other mathematical modelling tools. There are at least six US patents on extraction of cannabinoids available to date.

CONCLUSIONS

Irrespective of the extraction method, extraction temperature, extraction time and extraction pressure play a vital role in overall yield of extraction. Solvent polarity can also be an important factor in some extraction methods.

Bioactive Compounds in Wild Nettle (Urtica dioica L.) Leaves and Stalks: Polyphenols and Pigments upon Seasonal and Habitat Variations

This study evaluated the presence of bioactives in wild nettle leaves and stalks during the phenological stage and in the context of natural habitat diversity. Thus, wild nettle samples collected before flowering, during flowering and after flowering from 14 habitats situated in three different regions (continental, mountain and seaside) were analyzed for low molecular weight polyphenols, carotenoids and chlorophylls using UPLC-MS/MS and HPLC analysis, while the ORAC method was performed for the antioxidant capacity measurement. Statistical analysis showed that, when compared to the stalks, nettle leaves contained significantly higher amounts of analyzed compounds which accumulated in the highest yields before flowering (polyphenols) and at the flowering stage (pigments). Moreover, nettle habitat variations greatly influenced the amounts of analyzed bioactives, where samples from the continental area contained higher levels of polyphenols, while seaside region samples were more abundant with pigments. The levels of ORAC followed the same pattern, being higher in leaves samples collected before and during flowering from the continental habitats. Hence, in order to provide the product's maximum value for consumers' benefit, a multidisciplinary approach is important for the selection of a plant part as well as its phenological stage with the highest accumulation of bioactive compounds.

Recent advances on the sustainable approaches for conversion and reutilization of food wastes to valuable bioproducts

The increasing amounts of food wastage and accumulation generated per annum due to the growing human population worldwide often associated with environmental pollution issues and scarcity of natural resources. In view of this, science community has worked towards in finding sustainable approaches to replace the common practices for food waste management. The agricultural and food processing wastes rich in nutrients are often the attractive substrates for the bioconversion for valuable bioproducts such as industrial enzymes, biofuel and bioactive compounds. The sustainable approaches on the re-utilization of food wastes as the industrial substrates for production of valuable bioproducts has meet the goals of circular bioeconomy, results in the diversify applications and increasing market demands for the bioproducts. This review discusses the current practice and recent advances on reutilization of food waste for bioconversion of valuable bioproducts from agricultural and food processing wastes.