Microwave-assisted extractions of active ingredients from plants

Recent progress in the extraction of terpenoids from essential oils and separation of the enantiomers by GC-MS

Terpenoids possess significant physiological activities and are rich in essential oils. Some terpenoids have chiral centers and could form enantiomers with distinct physiological activities. Therefore, the extraction and separation of terpenoids enantiomers are very important and have attracted extensive attention in recent years. Meanwhile, the specific distribution and enantiomer excess results (the excess of one enantiomer over the other in a mixture of enantiomers) could be used as quality markers for illegitimate adulteration, origin identification, and exploring component variations and functional interrelations across different plant tissues. In this study, an overview of the progress in the extraction of terpenoids from essential oils and the separation of their enantiomers over the past two decades has been made. Extraction methods were retrieved by the resultant network visualization findings. The results showed that the predominant methods are hydrodistillation, solvent-free microwave extraction, headspace solid-phase microextraction and supercritical fluid extraction methods. GC-MS combined with chiral chromatography columns is commonly used for the separation of enantiomers, while 2D GC is found to have stronger resolution ability. Finally, some prospects for future research directions in the extraction and separation identification of essential oils are proposed.

Optimized microwave-assisted azadirachtin extraction using response surface methodology

The neem tree (Azadirachta indica A. Juss) is grown mainly for shade, fuel, and numerous non-timber forest products using its leaves, fruit, and bark. It produces an essential oil that is used as a source for obtaining bioinsecticides, with a broad spectrum of action in agricultural production. Its bioinsecticidal activity is due to the presence of triterpenes, such as azadirachtin, a product in continued growth of the global biopesticide market. Optimal conditions for neem oil extraction using response surface methodology (RSM) and microwave-assisted extraction (MAE) methods have been defined. However, the extraction conditions for these methods tend to consume high volumes of organic solvent and long extraction times. The aim of the present study is to determine the optimal conditions for the extraction of azadirachtin from neem seeds in a hydroalcoholic medium using MAE and RSM with a Box-Behnken design (BBD). A BBD was applied to evaluate the effects of the factors, magnetron voltage (X1), extraction time (X2), and pH of the extraction medium (X3), on the yield of the azadirachtin extraction process. The effect of each variable on the extraction yield was studied independently, considering the pure coefficients (linear and quadratic) on the three levels that were studied in the experiments. Moreover, the study experiments were conducted in triplicate, data were presented as mean and standard deviation, homogeneity of variances was estimated using Levene's test, and a two-way ANOVA with Tukey's post hoc analysis was performed to identify the experimental conditions that allowed us to find the highest extraction yield and to analyze whether the response surface model adequately described our data. The most significant effects of the model correspond to quadratic and interaction effects (p < 0.0001); the quadratic terms voltage (X1), extraction time (X2), and pH (X3); and the interaction effects between voltage-pH (X1*X3) and time-pH (X2*X3), which had a significant influence on the model. Moreover, a canonical analysis was performed. The optimal conditions were as follows: 69.22 V, 6.89 min, and a pH value of 4.35, coinciding with the zones shown in the contour plots. Furthermore, the response obtained at the optimal conditions was 37.5 μg of azadirachtin per gram of pretreated seed.

Potential use of yeast protein in terms of biorefinery, functionality, and sustainability in food industry

A growing demand for sustainable, alternative protein sources that are nutrient-dense, such as microorganisms, and insects, has gradually evolved. When paired with effective processing techniques, yeast cells contain substantial substances that could supply the population's needs for food, medicine, and fuel. This review article explores the potential of yeast proteins as a sustainable and viable alternative to animal and plant-based protein sources. It highlights the various yeast protein extraction methods including both mechanical and non-mechanical methods. The application of nanoparticles is one example of the fast-evolving technology used to damage microbial cells. SiO2 or Al2O3 nanoparticles break yeast cell walls and disrupt membranes, releasing intracellular bioactive compounds. Succinylation of yeast protein during extraction can increase yeast protein extraction rate, lower RNA concentration, raise yeast protein solubility, increase amino acid content, and improve yeast protein emulsification and foaming capabilities. Combining physical and enzymatic extraction methods generates the most representative pool of mannose proteins from yeast cell walls. Ethanol or isoelectric precipitation purifies mannose proteins. Mannoproteins can be used as foamy replacement for animal-derived components like egg whites due to their emulsification, stability, and foaming capabilities. Yeast bioactive peptide was separated by ultrafiltration after enzymatic hydrolysis of yeast protein and has shown hypoglycemic, hypotensive, and oxidative action in vitro studies. Additionally, the review delves into the physicochemical properties and stability of yeast-derived peptides as well as their applications in the food industry. The article infers that yeast proteins are among the promising sources of sustainable protein, with a wide range of potential applications in the food industry.

Polycyclic aromatic hydrocarbon (PAH) accumulation in selected medicinal plants: a mini review

The use of plant-based products in healthcare systems has experienced a tremendous rise leading to a substantial increase in global demand. However, the quality and effectiveness of such plant-based treatments are often affected due to contamination of various pollutants including polycyclic aromatic hydrocarbons (PAHs). Like other plants, medicinal plants also uptake and accumulate PAHs when exposed to a contaminated environment. The consumption of such medicinal plants and/or plant-based products causes negative effects on health rather than providing any therapeutic advantages. Unfortunately, research focusing on PAH accumulation in medicinal plants has received very limited attention. This review discusses a sizable number of literature regarding the concentration of sixteen priority PAH pollutants as recognised by the US Environmental Protection Agency (USEPA) in different medicinal plants. The review also highlights the risk assessment of cancer associated with some medicinal plants in terms of benzo[a]pyrene (BaP) equivalent concentrations.

Optimization of Extraction Conditions of Bioactive Compounds From Kurdistan Species Urtica dioica

INTRODUCTION

Phytotherapeutics derived from medicinal plants treat various illnesses, including viral infections such as SARS, MERS, and SARSCoV-2, as well as bacterial and fungal diseases. It highlights ongoing research into the chemical compositions of plant components for developing new drugs, with a particular emphasis on anti-cytotoxic agents for anticancer drugs. Traditional extraction methods have limitations, leading to the exploration of environmentally friendly technologies such as ultrasound-assisted, supercritical fluid, microwave-assisted, and accelerated solvent extraction. The paragraph concludes by stating the aim of a specific study to optimize extraction conditions of bioactive compounds from Urtica dioica in Kurdistan, comparing conventional and non-conventional extraction methods, solvents, and extraction times.

MATERIALS AND METHODS

The study was conducted between June 2022 and August 2022, fresh leaves and stems of U. dioica plant were collected and sequentially underwent four extraction methods (maceration, Soxhlet, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) by using petroleum ether, chloroform, ethanol, and distilled-water as solvents.

RESULTS

The results highlighted significant variations in the yields of bioactive compounds based on the extraction method, solvent type, and duration. Among conventional methods, Soxhlet was the most powerful method and had the most extraction yields, while maceration had the lowest yields. The modern techniques surpassed the conventional methods by producing high extraction yields within a shorter time (a few minutes) and using a lesser amount of solvent. Consequently, UAE and MAE emerge as the most efficient techniques. Hence, MAE effectively produced the highest extraction yields and is considered the preferred technique. The choice of solvents significantly influenced the extraction yields, with ethanol consistently emerging as an effective solvent across various extraction methods. In contrast, petroleum ether demonstrated the lowest efficacy as a solvent. Furthermore, the results unveiled the impact of extraction time on yields, indicating a correlation between increased time and extraction yield in certain cases.

CONCLUSION

Extraction is a very critical step in the study of medicinal plants. The amount of extracted compounds is significantly affected by the extraction method, solvent, and time. Ethanol stands out as the most effective solvent, producing the highest yields of bioactive compounds, while petroleum ether yields the least. Additionally, extraction yield shows a direct relation with extraction time. Soxhlet being the most powerful among conventional methods and maceration yields the least. Modern techniques, particularly UAE and MAE, surpass conventional methods by achieving high yields in shorter times with less solvent. MAE, in particular, offers advantages such as shortened extraction time, increased efficiency, reduced labor, and enhanced selectivity, making it the preferred method for extracting bioactive compounds from aerial parts U. dioica.

Alternative Assisted Extraction Methods of Phenolic Compounds Using NaDESs

A renewed understanding of eco-friendly principles is moving the industrial sector toward a shift in the utilization of less harmful solvents as a main strategy to improve manufacturing. Green analytical chemistry (GAC) has definitely paved the way for this transition by presenting green solvents to a larger audience. Among the most promising, surely DESs (deep eutectic solvents), NaDESs (natural deep eutectic solvents), HDESs (hydrophobic deep eutectic solvents), and HNaDESs (hydrophobic natural deep eutectic solvents), with their unique features, manifest a wide-range of applications, including their use as a means for the extraction of small bioactive compounds. In examining recent advancements, in this review, we want to focus our attention on some of the most interesting and novel 'solvent-free' extraction techniques, such as microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) in relation to the possibility of better exploiting DESs and NaDESs as plausible extracting solvents of the phenolic compounds (PCs) present in different matrices from olive oil components, such as virgin olive pomace, olive leaves and twigs, virgin and extra virgin olive oil (VOO and EVOO, respectively), and olive cake and olive mill wastewaters (OMWW). Therefore, the status of DESs and NaDESs is shown in terms of their nature, efficacy and selectivity in the extraction of bioactive phytochemicals such as secoiridoids, lignans, phenolic acids and alcohols. Related studies on experimental design and processes' optimization of the most promising DESs/NaDESs are also reviewed. In this framework, an extensive list of relevant works found in the literature is described to consider DESs/NaDESs as a suitable alternative to petrochemicals in cosmetics, pharmaceutical, or food applications.

Plant Protein-Derived Active Peptides: A Comprehensive Review

Active peptides are a class of physiologically active protein fragments, which can be prepared from different sources. In the past few decades, the production of peptides with various effects from different plant proteins continues to receive academic attention. With advances in extraction, purification, and characterization techniques, plant protein-derived active peptides continue to be discovered. They have been proven to have various functional activities such as antioxidant, antihypertensive, immunomodulatory, antimicrobial, anti-inflammatory, antidiabetic, antithrombotic, and so on. In this review, we searched Web of Science and China National Knowledge Infrastructure for relevant articles published in recent years. There are 184 articles included in this manuscript. The current status of plant protein-derived active peptides is systematically introduced, including their sources, preparation, purification and identification methods, physiological activities, and applications in the food industry. Special emphasis has been placed on the problems of active peptide exploration and the future trend. Based on these, it is expected to provide theoretical reference for the further exploitation of plant protein-derived active peptides, and promote the healthy and rapid development of active peptide industry.

Opuntia Ficus-Indica Peel By-Product as a Natural Antioxidant Food Additive and Natural Anticoccidial Drug

The present study was carried out to valorize the Opuntia ficus-indica (OFI) by-products by extracting and identifying their biochemical compounds and evaluating their antioxidant potential by in vitro activities (DPPH radical and FRAP), as well as their capacity to stabilize margarine oxidation (rancimat test). In addition, their in vitro anticoccidial effect on the destruction of Eimeria oocysts isolated from naturally infected chickens was also targeted. Microwaves and response surface methodology tools were used to extract the maximum amount of phenolic compounds (42.05 ± 0.46 GAE mg/g DW of total phenolic compounds in 90 s at 400 watts). Moreover, the effect of extraction factors was also studied. Eight phenolic compounds, including isorhamnetin, dihydrokaempferol, and kaempferol-3-O-rutinoside, were identified. The findings confirmed that OFI peel extract has strong antioxidant activities (DPPH radical, ferric reducing power). The rancimat test shows that OFI peel extract improves margarine stability by 3.2 h. Moreover, it has a notable destruction rate of Eimeria oocysts (30.06 ± 0.51%, LC50: 60.53 ± 0.38 mg/mL). The present investigation offers promise for the reuse of food waste as natural margarine additives, protection of the environment, and substitution of anticoccidial synthetic treatments.

Evaluation of maceration, microwave, ultrasound-assisted extraction methods on free, esterified and bound phenolic profile and antioxidant activity of black rice

Black rice (Oryza sativa L.) is a rich source of phenolics and anthocyanins. It was aimed to investigate the effect of different extraction methods such as conventional solvent extraction, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) on antioxidant activity and phenolic profiling of black rice free, esterified, and bound phenolics fractions. Spectrophotometric methods were used to evaluate antioxidant activity and HPTLC was used for phenolics profiling. The highest content of % yield, total anthocyanin (TAC), total phenolic (TPC), and total flavonoid (TFC) contents were detected in MAE. It was also observed that antioxidant activity based on DPPH, ABTS, superoxide radical-scavenging and ferric reducing antioxidant power (FRAP) assays showed highest activity in MAE. Eight phenolic compounds were identified and quantified by a validated HPTLC method. MAE showed most abundant phenolic compounds. A significant positive correlation was established between % yield, total phenolic content, and total flavonoid content (p < 0.05) where a significant negative correlation was established between % yield, TPC, and TFC with IC50 of antioxidant activity (p < 0.05). Diverse phenolic contents and antioxidant activity were studied with different forms of phenolics with the different extraction methods. It designates that the extraction techniques had effects on the bioactive compounds as well biological properties.

Dynamic high pressure microfluidization-assisted extraction of plant active ingredients: a novel approach

The extraction method has a great influence on the yield, quality, chemical structure, and biological activities of active ingredients. Safe and efficient extraction of active ingredients is one of the important problems facing the food and pharmaceutical industry. As a pretreatment approach for the extraction of active ingredients, dynamic high pressure microfluidization (DHPM) is a promising strategy that can not only effectively increase the yield of active ingredients but also strengthen the bioactivities of active ingredients, and take the advantages of mild operating temperature and environmental friendliness. In this review, the research progress of DHPM-assisted extraction of active ingredients from plant materials in recent ten years is overviewed. The DHPM equipment, strengthening mechanism, operating procedure, critical factors and application of DHPM-assisted extraction are introduced in detail, together with the advantages and disadvantages. Furthermore, its future development trend is discussed at the end. DHPM-assisted extraction is considered as the ideal technique of better homogenization effects, less solvent consumption, more reliable operation, and so on, making it a promising method to acquire active ingredients efficiently. Therefore, this technique is worthy of further theoretical research and experimental operation.

Natural complex substances: From molecules to the molecular complexes. Analytical and technological advances for their definition and differentiation from the corresponding synthetic substances

Natural complex substances (NCSs) are a heterogeneous family of substances that are notably used as ingredients in several products classified as food supplements, medical devices, cosmetics and traditional medicines, according to the correspondent regulatory framework. The compositions of NCSs vary widely and hundreds to thousands of compounds can be present at the same time. A key concept is that NCSs are much more than the simple sum of the compounds that constitute them, in fact some emerging phenomena are the result of the supramolecular interaction of the constituents of the system. Therefore, close attention should be paid to produce and characterize these systems. Today many natural compounds are produced by chemical synthesis and are intentionally added to NCSs, or to formulated natural products, to enhance their properties, lowering their production costs. Market analysis shows a tendency of people to use products made with NCSs and, currently, products made with ingredients of natural origin only are not conveniently distinguishable from those containing compounds of synthetic origin. Furthermore, the uncertainty of the current European regulatory framework does not allow consumers to correctly differentiate and identify products containing only ingredients of natural origin. The high demand for specific and effective NCSs and their high-cost offer on the market, create the conditions to economically motivated sophistications, characterized by the addition of a cheap material to a more expensive one, just to increase profit. This type of practice can concern both the addition of less valuable natural materials and the addition of pure artificial compounds with the same structure as those naturally present. In this scenario, it becomes essential for producers of natural products to have advanced analytical techniques to evaluate the effective naturalness of NCSs. In fact, synthetically obtained compounds are not identical to their naturally occurring counterparts, due to the isotopic composition or chirality, as well as the presence of different trace metabolites (since pure substances in nature do not exist). For this reason, in this review, the main analytical tests that can be performed to differentiate natural compounds from their synthetic counterparts will be highlighted and the main analytical technologies will be described. At the same time, the main fingerprint techniques useful for characterizing the complexity of the NCSs, also allowing their identification and quali-quantitative evaluation, will be described. Furthermore, NCSs can be produced through different manufacturing processes, not all of which are on the same level of quality. In this review the most suitable technologies for green processes that operate according to physical extraction principles will be presented, as according to the authors they are the ones that come closest to creating more life-cycle compatible NCSs and that are well suited to the European green deal, a strategy with the aim of transforming the EU into a sustainable and resource-efficient society by 2050.

Current status, technology, regulation and future perspectives of essential oils usage in the food and drink industry

Nowadays, essential oils (EOs) have a wide use in many applications such as in food, cosmetics, pharmaceutical and animal feed products. Consumers' preferences concerning healthier and safer foodstuffs lead to an increased demand for natural products, in replacement of synthetic substances, used as preservatives, flavourings etc. EOs, besides being safe, are promising alternatives as natural food additives, and much research has been carried out on their antioxidant and antimicrobial activity. The initial purpose of this review is to discuss conventional and 'green' extraction techniques along with their basic mechanism for the isolation of EOs from aromatic plants. This review aims to provide a broad overview of the current knowledge about the chemical constitution of EOs while considering the existence of different chemotypes, since bioactivity is attributed to the chemical composition - qualitative and quantitative - of EOs. Although the food industry primarily uses EOs as flavourings, an overview on recent applications of EOs in food systems and active packaging is provided. EOs exhibit poor solubility in water, oxidation susceptibility, negative organoleptic effect and volatility, restricting their use. Encapsulation techniques have been proven to be one of the best approaches to preserve the biological activities of EOs and minimize their effects on food sensory qualities. Herein, different encapsulation techniques and their basic mechanism for loading EOs are discussed. EOs are highly accepted by consumers, who are often under the misconception that 'natural' means safe. This is, however, an oversimplification, and the possible toxicity of EOs should be taken into consideration. Thus, in the final section of the current review, the focus is on current EU legislation, safety assessment and sensory evaluation of EOs. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Microwave-Assisted Dispersive Liquid-Liquid Microextraction Combined with HPLC for the Determination of Three Biogenic Amines in Beverages

Microwave-assisted dispersive liquid-liquid microextraction (MADLLME) coupled with high-performance liquid chromatography (HPLC) with diode array detector was used for the extraction and determination of three biogenic amines (BAs), including tryptamine, histamine and phenylethylamine in beverages (beer, cherry juice and white spirit). Compared with solid-phase extraction, solid-phase microextraction and liquid-phase microextraction, which is more solvent use with lower extraction efficiency, this MADLLME method obviously shortened analytical time, the rapid heating of aqueous samples with non-ionizing electromagnetic radiation, a lower solvent use and enhanced extraction efficiency. Because of good extraction for three BAs, [3C6PC14][FeCl4] was used as an extraction solvent. We showed a tunable selectivity of magnetic ionic liquids (MILs) toward extracting BAs by changing anion or cation due to the modification of the interaction between the MIL and the BAs. Extraction conditions including the type and volume of extraction solvent, microwave power, microwave-assisted extraction time, sample pH, disperser and interference experiment were investigated. Under the optimal conditions, a good linear relationship was found in the concentration range of 100-2,000 ng mL-1 for three BAs with correlation coefficient (R2) of 0.995-0.999. The limit of detections (S/N = 3) and limit of quantitations (S/N = 10) were in the range of 3.46-4.96 ng mL-1 and 10.44-14.88 ng mL-1, respectively. The recoveries of three targets were in the range of 84.3-108.5%, and the relative standard deviations based on the peak areas for six replicate analyses of beverages spiked with 10, 50 and 100 ng mL-1 of each biogenic amine were lower than 7.9%. This method has also been successfully applied to analyze the real samples at three different spiked concentrations, and excellent results have been obtained.

Phytochemical and Pharmacological Properties of a Traditional Herb, Strobilanthes Cusia (Nees) Kuntze

The present investigation aimed to determine the effectiveness of bioactive components extracted from Hom herbs (Strobilanthes cusia (Nees) Kuntze) using the solvent-free microwave-assisted extraction (MAE) method. The obtained bioactive components were analyzed for total phenolic content (TPC) and active ingredient content. The Hom extracts were examined for antioxidant, antibacterial, anti-inflammatory, cytotoxic, and anticancer activities. The comparative analysis of extraction methods MAE was studied by using different solvents such as ethanol (EtOH), 50% ethanol (50EtOH) and distilled water (DW). The results obtained by the MAE method with DW as solvent show the TPC of 104.41±1.36 mg GAE/g crude and tryptanthrin 0.1138±0.0014 mg/g crude and indigo 0.0622±0.0015 mg/g crude. Comparatively, values ​​detected in the 50% EtOH extract were not significantly different at the 95% confidence level. At the same time, levels of indirubin were detected at levels equivalent to that of ethanol extracts. The DW extract from MAE had an IC50 value against the DPPH scavenging assay of 0.1927±0.0756 mg/ml, comparable to the test results of extracts of ethanol and 50% ethanol. The bioactive extracted using the MAE with water as solvent had minimum inhibitory concentration (MIC) and could suppress infection at 10 mg/disc. It was also observed that the extracts from the conventional extraction technique using ethanol as the solvent continued to be highly effective against Bacillus cereus even after employing the EtOH or 50% EtOH. Hom extract's MIC value representing inhibiting B. cereus was 0.625 mg/disc. Still, EtOH-extracted Hom demonstrated the highest cytotoxicity against 16HBEo- by reducing cell survival rate by less than 50% while the others did not. Interestingly, Hom that had been extracted using 50EtOH and DW with MAE had an anticancer impact on A549 by reducing the survival rate in a dose-dependent manner.

Rutin: Family Farming Products' Extraction Sources, Industrial Applications and Current Trends in Biological Activity Protection

In vitro and in vivo studies have demonstrated the bioactivity of rutin, a dietary flavonol naturally found in several plant species. Despite widespread knowledge of its numerous health benefits, such as anti-inflammatory, antidiabetic, hepatoprotective and cardiovascular effects, industrial use of rutin is still limited due to its low solubility in aqueous media, the characteristic bitter and astringent taste of phenolic compounds and its susceptibility to degradation during processing. To expand its applications and preserve its biological activity, novel encapsulation systems have been developed. This review presents updated research on the extraction sources and methodologies of rutin from fruit and vegetable products commonly found in a regular diet and grown using family farming approaches. Additionally, this review covers quantitative analysis techniques, encapsulation methods utilizing nanoparticles, colloidal and heterodisperse systems, as well as industrial applications of rutin.

Comparison between Ultrasound- and Microwave-Assisted Extraction Methods to Determine Phenolic Compounds in Barley (Hordeum vulgare L.)

Barley (Hordeum vulgare L.) is one of the major cereal crops worldwide. It is grown not only to be used as fodder but also for human consumption. Barley grains are a great source of phenolic compounds, which are particularly interesting for their health-promoting antioxidant properties, among other benefits. Two extraction methods, namely ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), have been optimized and compared by using Box-Behnken design (BBD) to determine both the antioxidant power and the phenolic compound levels of the extracts. Three variables have been assessed based on these designs: solvent composition (% MeOH in water), temperature (°C), and sample-to-solvent ratio (mg sample mL^-1 solvent). The solvent composition used and the interaction between the solvent and the temperature were the most significant variables in terms of recovery of phenolic compounds and antioxidant capacity of the extracts. Short extraction times, a high precision level, and good recoveries have been confirmed for both methods. Moreover, they were successfully applied to several samples. Significant differences regarding the level of phenolic compounds and antioxidant power were revealed when analyzing three different barley varieties. Specifically, the amounts of phenolic compounds ranged from 1.08 to 1.81 mg gallic acid equivalent g^-1 barley, while their antioxidant capacity ranged from 1.35 to 2.06 mg Trolox equivalent g^-1 barley, depending on the barley variety. Finally, MAE was found to be slightly more efficient than UAE, presenting higher levels of phenolic compounds in the extracts.

Advances in Natural Product Extraction Techniques, Electrospun Fiber Fabrication, and the Integration of Experimental Design: A Comprehensive Review

The present review explores the growing interest in the techniques employed for extracting natural products. It emphasizes the limitations of conventional extraction methods and introduces superior non-conventional alternatives, particularly ultrasound-assisted extraction. Characterization and quantification of bioactive constituents through chromatography coupled with spectroscopy are recommended, while the importance of method development and validation for biomarker quantification is underscored. At present, electrospun fibers provide a versatile platform for incorporating bioactive extracts and have extensive potential in diverse fields due to their unique structural and functional characteristics. Thus, the review also highlights the fabrication of electrospun fibers containing bioactive extracts. The preparation of biologically active extracts under optimal conditions, including the selection of safe solvents and cost-effective equipment, holds promising potential in the pharmaceutical, food, and cosmetic industries. Integration of experimental design into extraction procedures and formulation development is essential for the efficient production of health products. The review explores potential applications of encapsulating natural product extracts in electrospun fibers, such as wound healing, antibacterial activity, and antioxidant properties, while acknowledging the need for further exploration and optimization in this field. The findings discussed in this review are anticipated to serve as a valuable resource for the processing industry, enabling the utilization of affordable and environmentally friendly, natural, and raw materials.

Antioxidant and Anti-Cytotoxicity Effect of Phenolic Extracts from Psidium guajava Linn. Leaves by Novel Assisted Extraction Techniques

Phytochemicals (PCs) are gaining popularity due to their antioxidant effects and potential protection against infection, cardiovascular disease, and cellular metabolic activity. These PCs must be retained as much as possible during extraction. This research focused on the extraction of PC from Psidium guajava Linn. leaves due to higher antioxidant potential. Solvent extraction (SE), microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE) using distilled water (DW) or 60% (v/v) ethanol/water (ET) were used for the extraction of PC. ET shows higher total phenolic (TPC) and total flavonoid content (TFC) as well as higher antioxidant activity than DW. Phytochemical screening demonstrated that all of the screening showed positive results in all extraction methods, except glycoside. There were no significant differences (p > 0.05) in TPC and TFC during MAE/ET, SE/ET, and UAE/ET. Antioxidant analysis shows that MAE and SE resulted in high (p < 0.05) DPPH and FRAP values for ET and DW, respectively. MAE/ET showed the highest inhibitory activity (IC₅₀ = 16.67 µg/mL). HPLC and TLC analysis reveal the fingerprint of morin, which might function as an anticancer agent with other bioactives. Increasing the extract content increased the inhibitory activity of SW480 cells via MTT assay. In conclusion, MAE/ET is the most efficient among the extraction techniques in terms of anti-cytotoxicity effects.

Valorization of Peanut Skin as Agricultural Waste Using Various Extraction Methods: A Review

Peanuts (Arachis hypogea) can be made into various products, from oil to butter to roasted snack peanuts and candies, all from the kernels. However, the skin is usually thrown away, used as cheap animal feed, or as one of the ingredients in plant fertilizer due to its little value on the market. For the past ten years, studies have been conducted to determine the full extent of the skin's bioactive substance repertoire and its powerful antioxidant potential. Alternatively, researchers reported that peanut skin could be used and be profitable in a less-intensive extraction technique. Therefore, this review explores the conventional and green extraction of peanut oil, peanut production, peanut physicochemical characteristics, antioxidant activity, and the prospects of valorization of peanut skin. The significance of the valorization of peanut skin is that it contains high antioxidant capacity, catechin, epicatechin resveratrol, and procyanidins, which are also advantageous. It could be exploited in sustainable extraction, notably in the pharmaceutical industries.

Review of available "extraction + purification" methods of natural ceramides and their feasibility for sewage sludge analysis

Natural ceramide, a biologically active compound present in plants, has been used widely in food, cosmetics, and pharmaceutical industries. Abundant ceramide has been detected in sewage sludge, which has inspired the idea to recycle ceramide from it. Therefore, the methods of extracting, purifying, and detecting ceramides from plants were reviewed, with the aim to establish methods to get condensed ceramide from sludge. Ceramide extraction methods include traditional methods (maceration, reflux, and Soxhlet extraction) and green technologies (ultrasound-assisted, microwave-assisted, and supercritical fluid extraction). In the past two decades, more than 70% of the articles have used traditional methods. However, green extraction methods are gradually improved and showed high extraction efficiency with lower solvent consumed. The preferred technique for ceramide purification is chromatography. Common solvent systems include chloroform-methanol, n-hexane-ethyl acetate, petroleum ether-ethyl acetate, and petroleum ether-acetone. For structural determination of ceramide, infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectrometry are used in combination. Among quantitative analysis methods for ceramide, liquid chromatography-mass spectrometry was the most accurate. This review concludes that with our prilemenary experiment results it is feasible to apply the plant "extraction + purification" process of ceramide to sludge, but more optimization need to be performed to get better results.

High-Throughput Screening of Natural Product and Synthetic Molecule Libraries for Antibacterial Drug Discovery

Due to the continued emergence of resistance and a lack of new and promising antibiotics, bacterial infection has become a major public threat. High-throughput screening (HTS) allows rapid screening of a large collection of molecules for bioactivity testing and holds promise in antibacterial drug discovery. More than 50% of the antibiotics that are currently available on the market are derived from natural products. However, with the easily discoverable antibiotics being found, finding new antibiotics from natural sources has seen limited success. Finding new natural sources for antibacterial activity testing has also proven to be challenging. In addition to exploring new sources of natural products and synthetic biology, omics technology helped to study the biosynthetic machinery of existing natural sources enabling the construction of unnatural synthesizers of bioactive molecules and the identification of molecular targets of antibacterial agents. On the other hand, newer and smarter strategies have been continuously pursued to screen synthetic molecule libraries for new antibiotics and new druggable targets. Biomimetic conditions are explored to mimic the real infection model to better study the ligand-target interaction to enable the designing of more effective antibacterial drugs. This narrative review describes various traditional and contemporaneous approaches of high-throughput screening of natural products and synthetic molecule libraries for antibacterial drug discovery. It further discusses critical factors for HTS assay design, makes a general recommendation, and discusses possible alternatives to traditional HTS of natural products and synthetic molecule libraries for antibacterial drug discovery.

Antimicrobial Activity of Sempervivum tectorum L. Extract on Pathogenic Bacteria Isolated from Otitis Externa of Dogs

The present study investigated the antimicrobial activity, total phenolic content, and proanthocyanidin concentration of ethanolic extracts from fresh leaves of Sempervivum tectorum L. The extracts were phytochemically analyzed and evaluated for antimicrobial activity. The broth microdilution method was used to assess antimicrobial activity against pathogenic bacteria isolated from ear swabs taken from dogs with otitis externa. Many compounds were present in the ethanolic aqueous extracts, which exhibited a broad spectrum of antimicrobial activity. They showed strong antibacterial activity against standard clinical Gram-positive strains such as S. aureus and Gram-negative strains such as P. aeruginosa. In our study, the obtained quantity of total phenolic compounds in the ethanol:water extract of leaves was 126.17 mg GAE/g. The proanthocyanidin concentration in the tested Sempervivum tectorum L. extracts was 15.39 mg PAC/g material. The high contents of total phenolics and proanthocyanidin indicated that these compounds contribute to antimicrobial activity. The antimicrobial activity of the tested S. tectorum L. extracts ranged from 1.47 to 63.75 µg/mL, starting with 1.47 µg/mL and 1.75 µg/mL against S. aureus ATCC 25923 and P. aeruginosa ATCC 27853 strains, respectively. Likewise, S. tectorum L. ethanol extract demonstrated a bacteriostatic effect against S. aureus clinical isolate with a median MIC of 23.25 µg/mL and MBC of 37.23 µg/mL; and bactericidal against S. aureus ATCC 25923 with the median MIC of 20.33 µg/mL and MBC of 37.29 µg/mL. In the Gram-negative P. aeruginosa clinical and standard strains, the expressed MIC and MBC values were 24.234 and 20.53 µg/mL for MIC, and 37.30 and 37.02 µg/mL for MBC, respectively.

Cannabis Extraction Technologies: Impact of Research and Value Addition in Latin America

The Cannabis genus of plants has been widely used in different cultures for various purposes. It is separated into three main species: sativa, indica, and ruderalis. In ancient practices, the plant was used as a multipurpose crop and valued for its fiber, food, and medicinal uses. Since methodologies for the extraction, processing, and identification of components have become available, medical, and food applications have been increasing, allowing potential development in the pharmaceutical and healthy functional food industries. Although the growing legalization and adoption of cannabis for the treatment of diseases are key factors pushing the growth of its market, the biggest challenge is to obtain higher-quality products in a time- and cost-effective fashion, making the process of extraction and separation an essential step. Latin American countries exhibit great knowledge of extraction technologies; nevertheless, it is still necessary to verify whether production costs are economically profitable. In addition, there has been an increase in commercial cannabis products that may or may not be allowed, with or without quality fact sheets, which can pose health risks. Hence, legalization is mandatory and urgent for the rest of Latin American countries. In this article, the phytochemical compounds (cannabinoids, terpenes, and phenolic compounds), the current status of legalization, extraction techniques, and research advances in cannabis in Latin America are reviewed.

Kinetics of Microwave-Assisted Extraction Process Applied on Recovery of Peppermint Polyphenols: Experiments and Modeling

The aim of this work was to investigate the microwave-assisted extraction (MAE) kinetics of polyphenolic compounds from organic peppermint leaves. The phytochemicals of peppermint (Mentha piperita L.) are increasingly used in food technology due to their numerous biological activities. The processing of various plant materials by MAE and the production of high-quality extracts is becoming increasingly important. Therefore, the influence of microwave irradiation power (90, 180, 360, 600, and 800 W) on total extraction yield (Y), total polyphenols yield (TP), and flavonoid yield (TF) were investigated. Common empirical models (first-order, Peleg's hyperbolic, Elovich's logarithmic, and power-law model) were applied to the extraction process. The first-order kinetics model provided the best agreement with the experimental results in terms of statistical parameters (SS_er, R², and AARD). Therefore, the influences of irradiation power on the adjustable model parameters (k and C_eq) were investigated. It was found that irradiation power exerted a significant influence on k, while its influence on the asymptotic value of the response was negligible. The highest experimentally determined k (2.28 min^-1) was obtained at an irradiation power of 600 W, while the optimal irradiation power determined by the maximum fitting curve determination predicted the highest k (2.36 min^-1) at 665 W.

Bioactive Compounds of Verbascum sinuatum L.: Health Benefits and Potential as New Ingredients for Industrial Applications

Verbascum sinuatum (V. sinuatum) is a plant belonging to the Scrophulariaceae family that has been used as an ingredient in traditional medicine infusions for the treatment of many diseases. The aerial part of this plant is a source of bioactive compounds, especially polyphenols and iridoids. Moreover, antioxidant activity studies have shown that V. sinuatum phenolic and flavonoid composition is higher than those in other plants of the same genus. V. sinuatum bioactive compound composition could vary according to the harvesting location, growing conditions of the plants, sample preparation methods, type and concentration of the extraction solvent, and the extraction methods. The obtention of these compounds can be achieved by different extraction techniques, most commonly, maceration, heat assisted extraction, and infusion. Nevertheless, since conventional extraction techniques have several drawbacks such as long times of extraction or use of large amounts of solvents, the use of green extraction techniques is suggested, without affecting the efficiency of the extraction. Moreover, V. sinuatum bioactive compounds have several biological activities, such as antioxidant, anticancer, cardiovascular, antimicrobial, antidiabetic, and neuroprotective activities, that may be increased by encapsulation. Since the bioactive compounds extracted from V. sinuatum present good potential as functional food ingredients and in the development of drugs or cosmetics, this review gives an approach of the possible incorporation of these compounds in the food and pharmacological industries.

Anticancer plant-derivatives: deciphering their oncopreventive and therapeutic potential in molecular terms

Background

Over the years, phytomedicines have been widely used as natural modalities for the treatment and prevention of various diseases by different ethnic groups across the globe. Although, 25% of drugs in the USA contain at least one plant-derived therapeutic compound, currently there is a paucity of plant-derived active medicinal ingredients in the pharmaceutical industry. Scientific evidence-based translation of plant-derived ethnomedicines for their clinical application is an urgent need. The anticancer and associated properties (antioxidative, anti-inflammatory, pro-apoptotic and epithelial-mesenchymal transition (EMT) inhibition) of various plant extracts and phytochemicals have been elucidated earlier. Several of the plant derivatives are already in use under prophylactic/therapeutic settings against cancer and many are being investigated under different phases of clinical trials.

Main body

The purpose of this study is to systematically comprehend the progress made in the area of prophylactic and therapeutic potential of the anticancerous plant derivatives. Besides, we aim to understand their anticancer potential in terms of specific sub-phenomena, such as anti-oxidative, anti-inflammatory, pro-apoptotic and inhibition of EMT, with an insight of the molecules/pathways associated with them. The study also provides details of classes of anticancer compounds, their plant source(s) and the molecular pathway(s) targeted by them. In addition to the antioxidative and antiproliferative potentials of anticancer plant derivatives, this study emphasizes on their EMT-inhibition potential and other ‘anticancer related’ properties. The EMT is highlighted as a phenomenon of choice for targeting cancer due to its role in the induction of metastasis and drug resistance. Different phytochemicals in pre-clinical or clinical trials, with promising chemopreventive/anticancer activities have been enlisted and the plant compounds showing synergistic anticancer activity in combination with the existing drugs have been discussed. The review also unravels the need of carrying out pan-signalome studies for identifying the cardinal pathways modulated by phytomedicine(s), as in many cases, the molecular pathway(s) has/have been randomly studied.

Conclusion

This review systematically compiles the studies regarding the impact of various plant derivatives in different cancers and oncogenic processes, as tested in diverse experimental model systems. Availability of more comprehensive information on anticancer phyto-constituents, their relative abundance in crude drugs, pathways/molecules targeted by phytomedicines, their long-term toxicity data and information regarding their safe use under the combinatorial settings, would open greater avenues of their utilization in future against this dreaded disease.

Graphical Abstract

Terminalia arjuna, a Cardioprotective Herbal Medicine-Relevancy in the Modern Era of Pharmaceuticals and Green Nanomedicine-A Review

Herbal medicines were the main source of therapeutic agents in the ancestral era. Terminalia arjuna (TA) is one such medicinal plant widely known for its several medicinal properties, especially its cardiovascular properties. They have several phytochemicals, such as flavonoids, polyphenols, triterpenoids, tannins, glycosides, and several minerals, proteins, and others that are responsible for the above-mentioned medicinal properties. In this review, we have first elaborated on the various processes and their parameters for the efficient extraction of relevant phytochemicals from TA extracts. Secondly, the mechanisms behind the various medicinal properties of TA extracts are explained. We have also highlighted the role of TA extracts on the green synthesis of metallic nanoparticles, especially silver and gold nanoparticles, with an elucidation on the mechanisms behind the synthesis of nanoparticles. Finally, TA extracts-based polymeric formulations are discussed with limitations and future perspectives. We believe that this review could help researchers understand the importance of a well-known cardioprotective medicinal plant, TA, and its biomedical properties, as well as their role in green nanotechnology and various formulations explored for encapsulating them. This review will help researchers design better and greener nanomedicines as well as better formulations to improve the stability and bioavailability of TA extracts.

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.

Biocolorants in food: Sources, extraction, applications and future prospects

Color of a food is one of the major factors influencing its acceptance by consumers. At presently synthetic dyes are the most commonly used food colorant in food industry by providing more esthetically appearance and as a means to quality control. However, the growing concern about health and environmental due to associated toxicity with synthetic food colorants has accelerated the global efforts to replace them with safer and healthy food colorants obtained from natural resources (plants, microorganisms, and animals). Further, many of these biocolorants not only provide myriad of colors to the food but also exert biological properties, thus they can be used as nutraceuticals in foods and beverages. In order to understand the importance of nature-derived pigments as food colorants, this review provides a thorough discussion on the natural origin of food colorants. Following this, different extraction methods for isolating biocolorants from plants and microbes were also discussed. Many of these biocolorants not only provide color, but also have many health promoting properties, for this reason their physicochemical and biological properties were also reviewed. Finally, current trends on the use of biocolorants in foods, and the challenges faced by the biocolorants in their effective utilization by food industry and possible solutions to these challenges were discussed.

Green approach for the recovery of secondary metabolites from the roots of Nardostachys Jatamansi (D. Don) DC using microwave radiations: Process optimization and anti-alzheimer evaluation

Nardostachys jatamansi (D. Don) DC is a highly valued medicinal herb that has been used in traditional medicinal systems for its remedial effects. Owing to the over-exploitation and unethical trade of N. jatamansi, the accelerating global demand of herbal products from this plant cannot be satisfied by the conventional extraction approach. In view of the progressive demand and incredible biological potential of herb, the present research was designed to optimize various extraction parameters for microwave-assisted extraction (MAE). The extracts obtained from the traditional and green approach were also assessed for the recovery of secondary metabolites and anti-Alzheimer's potential. Various parameters like microwave power, temperature, and time of irradiation were optimized for MAE using Box Behkhen Design (BBD) The scanning electron microscopy of different plant samples was also done to observe the effect of microwave radiations. Further, the metabolite profiling of different extracts was also done by gas chromatography-mass spectrometry (GC-MS) analysis. Also the different behavioral and biochemical parameters along with acetylcholinesterase (AChE) inhibitory potential were assessed to evaluate the anti-Alzheimer's potential. Optimized parameters for MAE were found to be as microwave power 187.04 W, temperature 90°C, and irradiation time 20 min. The extract yield in MAE was significantly enhanced as compared to the conventional method. Also, the total phenolic content and total flavonoid content (TFC) were improved pointedly from 32.13 ± 0.55 to 72.83 ± 1.1 mg of GAE/g of extract and 21.7 ± 0.85 to 39.21 ± 0.7 mg of RUE/g of extract respectively. Later, the GC-MS analysis of various extracts confirmed the enhancement in the concentration of various sesquiterpenes like jatamansone, spirojatamol, valerenal, valeric acid, globulol, nootkatone and steroidal compounds such as sitosterol, ergosterol, stigmastanone, etc. in the optimized extract. A significant improvement in anti-Alzheimer's potential was also observed owing to the better concentration of secondary metabolites in the optimized microwave extract. From the current findings, it could be concluded that the MAE could be a successful and green alternative for the extraction and recovery of secondary metabolites from the selected medicinal herb.

Plant Extraction in Water: Towards Highly Efficient Industrial Applications

Since the beginning of this century, the world has experienced a growing need for enabling techniques and more environmentally friendly protocols that can facilitate more rational industrial production. Scientists are faced with the major challenges of global warming and safeguarding water and food quality. Organic solvents are still widely used and seem to be hard to replace, despite their enormous environmental and toxicological impact. The development of water-based strategies for the extraction of primary and secondary metabolites from plants on a laboratory scale is well documented, with several intensified processes being able to maximize the extraction power of water. Technologies, such as ultrasound, hydrodynamic cavitation, microwaves and pressurized reactors that achieve subcritical water conditions can dramatically increase extraction rates and yields. In addition, significant synergistic effects have been observed when using combined techniques. Due to the limited penetration depth of microwaves and ultrasonic waves, scaling up entails changes to reactor design. Nevertheless, the rich academic literature from laboratory-scale investigations may contribute to the engineering work involved in maximizing mass/energy transfer. In this article, we provide an overview of current and innovative techniques for solid-liquid extraction in water for industrial applications, where continuous and semi-continuous processes can meet the high demands for productivity, profitability and quality.

Ultrasound and Microwave-assisted Extraction of Proteins from Coffee Green Beans: Effects of Process Variables on the Protein Integrity

The demand for proteins is constantly increasing and green extraction methodologies are needed to achieve environmental sustainability goals. The recovery of the by-products of the agri-food chain has also become a priority from a circular economy perspective. Some by-products are still little exploited for the extraction of proteins, such as coffee by-products. In this work, various innovative extraction technologies were applied to recover the protein fraction from the non-compliant coffee green beans (CGB), using a methodological approach that allowed to correlate the process parameters with the final quality of the extracted proteins. The ultrasound-assisted extraction (UAE) technique has been shown to have a minor impact on the quality of the proteins, thanks to the possibility of refrigerating the system, while the microwave-assisted extraction (MAE) shows a certain degree of degradation due to the high temperatures reached. The results indicate that strict temperature control is required during alkaline extraction to preserve the quality of the protein fraction.

Extraction of High-Value Chemicals from Plants for Technical and Medical Applications

Plants produce a variety of high-value chemicals (e.g., secondary metabolites) which have a plethora of biological activities, which may be utilised in many facets of industry (e.g., agrisciences, cosmetics, drugs, neutraceuticals, household products, etc.). Exposure to various different environments, as well as their treatment (e.g., exposure to chemicals), can influence the chemical makeup of these plants and, in turn, which chemicals will be prevalent within them. Essential oils (EOs) usually have complex compositions (>300 organic compounds, e.g., alkaloids, flavonoids, phenolic acids, saponins and terpenes) and are obtained from botanically defined plant raw materials by dry/steam distillation or a suitable mechanical process (without heating). In certain cases, an antioxidant may be added to the EO (EOs are produced by more than 17,500 species of plants, but only ca. 250 EOs are commercially available). The interesting bioactivity of the chemicals produced by plants renders them high in value, motivating investment in their production, extraction and analysis. Traditional methods for effectively extracting plant-derived biomolecules include cold pressing and hydro/steam distillation; newer methods include solvent/Soxhlet extractions and sustainable processes that reduce waste, decrease processing times and deliver competitive yields, examples of which include microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), subcritical water extraction (SWE) and supercritical CO2 extraction (scCO2). Once extracted, analytical techniques such as chromatography and mass spectrometry may be used to analyse the contents of the high-value extracts within a given feedstock. The bioactive components, which can be used in a variety of formulations and products (e.g., displaying anti-aging, antibacterial, anticancer, anti-depressive, antifungal, anti-inflammatory, antioxidant, antiparasitic, antiviral and anti-stress properties), are biorenewable high-value chemicals.

Cereal Waste Valorization through Conventional and Current Extraction Techniques-An Up-to-Date Overview

Nowadays, in the European Union more than 100 million tons of food are wasted, meanwhile, millions of people are starving. Food waste represents a serious and ever-growing issue which has gained researchers’ attention due to its economic, environmental, social, and ethical implications. The Sustainable Development Goal has as its main objective the reduction of food waste through several approaches such as the re-use of agro-industrial by-products and their exploitation through complete valorization of their bioactive compounds. The extraction of the bioactive compounds through conventional methods has been used for a long time, whilst the increasing demand and evolution for using more sustainable extraction techniques has led to the development of new, ecologically friendly, and high-efficiency technologies. Enzymatic and ultrasound-assisted extractions, microwave-assisted extraction, membrane fractionation, and pressure-based extraction techniques (supercritical fluid extraction, subcritical water extraction, and steam explosion) are the main debated green technologies in the present paper. This review aims to provide a critical and comprehensive overview of the well-known conventional extraction methods and the advanced novel treatments and extraction techniques applied to release the bioactive compounds from cereal waste and by-products.

Valorization of Tomato Seed By-Products as a Source of Fatty Acids and Bioactive Compounds by Using Advanced Extraction Techniques

In this work, lipids and bioactive compounds from tomato seed by-products were extracted and compared by using advanced extraction techniques, such as microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE). The influence of different extraction parameters, including extraction temperature (T), time (t) and solvent volume (V) for MAE as well as extraction temperature (T), pressure (P) and flow rate (F) for SFE-CO₂, was evaluated on tomato seed oil (TSO) yield and fatty acids composition using response surface methodology (RSM). Optimum extraction conditions for MAE were 56.2 °C, 29.0 min, and 67.6 mL, whereas conditions of 60.2 °C, 400.0 bar, and 64.6 g min⁻¹ were found for SFE-CO₂. Under these conditions, higher TSO extraction yields were obtained by MAE compared to SFE-CO₂ (25.3 wt% and 16.9 wt%, respectively), while similar fatty acids profiles were found by GC in terms of FAMEs composition: methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate, accounting for around 80 wt% of unsaturated fatty acids. TSO MAE extracts showed high DPPH• radical scavenging activity which was related to the presence of tocopherols; in particular γ-tocopherol, which was found as the dominant homologue (260.3 ± 0.6 mg kg_TS⁻¹) followed by a lower amount of α-tocopherol (6.53 ± 0.12 mg kg_TS⁻¹) by HPLC-DAD. The obtained results suggested that tomato seeds are an interesting source of bioactive compounds with potential use in a wide range of nutritional and food applications, increasing the added value of this by-product, which is currently underexploited.

Advances in the Utilization of Tea Polysaccharides: Preparation, Physicochemical Properties, and Health Benefits

Tea polysaccharide (TPS) is the second most abundant ingredient in tea following tea polyphenols. As a complex polysaccharide, TPS has a complex chemical structure and a variety of bioactivities, such as anti-oxidation, hypoglycemia, hypolipidemic, immune regulation, and anti-tumor. Additionally, it shows excellent development and application prospects in food, cosmetics, and medical and health care products. However, numerous studies have shown that the bioactivity of TPS is closely related to its sources, processing methods, and extraction methods. Therefore, the authors of this paper reviewed the relevant recent research and conducted a comprehensive and systematic review of the extraction methods, physicochemical properties, and bioactivities of TPS to strengthen the understanding and exploration of the bioactivities of TPS. This review provides a reference for preparing and developing functional TPS products.

Valorization of Aloe vera Skin By-Products to Obtain Bioactive Compounds by Microwave-Assisted Extraction: Antioxidant Activity and Chemical Composition

Aloe vera skin (AVS) is a major by-product of Aloe processing plants all over the world. In this study, response surface methodology was used to optimize microwave-assisted extraction (MAE) of bioactive compounds from AVS. The influence of extraction parameters, such as ethanol concentration (%Et), extraction temperature (T), time (t) and solvent volume (V), on extraction yield (Y), total phenolic content (TPC), antioxidant activity (DPPH and FRAP methods) and aloin content, was studied. Optimum extraction conditions were determined as 80% ethanol, 80 °C, 36.6 min and 50 mL and optimized extracts showed interesting contents of polyphenols and antioxidant performance. The phenolic profile was determined by HPLC-DAD/MS and some major phenolic compounds, such as aloin A, aloin B, aloesin, aloe-emodin, aloeresin D, orientin, cinnamic acid and chlorogenic acid, were quantified while eight other compounds were tentatively identified. Moreover, structural and thermal properties were studied by FTIR and TGA analyses, respectively. The obtained results suggested the potential of AVS as a promising source of bioactive compounds, thus increasing the added value of this agricultural waste.

Recovery of Phenolic Compounds and Antioxidants from Coffee Pulp (Coffea canephora) Waste Using Ultrasound and Microwave-Assisted Extraction

Coffee pulp is a by-product generated from coffee bean production. This waste is a potential source of bioactive compounds, which can be recovered for use as an ingredient for many products. However, this by-product is typically dumped in landfills or made into compost. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) were employed to recover bioactive compounds from coffee pulp waste. Results showed that time and instrument power significantly affected the recovery yield in both UAE and MAE. The temperature was also a significant factor in UAE. The optimal MAE conditions were a radiation time of 70 min, a power of 700 W, and a 50% (v/v) ethanol solvent to sample ratio of 100:5 (mL/g), approximately 47 mg of phenolic compounds, 36 mg of flavonoid, 8 mg of chlorogenic acid, and 6 mg of caffeine could be recovered from 1 g of the material. The optimal UAE condition were an ultrasonic time of 35 min, a temperature of 60 °C, and a power of 250 W; however, bioactive compounds and antioxidant capacity constituted around one half of MAE. Therefore, MAE is recommended as the extraction technique for the bioactive compound and antioxidant recovery from the coffee pulp.

Application of Green Technologies in Design-Based Extraction of Celastrus paniculatus (Jyotishmati) Seeds, SEM, GC-MS Analysis, and Evaluation for Memory Enhancing Potential

Background

The Celastrus paniculatus (CP), commonly known as Jyotishmati, is considered as “elixir of life” by Indian people for the prevention or management of many ailments. The seed powder and its extract have widely used commercially for the preparation of various Ayurvedic formulations for the improvement of memory. CP seeds were generally extracted by conventional extraction methods (CEMs) which are assumed to impact environment burden and also produce low extract yield. Green extraction with possible improvement in extract yield has always been the need of hour for selected medicinal plant.

Objective

In the present research, we aimed to optimize the different extraction factors in microwave and ultrasound-based extraction. The various extracts obtained in conventional and green methods are also evaluated for the possible improvement in memory enhancing potential.

Materials and Methods

The selected medicinal herb was extracted by CEM (maceration and percolation). In green methods such microwave-assisted extraction (MAE) and ultrasound assisted-extraction (UAE), various parameters were optimized using Box-Behnken design coupled with response surface methodology. The scanning electron microscopy (SEM) and gas chromatography–mass spectroscopy (GC-MS) analyses were also done to confirm the possible improvement in concentration of plant actives. The Swiss albino mice were used to evaluate memory enhancing potential of different extracts.

Results

At the optimized conditions MAE and UAE the extraction yield, total phenolic content (TPC) and Total flavonoid content (TFC) are significantly improved. The GC-MS analysis further confirms the improvement in concentration of certain fatty acid esters, pilocarpine, and steroidal compounds in optimized extracts. The optimized extracts also exhibited the significant improvement in behavioral parameters, oxidative stress-induced parameters, and acetylcholinesterase inhibitory potential.

Discussion and Conclusion

From the results, we can say that the application of green technologies in design-based extraction of selected herb not only significantly reduces the extraction time but also improves the extract yield and concentration of plant actives. In nutshell, it can be concluded that the green approaches for extraction of seeds of Celastrus paniculatus could be scale up at a commercial level to meet the rising demand for herbal extract.

Optimization of the Extraction of Total Phenols from Medicago sativa and Its Antioxidant Capacity

The phenolic compounds from alfalfa (Medicago sativa L.) are used as antioxidants and in native medicine. They play an indispensable role in defense and signal transduction of the plant under stress conditions. This exploration of the optimal extraction parameters of the total phenols from alfalfa by using ultrasonic-assisted extraction (UAE) was aimed at providing a theoretical basis for better utilization of the total phenols in alfalfa. In this study, the effects of solvent volume fraction (A), extraction time (B), solid-liquid ratio (C) and extraction temperature (D) on the total phenols content and the total antioxidant capacity of Medicago sativa L. WL363HQ after thrips infestation were determined through single-factor experiments. Additionally, the extraction conditions of total phenols were optimized by using Box-Behnken design (BBD) of response surface methodology (RSM). The results showed that the proposed model had a good fitting degree for total phenols extraction (R² =0.9564). The total phenols extraction from WL363HQ had significant relationship with solid-liquid ratio (C) and extraction temperature (D) (P<0.05). The influence levels of the four factors on total phenols extraction were as follows: extraction temperature (D) > solid-liquid ratio (C)>acetone volume fraction (A)>extraction time (B). The optimum extraction conditions of total phenols from WL363HQ were 50 % acetone, solid-liquid ratio of 1 : 20 (g/mL), extraction time of 45 min and extraction temperature of 60 °C. The corresponding content and total antioxidant capacity under the optimized conditions were 15.76 mg g^-1 and 28.79 μmol Trolox g^-1 . These results provided a new extraction method of total phenols from alfalfa.

Hepatoprotective Effect of Carob Pulp Flour (Ceratonia siliqua L.) Extract Obtained by Optimized Microwave-Assisted Extraction

To examine antioxidant capacity and the hepatoprotective effect of carob pulp flour, microwave-assisted extraction was performed. The influence of ethanol concentration (0–40% w/w), extraction time (5–25 min) and irradiation power (400–800 W) on DPPH, FRAP and ABTS antioxidant activity of carob pulp flour extract was evaluated. The strongest influence was that of the ethanol concentration, followed by extraction time. Optimal process parameters for maximizing total antioxidant activity were determined, using response surface methodology: ethanol concentration 40%, time 25 min and power 800 W. Carob extract obtained at optimal conditions (CE) was analyzed in vivo using a paracetamol-induced hepatotoxicity model in mice. Treatment with CE attenuated the parameters of liver injury, especially aspartate and alanine aminotransferase activity, and prevented paracetamol-induced increase in malondialdehyde levels. Pretreatment with CE reversed the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferase enzymes after the high dose of paracetamol in the liver. Hepatotoxicity induced using a toxic dose of paracetamol was also seen through histopathological alterations, which were significantly reduced in the groups treated with CE prior to paracetamol. Still, the number of Kupffer cells and macrophages did not differ among groups. Finally, pretreatment of mice with CE and paracetamol significantly decreased the expression of cytochrome P450 2E1 (CYP2E1) in hepatocytes.

An efficient approach for simultaneously obtaining oil and epigoitrin from Orychophragmus violaceus seeds by microwave-mediated immiscible binary solvent extraction

Microwave-mediated immiscible binary solvent extraction (MIBSE) was applied to simultaneously extract oil and epigoitrin from Orychophragmus violaceus seeds. The upper phase of n-hexane was used to obtain oil, and the lower phase of ethanol solution was used to obtain epigoitrin. Factors potentially affecting the yields of oil and epigoitrin were systematically investigated. The optimum conditions were an ethanol volume fraction of 65%, liquid-solid ratio of lower-phase of 20 mL/g, liquid-solid ratio of upper-phase of 12 mL/g, microwave irradiation power of 393 W, and microwave irradiation time of 29 min. The actual yields of oil and epigoitrin were 34.08% ± 1.38% and 11.86 ± 0.47 mg/g, respectively. GC-MS analysis illustrated that the seed oils obtained by MIBSE and Soxhlet extraction exhibited similar fatty acid compositions. The separated epigoitrin was determined by HPLC analyses, which obtained a purity of 91.25% ± 3.83%, follwed by NMR determinations.