Microwave-assisted Extraction Research Articles

Research Progress on Taxus Extraction and Formulation Preparation Technologies

Taxus, as a globally prevalent evergreen tree, contains a wealth of bioactive components that play a crucial role in the pharmaceutical field. Taxus extracts, defined as a collection of one or more bioactive compounds extracted from the genus Taxus spp., have become a significant focus of modern cancer treatment research. This review article aims to delve into the scientific background of Taxus extracts and their considerable value in pharmaceutical research. It meticulously sifts through and compares various advanced extraction techniques such as supercritical extraction, ultrasound extraction, microwave-assisted extraction, solid-phase extraction, high-pressure pulsed electric field extraction, and enzymatic extraction, assessing each technology’s advantages and limitations across dimensions such as extraction efficiency, extraction purity, economic cost, operational time, and environmental impact, with comprehensive analysis results presented in table form. In the area of drug formulation design, this paper systematically discusses the development strategies for solid, liquid, and semi-solid dosage forms based on the unique physicochemical properties of Taxus extracts, their intended medical uses, and specific release characteristics, delving deeply into the selection of excipients and the critical technical issues in the drug preparation process. Moreover, the article looks forward to the potential directions of Taxus extracts in future research and medical applications, emphasizing the urgency and importance of continuously optimizing extraction methods and formulation design to enhance treatment efficacy, reduce production costs, and decrease environmental burdens. It provides a comprehensive set of preparation techniques and formulation optimization schemes for researchers in cancer treatment and other medical fields, promoting the application and development of Taxus extracts in pharmaceutical sciences.

Microwave-assisted extraction of Tiliacora triandra leaves for functional ice cream production

Ice cream is widely enjoyed by consumers of all ages, but its high sugar and fat content may have adverse effects on health. This research aims to develop a functional form of ice cream by incorporating Tiliacora triandra leaves, which are rich in antioxidants. The substances from the leaves were extracted using high-power microwaves at 600 W for 30 sec, repeated three times. These extracts were then incorporated into the ice cream recipe, which utilized skim milk powder instead of fresh milk and stevia syrup instead of sugar. The antioxidant activity was assessed using DPPH and ABTS assays, while the total phenolic compounds were measured using the Folin-Ciocalteu assay. The findings indicated that ice cream supplemented with the extract at a 20% leaf ratio (T20) exhibited the highest antioxidant activity against DPPH and ABTS, with values of 54.30 ± 1.42% and 73.83 ± 1.90%, respectively. Additionally, the highest total phenolic compounds content was observed at 3.48 ± 0.10 mg GAE/g sample. The addition of T. triandra leaf extract resulted in a significantly darker green color and a firmer texture. However, the ice cream’s ability to resist melting showed slight change. Sensory assessment revealed that ice cream enhanced with 5% (T5) and 10% leaf ratios (T10) of the extract received higher scores for taste, color, odor, and overall acceptance compared to T20, and showed no difference from the control (T0). These finding suggest that T10 could serve as a viable alternative for health-conscious consumers seeking functional ice cream options.

Oregano and thyme by-products of olive oil aromatization process with microwave assisted extraction as a rich source of bio-active constituents

IntroductionProcessing of Medicinal Aromatic Plants (MAPs) results in the production of a significant amount of by-products, which are not commercially exploitable. Towards this direction, we studied extensively the by-products of oregano and thyme, remaining after the aromatization of olive oils with microwave assisted extraction (MAE). The purpose of the study was the exploitation of the “wastes” of these two economically significant herbs of Greece, for the potential development of innovative bioactive products.MethodsHence, superior and inferior quality plant material from Origanum vulgare subsp. hirtum and Thymus vulgaris, were extracted with extra virgin olive oil using MAE. For the evaluation of raw plant material, beside the characterization of the essential oils (EOs), the hydroalcoholic extracts of superior and inferior plant material were afforded by ultrasound assistant extraction (UAE). In addition, the remaining plant material after the flavoring of olive oil by MAE, was extracted with c-Hex, MeOH, H2O:MeOH using UAE. All the extracts were evaluated for their DPPH free radical scavenging activity and total phenolic content (TPC) as well as their chemical profile was investigated by HPTLC. In parallel, the EOs, the olive oils and the c-Hex extracts were analyzed by GC–MS and Headspace Solid Phase Microextraction (HS-SPME)-GC–MS.Results and DiscussionThe results showed that the composition of the EOs and the volatile fraction of the olive oil extracts were similar for the superior quality material whereas for the inferior the composition of the volatile fraction of olive oil extracts was not analogous to the respective EOs. GC–MS analyses of oregano and thyme by-products revealed the presence of carvacrol, thymol, γ-terpinene and p-cymene among the major constituents. Moreover, the hydroalcoholic extracts obtained from the plant material remaining after olive oil flavoring with MAE showed similar phenolic content and scavenging activity with the hydroalcoholic extracts of the corresponding raw plant materials underlying their potent use in the preparation of high-added value products such as nutraceuticals and cosmeceuticals as well as enriched animal nutrition products.

A novel source of biologically active compounds – The leaves of Serbian herbaceous peonies

In order to gain further insight into how various extraction techniques (maceration, microwave-, and ultrasound-assisted extractions) affect the chemical profile and biological activities of leaf extracts from Paeonia tenuifolia L., Paeonia peregrina Mill., and Paeonia officinalis L., this research was performed. The targeted chemical characterization of the extracts was achieved using the Ultra-High-Performance-Liquid-Chromatography-Linear-Trap-Mass-Spectrometry OrbiTrap instrumental technique, while Fourier Transform Infrared Spectroscopy was conducted to investigate the structural properties of the examined leaf extracts. According to the results, the species P. officinalis, Božurna locality as the origin of the plant material, and microwave-assisted extraction produced the maximum polyphenol yield, (491.9 ± 2.7 mg gallic acid equivalent (GAE)/mL).The ethanolic extracts exhibited moderate antioxidant activity as evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and phosphomolybdenum tests. With MIC values of 0.125 mg/mL, the leaf extracts produced by ultrasound-assisted extraction and maceration (Deliblato sands and Bogovo gumno) had the best antibacterial activity against Pseudomonas aeruginosa and Salmonella Typhimurium. Ultrasound-assisted extraction has proven to produce the most effective antimicrobial agents. Inhibitory potential towards glucosidase, amylase, cholinesterases, and tyrosinase was evaluated in enzyme inhibition assays and molecular docking simulations. Results show that leaves of P. tenuifolia L. obtained by ultrasound-assisted extraction had the highest acetylcholinesterase and butyrylcholinesterase inhibitory activity. Namely, the complexity of the polyphenol structures, the extraction method, the used locality, and the different mechanisms of the reactions between bioactives from leaf extracts and other components (free radicals, microorganisms, and enzymes) are the main factors that influence the results of the antioxidant tests, as well as the antibacterial and enzyme-inhibitory activities of the extracts. Hydroxymethyl-phenyl pentosyl-hexoside and acetyl-hydroxyphenyl-hexoside were the first time identified in the leaf extract of the Paeonia species. Due to their proven biological activities and the confirmed existence of bioactive compounds, leaf extracts may find use in foodstuffs, functional foods, and pharmaceutical products.

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

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

Total Iodine Quantification and In Vitro Bioavailability Study in Abalone (Haliotis discus hannai) Using Inductively Coupled Plasma Mass Spectrometry.

The aim of this study is to determine the total iodine content in Korean abalone (Haliotis discus hannai) and to investigate the bioavailability of iodine using an in vitro method. This research paper focuses on total iodine quantification in abalone (Haliotis discus hannai) and its components (viscera and muscle) using inductively coupled plasma mass spectrometry (ICP-MS). Additionally, an in vitro bioavailability study explored iodine absorption potential. Abalone pretreatment involved both the European standard method (ES) and microwave-assisted extraction method (MAE). The limits of detection (LOD) were 0.11 ng/g for both ES and MAE, with a limit of quantification (LOQ) of 5.4 ng/g for MAE. Accuracy, assessed using a reference material (fish muscle, ERM-BB422), showed values of 1.5 ± 0.010 mg/kg for ES and 1.6 ± 0.066 mg/kg for MAE, within an acceptable range of 1.4 ± 0.42 mg/kg. Precision, evaluated using the Horwitz ratio (HorRat) with a reference material, was determined to be 0.45 for ES and 0.27 for MAE. Therefore, total iodine contents were estimated as 74 ± 2.2 µg/g for abalone viscera and 17 ± 0.77 µg/g for abalone muscle with ES, and 76 ± 1.0 µg/g for abalone viscera and 17 ± 0.51 µg/g for abalone muscle with MAE. Recovery tests demonstrated an acceptable range of 90-110%. In the in vitro bioavailability assessment, digestion efficiency yielded ranges of 42-50.2% for viscera and 67-115% for muscle. Absorption efficiency variations were determined as 37-43% for viscera and 48-75% for muscle.

A simulation‐guided tri‐spiral condenser design for enhancing lemongrass essential oil recovery

AbstractWe present a groundbreaking achievement in essential oil extraction, showcasing the development of a highly efficient tri‐spiral condenser for use in microwave‐assisted extraction (MAE) setups. This innovative condenser is specifically designed to swiftly cool vapors, optimizing oil yield during the MAE process. Our investigations demonstrate a notable improvement in oil purity, attributed to the expedited condensation facilitated by the tri‐spiral design. Traditional heat exchangers, like the Liebig condenser, fall short in efficiently handling the high vapor production rates of MAE. In response to this challenge, our tri‐spiral condenser design enhances condensation speed, resulting in a remarkable 12.2% increase in oil yield compared with the Liebig condenser (2.1% with tri‐spiral vs. 1.87% with Liebig), as validated by Gas Chromatography–Mass Spectrometry. Beyond elevating oil purity, our design holds promise for diverse applications requiring rapid cooling. This work not only advances laboratory practices but also contributes to the broader societal need for efficient and sustainable methods in the essential oil extraction industry.Practical applicationsThe innovative tri‐spiral condenser design, as elucidated in this article, presents significant practical applications, especially in the realm of lemongrass essential oil recovery. This breakthrough technology holds promise for the fragrance and cosmetics industries, where lemongrass essential oil is a valuable ingredient. The novel condenser design enhances extraction efficiency, leading to a higher concentration of essential oil with improved aromatic compounds. Cosmetic manufacturers can benefit from a more potent and fragrant lemongrass oil for skincare and aromatherapy products. Additionally, the pharmaceutical sector could leverage this advancement for developing therapeutic products harnessing the medicinal properties of lemongrass. By optimizing essential oil recovery, the tri‐spiral condenser design not only caters to the needs of the fragrance, cosmetic, and pharmaceutical industries, but also aligns with a broader trend towards sustainable and efficient manufacturing practices, ensuring the accessibility of high‐quality lemongrass essential oil for diverse applications.

Transformation of agricultural wastes into functional oligosaccharides using enzymes and emerging technologies.

Pectin-oligosaccharides (POS) serve diverse purposes as a food ingredient, antimicrobial and biostimulant in plants, and their functionality is linked to the degree of esterification. Grape and broccoli wastes emerge as environmentally friendly alternatives to obtaining pectin, serving as a sustainable source to producing POS. For example, microwaves have proven to be an effective and sustainable method to extract polysaccharides from plant matrices. This work aims to use grape and broccoli wastes as alternative sources for obtaining pectin by microwave-assisted extraction and biotransformation into POS, which possess biological properties. The extraction conditions were identified at a power of 400 W, 300 s for the extraction of pectin from grape pomace and broccoli waste. Biotransformation of pectins into POS, using commercial enzyme preparations (Viscozyme L and Pectinase). Characterisation was carried out by Fourier-transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Physicochemical analysis indicated grape pomace and broccoli waste pectins had galacturonic acid content of 63.81 ± 1.67 and 40.83 ± 2.85 mg 100 mg-1, low degree of esterification of 34.89% and 16.22%, respectively. Biotransformation of pectins into POS resulted in a 20% hydrolysis rate. The main enzymatic activity was polygalacturonase for the degradation of the main structure of the pectin. Production of POS from agro-industrial wastes by emerging technologies, such as the combined use of microwave-assisted extraction and enzymatic processes, represents an alternative method for the generation of bioactive compounds with distinctive properties suitable for different applications of interest.

A Review of Emerging Technologies for the Extraction of Bioactive Compounds from Berries (Phalsa Berries)

Berries have been gaining in popularity among consumers and producers due to their natural bioactive compounds that have beneficial effects on human health. This review aimed to identify effective techniques for the extraction of bioactive compounds from berries, consolidate the findings of recent studies using various extraction technologies, and provide a global perspective on the research trends in this field. These extraction techniques include pulsed electric field, ultrasound-assisted extraction, pressurized liquid extraction, microwave-assisted extraction, and supercritical CO2 extraction. The solid waste generated during the industrial berry juice production process is assumed to be a less expensive source of raw materials for the natural extraction of bioactive compounds. The main aim of modern techniques is to produce more of the desired compound and find a method to extract bioactive compounds from berries without the use of hazardous solvents. These include flavonoids, phenols, anthocyanins, and antioxidants. Regarding the characterization of the bioactive compounds that are isolated from berries, aspects such as scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and nuclear magnetic resonance were reviewed.

Polysaccharides from Russula: a review on extraction, purification, and bioactivities.

Russula, a renowned edible fungus, has gained popularity as a functional food among diverse populations due to the abundant presence of amino acids, proteins, and polysaccharides. As the primary constituents of Russula, polysaccharides exhibit a wide range of biological properties, making them an exceptional choice for incorporation into food, medicines, and diverse biotechnological applications. This review provides a summary of the recent research on the extraction, purification, and biological applications of polysaccharides from various Russula spp. Currently, there are many advanced extraction technologies, such as hot water-based extraction, alkali-based extraction, ultrasonic-assisted extraction and microwave-assisted extraction. Hence, the latest progress of extraction technologies, as well as their advantages and limitations will be discusses and summarizes in this review. The separation and purification methods of polysaccharide from Russula were introduced, including ethanol precipitation, deproteinization and gel filtration chromatography. It also focuses on exploring the diverse bioactive capabilities of Russula, including anti-oxidant, anti-tumor, immunomodulatory, anti-inflammation, and anti-bacterial properties. Hence, this review aims to foster a comprehensive understanding of the polysaccharides from various Russula spp. and pave the way for their promising and potential future applications in the medical and functional fields.

Phenolics from Polygonatum cyrtonema Hua extracted using natural deep eutectic solvents combined with auxiliary techniques: Composition, bioactivity, and mechanistic elucidation

This study investigated the natural extraction of polyphenolic compounds from Polygonatum cyrtonema Hua (P. cyrtonema). Employing the combination of natural deep eutectic solvents (NADESs) and auxiliary extraction techniques, we mainly focused on yield, total phenolics, total flavonoids, antioxidant capacity, and enzyme inhibition efficiency. Compared to hot reflux extraction (HRE), the NADES extract using a 1:2 ratio of choline chloride-lactic acid (ChCl-Lac) significantly increased the total phenolic content (TPC), total flavonoid content (TFC), and α-glucosidase inhibition (p < 0.05). The HPLC-MS-MS identified the five most abundant phenolic compounds. Quantitative analysis showed that these compounds had the highest leaching rates in the ultrasonic-assisted extraction (UAE) combined with lactic acid-based NADES system, followed by microwave-assisted extraction (MAE), requiring less than 4 min. Notably, rutin exhibited the highest extraction rate of 281.1 μg/g in the UAE-ChCl-Lac system, 9.82 times higher than conventional methods. The extraction mechanism was elucidated from the perspectives of surface charge density distribution and interaction energy. Therefore, ultrasound or microwave-assisted NADES extraction aligns with sustainable development principles, offering a green approach to enrich polyphenolic compounds in P. cyrtonema.

A New Revolutionary Green Technology for the Extraction of Essential Oil Using Microwave and Ultrasound-assisted Techniques

Background: Essential oils are utilized in various food applications and are a rich source of naturally occurring volatile components. The extraction of essential oils has used conventional techniques for several years, but these methods require a long duration of time, more solvent, and high energy. However, recent advancements have led to novel and eco-friendly techniques that significantly enhance the essential oil yield while minimizing the use of resources. Method: This study describes the recent research on the extraction of essential oils and their components, focusing on microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). Result: This review explores the instrumentation, mechanism, and applications behind MAE and UAE. It also describes the emerging technologies for the extraction of essential oils, along with their optimized conditions. Conclusion: These techniques represent a more sustainable and efficient approach for the extraction of essential oil from various plant sources, aligning with the principles of green chemistry.

The Effect of Microwave-Assisted Extraction Temperature and Material to Solvent Ratio on the Characteristics of Pandan (Pandanus amaryllifolius Roxb.) Leaf Extract

Fresh pandan leaf fragrance has been applied to enhance the aroma of many traditional foods. However, the fresh leaf has a limited shelf life—only 1 day after harvest. Therefore, in liquid or powdered form, pandan extract can be utilized as an alternative aromatic component in food production. The purpose of this study was to determine the effect of extraction temperatures (50, 60, and 70°C) utilizing microwave-assisted extraction (MAE) and the ratio of pandan leaf as material to ethanol as solvent (1:3, 1:7, and 1:11) on the characteristics of pandan extract in liquid form. The study found that the properties of pandan extract treated at MAE 60°C with a material-solvent ratio of 1:7 were the best among all treatments. The pH of this liquid pandan extract was 5.31, the antioxidant activity was 32.86 ppm, and the chlorophyll content was 7.76 mg/L. The powdered pandan extract generated by drying the liquid pandan extract using a spray dryer and adding maltodextrin had properties such as water activity 0.45, solubility 96.09%, solubility rate 0.01 g/s, color L 85.65, a* -6.68, b* 8.51, yield 3.88%, and was detected to contain 0.17% of the aromatic compound 2-acetyl-1-pyrroline. Powdered pandan extract has the potential to be developed as an aromatic food additive. Panelists liked the Lumpang cakes, a traditional cake consisting of rice flour and coconut milk made by adding 1% pandan leaf extract powder.

Valorisation of Agri-Food Waste for Bioactive Compounds: Recent Trends and Future Sustainable Challenges.

Worldwide, a massive amount of agriculture and food waste is a major threat to the environment, the economy and public health. However, these wastes are important sources of phytochemicals (bioactive), such as polyphenols, carotenoids, carnitine, coenzymes, essential oils and tocopherols, which have antioxidant, antimicrobial and anticarcinogenic properties. Hence, it represents a promising opportunity for the food, agriculture, cosmetics, textiles, energy and pharmaceutical industries to develop cost effective strategies. The value of agri-food wastes has been extracted from various valuable bioactive compounds such as polyphenols, dietary fibre, proteins, lipids, vitamins, carotenoids, organic acids, essential oils and minerals, some of which are found in greater quantities in the discarded parts than in the parts accepted by the market used for different industrial sectors. The value of agri-food wastes and by-products could assure food security, maintain sustainability, efficiently reduce environmental pollution and provide an opportunity to earn additional income for industries. Furthermore, sustainable extraction methodologies like ultrasound-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, microwave-assisted extraction, pulse electric field-assisted extraction, ultrasound microwave-assisted extraction and high hydrostatic pressure extraction are extensively used for the isolation, purification and recovery of various bioactive compounds from agri-food waste, according to a circular economy and sustainable approach. This review also includes some of the critical and sustainable challenges in the valorisation of agri-food wastes and explores innovative eco-friendly methods for extracting bioactive compounds from agri-food wastes, particularly for food applications. The highlights of this review are providing information on the valorisation techniques used for the extraction and recovery of different bioactive compounds from agricultural food wastes, innovative and promising approaches. Additionally, the potential use of these products presents an affordable alternative towards a circular economy and, consequently, sustainability. In this context, the encapsulation process considers the integral and sustainable use of agricultural food waste for bioactive compounds that enhance the properties and quality of functional food.

Microwave-assisted extraction of rare earth elements from phosphogypsum—Effect of hydrogen peroxide addition

Phosphogypsum (PG) is a by-product of phosphate fertilizer manufacturing which is produced in significant amount. It is one of the promising secondary sources of rare earth elements (REEs). The study investigated microwave-assisted extraction (MAE) of yttrium (Y), lanthanum (La), and neodymium (Nd) from the PG, obtained from a fertilizer company in Gresik, Indonesia, using hydrochloric acid (HCl). Extraction efficiency increased as acid concentration increased from 0.25 N to 1.0 N, and increased slightly as reaction temperature increased from 100 °C to 150 °C. When using 1.0 N HCl, solid concentration of 20 g/L, 100 °C, and reaction time of 5 min, complete leaching of REEs was achieved, while 87.0 % of P was leached out. The total energy consumption was 3.74×105 kJ/kg, implying the MAE process was very energy-efficient. The addition of 1 or 2 wt% H2O2, however, decreased leaching efficiency of REEs. It was because the MW/H2O2 system produced hydroxyl radical (•OH), which induced the formation of the passivation layer of zirconium dioxide (ZrO2) on PG surfaces, and hindered REEs leaching. Simulation results revealed that recovery of P via selective precipitation was not feasible due to the interference of calcium (Ca) in the extractant.

Microwave-Assisted Extraction of Secondary Metabolites Using Ethyl Lactate Green Solvent from Ambrosia arborescens: LC/ESI-MS/MS and Antioxidant Activity.

Alternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry.

Extraction of phenolic compounds from edible flowers (Phlogacanthus thyrsiflorus) using ultrasound‐microwave‐assisted extraction and its screening by HPLC

AbstractPhlogacanthus thyrsiflorus flowers have been consumed as a traditional delicacy in the north‐eastern region of India. The present investigation utilized the microwave‐assisted extraction (MAE) technique in conjunction with an ultrasound pretreatment (at 250 W for 15 min) to extract phenolic compounds from Phlogacanthus thyrsiflorus flowers. Here, independent factors for optimization of MAE were microwave power (300, 500, and 700 W) and extraction time (2, 4, and 6 min), and responses were total phenolic content (TPC), total flavonoid content (TFC) and DPPH (2,2‐dipheny‐1‐picrylhydrazyl) activity. For the experimental design, a Response surface methodology and a central composite design were followed. The optimum MAE condition was found at microwave power 700 W for 5 min resulting 30.204 mg GAE/g TPC, 81.26% DPPH and 22.50 mg QAE/g of TFC. The extraction of phenolic compounds was significantly impacted by both the microwave power and the extraction time. The high‐performance liquid chromatography (HPLC) analysis detected various phenolic compounds in both conventional and MAE extracts. However, compared to conventional extract, the majority of the identified phenolic compounds were found to be higher in quantities in MAE extract. These results highlighted that MAE‐optimized flower extract could be beneficial as a functional ingredient for food product development.Practical applicationsPhlogacanthus thyrsiflorus is a highly nutritious flower with medicinal properties. Though traditionally edible flowers have been consumed in the northeastern part of India but people are still neophobic and there is scanty awareness available regarding the benefits of consuming edible flowers. This scientific justification regarding the advantages of edible flowers makes them appealing for future novel use in food technology and also for further scientific study. High perishability of flowers makes them limited for market viability and extraction of its phenolic compounds is one of the novel solutions to utilize the flowers before spoilage. Also, using ultrasound as a pretreatment could enhance the efficiency of microwave‐assisted extraction techniques for a higher yield of phenolic compounds. Microwave‐assisted extraction technique as its novel and was proven an easy successful extraction technique on this flower. Also, the study of phenolic compounds through HPLC provides important information regarding the presence of various phenolic compounds in the Phlogacanthus thyrsiflorus flower. This research can be supportive of both food technology and the medicinal industry.

High-Temperature Hydrothermal Extraction of Phenolic Compounds from Brewer's Spent Grain and Malt Dust Biomass Using Natural Deep Eutectic Solvents.

Aligned with the EU Sustainable Development Goals 2030 (EU SDG2030), extensive research is dedicated to enhancing the sustainable use of biomass waste for the extraction of pharmaceutical and nutritional compounds, such as (poly-)phenolic compounds (PC). This study proposes an innovative one-step hydrothermal extraction (HTE) at a high temperature (120 °C), utilizing environmentally friendly acidic natural deep eutectic solvents (NADESs) to replace conventional harmful pre-treatment chemicals and organic solvents. Brewer's spent grain (BSG) and novel malt dust (MD) biomass sources, both obtained from beer production, were characterized and studied for their potential as PC sources. HTE, paired with mild acidic malic acid/choline chloride (MA) NADES, was compared against conventional (heated and stirred maceration) and modern (microwave-assisted extraction; MAE) state-of-the-art extraction methods. The quantification of key PC in BSG and MD using liquid chromatography (HPLC) indicated that the combination of elevated temperatures and acidic NADES could provide significant improvements in PC extraction yields ranging from 251% (MD-MAC-MA: 29.3 µg/g; MD-HTE-MA: 103 µg/g) to 381% (BSG-MAC-MA: 78 µg/g; BSG-HTE-MA: 375 µg/g). The superior extraction capacity of MA NADES over non-acidic NADES (glycerol/choline chloride) and a traditional organic solvent mixture (acetone/H2O) could be attributed to in situ acid-catalysed pre-treatment facilitating the release of bound PC from lignin-hemicellulose structures. Qualitative 13C-NMR and pyro-GC-MS analysis was used to verify lignin-hemicellulose breakdown during extraction and the impact of high-temperature MA NADES extraction on the lignin-hemicellulose structure. This in situ acid NADES-catalysed high-temperature pre-treatment during PC extraction offers a potential green pre-treatment for use in cascade valorisation strategies (e.g., lignin valorisation), enabling more intensive usage of available biomass waste stream resources.

Optimization of toothtablets incorporating Albizia myriophylla Benth. stem extract obtained by eco-friendly microwave-assisted extraction

Albizia myriophylla Benth. stems are composed of the bioactive compound lupinifolin, which has exhibited anti-Streptococcus mutans activity. Extracting this plant for incorporation into oral healthcare products is challenging. This study aimed to optimize the eco-friendly microwave-assisted extraction of A. myriophylla stems. It also optimized toothtablets incorporating A. myriophylla stem extract. First, lupinifolin was isolated, and its structure was determined for use as a biomarker in this study. Next, three extraction parameters—the solvent-to-solid ratio, microwave power, and microwave time—were screened using a one-factor-at-a-time approach before being optimized using a Box–Behnken design. The results showed that the optimized conditions that maximized the extraction yield and lupinifolin content were a solvent-to-solid ratio of 23:1, microwave power of 800 W, and microwave time of 70 s. This extract contained 16.27 ± 0.43 % lupinifolin. The extract exhibited a minimum inhibitory concentration of 32 μg/mL and a minimum bactericidal concentration of 256 μg/mL. The half-maximal inhibitory concentration with human gingival fibroblast cells was 102.70 ± 1.02 μg/mL for the extract and 76.75 ± 1.03 μg/mL for lupinifolin. The extract was solidified using microcrystalline cellulose and colloidal silicon dioxide before being incorporated into the toothtablet formulation. Three factors in toothtablet production—compression force, microcrystalline cellulose content, and hydrated silica content—were also screened using a one-factor-at-a-time approach before being optimized using a Box–Behnken design. The results showed that the optimized conditions that approached the desired properties were a compression force of 2500 psi, microcrystalline cellulose content of 12 %, and hydrated silica content of 10 %. The developed toothtablets contained 35.64 ± 0.45 mg of lupinifolin per 650 mg toothtablet (or approximately 5.5 % lupinifolin per toothtablet) and retained their anti-S. mutans activity. They appeared safe for human gingival fibroblasts, even when treated for 2 min, with a maximum concentration of 2000 μg/mL. In conclusion, the developed toothtablets incorporating A. myriophylla stem extract can potentially serve as a high-quality, antibacterial, and safe alternative to traditional toothpaste.

Microwave assisted extraction of cellulose from lemon grass: Effect on techno-functional and microstructural properties

The study focused on utilizing lemon grass straw to generate cellulose through the process of delignification, which involves the removal of hemicelluloses, followed by bleaching. The study involves the microwave-assisted alkali extraction, followed by characterizing the extracted material. At microwave power of 540 W using 8 % NaOH for 3 min for lignin removal and 540 W for 2 min for bleaching showed the maximum yield of 37.46 %. Fourier transform infrared spectroscopy is employed to analyze the physical properties of extracted cellulose, namely the hydroxyl (OH), carbonyl (C=O), C–H bonds, C–O and C–C bonds, and glycosidic linkage (C–O–C) within the cellulose polymer chain. The extracted cellulose exhibited excellent thermal stability, as indicated by its high breakdown temperature. The X-ray diffraction (XRD) analysis revealed prominent peaks at 14.8°, 16.5°, and 22.5°, demonstrating the presence of crystalline cellulose. The crystallinity index value of 70.02 % further confirmed the crystalline nature of the extracted cellulose.