Microwave assisted extraction of soy isoflavones

Optimization of ultrasound-assisted extraction of phenols from Crocus sativus by-products using sunflower oil as a sustainable solvent alternative

In the last decade, there's been a rising emphasis on eco-friendly solvents in industry and academia due to environmental concerns. Vegetable oils are now recognized as a practical, non-toxic option for extracting phytochemicals from herbs. This study presents a novel, green, and user-friendly method for extracting phenolic content from Crocus sativus L. waste using ultrasound. It replaces conventional organic solvents with sustainable sunflower oil, making the process eco-friendly and cost-effective. The effects of temperature (18-52 °C), ultrasonic time (5-55 min), and solid-solvent ratio (5-31 g/100 mL) were assessed by applying response surface methodology (RSM) and Central composite design. The combined impact of solid-solvent ratio, temperature, and ultrasonic time led to heightened phenolic content and antioxidant activity in the enriched oil. However, when these variables were at their maximum levels, there was a decline in these attributes. The specific conditions found to be ideal were a solid-to-liquid ratio of 26 g/100 mL, a temperature of 45 °C, and a duration of 45 min. The optimum extraction condition yielded the expected highest phenolic content (317.15 mg/ Kg), and antioxidant activity (89.34%). The enriched oil with flower saffron enabled the utilization of renewable natural ingredients, ensuring the production of a healthy extract or product. Also, enriched oils find diverse applications in areas such as food, aquaculture, and cosmetics.

Valorization of pawpaw (Carica papaya L.) leaves as a source of polyphenols by ionic liquid-based microwave-assisted extraction: Comparison with other extraction methods and bioactivity evaluation

This study aimed to valorize pawpaw (Carica papaya L.) leaves as a rich source of polyphenols through the application of ionic liquid-based microwave-assisted extraction (ILMAE). Initially, the ILMAE process was optimized using response surface methodology (RSM), resulting in a total polyphenols yield of 27.84 ± 0.33 mg GAE/g DW under the optimal conditions: [BMIM]Br concentration of 0.57 mol/L, extraction time of 14 min, microwave power of 460 W, extraction temperature of 77 °C, solvent-to-material ratio of 30 mL/g, and three extraction cycles. Compared to conventional methods such as maceration extraction (ME), heat reflux extraction (HRE), and microwave-assisted extraction (MAE), the ILMAE method exhibited a significantly higher PLTP yield. Furthermore, the PLTP extracts demonstrated strong antioxidant activity against DPPH• and ABTS+• radicals, as well as a significant inhibitory effect on α-glucosidase activity. This work demonstrates that ILMAE is a green and efficient strategy for the valorization of pawpaw leaves.

Valorization of Fruit Waste for Bioactive Compounds and Their Applications in the Food Industry

The fruit production and processing sectors produce tremendous amounts of by-products and waste that cause significant economic losses and an undesirable impact on the environment. The effective utilization of these fruit wastes can help to reduce the carbon footprint and greenhouse gas emissions, thereby achieving sustainable development goals. These by-products contain a variety of bioactive compounds, such as dietary fiber, flavonoids, phenolic compounds, antioxidants, polysaccharides, and several other health-promoting nutrients and phytochemicals. These bioactive compounds can be extracted and used as value-added products in different industrial applications. The bioactive components extracted can be used in developing nutraceutical products, functional foods, or food additives. This review provides a comprehensive review of the recent developments in fruit waste valorization techniques and their application in food industries. The various extraction techniques, including conventional and emerging methods, have been discussed. The antioxidant and antimicrobial activities of the active compounds extracted and isolated from fruit waste have been described. The most important food industrial application of bioactive compounds extracted from fruit waste (FW) has been provided. Finally, challenges, future direction, and concluding remarks on the topic are summarized.

Microwave- and Ultrasound-Assisted Extraction of Cucurbitane-Type Triterpenoids from Momordica charantia L. Cultivars and Their Antiproliferative Effect on SAS Human Oral Cancer Cells

Cucurbitane-type triterpenoids are a major class of bioactive compounds present in bitter melon. In the present study, six different cultivars of bitter melon were extracted by using microwave- or ultrasound-assisted techniques to identify the prominent method that can extract the majority of cucurbitane-type triterpenoids. A UHPLC–MS/MS (ultra-high-performance liquid chromatography tandem mass spectrometry) system was used for the identification and quantification of ten cucurbitane-type triterpenoids. The results suggest that the use of microwave-assisted extraction on cultivars 4 and 5 produced higher amounts of the selected cucurbitane-type triterpenoids. The interpretation of principal component analysis also identified that cultivar 4 is significantly different from the others in which the compounds 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al and momordicine I were found in higher quantities. Upon further evaluation, it was also identified that these two triterpenoids can act as antiproliferative agents due to their effects on SAS human oral cancer cell lines.

Screening of Novel Source for Genistein by Rapid and Sensitive UPLC-APCI-TOF Mass Spectrometry

Genistein has been shown to have a broad spectrum of health advantages. Only legumes were reported to have a significant amount of genistein with the highest concentration in Soybean. Soybean was found to cause allergies in children with atopic dermatitis and in adults. Limited food sources have hindered the use of genistein in daily diets, medications, and nutraceuticals. The main objective of the current research work was to discover the novel source for genistein by the simple method of extraction and quantification. Genistein was extracted by solid-liquid extraction technique. Extraction parameters were optimized by a single factor test. Identification and quantification of genistein from the selected seeds of Apiaceae were carried out using UPLC-APCI-TOF-MS. UPLC-APCI-TOF-MS method was successfully developed, validated (linearity (R² = 0.999), precision (R.S.D. <5%), and accuracy (107.23%)), and used for the study. Remarkably, a high concentration of the genistein (811.57 μg/g) was found in the Cuminum cyminum. Solvent mixture (50 mL Methanol+25 mL Dimethyl sulphoxide+25 mL Water (v/v/v)), temperature (80°C), and time (1 h) were found to be the optimum extraction conditions. The concentration of genistein before optimization was 226.67 μg/g and after optimization is 811.57 μg/g. This shows the efficiency of the extraction method in the extraction of genistein without the need for hydrolysis. Novel source for genistein is identified in regular human food can be consumed in a regular diet which increases wellness of human health along with enhancing the taste of the food. The developed extraction method coupled with high throughput, sensitive, and selective UPLC-APCI-TOF-MS technique facilitates rapid quantification (8 minutes of run time) without primary purification of complex extract.

Ultraviolet blocking and antioxidant polyvinyl alcohol films incorporated with baicalin extraction from Scutellaria baicalensis Georgi

Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.

Selectivity of Current Extraction Techniques for Flavonoids from Plant Materials

Flavonoids have a broad spectrum of established positive effects on human and animal health. They find an application in medicine for disease therapy and chemoprevention, whence the interest in flavonoids increases. In addition, they are used in food and cosmetic industries as pigments and biopreservatives. Plants are an inexhaustible source of flavonoids. The most important step of plant raw material processing is extraction and isolation of target compounds. The quality of an extract and efficiency of a procedure are influenced by several factors: Plant material and pre-extracting sample preparation, type of solvent, extraction technique, physicochemical conditions, etc. The present overview discusses the common problems and key challenges of the extraction procedures and the different mechanisms for selective extraction of flavonoids from different plant sources. In summary, there is no universal extraction method and each optimized procedure is individual for the respective plants. For an extraction technique to be selective, it must combine an optimal solvent or mixture of solvents with an appropriate technique. Last but not least, its optimization is important for a variety of applications. Moreover, when the selected method needs to be standardized, it must achieve acceptable degree of repeatability and reproducibility.

An Overview on Analytical Methods for Quantitative Determination of Aristolochic Acids

Background:

Aristolochic acids are chemically linked to nitrophenanthrene carboxylic acids which are found in aristolochia plants. These compounds are intrinsically carcinogenic, while they have been used in traditional medicine from a long time ago. Despite the beneficial effects of herbals for treating some diseases, they possess some side effects.

Methods:

Therefore, the development of a sensitive and selective procedure for the determination of these harmful components in various complicated samples is an important task for health systems and drug authorities. In the past years, ultra-pressure liquid chromatography, high performance liquid chromatography and capillary electrophoresis with different detection systems were used for determination of aristolochic acids in various samples.

Results:

In this review, different analytical methods have been discussed in brief and applications of them in diverse samples have been summarized.

Conclusion:

Different approaches are compared from point of sensitivity, selectivity, and extraction efficiency.

Recent Advances in Microwave Assisted Extraction of Bioactive Compounds from Complex Herbal Samples: A Review

Microwaves are utilized for extraction of Phytoconstituents from complex herbal sample as a result of incredible research. Conventional extraction strategies are tedious and need more solvents and are no more relevant for thermal sensitive plant components. This review emphasize on the working and significance of microwave extraction technology in herbal research and medical field. The extraction step must be more yielding; quick, particular, not more solvent consuming, ensuring stability of thermolabile components and these features are available with microwave extraction method. In this nonconventional technology heat is created utilizing microwave energy. The important parameters that influence extraction efficiency are solvent properties, volume, duration of exposure, microwave control, system attributes, temperature and application were discussed in this article. The microwave assisted extraction, as green technology is contrasted with other extraction technique. This review is intended to discuss this green extraction technique along with its critical parameters for extracting bioactive compounds from complex plant matrices.

Microwave-Assisted Extraction of Ricinine from Ricinus communis Leaves

The alkaloid ricinine (3-cyano-4-methoxy-N-methyl-2-pyridone) is found in different parts of the Ricinus communis plant and is known to possess several bioactive properties, including strong antioxidant activity. In this study, a new microwave-assisted extraction (MAE) method was developed for the recovery of ricinine from R. communis leaves. The extraction variables studied were extraction temperature (between 125 °C and 175 °C), microwave power (between 500 W and 1000 W), extraction time (between 5 min and 15 min), extraction solvent (between 10% and 90% of EtOAc in MeOH), and solvent-to-sample ratio (between 25:1 mL and 50:1 mL of solvent per gram of the sample). On studying the effects of extraction variables, both solvent and liquid-to-solid ratio were found to exhibit the highest effects on ricinine recovery. A fast (15 min) microwave-assisted extraction method was developed (high temperatures can be applied because the stability of ricinine is proven in the literature), allowing for the recovery of ricinine from R. communis leaves. The study revealed that R. communis leaves had almost 1.5 mg g⁻¹ (dried weight) of ricinine.

Soy Isoflavones and their Effects on Xenobiotic Metabolism

BACKGROUND

Soy isoflavones, such as genistein and daidzein, are bioflavonoids found in soy products that are able to interact with various hormones such as estrogen. Epidemiological studies reveal a proper level of isoflavones in diet can prevent many diseases like cancers or diabetes. Therefore, it is important to study the biotransformation and xenobiotic metabolism of soy isoflavones.

METHODS

A systematic review of published studies was carried out to investigate the characterization of isoflavones and their metabolites, sample pretreatment and quantitative analysis of isoflavones, and the influence of soy isoflavones on drug and xenobiotic metabolism.

RESULTS

Aglycones with weak estrogen-like activities are the biologically active forms of the soy isoflavones in mammals. The most recent advances including extraction, purification and detection of isoflavones in soybean and soy products are discussed. The effects of soy isoflavones on drug and xenobiotic metabolism involve in regulation of phase I cytochrome P450 (CYPs) enzyme and phase I detoxifying enzymes expression and activity. At the molecular level, soy isoflavones have proved capable of estrogenic/antiestrogenic with tissue-selective, anti-cancer, antiobesity, anti-oxidation, and tyrosine kinase inhibition activities.

CONCLUSION

This review summarized different aspects of soy isoflavones and their molecular mechanisms of pharmacological action on xenobiotic, which demonstrated that soy isoflavones can decrease the incidence of many diseases and benefit for human health. However, since the lack of clinical research for evaluation of the proper dosage of intake of soy isoflavones in diet or adjunctive therapy, there is a need for further studies on the selection of doses, biomedical applications and adverse effects of isoflavones for human health.

Deep Eutectic Solvent-Based Ultrahigh Pressure Extraction of Baicalin from Scutellaria baicalensis Georgi

Deep eutectic solvents (DESs), promising green solvents, and ultrahigh pressure extraction (UPE) as an effective auxiliary extraction method, have attracted wide attention. In this study, DES was coupled with UPE to efficiently extract baicalin from Scutellaria baicalensis Georgi. First, choline chloride: lactic acid (ChCl-LA, molar ratio 1:1) was selected as the most appropriate DES by comparing the extraction yield of different DESs. Second, the extraction protocol was optimized by response surface methodology (RSM) considering the impacts of ChCl-LA concentration, extraction pressure, extraction time and liquid-solid ratio on the extraction yield. Under the optimal condition (40 vol% water content, extraction pressure of 400 MPa, extraction time of 4 min and a liquid-solid ratio of 110 mL/g), a maximum yield of 116.8 mg/g was achieved, higher than that obtained by the traditional extraction method. The microstructure of the raw and extracted Scutellaria baicalensis Georgi samples according to scanning electron microscope (SEM) images revealed that the dissolution of chemical components was enhanced from the disrupted root tissues after DESs-UPE. DESs coupled with UPE could effectively extract the baicalin from Scutellaria baicalensis Georgi as a rapid and efficient extraction method.

Solid-liquid extraction of daidzein and genistein from soybean: Kinetic modeling of influential factors

The extraction of daidzein and genistein from soybean has been studied and the kinetic modeling was established using four modeling equations. The goodness of fit was evaluated by statistical errors including the standard error of means (SEM), the adjusted correlation coefficient (R2), and chi-square (χ2). The best model was considered to be the So and Macdonald model and it could give the most adequate description of solid-liquid extraction of daidzein and genistein from soybean sample. The effect of process parameters on extraction yields of daidzein and genistein also has been investigated. The optimized extraction condition was at 333.2 K using 70% ethanol solvent at a solvent-to-solid ratio of 20 mL g-1 with an agitation speed of 300 rpm. The highest extraction yields of daidzein and genistein from soybean were 0.126 ± 0.006 and 0.184 ± 0.013 mg g-1, respectively. The activation energies for extraction kinetics of soybean were found to be 11.10 kJ mol-1 (washing step) and 13.96 kJ mol-1 (diffusion step) for daidzein, 10.47 kJ mol-1 (washing step) and 19.70 kJ mol-1 (diffusion step) for genistein, respectively.

Development of extraction method for characterization of free and bonded polyphenols in barley (Hordeum vulgare L.) grown in Czech Republic using liquid chromatography-tandem mass spectrometry

Complete characterizations of free and bonded phenolic compounds, presented in four cultivars of barley from two regions of Czech Republic, were achieved, using optimized solvent extraction and liquid chromatography coupled with tandem mass spectrometry. The optimization of extraction of free polyphenols was performed using Box-Behnken design and response surface methodology. The intra-day and extra-day precision of developed method were below 6% and 12%, respectively. The isolation of polyphenols bonded to the cell wall structure was carried out by a hydrolysis process. In all cultivars, p-hydroxybenzoic, p-coumaric and ferulic acids were the most abundant compounds. Their average amounts in barley samples were 17.6, 15.2 and 54.4% (m/m), respectively. The highest amount of these compounds was found in the bonded form, proving the importance of this procedure for the correct characterization of total polyphenols in food matrices.

Optimization of ultrasound and microwave assisted extractions of polyphenols from black rice (Oryza sativa cv. Poireton) husk

Phenolic compounds were extracted from the husk of milled black rice (cv. Poireton) by using a combination of ultrasound assisted extraction and microwave assisted extraction. Extraction parameters were optimized by response surface methodology according to a three levels, five variables Box-Behnken design. The appropriate process variables (extraction temperature and extraction time) to maximize the ethanolic extraction of total phenolic compounds, flavonoids, anthocyanins and antioxidant activity of the extracts were obtained. Extraction of functional components with varying ethanol concentration and microwave time were significantly affected by the process variables. The best possible conditions obtained by RSM for all the factors included 10.02 min sonication time, 49.46 °C sonication temperature, 1:40.79 (w/v) solute solvent ratio, 67.34% ethanol concentration, and 31.11 s microwave time. Under the given solutions, the maximum extraction of phenolics (1.65 mg/g GAE), flavonoids (3.04 mg/100 g), anthocyanins (3.39 mg/100 g) and antioxidants (100%) were predicted, while the experimental values included 1.72 mg/g GAE of total phenolics, 3.01 mg/100 g of flavonoids, 3.36 mg/100 g of anthocyanins and 100% antioxidant activity. The overall results indicated positive impact of co-application of microwave and ultrasound assisted extractions of phenolic compounds from black rice husk.

Evaluation of new natural deep eutectic solvents for the extraction of isoflavones from soy products

Natural deep eutectic solvents (NADESs) are considered to be new, safe solvents in green chemistry that can be widely used in many chemical processes such as extraction or synthesis. In this study, a simple extraction method based on NADES was used for the isolation of isoflavones (daidzin, genistin, genistein, daidzein) from soy products. Seventeen different NADES systems each including two or three components were tested. Multivariate data analysis revealed that NADES based on a 30% solution of choline chloride: citric acid (molar ratio of 1:1) are the most effective systems for the extraction of isoflavones from soy products. After extraction, the analytes were detected and quantified using ultra-high performance liquid chromatography with ultraviolet detection (UHPLC-UV). The proposed NADES extraction procedure achieved enrichment factors up to 598 for isoflavones and the recoveries of the analytes were in the range 64.7-99.2%. The developed NADES extraction procedure and UHPLC-UV determination method was successfully applied for the analysis of isoflavones in soy-containing food samples. The obtained results indicated that new natural deep eutectic solvents could be an alternative to traditional solvents for the extraction of isoflavones and can be used as sustainable and safe extraction media for another applications.

Development of new efficient method for isolation of phenolics from sea algae prior to their rapid resolution liquid chromatographic-tandem mass spectrometric determination

The extraction of phenolic compounds from 4 different sea algae samples, three brown algae (Cystoseira abies-marina, C. abies-marina grinded under cryogenic conditions with liquid nitrogen, Undaria pinnatifida and Sargassum muticum) and one red algae (Chondrus crispus) via solid phase extraction using micro-elution solid-phase extraction (μ-SPE) plate method was studied. Prior to μ-SPE, 50mg of algae with 80% methanol mixture was extracted in hyphenated series by various extraction techniques, such as pressurized liquid extraction and Ika Ultra-Turrax® Tube Drive, in combination with ultrasound assisted extraction. The μ-SPE plate technique reduced the time of sample pre-treatment thanks to higher sensitivity and pre-concentration effect. Selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic, and syringic acids), hydroxybenzaldehydes (4-hydroxybenzaldehyde, and 3,4-dihydroxybenzaldehyde), and cinnamic acid derivatives (p-coumaric, caffeic, ferulic, sinapic, and chlorogenic acids) were determined using rapid resolution liquid chromatography coupled to mass spectrometry detection with negative ion electrospray ionization (RRLC-ESI-MS) using multiple reactions monitoring. LOQs of measured samples varied in the range 0.23-1.68ng/mL and LODs in the range 0.07-0.52ng/mL. The applied method allowed a simultaneous determination of phenolics (i.e. free, esters soluble in methanol, glycosides, and esters insoluble in methanol) in less than 5min (including alkaline or acidic hydrolysis of raw extracts) from sea algae extracts.

Green Extraction Methods for Polyphenols from Plant Matrices and Their Byproducts: A Review

Polyphenols as phytochemicals have gained significant importance owing to several associated health benefits with regard to lifestyle diseases and oxidative stress. To date, the development of a single standard method for efficient and rapid extraction of polyphenols from plant matrices has remained a challenge due to the inherent limitations of various conventional extraction methods. The exploitation of polyphenols as bioactive compounds at various commercial levels has motivated scientists to explore more eco-friendly, efficient, and cost-effective extraction techniques, based on a green extraction approach. The current review aims to provide updated technical information about extraction mechanisms, their advantages and disadvantages, and factors affecting efficiencies, and also presents a comparative overview of applications of the following modern green extraction techniques-supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction, and pressurized hot water extraction-as alternatives to conventional extraction methods for polyphenol extraction. These techniques are proving to be promising for the extraction of thermolabile phenolic compounds due to their advantages over conventional, time-consuming, and laborious extraction techniques, such as reduced solvent use and time and energy consumption and higher recovery rates with lower operational costs. The growing interest in plant-derived polyphenols prompts continual search for green and economically feasible modern extraction techniques. Modern green extraction techniques represent promising approaches by virtue of overcoming current limitations to the exploitation of polyphenols as bioactive compounds to explore their wide-reaching applications on an industrial scale and in emerging global markets. Future research is needed in order to remove the technical barriers to scale-up the processes for industrial needs by increasing our understanding and improving the design of modern extraction operations.

Green ultrasound-assisted extraction of carotenoids from pomegranate wastes using vegetable oils

The objective of this work was to develop a new process for pomegranate peels application in food industries based on ultrasound-assisted extraction of carotenoids using different vegetable oils as solvents. In this way, an oil enriched with antioxidants is produced. Sunflower oil and soy oil were used as alternative solvents and the effects of various parameters on extraction yield were studied. Extraction temperature, solid/oil ratio, amplitude level, and extraction time were the factors investigated with respect to extraction yield. Comparative studies between ultrasound-assisted and conventional solvent extraction were carried out in terms of processing procedure and total carotenoids content. The efficient extraction period for achieving maximum yield of pomegranate peel carotenoids was about 30min. The optimum operating conditions were found to be: extraction temperature, 51.5°C; peels/solvent ratio, 0.10; amplitude level, 58.8%; solvent, sunflower oil. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound extraction under different processing parameters.

Determination of Isoflavone Content in SRM 3238 Using Liquid Chromatography-Particle Beam/Electron Ionization Mass Spectrometry

The characterization of marker components in botanical materials is a challenging task, and the increased consumption of botanicals and dietary supplements demands a greater understanding of the associated health benefits and risks. In order to successfully acquire and compare clinical results and correlate health trends, accurate, precise, and validated methods of analysis must be developed. Presented here is the development of a quantitative method for the determination of soy isoflavones (daidzin, glycitin, genistin, daidzein, and genistein) using LC-particle beam/electron ionization-MS (LC-PB/EIMS). An internal standard (IS) approach for quantitation with 7-hydroxy-4- chromone as the IS compound was used, with response factors for each individual isoflavone obtained from calibrant solutions. The results from this method were compared with the certified and reference values for National Institute of Standards and Technology (NIST) SRM 3238 Soy-Containing Solid Oral Dosage Form to demonstrate that the method was in control. Results obtained using LC-PB/EIMS were consistent with the NIST certified or reference values and their uncertainties for all five isoflavones, demonstrating that the LC-PB/EIMS approach is both accurate and precise when used for the determination of the target isoflavones in soy-containing dietary supplement finished products while simultaneously providing structural information.

Optimization extraction, characterization and antioxidant activities of pectic polysaccharide from tangerine peels

Response surface methodology (RSM) was employed to optimize the microwave-assisted extraction (MAE) process of pectic polysaccharide (TPPs) from tangerines peel. The optimal extraction conditions were as follows: microwave power 704 W, extraction temperature 52.2 °C, and extraction time 41.8 min Under these conditions, the experimental yield was 19.9 ± 0.2%. The purified pectic polysaccharide TPPs-2-1 was successfully obtained by anion-exchange and gel filtration chromatography. TPPs-2-1, linked mainly by α-glycosidic bonds, consisted of galacturonic acid (GalA), arabinose (Ara), galactose (Gal), rhamnose (Rha), glucose (Glc) and mannose (Man) with the average molecular weight of 17.8 kDa, and had typical IR spectra characteristic of pectic polysaccharides. Antioxidant activities were investigated on the basis of ferric-reducing antioxidant power (FRAP), hydroxyl radical (OH), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and superoxide radical (O2(-)) scavenging assay. TPPs-2-1 exhibited significant antioxidant activity in a concentration-dependent manner and might be exploited as effective natural antioxidant applied in functional food and medicine.

Microwave-assisted extraction and purification of chlorogenic acid from by-products of Eucommia Ulmoides Oliver and its potential anti-tumor activity

An efficient method for the rapid extraction, separation and purification of chlorogenic acid (CGA) from by-products of Eucommia Ulmoides Oliver (E. ulmoides) by microwave-assisted extraction (MAE) coupled with high-speed counter-current chromatography (HSCCC) was developed. The optimal MAE parameters were evaluated by response surface methodology (RSM), and they were extraction time of 12 min, microwave power of 420 W, ethanol concentration of 75 %, solvent/sample ratio of 30:1 (mL/g), yield of CGA reached 3.59 %. The crude extract was separated and purified directly by HSCCC using ethyl acetate-butyl alcohol-water (3:1:4, v/v) as the two-phase solvent system. The 14.5 mg of CGA with the purity of 98.7 % was obtained in one-step separation from 400 mg of crude extract. The chemical structure of CGA was verified with IR, ESI-MS analysis. Meanwhile, the purified CGA extract was evaluated by MTT assay and results indicate that CGA extract exhibited potential anti-tumor activity for AGS gastric cancer cell.

A Review of Extraction and Analysis of Bioactives in Oat and Barley and Scope for Use of Novel Food Processing Technologies

Oat and barely are cereal crops mainly used as animal feed and for the purposes of malting and brewing, respectively. Some studies have indicated that consumption of oat and barley rich foods may reduce the risk of some chronic diseases such as coronary heart disease, type II diabetes and cancer. Whilst there is no absolute consensus, some of these benefits may be linked to presence of compounds such as phenolics, vitamin E and β-glucan in these cereals. A number of benefits have also been linked to the lipid component (sterols, fatty acids) and the proteins and bioactive peptides in oats and barley. Since the available evidence is pointing toward the possible health benefits of oat and barley components, a number of authors have examined techniques for recovering them from their native sources. In the present review, we summarise and examine the range of conventional techniques that have been used for the purpose of extraction and detection of these bioactives. In addition, the recent advances in use of novel food processing technologies as a substitute to conventional processes for extraction of bioactives from oats and barley, has been discussed.

Analysis of phytohormones in vermicompost using a novel combinative sample preparation strategy of ultrasound-assisted extraction and solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry

Vermicompost (VC), a widely used premium organic fertilizer, is the by-product of symbiotic interactions between earthworms and microorganisms living within them. It has been postulated that phytohormones are plausible "magic compounds" in VC that are responsible for making them such good fertilizers. Thus, a novel approach involving ultrasound-assisted extraction (UAE) and solid-phase extraction (SPE) was developed as a fast and efficient sample preparation method to screen for different classes of phytohormones in VC by liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis. Nine phytohormones from three different classes, including trans-zeatin (tZ), kinetin (K), N(6)-[2-isopentyl]adenine (iP), N(6)-benzyladenine (BA), N(6)-isopentenyladenosine (iPR), indole-3-acetic acid (IAA), 4-[3-indolyl]butyric acid (IBA), 1-naphthaleneacetic acid (NAA) and (+)-abscisic acid (ABA), were simultaneously screened. The extraction parameters influencing UAE efficiency were optimized to provide comparable recovery to the conventional mix-stirring (MSt) method. The optimized UAE method was subsequently applied on the analysis of phytohormones in VC, i.e. phytohormone extract was further pre-concentrated and purified using C18 and MCX SPE cartridges prior to LC-MS/MS analysis. The following phytohormones, namely iP, iPR and IAA, were detected and quantified to be 0.49, 0.53, 79.78ngg(-1), respectively; tZ was found to be below the limit of quantitation. Recoveries of 10.2%, 9.1%, 18.9% and 0.3% for tZ, iP, iPR and IAA were obtained. This is one of the few reported works for the successful detection and quantitation of cytokinins and auxins in VC, that provided the key empirical evidence to explain the growth efficacy of applying VC in promoting plant growth. Additionally, this pioneering work could potentially be applicable for the analysis of other types of organic fertilizers such as composts and activated composted materials awaiting phytohormone analyzes for quality assessment and control.

Comparative study of the methodology used in the extraction of isoflavones from legumes applying a modified QuEChERS approach

INTRODUCTION

Isoflavones are phytochemicals of great interest because of their association with a large variety of positive effects on human health. The major sources of isoflavones in the diet are plants of the Leguminosae family, especially soybeans, although many other legumes more widely consumed in the Mediterranean diet have also been reported to contain these compounds. In previous work we extracted isoflavones from samples using a modified QuEChERS (Quick Easy Cheap Effective Rugged Safe) methodology.

OBJECTIVE

To compare different methods for placing the sample and the solvent in contact to optimise the extraction of isoflavones from legumes (chickpeas, lentils and white beans) using a modified QuEChERS methodology.

METHOD

Five different approaches to sample agitation were tested: vortex agitation, thermostatted stirring agitation and thermostatted tray shaking, and a thermostatted ultrasound bath and an ultrasound probe. To evaluate the different methodologies a modified QuEChERS approach was used as the extraction method. The separation and quantification of isoflavones was carried out using liquid chromatography-triple quadrupole/mass spectrometry (LC-MS/MS).

RESULTS

The best methods were found upon using a thermostatted shaking tray for the extraction of chickpeas and white beans and the ultrasound probe for lentil samples. These methods were chosen based on the highest amount of analytes obtained as well as the best recovery values.

CONCLUSION

Determination of isoflavones in foods may be affected by the different methods used to place the sample and the solvent in contact in the extraction step. The main advantages of the proposed extraction procedures are their simplicity, speed, reliability and low cost.

Chemical composition, properties, and antimicrobial activity of the water-soluble pigments from Castanea mollissima shells

Agricultural residues Castanea mollissima shells represent a promising resource for natural pigments for the food industry. This study provides a comprehensive and systematic evaluation of water-soluble pigments (CSP) from C. mollissima shells, which were obtained by 50% ethanol with microwave-assisted extraction. Spectroscopic techniques (UV, FT-IR, (13)C NMR), elemental analysis, and chromatographic techniques (HPAEC, GPC) revealed that the main components in the CSP were flavonoids procyanidin B3 (condensed tannin), quercetin-3-O-glycoside, and steroidal sapogenins. As a consequence, CSP was water-soluble and presented significant DPPH scavenge capacity (EC50 value was 0.057 mg/mL). Specially, CSP gave excellent antibacterial activity, and even better than 5% aqueous phenol in some case. Moreover, CSP was practically nontoxic and exhibited good stability with temperature, natural light, and metal ions. These outstanding properties will enlarge the application of CSP for natural food additives production.

An outlook on chlorogenic acids-occurrence, chemistry, technology, and biological activities

Phenolics are widespread dietary antioxidants. Among these, chlorogenic acids (CGAs) received considerable attention for their wide distribution and part of human diet with potential biological effects. CGAs (71 compounds), being esters of derivatives of cinnamic acids with quinic acid are widely distributed in plant materials. Coffee is among the highest found in plants, ranging from 4 to 14%. Besides, these are reported in plant foods such as apples, pears, carrot, tomato, sweet potato, Phyllostachys edulis, oilseeds, Prunus domestica L, cherries, and eggplant. The traditional Chinese medicinal plants such as flowers and buds of Lonicera japonica Thunb and the leaves of Eucommia ulmodies contained CGAs as bioactive compound. These play an important role in the formation of roasted coffee flavor and have a marked influence on coffee cup quality. CGAs are considered as main precursors of coffee flavor and pigments. Recent technological advancements in the separation and purification of CGAs such as molecular-imprinted polymer technique; microwave-assisted extraction; pH gradient counter current chromatography has also been described. The consumption of coffee correlated to several health benefits such as reducing the risk of human chronic diseases such as inflammation, diabetes, and cardiovascular disease owing to its antioxidant potential.

Examination of 1-methylimidazole series ionic liquids in the extraction of flavonoids from Chamaecyparis obtuse leaves using a response surface methodology

Ionic liquids (ILs) are a new type of reagent that has accelerated research in extraction technology. On the other hand, few studies have systematically applied 1-methylimidazole ([MIM]) series ILs to the extraction of bioactive compounds from plants. In this study, [MIM] series ILs were used to extract four bioactive flavonoids, such as dihydrokaempferol, quercitrin, amentoflavone and myricetin, from Chamaecyparis obtuse (CO) leaves. First, a screen of the extraction method and solvent revealed the [MIM] series ILs to be suitable as additives in methanol in Soxhlet extraction. Second, an examination of a range of cations and anions of [MIM] series ILs for extraction revealed 1-decyl-3-methylimidazolium bromide ([DMIM][Br]) to be the best selection as an additive in methanol for the Soxhlet extraction of flavonoids from (CO) leaves. Finally, some factors of extraction, such as temperature, time and amount of samples, were examined systematically using a response surface methodology (RSM). Based on the above optimization, 2.41, 3.47, 0.76 and 3.15mg/g of dihydrokaempferol, quercitrin, amentoflavone and myricetin, respectively, were extracted from 15g of CO leaves by 2.5mgmL(-1) of [DMIM][Br] as additives in 200mL of methanol in Soxhlet extraction at 200°C for 8h. This study highlights the potential of [MIM] series ILs as promising reagents for the extraction of bioactive compounds from plants.