Application of Green Technology to Extract Clean and Safe Bioactive Compounds from Tetradesmus obliquus Biomass Grown in Poultry Wastewater.

Microalgae are capable of assimilating nutrients from wastewater (WW), producing clean water and biomass rich in bioactive compounds that need to be recovered from inside the microalgal cell. This work investigated subcritical water (SW) extraction to collect high-value compounds from the microalga Tetradesmus obliquus after treating poultry WW. The treatment efficiency was evaluated in terms of total Kjeldahl nitrogen (TKN), phosphate, chemical oxygen demand (COD) and metals. T. obliquus was able to remove 77% TKN, 50% phosphate, 84% COD, and metals (48-89%) within legislation values. SW extraction was performed at 170 °C and 30 bar for 10 min. SW allowed the extraction of total phenols (1.073 mg GAE/mL extract) and total flavonoids (0.111 mg CAT/mL extract) with high antioxidant activity (IC50 value, 7.18 µg/mL). The microalga was shown to be a source of organic compounds of commercial value (e.g., squalene). Finally, the SW conditions allowed the removal of pathogens and metals in the extracts and residues to values in accordance with legislation, assuring their safety for feed or agriculture applications.

Comparative Study of the Essential Oil and Hydrosol Composition of Sweet Wormwood (Artemisia annua L.) from Serbia.

The most abundant volatile compounds of sweet wormwood (Artemisia annua L.) essential oil were artemisia ketone (25.4 %) and trans-caryophyllene (10.2 %), followed by 1,8-cineole, camphor, germacrene D and ß-selinene. The major volatile compounds in the hydrosol were camphor (25.1 %), 1,8-cineole (20.5 %) and artemisia ketone (10.7 %), followed by trans-pinocarveol and yomogi alcohol. Tested essential oil was rich in oxygenated monoterpenes and sesquiterpene hydrocarbons, while the former were identified as the major class of volatile compounds in the hydrosol, due to higher water solubility. Classification of all sweet wormwood chemotypes, according to essential oil composition, in available literature (17 studies and 61 accessions) could be done according to four chemotypes: artemisia ketone+artemisia alcohol (most abundant), artemisia ketone, camphor and nonspecific chemotype. According to this classification, essential oil of sweet wormwood from this study belongs to artemisia ketone (content varied between 22.1 and 55.8 %). Bearing in mind that hydrosols are a by-product of industrial production of essential oils, and the fact that sweet wormwood hydrosol has high contents of camphor, 1,8-cineole and artemisia ketone, there is a great potential for the use of this aromatic plant primary processing waste product as a water replacement in cosmetic industry, beverages flavoring, for food preservation, as well as in post-harvest pre-storage treatments in organic agriculture.

Impact of Short-Time Micronization on Structural and Thermal Properties of Sugar Beet Fibre and Inulin.

Research background: By tailoring dietary fibre's structural and physicochemical properties, their functionality and applicability can be remarkably increased. One of the approaches used in this respect is fibre particle size reduction. Accordingly, the present study explores the impact of short-time micronization in a planetary ball mill on structural and thermal changes of modified and commercial sugar beet fibre, inulin and sucrose for their potential application as food excipients. Experimental approach: Short-time micronization in a planetary ball mill (30 and 60 min) was applied for particle size reduction of modified and commercial sugar beet fibre, inulin and sucrose as less energy-consumptive and less destructive approach than long-time micronization. Dietary fibre and sucrose samples were characterised in terms of particle size, morphology, intermolecular bonds and presence of functional groups, crystallinity and thermal properties, before and after the short-time micronization. Results and conclusions: Particle size was successfully reduced to micron-scale already after 30 min of micronization in most of the samples without significant changes in thermal properties and crystallinity or present functional groups. An enhanced particle size decrease with prolonged micronization time (60 min) was noticed in modified sugar beet fibre with slightly wider particle size distribution than in other examined samples. Furthermore, morphology and exposure of the present functional groups in samples were altered by the micronization, which is favourable for their further application as excipients in the food matrix. Novelty and scientific contribution: The corresponding research reports the short-time micronization impact on sugar beet fibre and modified sugar beet fibre, inulin and sucrose for the first time, hence contributing to the widening of their application as excipients in diverse products.

Supercritical Carbon Dioxide Extraction of Allium ursinum: Impact of Temperature and Pressure on the Extracts Chemical Profile.

The aim of this study was to extract Allium ursinum L. for the first time by supercritical carbon dioxide (SC-CO2 ) as green sustainable method. The impact of temperature in the range from 40 to 60 °C and pressure between 150 and 400 bar on the quality of the obtained extracts and efficiency of the extraction was investigated. The highest extraction yield (3.43 %) was achieved by applying the extraction conditions of 400 bar and 60 °C. The analysis of the extracts was performed by gas chromatography and mass spectrometry (GC/MS). The most dominant sulfur-containing constituent of the extracts was allyl methyl trisulfide with the highest abundance at 350 bar and 50 °C. In addition, the presence of other pharmacologically potent sulfur compounds was recorded including S-methyl methanethiosulfinate, diallyl trisulfide, S-methyl methylthiosulfonate, and dimethyl trisulfide. Multivariate data analysis tool was utilized to investigate distributions of the identified compounds among the extracts obtained under various extraction conditions and yields. It was determined that the SC-CO2 extraction can by efficiently used for A. ursinum.

Valorization of Yarrow (Achillea millefolium L.) By-Product through Application of Subcritical Water Extraction.

In the present study, valorization of yarrow (Achillea millefolium) by-product from the filter tea industry was investigated through the application of subcritical water for the extraction of bioactive compounds. The influence of different process parameters (temperature 120-200 °C, extraction time 10-30 min, and HCl concentration in extraction solvent 0-1.5%) on extract quality in terms of content of bioactive compounds and antioxidant activity was investigated. Optimal conditions of the extraction process (temperature 198 °C, extraction time 16.5 min, and without acidifer) were determined and, when applied, the most efficient exploitation of by-products is achieved, that is, attainment of extracts rich in total phenols and flavonoids and high antioxidant activity. In addition, by applying the high performance liquid chromatographic analysis, the content of chlorogenic acid was determined as well as the hydroxymethylfurfural content in obtained extracts. The results demonstrated that subcritical water can be successfully used for utilization of yarrow by-products for obtaining extracts rich in antioxidants.

Comparative Study of Subcritical Water and Microwave-Assisted Extraction Techniques Impact on the Phenolic Compounds and 5-Hydroxymethylfurfural Content in Pomegranate Peel.

Two environmentally friendly innovative extraction techniques - subcritical water (SWE) and microwave-assisted extraction (MAE) were applied for the extraction of phenolics from pomegranate peel. The impact of process conditions (SWE: temperature 100-220 °C, extraction time 5-30 min; MAE: solvent water and 50% ethanol, irradiation power 470 and 800 W) on the quality of extracts in terms of the content of total phenolics, total flavonoids, major phenolic constituents (gallic acid, ellagic acid, punicalin, punicalagin), as well as 5-hydroxymethylfurfural(HMF) amount was investigated. For SWE, temperature of 130 °C and 20 min extraction time were found optimal for obtaining high content of bioactive compounds and minimizing the yield of HMF. During MAE, phenolic compounds were effectively extracted by using lower microwave power and 50% ethanol. Comparing two techniques, MAE is more efficient than SWE for the extraction of phenolics from pomegranate peel while obtaining a HMF-free extracts.

Aronia Berry Processing by Spray Drying: From Byproduct to High Quality Functional Powder.

The main aim of this study is to analyze the solid-liquid extraction followed by spray drying as a technological pathway for utilization of aronia fruit dust, a byproduct of filter tea factory. In the current study, ultrasound-assisted extraction was applied for the production of aronia liquid feed and maltodextrin was used as a carrier and encapsulating agent. In spray drying, the influence of inlet temperature and maltodextrin type and mass fraction on process efficiency and powder properties were observed. The physical and chemical properties of the obtained powders were characterized. It was determined that the powder produced using inlet temperature 140 °C and 40% maltodextrin with dextrose equivalent (DE) 19.7 had the most desirable characteristics. It was observed that the increase in maltodextrin mass fraction decreases the powder moisture content, hygroscopicity and the content of bioactive compounds, but increases water solubility index and particle size. The increase in dextrose equivalent of maltodextrin increases the powder hygroscopicity and water solubility index, while the increase of inlet temperature causes a decrease in moisture content of aronia powders.

Recovery of Antioxidant Compounds from Aronia Filter Tea Factory by -Product: Novel Versus Conventional Extraction Approaches.

Black chokeberry (Aronia melanocarpa L.) by-product from filter tea factory underwent subcritical water extraction (SWE) in order to recover polyphenolics and determine its antioxidant potential. In the current study Box-Behnken design was applied for optimization. Independent variables used in experimental design were temperature (T, 120-200 °C), extraction time (t, 15-35 min) and hydrochloride concentration (c, 0-1.5%). Experimental results were fitted to a second-order polynomial model where multiple regression analysis and analysis of variance were used to determine fitness of the model and optimal conditions. The optimized SWE conditions for maximum responses of total phenols (TP), total flavonoids (TF) and monomeric anthocyanins (MA) contents, and minimum response of IC50 were temperature of 120.4 °C, extraction time of 15.2 min and absence of acidifier. The predicted values of TP, TF, MA and IC50 at these conditions were: 32.8863 mg GAE/g, 23.5164 mg CE/g, 0.5124 mg C3G/g and 0.0055 mg/mL, respectively.

Supercritical CO2 Extraction of Lavandula angustifolia Mill. Flowers: Optimisation of Oxygenated Monoterpenes, Coumarin and Herniarin Content.

INTRODUCTION: Lavandula angustifolia is good source of oxygenated monoterpenes containing coumarins as well, which are all soluble in supercritical CO2 (SC-CO2 ). OBJECTIVE: The study objective is to investigate SC-CO2 extraction parameters on: the total yield; GC-MS profile of the extracts; relative content of oxygenated monoterpenes; the amount of coumarin and herniarin; and to determine optimal SC-CO2 extraction conditions by response surface methodology (RSM). METHODOLOGY: SC-CO2 extraction was performed under different pressure, temperature and CO2 flow rate determined by Box-Behnken design (BBD). The sample mass and the extraction time were kept constant. The chemical profiles and relative content of oxygenated monoterpenes (as coumarin equivalents, CE) were determined by GC-MS. Coumarin and herniarin concentrations were dosed by HPLC. RESULTS: SC-CO2 extracts contained linalool (57.4-217.9 mg CE/100 g), camphor (10.6-154.4 mg CE/100 g), borneol (6.2-99.9 mg CE/100 g), 1,8-cineole (5.0-70.4 mg CE/100 g), linalyl acetate (86.1-267.9 mg CE/100 g), coumarin (0.95-18.16 mg/100 g), and herniarin (0.95-13.63 mg/100 g). The interaction between the pressure and CO2 flow rate as well as between the temperature and CO2 flow rate showed statistically significant influence on the extraction yield. Applying BBD, the optimum extraction conditions for higher monoterpenes and lower coumarin content were at 10 MPa, 41°C and CO2 flow rate 2.3 kg/h, and at 30 MPa, 50°C and CO2 flow rate 3 kg/h for higher monoterpenes and coumarin content. CONCLUSION: SC-CO2 extraction is a viable technique for obtaining lavender extracts with desirable flavour components. The second-order model based on BBD predicts the results for SC-CO2 extraction quite satisfactorily. Copyright © 2017 John Wiley & Sons, Ltd.

Optimization of microwave-assisted extraction (MAE) of coriander phenolic antioxidants - response surface methodology approach.

BACKGROUND: Microwave-assisted extraction (MAE) of polyphenols from coriander seeds was optimized by simultaneous maximization of total phenolic (TP) and total flavonoid (TF) yields, as well as maximized antioxidant activity determined by 1,1-diphenyl-2-picrylhydrazyl and reducing power assays. Box-Behnken experimental design with response surface methodology (RSM) was used for optimization of MAE. Extraction time (X1 , 15-35 min), ethanol concentration (X2 , 50-90% w/w) and irradiation power (X3 , 400-800 W) were investigated as independent variables. Experimentally obtained values of investigated responses were fitted to a second-order polynomial model, and multiple regression analysis and analysis of variance were used to determine fitness of the model and optimal conditions. RESULTS: The optimal MAE conditions for simultaneous maximization of polyphenol yield and increased antioxidant activity were an extraction time of 19 min, an ethanol concentration of 63% and an irradiation power of 570 W, while predicted values of TP, TF, IC50 and EC50 at optimal MAE conditions were 311.23 mg gallic acid equivalent per 100 g dry weight (DW), 213.66 mg catechin equivalent per 100 g DW, 0.0315 mg mL(-1) and 0.1311 mg mL(-1) respectively. CONCLUSION: RSM was successfully used for multi-response optimization of coriander seed polyphenols. Comparison of optimized MAE with conventional extraction techniques confirmed that MAE provides significantly higher polyphenol yields and extracts with increased antioxidant activity. © 2016 Society of Chemical Industry.

Characterisation of volatiles in dried white varieties figs (Ficus carica L.).

The aromatic profile of volatiles in dried figs varieties Bruzetka Bijela and Zimnica were characterised by headspace solid-phase (HS-SPME) procedure with gas chromatography-mass spectrometry analysis (GC-MS). The volatile compounds were distributed by distinct chemical classes, including alcohols, aldehydes, esters, terpenic compounds, and other compounds. The figs were dried in a pilot plant cabinet dryer. Prior to drying process, figs were pre-treated by sulphur dioxide, immersed in solution of citric acid and ascorbic acid, respectively. Several mathematical thin-layer drying models, available in the literature, were fitted to experimental data of figs, implementing non-linear regression analysis techniques. The results showed that pre-treatments of figs decrease significantly the drying time. The best thin-layer drying model in terms of fitting performance was Wang and Singh model. The major volatile compound in dried figs was benzaldehyde. After benzaldehyde, the most abundant aldehyde in dried figs was hexanal. The comparison among dried figs showed the highest abundance of aldehydes, in general, in non-treated (control) dried figs compared to pre-treated samples. Furthermore, ascorbic acid was the most efficient in preserving esters and alcohols in case of Bruzetka Bijela, whereas in case of Zimnica, sulphur dioxide was in advance compared to ascorbic acid. Ethyl acetate was the most abundant ester found in dried figs. Among other compounds, 2-butanone,3-hydroxy was the most abundant identified volatiles. Linalool, as the only identified terpen, was in case of both dried fig varieties, preserved by immersion into ascorbic acid. The immersion into citric acid has not been so successful in volatiles conservation.

Ultrasound-assisted and subcritical water extraction techniques for maximal recovery of phenolic compounds from raw ginger herbal dust toward in vitro biological activity investigation.

This study examined the impact of two green extraction techniques in order to maximize the usage and recovery of phenolic compounds from the by-product of the filter tea industry, the so-called ginger herbal dust. The main phenolic compounds extraction was performed by ultrasound-assisted extraction (UAE) with the sonication amplitude ranging from 20% to 100%, and the subcritical water extraction (SWE), with the temperature ranging from 120 °C to 220 °C. All obtained extracts were characterized in terms of extraction yield, total phenolic content (TPC), and 6-ginerol, 6-shogaol, and 8-ginerol contents using RP-HPLC-DAD. Based on the results, we selected the extract obtained from raw ginger herbal dust using a sonication amplitude of 100% for further biological investigation of the cytotoxic effect on short- and long-term cell viability on liver and pancreatic cancer cells. This extract contained high TPC concentration, and 6-gingerol (44.57 mg/gDE), 8-gingerol (8.62 mg/gDE), and 6-shogaol (6.92 mg/gDE).

Green Processing of Black Raspberry Pomace: Application of Sonotrode-Based Extraction Technique and Particles from Gas-Saturated Solutions (PGSS) Technology.

The aim of this study was to develop, for the first time, anthocyanin-enriched fractions from black raspberry pomace (BRP) using ultrasound-assisted extraction (UAE) via sonotrode and the Particles from Gas-Saturated Solutions (PGSS) process. UAEs with different amplitudes and sonication times were evaluated and showed relevant effects on the yields of target analytes. The raspberry pomace extracts were formulated in a powder form by PGSS using glyceryl monostearate as a carrier at different extract-to-carrier ratios of 1:11, 1:5, and 1:3. The effects of all variables were evaluated in terms of extraction yield, total phenolic content, and encapsulation yield. UAE was strongly affected by amplitude, and the highest amplitude (100%) provided the best results for extraction yield and total phenolics. HPLC of UAE extracts and powders was utilized for quantification of polyphenol compounds, showing cyanidin-3-rutinoside as a main compound, followed by cyanidin-3-glucoside, rutin, ellagic acid, and gallic acid. These results show that these time-efficient and high-performance techniques enable the production of natural fractions from industrial BRP with acceptable characteristics to be used for the development of nutraceuticals and different food formulations.

Recovery of Polyphenols from Rosehip Seed Waste Using Natural Deep Eutectic Solvents and Ultrasonic Waves Simultaneously.

Rosehips are processed and consumed in numerous forms, such as juice, wine, herbal tea, yogurt, preserved fruit, and canned products. The seeds share in fruit is 30-35% and they have recently been recognized as an important source of oil rich in unsaturated fatty acids. However, after defatting, seed waste may still contain some polar polyphenolic compounds, which have been scarcely investigated. The aim of this study was to examine the potential of the defatted seed waste as a source of polyphenols. For the defatting process, supercritical carbon dioxide extraction at 300 bar and 40 °C was applied. The capacity of eight different natural deep eutectic solvents (NADES) for the recovery of phenolics from defatted rosehip seed powder (dRSP) was examined. In the extracts obtained with ultrasound-assisted NADES extraction, twenty-one phenolic compounds were identified with LC-MS/MS, among which the most abundant were quinic acid (22.43 × 103 µg/g dRSP) and catechin (571.93 µg/g dRSP). Ternary NADES formulations based on lactic acid proved to be superior. Potential correlations between identified chemical compounds, solvent polarity and viscosity, as well as the compound distributions across studied solvent combinations in PCA hyperspace, were also investigated. PCA demonstrated that more polar NADES mixtures showed improved extraction potential. The established environmentally friendly process represents an approach of transforming rosehip seed waste into value-added products with the potential to be applied in the food industry and to contribute to sustainable production.

The protective effect of a mix of Lactarius deterrimus and Castanea sativa extracts on streptozotocin-induced oxidative stress and pancreatic ß-cell death.

Pancreatic ß-cell death or dysfunction mediated by oxidative stress underlies the development and progression of diabetes mellitus. In the present study, we tested extracts from the edible mushroom Lactarius deterrimus and the chestnut Castanea sativa, as well as their mixture (MIX Ld/Cs), for potential beneficial effects on streptozotocin (STZ)-induced pancreatic ß-cell death. Analysis of chelating effects, reducing power and radical-scavenging assays revealed strong antioxidant effects of the C. sativa extract and MIX Ld/Cs, while the L. deterrimus extract displayed a weak to moderate effect. The antioxidative effect of the chestnut extract corresponds with the high content of phenolics and flavonoids identified by HPLC analysis. In contrast, the mushroom extract contains relatively small amounts of phenols and flavonoids. However, both extracts, and especially their combination MIX Ld/Cs, increased cell viability after the STZ treatment as a result of a significant reduction of DNA damage and improved redox status. The chestnut extract and MIX Ld/Cs significantly lowered the STZ-induced increases in superoxide dismutase and catalase activities, while the mushroom extract had no impact on the activities of these antioxidant enzymes. However, the L. deterrimus extract exhibited good NO-scavenging activity. Different mechanisms that underlie antioxidant effects of the mushroom and chestnut extracts were discussed. When combined as in the MIX Ld/Cs, the extracts exhibited diverse but synergistic actions that ultimately exerted beneficial and protective effects against STZ-induced pancreatic ß-cell death.

Antibacterial Potential of Allium ursinum Extract Prepared by the Green Extraction Method.

The antimicrobial activity of Allium ursinum aqueous extract prepared using high pressure extraction was evaluated. Minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of A. ursinum extract for six bacterial pathogens were determined using the broth macrodilution method. Although the A. ursinum extract was shown to be effective toward all investigated foodborne bacteria, its antimicrobial activity depended on its concentration and bacterial strain. Listeria monocytogenes was the most sensitive to antimicrobial activity of A. ursinum extract among all tested pathogens. Accordingly, the lowest MIC and MBC of A. ursinum extract were determined for L. monocytogenes (28 and 29 mg/mL). The tested extract showed a similar antimicrobial potential to other examined bacterial strains (Salmonella Enteritidis, Proteus hauseri, Enterococcus faecalis and two strains of Escherichia coli) with MIC and MBC values at concentrations of 29 and 30 mg/mL, respectively. The dependence of the antimicrobial activity of the A. ursinum extract on the level of contamination of tested pathogens was also observed. The increase in the contamination level caused an intense reduction in antibacterial potential of the A. ursinum extract. The composition of the A. ursinum extract was analyzed and found to be a good source of polyphenols and sulfur compounds. However, considering the applied extraction method and the HPLC analysis of bioactive compounds, the antimicrobial potential may be attributed more to polyphenol content. The obtained results that the extracts have shown toward food pathogens open the possibility of using the tested extracts as natural additives in a variety of food products.

The Application of Ultrasonic Waves and Microwaves to Improve Antihyperglycaemic and Antimicrobial Activities of Marrubium vulgare Extracts.

Having scarce information about ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) of white horehound (Marrubium vulgare L.), the idea has emerged to determine the optimal process parameters for the maximization of polyphenols and to compare the efficiency of these green extraction technologies. The optimal UAE parameters are temperature of 73.6 °C, extraction time of 40 min and ultrasound power of 30.3 W/L, while the optimal MAE parameters are 63.8% ethanol, extraction time of 15 min and microwave power of 422 W. Extract obtained at optimal UAE parameters shows the highest antihyperglycemic activity (α-amylase inhibition: 50.63% and α-glucosidase inhibition: 48.67%), which can potentially be explained by the presence of chlorogenic acid and quercetin, which were not identified in the macerates. The most sensitive bacterial strain to optimal ultrasonic extract is Bacillus cereus, whereas the most sensitive fungal strain is Saccharomyces cerevisiae.

The Effects of Resveratrol-Rich Extracts of Vitis vinifera Pruning Waste on HeLa, MCF-7 and MRC-5 Cells: Apoptosis, Autophagia and Necrosis Interplay.

Resveratrol is a well-studied plant-derived molecule in cancer biology, with a plethora of documented in vitro effects. However, its low bioavailability and toxicity risk hamper its wider use. In this study, vine shoots after pruning were used as a source of resveratrol (RSV). The activity of subcritical water extract (SWE) and dry extract (DE) is examined on three cell lines: HeLa, MCF-7 and MRC-5. The cytotoxic effect is assessed by the MTT test and EB/AO staining, levels of apoptosis are determined by Annexin V assay, autophagia by ULK-1 expression using Western blot and NF-kB activation by p65 ELISA. Our results show that both resveratrol-rich extracts (DE, SWE) have a preferential cytotoxic effect on malignant cell lines (HeLa, MCF-7), and low cytotoxicity on non-malignant cells in culture (MRC-5). Further experiments indicate that the investigated malignant cells undergo different cell death pathways. MCF-7 cells died preferentially by apoptosis, while the HeLa cells died most likely by necrosis (possibly ferroptosis). Protective autophagia is diminished upon treatment with DE in both HeLa and MCF-7 cells, while SWE does not influence the level of autophagia. The extracts are effective even at low concentrations (below IC50) in the activation of NF-kB (p65 translocation).

Black Elderberry Press Cake as a Source of Bioactive Ingredients Using Green-Based Extraction Approaches.

To study the efficiency of two green-based extraction techniques for the isolation of bioactive constituents from black elderberry press cake, changes in phenolic compounds and main anthocyanin contents were analyzed. Polyphenolic content was correlated with antioxidant and antidiabetic potential by radical-scavenging activity and monitoring of α-amylase inhibition. Black elderberry press-cake extracts were obtained by ultrasound-assisted (UAE) and microwave-assisted (MAE) extractions under different extraction conditions. High-performance liquid chromatography (HPLC) analysis revealed that cyanidin-3-sambubioside and cyanidin-3-glucoside were the principal anthocyanins in all the obtained extracts, with their content being highest in MAE obtained at 80 °C over 5 min. The same extract induced two-fold higher antioxidant activity (IC50 6.89 µg/mL) and α-amylase inhibitory potential (IC50 2.18 mg/mL) in comparison to UAE extracts. The main compositional differences between extracts obtained by the same extraction technique were assigned to the extraction temperature. A principal component analysis confirmed that the antidiabetic feature is to be attributed to the rich content of anthocyanins in black elderberry press cake. Our results indicate the great potential of underutilized black elderberry press cake for the development of novel food and herbal formulations due to notable anthocyanin contents highly correlated with antidiabetic activity.

Supercritical CO2 extraction of Marrubium vulgare: intensification of marrubiin.

Supercritical carbon dioxide and Soxhlet extraction were employed for delivering Marrubium vulgare extracts. By varying process temperature and pressure, the impact of different densities of carbon dioxide on the extraction yield and chemical profile of the extracts was investigated. The highest extraction yields of M. vulgare were obtained by supercritical carbon dioxide extraction (3.51%) at 300 bar and 60 °C, while the yield obtained with the Soxhlet extraction was 3.23%. The chemical profiles of these two extracts were significantly different and marrubiin, the most dominant component of supercritical extracts was not present in extracts obtained by this conventional method. This labdane diterpene was the most abundant in extracts obtained at 200 bar and temperatures of 40, 50, and 60 °C (62.60, 68.41, and 71.96%, respectively). For the intensification of marrubiin, supercritical fractions were collected in successive time intervals over the course of the extraction (300 bar/60 °C). It was determined that after 1 h of extraction the highest content of marrubiin (75.14%) can be achieved. The similarities between the obtained extracts were estimated and the correlations to the content of identified lipophilic compounds were established using multivariate data analysis tools.