Optimization Of Extraction Parameters Research Articles

ZIF-8/nitrogen-doped reduced graphene oxide as thin film microextraction adsorbents for simultaneous determination of novel halogenated flame retardants in crayfish-aquaculture water systems

Novel halogenated flame retardants (HFRs) have attracted much attention due to their environmental hazard and adverse effects on human health. In this study, a sensitive and simultaneous method for the determination of six novel HFRs was developed, including tetrabromobisphenol A (TBBPA), tetrachlorobisphenolA, TBBPA bis(2-hydroxyethyl ether), TBBPA bis(allyl ether), TBBPA bis(2,3-dibromopropyl ether) and 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine. ZIF-8 modified nitrogen-doped reduced graphene oxide (ZIF-8@N-rGO) was synthesized and coated onto a syringe filter to prepare a thin film microextraction (TFME) device. The adsorption capacities of ZIF-8@N-rGO for novel HFRs ranged from 50.98 to 112.84 mg g−1, exhibiting good extraction efficiency through a combination of π-π, hydrophobic, and hydrogen bonding interactions. The TFME device was coupled to a high-performance liquid chromatography-ultraviolet detection system to simultaneously determine target HFRs in crayfish-aquaculture water systems. Under the optimal extraction parameters, the linearities ranged from 0.1 to 100 ng mL−1. The method detection limits ranged from 0.030 to 0.14 ng mL−1 and relative recoveries ranged from 88.6 to 106.2%. We found that novel HFRs were detected in water and crayfish samples and were primarily distributed in the viscera and head shell of the crayfish. The bioconcentration factors ranged from 0.25 to 19.20 L kg−1, indicating non-bioaccumulation in the crayfish. This study provides valuable technology and information for potential health risks of exposure to novel HFRs from consuming crayfish.

QUANTITATIVE CONTENT OF THE MAIN ACTIVE SUBSTANCES IN THE ROOTS OF THE NATURAL AND IN-TRODUCED PLANT SAPOSHNIKOVIA DIVARICATE (TURCZ.) SCHISCHK.

A HPLC-UV method was developed for the quantitative analysis of chromones in the roots of Saposhnikovia divaricata (Turcz.) Schischk. The optimal parameters of chromones extraction (two-fold ultrasonic extraction with a duration of 40 min with 50% ethyl alcohol at a raw material-extractant ratio of 1:10) were selected. The validation analysis showed that the proposed method is characterized by satisfactory metrological parameters. The method was used for the analysis of raw materials of wild, introduced and commercial samples of S. divaricata. In this work, for the first time in the roots of S. divaricata from natural populations of Buryatia, Trans-Baikal Territory, Mongolia and in the introduced samples, the HPLC-UV method was used to determine the quantitative content of the main active substances: prim-O-glucosylcimifugine (0.13–5.22 mg/g), cimifugine (0.01– 1.82 mg/g) and 4’-O-β-D-glucosyl-5-O-methylvisamminol (0.98–3.25 mg/g). The total content of chromones varies depending on the place of collection and the phase of vegetation. The content of chromones in two samples of roots from introduced S. divaricatae, collected in the first year of introduction in different climatic conditions, was established.

Structures, physicochemical and bioactive properties of polysaccharides extracted from Panax notoginseng using ultrasonic/microwave-assisted extraction

In this study, Panax notoginseng polysaccharides (PNPS) were extracted using ultrasonic/microwave-assisted extraction (UMAE). Based on single-factor experiments, ultrasonic duration, ultrasonic power, microwave duration, and microwave power were optimized using the response surface methodology (RSM). The results indicated that the optimal extraction parameters were an ultrasonic duration of 10 min, ultrasonic power of 50 W, microwave duration of 4 min, and microwave power of 540 W, which resulted in the highest extraction rate of PNPS at 11.03 ± 0.16%. Scanning electron microscopy images indicated that PNPS exhibited a porous and rough structure. The chemical structure of PNPS was analyzed using Fourier transform infrared spectroscopy and ultraviolet–visible spectroscopy. The molecular weight of PNPS was measured to be 4.148 × 105 Da; moreover, PNPS was found to be composed of glucose, galactose, galacturonic acid, arabinose, glucuronic acid, rhamnose, mannose, and ribose. The DPPH scavenging efficiency of PNPS (5 mg/mL) was evaluated to be 65.74%. Upon in vitro simulated saliva–gastrointestinal digestion, partly digested PNPS was obtained. In addition, differential scanning calorimetry (DSC) analysis and rheological testing results indicated that PNPS exhibited high thermal stability and favorable rheological properties. Therefore, PNPS extracted using UMAE exhibited broad application prospects for functional foods and pharmaceuticals.

Optimization of the extraction process of bioactive compounds from Rhamnus alaternus leaves using Box-Behnken experimental design

The Rhamnus alaternus plant is a rich source of excellent bioactive compounds including polyphenols and flavonoids. Yet, the improvement of the extraction yield of total polyphenol content (TPC) and total flavonoid content (TFC) from this plant has never been inspected in depth. Hence, using a 15-run Box-Behnken design, a dynamic maceration process was optimized for the extraction of TPC and TFC in order to investigate the antioxidant capacity of the various fractions by DPPH assay. Three factors (i.e., ratio of solvent-to-solid material plant, stirring speed and extraction time), were investigated and optimized for establishing a cost-effective process in order to produce extracts rich in phenolic components. With a desirability value of 0.970, the optimal extraction parameters of polyphenols and flavonoids were as follows: a ratio of solvent-to-solid of 10:1 mL/g, a stirring speed of 518 rpm, and 24 h of extraction. For such optimized conditions of dynamic maceration, the highest total polyphenols and total flavonoids contents were experimentally determined at 230.9 mg GAE/g and 121.1 mg QE/g of extract, respectively with an IC50 value of 22.5 μg/mL, and were in agreement with the obtained model values.

Optimization of heat-, microwave-assisted and subcritical water extraction of phenolic compounds from ground ivy (Glechoma hederacea L.) using response surface methodology

This study aimed to optimize heat- (HAE), microwave-assisted (MAE) and subcritical water extraction (SWE) of phenolic compounds from underutilized traditional herb ground ivy (Glechoma hederacea L.) using response surface methodology. Independent variables were extraction time, temperature and sample/solvent ratio, while dependent variables were total phenolic content (TPC) and antioxidant capacity (determined by DPPH and ABTS assays). Extracts obtained under optimum extraction parameters, determined through analysis of the response surface plots and generated mathematical models, were subjected to HPLC-PAD analysis to investigate the presence of individual phenolic compounds. Regardless of the extraction technique, sample solvent ratio 1 g/100 ml resulted in the highest extraction efficiency, while for the same purpose different combinations of temperature and time, depending on the technique, had to be applied - for HAE 100 °C during 10 min, for MAE 90 °C during 4.93 min and for SWE 200 °C during 5.00 min. SWE under optimum parameters yielded extract with the highest TPC (60.1 mg GAE/g dmb) and antioxidant capacity (0.280 and 0.349 mmol Trolox/g dmb) and HPLC analysis revealed formation of new antioxidant that was not detected neither in HAE nor in MAE. On the other side, MAE extract was characterized with the highest content of phenolic compounds characteristic for ground ivy - chlorogenic (1.10 mg/g dmb), cryptochlorogenic (0.59 mg/g dmb), caffeic (0.45 mg/g dmb), rosmarinic (5.56 mg/g dmb) acid and rutin (1.64 mg/g dmb).

Extraction Optimization of Polysaccharides From Corn Silk and Their Antioxidant Activities in vitro and in vivo.

Response surface technique was employed for improving the extraction of corn silk polysaccharides (CSP). Temperature, liquid-to-solid ratio, and per extraction time were all examined as separate factors. The optimal extraction parameters were determined by fitting experimental data to a second-order polynomial; a liquid-to-solid ratio of 21.5 ml/g, temperature equivalent to 88°C, and extraction time of 1.87 h. The experimental yield of the extracted polysaccharides following the application of these conditions was 4.33 ± 0.08% (dry weight), which fit quite well with the predicted value. CSP’s strong scavenging capabilities against hydroxyls, 1,1-diphenyl-2-picrylhydrazyl radicals, and superoxide anions along with its excellent reducing potential, were demonstrated in an in vitro antioxidant experiment. Meanwhile, in vivo testing revealed that CSP substantially enhanced glutathione peroxidase and superoxide dismutase activities. The Malondialdehyde levels in the liver and serum of aged mice also underwent a decrease. This study found that CSP has a substantial antioxidant potential in vitro and in vivo, suggesting that it might be used as an antioxidant in food and medicine.

Multiplexed Photon Number Measurement

When a two-level system -- a qubit -- is used as a probe of a larger system, it naturally leads to answering a single yes-no question about the system state. Here we propose a method where a single qubit is able to extract, not a single, but many bits of information about the photon number of a microwave resonator using continuous measurement. We realize a proof-of-principle experiment by recording the fluorescence emitted by a superconducting qubit reflecting a frequency comb, thus implementing multiplexed photon counting where the information about each Fock state -- from 0 to 8 -- is simultaneously encoded in independent measurement channels. Direct Wigner tomography of the quantum state of the resonator evidences the back-action of the measurement as well as the optimal information extraction parameters. Our experiment unleashes the full potential of quantum meters by replacing a sequential quantum measurements with simultaneous and continuous measurements separated in the frequency domain.

Enhancing recovery of bioactive compounds from Cosmos caudatus leaves via ultrasonic extraction

Cosmos caudatus (C. caudatus) is a medicinal plant that is high in bioactive compounds such as phenolics. In this study, an ultrasound extraction method was used to optimise the extraction of bioactive compounds from C. caudatus leaves. Response surface methodology (RSM) based on a Box-Behnken design (BBD) was applied to obtain the optimum extraction parameters which is solid–liquid ratio (10–30 g/mL), particle size (180–850 µm) and extraction time (20–30 min) for maximal quercitrin and total phenolic content (TPC) yields. Analysis of antimicrobial activity was performed against two human pathogenic microbes: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by the agar well diffusion method. The optimal ultrasonic extraction condition was as follow: solvent-liquid ratio of 1:28 (g/mL), particle size of 485 µm, and duration of 30 min, respectively. Remarkably, extraction using ultrasonic method had recovered more bioactive content and antioxidant activity than the Soxhlet method. The extract also exhibited good antimicrobial activities. Due to the above findings, the ultrasonic extraction was found to be suitable to improve recovery extraction of quercitrin and TPC from C. caudatus leaves. It also opens the possibility that the plant extract can be used for functional food and antimicrobial agents in various applications.

Chondrus crispus treated with ultrasound as a polysaccharides source with improved antitumoral potential

Ultrasound-assisted extraction was used to recover gelling biopolymers and antioxidant compounds from Chondrus crispus with improved biological potential. The optimal processing conditions were evaluated using a Box-Behnken design, and the impact on the biological and thermo-rheological properties of the carrageenan fraction and on the bioactive features of the soluble extracts were studied. The optimum extraction parameters were defined by extraction time of ~34.7 min; solid liquid ratio of ~2.1 g/100 g and ultrasound amplitude of ~79.0% with a maximum power of 1130 W. The dependent variables exhibited maximum carrageenan yields (44.3%) and viscoelastic modulus (925.9 Pa) with the lowest gelling temperatures (38.7 °C) as well as maximum content of the extract in protein (22.4 mg/g), gallic acid (13.4 mg/g) and Trolox equivalents antioxidant capacity (182.4 mg TEAC/g). Tested hybrid carrageenans exhibited promising biological activities (% of growth inhibition around 91% for four human cancer cellular lines: A549; A2780; HeLa 229; HT-29).

Optimization of ultrasound‐assisted extraction parameters for improving content of acteoside, luteolin‐7‐ O ‐glucoside, and total polyphenols in extracts of Plantago lanceolata aerial parts

This study was designed in order to determine optimal parameters for ultrasound-assisted extraction (UAE) of polyphenols from plantain herb using response surface methodology (RSM) as well as UV-visible spectrophotometric and reverse-phase high-performance liquid chromatographic (RP-HPLC) method. Solvent extraction was performed based on four factors-five levels central composite design (CCD). The influence of extraction time (X1: 5–65 min), ethanol concentration (X2: 10%–90%), solid to solvent ratio (X3: 1:10–1:50), and extraction temperature (X4: 20–80°C) on total polyphenols content (TPC) as well on content of dominant individual polyphenolic compounds (acteoside and luteolin-7-O-glucoside) was analyzed. The optimal extraction parameters were as follows: extraction time of 64 min, ethanol concentration of 45%, solid to solvent ratio of 1:49, and extraction temperature of 40°C. Under these optimal conditions, the experimental values for total phenolics and acteoside and luteolin-7-O-glucoside content in plantain herb extract were 42.15, 24.15, and 0.87 mg/g DW, respectively. Experimental validation of optimized parameters was performed and close agreement with predicted values suggested the effectiveness of the applied model and the achievement of RSM in optimizing the extraction parameters. Practical applications In this study, we have analyzed optimal conditions for ultrasound-assisted extraction of polyphenols from ribwort plantain aerial part using response surface methodology. These developed conditions will help other researchers and industrialists to develop functional food products with a high range of phytochemical potential.

Magnetic dispersive solid phase extraction of ZEAralenone using Fe3O4@ hydroxy propyl methyl cellulose nanocomposite from wheat flour samples prior to fluorescence determination: Multivariate optimization by Taguchi design

The contamination of cereals and cereal products with ZEAralenon (ZEA) is a permanent challenge in human health. A new, sensitive, and fast magnetic dispersive micro solid phase extraction (Magnetic D-µ-SPE) was developed for preconcentration and quantitative spectrofluorometric determination of ZEA in wheat flour samples. The Fe3O4@hydroxypropyl methylcellulose (Fe3O4@HPMC) nanocomposite was prepared and used as an efficient magnetic adsorbent. The characterization of the synthesized nanocomposite by the co-precipitation method was confirmed by the FT-IR, TEM, XRD, and VSM analysis. Taguchi L16 array was used for the design of experiments to investigate the influences of extraction parameters on the recovery percentage of µ-SPE. A pH of 4, a magnetic nanoparticle weight of 30 mg, ionic strength of (6 w/v %), extraction time of 3 min, desorption time of 6 min, and 500 µL of MeOH as an efficient eluent solvent were the optimized extraction parameters. Under the optimal working conditions, this method showed good linearity in the range of 8–320 ng g−1 (R2 = 0.9991) with a limit of detection of 6.01 ng g−1. The method recoveries ranged from 83.8 to 111.0 % for wheat flour samples. The results showed that this simple, inexpensive method with low organic solvent consumption was accurate and significantly free from interference effects. The proposed method was successfully applied to determine trace amounts of ZEA from wheat flour sample matrices. This method is rapid with an average extraction time of 9 min and high enrichment (~53 %) and has many advantages such as operational simplicity without using expensive methods such as HPLC or immunoassay column, minimization of solvent utilization, and good accuracy.

Preparation of Heat-Sensitivity Proteins from Walnut Meal by Sweep Frequency Ultrasound-Assisted Alkali Extraction

Sweep frequency ultrasound- (SFU-) assisted alkali extraction was conducted to increase the yield and content of heat-sensitive protein of walnut meal under a relatively mild condition. The physicochemical and structural characteristics of the proteins obtained by SFU-assisted alkali extraction and the conventional alkali extraction were compared. It was found that the optimal parameters for the SFU-assisted extraction were the solid-liquid ratio of 1 : 12, pH value of 9, initial temperature of 25°C, ultrasonic frequency of 28 kHz, sweep frequency amplitude of 1.5 kHz, sweep frequency cycle of 100 ms, duty ratio of 77%, and ultrasonic time of 90 min. Under this condition, a vast improvement in the walnut protein yield (34.9%) and the walnut protein content (9.8%) was observed. Such improvement was due to the structural changes of the sonicated protein; e.g., SFU decreased the intermolecular/intramolecular hydrogen bond force of proteins and, therefore, caused more order secondary structures and more loosen microstructures. This helped to improve the thermoplastic and solubility of the heat-sensitivity protein. Thus, SFU treatment could be an effective auxiliary technology in the alkali extraction of heat-sensitivity walnut protein. It might also be a promising technology for the extraction of heat-sensitivity protein from other agricultural by-products.

Field sample preparation of trace inorganic anions in environmental waters with in-tip microextraction device based on anion-exchange monolithic adsorbent followed by ion chromatography quantification

In this study, a new field preparation method for the quantification of inorganic anions (including F−, BrO3−, Cl−, NO2− and Br−) at trace levels in environmental waters was proposed and developed. Glycidyl methacrylate was copolymerized with ethylene dimethacrylate in a pipette tip to obtain epoxy group-rich monolith, and then trimethylamine was employed to perform ring-opening reaction and got anion-exchange monolithic adsorbent (AMA). The resultant adsorbent was used as the extraction medium of three-channel in-tip microextraction device (TCMD) which was employed to conduct field sample preparation of inorganic anions in different water samples followed by analysis with ion chromatography with conductivity detector (IC/CD). The AMA exhibited satisfactory capture capability to studied anions through anion-exchange interaction. After optimization of extraction parameters, a method with low limits of detection (LODs, 0.019–0.33 μg/L), satisfactory coefficients of correlation (0.9925–0.9985) and good precision (RSDs ≤ 10%) was developed. The introduced approach was successful applied to detect studied anions in environmental waters, and the fortified recoveries varied from 77.3 to 113%. Additionally, the accuracy of suggested method was inspected by confirmatory testing. Compared with reported methods, the current approach displays some attractive features such as semi-automation, high throughput and low LODs. The suggested AMA/TCMD for on-site preparation of inorganic anions not only circumvents the storage and transportation of a great quantity of waters, but also ensures the quantification accuracy.

Optimization of Extraction Process and the Antioxidant Activity of Phenolics from Sanghuangporus baumii.

Sanghuangporus baumii, is a widely used medicinal fungus. The polyphenols extracted from this fungus exert antioxidant, anti-inflammatory, and hypoglycemic effects. In this study, polyphenols from the fruiting bodies of S. baumii were obtained using the deep eutectic solvent (DES) extraction method. The factors affecting the extraction yield were investigated at different conditions. Based on the results from single-factor experiments, response surface methodology was used to optimize the extraction conditions. The scavenging ability of the polyphenols on •OH, DPPH, and ABTS+ was determined. The results showed that the DES system composed of choline chloride and malic acid had the best extraction yield (6.37 mg/g). The optimal extraction parameters for response surface methodology were as follows: 42 min, 58 ℃, 1:34 solid–liquid (mg/mL), and water content of 39%. Under these conditions, the yield of polyphenols was the highest (12.58 mg/g). At 0.30 mg/mL, the scavenging ability of the polyphenols on •OH, DPPH, and ABTS+ was 95.71%, 91.08%, and 85.52%, respectively. Thus, the method using DES was more effective than the conventional method of extracting phenolic compounds from the fruiting bodies of S. baumii. Moreover, the extracted polyphenols exhibited potent antioxidant activity.

Vegetable oils as green solvents for carotenoid extraction from pumpkin (Cucurbita argyrosperma Huber) byproducts: Optimization of extraction parameters

Pumpkin pulp is the main waste generated by pumpkin seed growers. This agro-industrial waste is a valuable source of bioactive compounds, especially carotenoids (β-carotene, α-carotene, and lutein), which exhibit a broad spectrum of health-promoting effects. In this study, vegetable oils (canola, corn, and soybean oil) were used as green solvent alternatives to conventional organic solvents for carotenoid extraction from dried pumpkin pulp (DPP) waste. The highest carotenoid extraction yield (CEY) was obtained with canola oil, at a 1:10 DPP/oil ratio. Response surface methodology (RSM) was used to optimize the extraction process parameters (temperature, time, and stirring rate) through a Box-Behnken design (BBD) maximizing CEY in canola oil. The extraction temperature and stirring rate were found to have a significant linear and quadratic effect, respectively, on CEY. Optimum conditions were achieved at 21.8min, 250rpm, and 60°C. Under these optimized conditions, the estimated value for CEY was 378.1µg β-carotene equivalents/g of DPP, corresponding to 61.6% of the total carotenoid content present in the DPP. In contrast, the observed experimental value was 373.2µg β-carotene equivalents/g of DPP (61.2%). The experimental value was very close to the estimated value, which verifies the model's adequacy and fit. This study shows an alternative method to extract carotenoids from DPP with canola oil, obtaining an oil naturally enriched with carotenoids that could be used as a potential functional ingredient in the development of food, cosmetics, and medicinal products. PRACTICAL APPLICATION: Pumpkin by-products are a potential carotenoid source. Vegetable oil can be used as an alternative solvent for carotenoid extraction from pumpkin residues to obtain an enriched carotenoid oil that can be used to formulate food products.

Influences of Microwave-Assisted Extraction Parameters on Antioxidant Activity of the Extract from Akebia trifoliata Peels.

Akebia trifoliata is a fruit with rich nutritional properties, and its peel is produced as a by-product. In this research, we investigated the influences of microwave-assisted extraction parameters on antioxidant activity of the extract from Akebia trifoliata peels, and the ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) as well as total phenolic contents (TPC) were used to optimize extraction parameters. The influences of ethanol concentration, microwave power and solvent-to-material ratio, as well as extraction temperature and time on TPC, FRAP and TEAC values, were assessed using single-factor tests. Three parameters with obvious effects on antioxidant capacity were selected to further investigate their interactions by response surface methodology. The optimal extraction parameters of natural antioxidants from Akebia trifoliata peels were ethanol concentration, 49.61% (v/v); solvent-to-material ratio, 32.59:1 mL/g; extraction time, 39.31 min; microwave power, 500 W; and extraction temperature, 50 °C. Under optimal conditions, the FRAP, TEAC and TPC values of Akebia trifoliata peel extracts were 351.86 ± 9.47 µM Fe(II)/g dry weight (DW), 191.12 ± 3.53 µM Trolox/g DW and 32.67 ± 0.90 mg gallic acid equivalent (GAE)/g DW, respectively. Furthermore, the main bioactive compounds (chlorogenic acid, rutin and ellagic acid) in the extract were determined by high-performance liquid chromatography. The results are useful for the full utilization of the by-product from Akebia trifoliate fruit.

Optimization of ultrasonic-assisted extraction of polysaccharides from Hemerocallis citrina and the antioxidant activity study.

The present study discussed the optimization of the ultrasonic-assisted extraction of polysaccharides from daylily polysaccharides (DPs). The extracted crude polysaccharides were further separated and purified, and the antioxidant activities including 1,1-diphenyl-2-111 picrylhydrazyl (DPPH) radical scavenging, 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical scavenging, hydroxyl radical scavenging, and ferric-reducing antioxidant power (FRAP) activities of the obtained fractions were also evaluated. The results showed that the optimal ultrasonic-assisted extraction parameters with DPs yield of 15.25 ± 1.13% were water to powder ratio of 25 ml/g, extraction power of 694 W, extraction temperature of 71°C, extraction time of 38 min, and three times extraction. By DEAE Sepharose Fast Flow column, four water-soluble polysaccharide fractions (DP-1, DP-2, DP-3, and DP-4) were successfully obtained. Monosaccharide component analysis showed that the four obtained fractions were all hetero-polysaccharides that mainly contained rhamnose, arabinose, fructose, galactose, glucose, galacturonic acid, and glucuronic acid in different molar ratios. All the four DP fractions did show obvious antioxidant activities in vitro, and the DP-3 component had relatively high ABTS free radical scavenging activity. Overall, our research showed that DPs could provide cheap raw materials for the development of natural antioxidants in medicines, functional foods, and even cosmetics. PRACTICAL APPLICATION: This article deals with the optimization of the ultrasonic-assisted extraction of polysaccharides from daylily and its antioxidant activities. The results showed that the optimal ultrasonic-assisted extraction yield of DPs was 15.25 ± 1.13%. By DEAE Sepharose Fast Flow column, four water-soluble polysaccharide fractions were successfully obtained, and all the four DP fractions did show obvious antioxidant activities in vitro. Daylily polysaccharides could provide cheap raw materials for the development of natural antioxidants in medicines, functional foods, and even cosmetics.

Preliminary Investigation of Different Drying Systems to Preserve Hydroxytyrosol and Its Derivatives in Olive Oil Filter Cake Pressurized Liquid Extracts.

Phenolic compounds present in extra virgin olive oil (EVOO) could be retained in its byproducts during processing. Among them, hydroxytyrosol and its derivatives deserve special attention due to their health benefits recognized by The European Food Safety Authority (EFSA). In the present research, the presence of these compounds in the filter cake byproduct was studied by combining pressurized liquid extraction (PLE) and high-performance liquid chromatography coupled to time-of-flight mass spectrometry (HPLC-TOF-MS). The applied optimum extraction parameters were 1500 psi, 120 °C and aqueous ethanol (50:50, v/v). The influence of different drying methods (vacuum-, freeze- and spray-drying) in the recovery of phenolic compounds was also evaluated. A total of 16 compounds from EVOO were identified in the extracts, 3 of them being hydroxytyrosol-related compounds, 6 substances of oleoside and elenolic acid derivatives, together with 6 secoiridoids and 1 lignan. The results highlighted the great number of phenolic compounds recovered from filter cake with these techniques, being even higher than the reported content in EVOO and other byproducts. The combination of PLE and freeze-drying resulted in being the best procedure for the recovery of phenolic compounds from filter cake byproduct.

Optimization of extraction parameters, characterization and assessment of bioactive properties of Ziziphus lotus fruit pulp for nutraceutical potential

Optimization of extraction parameters, characterization and assessment of bioactive properties of Ziziphus lotus fruit pulp for nutraceutical potential

Каллусные культуры Thymus vulgaris и Trifolium pratense – перспективные источники активных веществ геропротекторного действия

Introduction. Geroprotectors are biologically active substances that inhibit the aging process. Many plant species are natural geroprotectors. For instance, Thymus vulgaris and Trifolium pratense are callus cultures with strong geroprotective properties.
 Study objects and methods. The present research featured T. vulgaris and T. pratense grown in vitro on various nutrient media. Their extracts were obtained by aqueous-alcoholic extraction using the following parameters: water-ethanol solvent Se = 30, 50, and 70 %; temperature Te = 30, 50, and 70°C; time τe = 2, 4, and 6 h. The quantitative and qualitative analysis was based on high-performance liquid mass spectrometry, gas mass spectrometry, and thin-layer chromatography.
 Results and discussion. The optimal extraction parameters for T. vulgaris were τe = 4 h, Te = 50°C, Se = 70 %, for T. pratense – τe = 6 h, Te = 70°C, Se = 70 %. The chromatography detected flavonoids, phenylpropanoids, simple phenols, higher fatty acids, mono- and sesquiterpenes, and aliphatic hydrocarbons. T. vulgaris appeared to have the highest content of thymol (23.580 ± 1.170 mg/mL); its thymol, apigenin, gallic, chlorogenic, and caffeic components demonstrated geroprotective properties. The extract of T. pratense possessed the highest rutin content (10.05 ± 0.35 mg/mL), and it owed its geroprotective characteristics to rutin, chlorogenic and p-coumaric acids.
 Conclusion. The callus cultures of T. vulgaris and T. pratense proved to be promising sources of geroprotective biologically active substances.