Extraction Of Polyphenolic Compounds Research Articles

Harnessing the Power of Artificial Neural Networks Methodology and Multi-Objective Optimization for Enhanced Yield and Bioactivity of Plants Polyphenolic Compounds

The extraction of polyphenolic compounds from plants is crucial in the industrial production of functional nutraceuticals, but traditional methods often yield low and variable results. In this research, an innovative strategy for optimizing polyphenol extraction from two plants Cistus creticus L. and Ephedra alata subsp. alenda (Stapf) Trab., known for their rich composition in polyphenols and their bioactivities, using Ultrasound-Assisted Extraction in conjunction with artificial neural networks (ANNs) and multi-objective optimization is presented. ANNs were trained to model the intricate relationships among UAE parameters, including solvent concentration, temperature, and time, and the outcomes, encompassing polyphenol yield and bioactivity. Multi-objective optimization techniques were subsequently applied to identify extraction conditions that maximize both yield and bioactivity simultaneously. Results validate the accuracy of the ANNs model in predicting polyphenol yields and the significant enhancement in extraction efficiency and bioactivity achieved through multi-objective optimization. The extracts prepared in the optimal conditions have demonstrated superior antioxidant activities, compared to the non-optimized extracts, with the smallest values of IC50 of 242,378µg/mL, and 146,736µg/mL for the plants Ephedra alata subsp alenda (Stapf) Trab. and Cistus creticus L. respectively. This study introduces a promising approach for elevating the extraction of plant-derived polyphenols, augmenting their bioactivity with ANNs and multi-objective optimization. In light of the obtained results, it is recommended that further research explore the scalability and applicability of the presented innovative strategy in larger-scale industrial settings. Considering the demonstrated success in optimizing polyphenol extraction from Cistus creticus L. and Ephedra alata subsp. alenda (Stapf) Trab., extending the application of Ultrasound-Assisted Extraction, coupled with artificial neural networks (ANNs) and multi-objective optimization, to other plant species could offer valuable insights. Additionally, investigating the economic feasibility and environmental impact of implementing this strategy on an industrial scale would contribute to its practical viability.

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

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

Separation of polyphenolic compounds from Citrus aurantium L. peel by deep eutectic solvents and their recovery using a new DES-based aqueous two-phase system

This study aims to investigate the extraction of polyphenolic compounds (PCs) from Citrus aurantium L. peel using Deep Eutectic Solvents (DESs) and ultrasound-assisted extraction (UAE). A screening process evaluated various DESs based on Choline Chloride (ChCl) with polyol, acids, and amides. ChCl-1,4-butanediol performs highest among the tested DESs and the benchmark solvent (70 % ethanol and water). The extraction efficiency, measured by total phenolic content (TPC) using the Folin − Ciocalteu method, was influenced by temperature, time, liquid-to-solid ratio, and water content. Optimal conditions were found at a temperature of 40 °C, extraction time of 30 min, water content of 49.95 %, and 18.97:1 solvent to biomass ratio with a yield of 7.85 mg gallic acid equivalent per gram of peel.Under these conditions, we employed an Aqueous Two-Phase System (ATPS) consisting of salt and DES to recover polyphenols from DES extracts. Various salts (K2HPO4, K3PO4, Na2SO4, LiCL, BaCl2, Na3cit, and NaCl) were assessed for their potential to form the ATPS. Among them, only K2HPO4, and K3PO4 demonstrated the ability to induce phase separation. The effect of the salt concentration was carefully investigated on the partitioning of the PCs. K3PO4 demonstrated a higher performance compared to K2HPO4 with an extraction efficiency of 88.54 %. An ATPS containing DES (0.67 % w/w) and K3PO4 (0.32 % w/w) proved advantageous for back-extraction. Water-immiscible organic solvents, including n-hexane, ethyl acetate, n-butanol, and isoamyl alcohol, were assessed as back-extraction agents. Notably, n-butanol achieved an impressive polyphenol recovery efficiency of 98.11 %.

Optimizing ultrasonic-assisted extraction and untargeted metabolite identification from red water lily (Nymphaea rubra) leaves with enhanced antioxidant activity

This study aimed to optimize the ultrasonic-assisted extraction of polyphenolic compounds from red water lily (Nymphaea rubra) leaves (NRL) with heightened antioxidant activities and perform untargeted metabolite identification. Response surface methodology, employing Box-Behnken design, determined optimal conditions: 53.0 % ethanol, 32.0 min extraction time, and 53.0 °C temperature. The resulting extraction demonstrated significant total phenolic content of 45.12 ± 1.12 mgGAE/g and total flavonoid content of 44.05 ± 1.65 mgCAE/g. High-resolution mass spectrometry identified 150 secondary metabolites, encompassing phenols, flavonoids, tannins, terpenoids, and fatty acids. The optimized NRL extract exhibited notably increased radical scavenging abilities (19.21 ± 1.71 μM ASCE/g for DPPH and 24.59 ± 1.35 μM ASCE/g for ABTS) along with elevated reducing power potential (63.35 ± 4.28 μM ASCE/g for CUPRAC and 61.32 ± 2.56 μM ASCE/g for FRAP) in comparison to traditional extracts, which ranged from (7.23 ± 1.58 to 15.13 ± 1.79 μM ASCE/g, 13.29 ± 1.32 to 19.29 ± 1.69 μM ASCE/g, 22.74 ± 1.68 to 54.37 ± 3.38 μM ASCE/g, 24.14 ± 2.00 to 52.77 ± 2.33 μM ASCE/g for DPPH, ABTS, CUPRAC and FRAP, respectively). This suggests its promising potential for incorporation into antioxidant-rich functional foods. These findings underscore NRL's promise for commercial applications in the nutraceutical, food, and pharmaceutical industries.

Optimization, Metabolomic Analysis, Antioxidant Potential andDepigmenting Activity of Polyphenolic Compounds fromUnmature Ajwa Date Seeds (Phoenix dactylifera L.) Using Ultrasonic-Assisted Extraction.

This study sought to optimize the ultrasonic-assisted extraction of polyphenolic compounds from unmature Ajwa date seeds (UMS), conduct untargeted metabolite identification and assess antioxidant and depigmenting activities. Response surface methodology (RSM) utilizing the Box-Behnken design (BBD) and artificial neural network (ANN) modeling was applied to optimize extraction conditions, including the ethanol concentration, extraction temperature and time. The determined optimal conditions comprised the ethanol concentration (62.00%), extraction time (29.00 min), and extraction temperature (50 °C). Under these conditions, UMS exhibited total phenolic content (TPC) and total flavonoid content (TFC) values of 77.52 ± 1.55 mgGAE/g and 58.85 ± 1.12 mgCE/g, respectively, with low relative standard deviation (RSD%) and relative standard error (RSE%). High-resolution mass spectrometry analysis unveiled the presence of 104 secondary metabolites in UMS, encompassing phenols, flavonoids, sesquiterpenoids, lignans and fatty acids. Furthermore, UMS demonstrated robust antioxidant activities in various cell-free antioxidant assays, implicating engagement in both hydrogen atom transfer and single electron transfer mechanisms. Additionally, UMS effectively mitigated tert-butyl hydroperoxide (t-BHP)-induced cellular reactive oxygen species (ROS) generation in a concentration-dependent manner. Crucially, UMS showcased the ability to activate mitogen-activated protein kinases (MAPKs) and suppress key proteins including tyrosinase (Tyr), tyrosinase-related protein-1 and -2 (Trp-1 and -2) and microphthalmia-associated transcription factor (MITF), which associated melanin production in MNT-1 cell. In summary, this study not only optimized the extraction process for polyphenolic compounds from UMS but also elucidated its diverse secondary metabolite profile. The observed antioxidant and depigmenting activities underscore the promising applications of UMS in skincare formulations and pharmaceutical developments.

Recent Progress on Green New Phase Extraction and Preparation of Polyphenols in Edible Oil.

With the proposal of replacing toxic solvents with non-toxic solvents in the concept of green chemistry, the development and utilization of new green extraction techniques have become a research hotspot. Phenolic compounds in edible oils have good antioxidant activity, but due to their low content and complex matrix, it is difficult to achieve a high extraction rate in a green and efficient way. This paper reviews the current research status of novel extraction materials in solid-phase extraction, including carbon nanotubes, graphene and metal-organic frameworks, as well as the application of green chemical materials in liquid-phase extraction, including deep eutectic solvents, ionic liquids, supercritical fluids and supramolecular solvents. The aim is to provide a more specific reference for realizing the green and efficient extraction of polyphenolic compounds from edible oils, as well as another possibility for the future research trend of green extraction technology.

Optimising certain factors influencing the process of extracting polyphenolic compounds from areca nuts (Areca catechu L.) using response surface methodology

Polyphenols are a group of natural compounds found in plants with antibacterial and antioxidant properties, offering significant potential applications in pharmaceutical and agricultural production. To extract and obtain a high content of polyphenolic compounds from areca nuts (Areca catechu L.), the study utilised a surface response methodology to assess the impact of various technical factors such as solvent concentration (X1), solvent-to-material ratio (v/w) (X2), and soaking time (hours) (X3) on the yield of polyphenolic compounds (Y) extracted from areca nuts. The study’s results yielded a model describing the extraction of polyphenolic compounds from areca nuts using the objective function Y = 80.64 + 3.10X1 - 1.27X3 - 6.00X12 - 3.66X22 - 5.07X32. Based on the objective function, the highest polyphenol content obtained was 80.72 mg GAE/g of raw material under the following conditions: ethanol solvent concentration of 55%, solvent-to-material ratio (v/w) of 35/1, and soaking time of 2 hours. The experimental polyphenol content results showed no statistically significant differences compared to the model-predicted outcomes. These results serve as a basis for the polyphenol extraction process from areca nuts with antibacterial applications in agriculture and medicine.

EXTRACTION OPTIMIZATION AND PHENOLIC COMPOUNDS ANALYSIS IN FICUS CARICA L. FRUITS BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD

One of the important tasks of modern pharmacology and pharmacy is the search and development of safe and effective medicines. On the pharmaceutical market of Ukraine, there is a trend of development of organic chemistry and the emergence of new synthetic medicines. However, the search and in-depth study of plant raw materials remains relevant, as medicinal products based on it show low toxicity and have high indicators of biological activity. According to literature sources, ripe fruits of Ficus carica L. of the Moraceae family are a promising object for further research. It is known that the fruits of Ficus carica L. contain a whole complex of biologically active substances that provide them with antioxidant, antiinflammatory, choleretic and antispasmodic effects. The aim of the work was to study the qualitative composition and quantitative content of biologically active compounds of phenolic nature in ripe fruits of Ficus carica L. by the method of high-performance liquid chromatography. The fruits of Ficus carica L. were extracted under different conditions and methods of extraction. Various concentrations of the water-ethanol mixture (30%, 50% and 70%) were chosen as the solvent, with a ratio of solvent to plant material of 1:8 and grinding of the plant material to a size of 5 mm. A series of extractions was carried out in a Soxhlet apparatus and by the maceration method until the target product was completely extracted. The main criterion for evaluating the optimal conditions and extraction method was the quantitative content of phenolic compounds, which was determined spectrophotometrically according to the Folin-Chocalteu method in terms of gallic acid. It was established that the optimal conditions that ensure the maximum extraction of polyphenolic compounds from plant raw materials are the use of 70% alcohol as an extractant when using both extraction methods. It has also been proven that higher rates of target product yield are observed when extracted in a Soxhlet apparatus. Using the method of high-performance liquid chromatography at a wavelength of 225 nm, it was established that the extract of Ficus carica L. contains such groups of phenolic compounds as: phenolic acids (101.4 μg/ml), catechins (98.08 μg/ml), catechin-like substances (599.29 μg/ml), flavanols (1.07 μg/ml), flavonol-like (43.10 μg/ml), flavonoids (99.15 μg/ml). The total content of polyphenolic compounds in the studied sample of the extract from the fruits of Ficus carica L. is 1420.28 μg/ml, where the share of unidentified compounds is 478.19 μg/ml.

Synergistic combination of natural deep eutectic solvents and green extraction techniques for the valorization of date palm leaves: Optimization of the solvent-biomass interaction

This study was designed to explore date palm leaves as natural polyphenolics potential source using appropriate green Natural Deep Eutectic Solvent (NADES) and emerging green extraction technologies. Among the studied NADES, Glycerol-based NADES showed higher phenolics yield compared to saccharide and organic acid-based NADES. Experimental conditions for microwave (MAE)-NADES and ultrasonication (UAE)-NADES couplings were optimized using a 23-factorial design. Interestingly, it was found the UAE-NADES was not effective enough to enhance phenolics recovery, while MAE-NADES was significantly effective. Furthermore, MAE-NADES-based extracts portrayed higher bioactive properties compared to UAE-NADES-based extracts. Accordingly, MAE-NADES extraction parameters were further optimized using a Box-Behnken design of Response Surface Methodology (RSM). RSM predicted that MAE-NADES extraction can be maximized at a NADES concentration of 49 %, and power of 800 W for 0.84 min. The current study concludes that the application of MAE-NADES green extraction technology can be an effective approach for bioactive compounds recovery from date palm leaves.Industrial relevance:There are more than 120 million date palm trees in the world producing around 20–35 kg of leaves per palm tree annually. This is a huge burden on the environment and if explored as a potential source of polyphenols and other components may turn out to be a viable economic source for desert regions. During the last few decades, a special focus has been raised on ensuring that the extraction process is monitored in an economical and eco-friendly manner without downgrading the biological functionality of the resulting extracts. Recently, Natural Deep Eutectic Solvents (NADES) have been applied for the extraction of polyphenolic compounds. Moreover, the utilization of green extraction techniques, such as ultrasonication and microwave, have been extensively investigated for the extraction of bioactive compounds from plant-based matrices with promising future prospectus, in terms of the reduction in extraction time and higher recovery yields.

Enhanced extraction of phenolic compounds from mango by-products using deep eutectic solvents

Deep eutectic solvents (DESs) potential for the extraction of polyphenolic compounds (PC) from mango by-products (peel and seed) was evaluated. Ultrasound (US) and agitation were applied to evaluate the effects of solvent and extraction methodology. The extracts were characterized with antioxidant capacity and HPLC-DAD profile. A theoretical study was performed using density functional theory and the QTAIM approach. β-alanine and choline chloride based DESs were effective to extract PC from peel and seed. Some DES increased PC extraction up to three times for peel (23.05 ± 1.22 mg/g DW) and up to five time for seeds (60.01 ± 1.40 mg/g DW). The PC profile varied with the solvent (DES vs EtOH/MeOH), procedure (US vs agitation) and material (peel or seed). Mangiferin extraction from peels was significantly increased with β-alanine based DES (676.08 ± 20.34 μg/gDW). The strength of H-bonds had a determining effect on the viscosity of DESs. The solute-solvent solvation energy was suitable to estimate the strength of H-bond interactions between DES and target compounds. This study demonstrates the remarkable capacity of DESs to extract PC from mango by-products and provides insights into the factors controlling extraction properties.

From purple corn waste (pericarp) to polyphenol-rich extract with higher bioactive contents and superior product qualities using two-step optimization techniques

The pericarp of purple corn has traditionally been thought of as being a byproduct. However, it is an excellent source of high-value polyphenols (such as anthocyanins, proanthocyanins, etc.) that could be extracted and used as nutraceuticals, cosmeceuticals, and valuable starting material for synthesizing food colorants and food additives. Hence, this study aimed to optimize the recovery of anthocyanins, phenolic acids, and condensed tannins (CT) from purple corn pericarp using a two-stage multivariate design and evaluated the phenolic profiles, antioxidants, product quality, and structural characteristics of the recovered extracts. According to Plackett-Burman design (PBD) screening, the key extraction variables identified were acetic acid concentration, extraction time, and ethanol concentration. This was followed by optimization using Box-Behnken design (BBD), facial central composite design (FCCD), and full-factorial design (FFD), and the best design was identified after comparative analysis. The models were found to be acceptable, as evidenced by the desirability values of 0.836–0.933. A comparison of the BBD, FCCD, and FFD was done, and it was found that the PBD-BBD produced a lower residual standard error (RSE) than the PBD-FCCD for most of the responses and yielded the lowest extraction time (∼8.6 h), proving that the BBD could forecast the data more accurately. To evaluate the extracts' bioactive extraction efficiency, antioxidant properties, product quality, and structural parameters, samples from a single factor (SF) experiment and BBD were compared. The BBD extract had better color properties (lower ΔE, higher a*, C, and H0) and a greater extraction yield (17.5%) than SF and was confirmed by the principal component and hierarchical cluster analysis. Although the scanning electron microscopy and the optical profilometer for BBD revealed irregular, loosely arranged granules, it had a less adverse effect on product quality and aligned with the Fourier transform infrared spectroscopy results. The BBD samples had lower levels of phenolic acids but higher levels of total phenolic content (118.86 ± 3.60 g GAE/kg), condensed tannins (231.74 ± 8.45 g EE/kg), antioxidants, cyanidin-3-glucoside (90.46 ± 4.47 mg/g), naringin (7.68 ± 0.58 mg/g), and cyanidin-chloride (49.81 ± 1.78 mg/g). This shows that BBD can effectively be used to optimize the extraction of polyphenolic compounds from purple corn pericarp using optimal extraction conditions, resulting in a higher yield of polyphenols having superior antioxidant properties and product quality in a comparatively shorter extraction time.

Catalytic pyrolysis of olive mill wastes towards advanced bio-fuels and bio-chemicals using metal oxide catalysts

Among the environmental challenges that Mediterranean countries have to address are the abundant amounts of olive mill wastewater (OMWW) produced by olive oil agro-industry, such as those found in Greece and Tunisia, which lead to significant land and water pollution. The most common disposal method of olive mill wastewater, includes storage ponds, where most of the water is evaporated, while the residual sludge (olive mill wastewater sludge, OMWWS) is sent to landfills. Fast pyrolysis of OMWWS was investigated as an alternative approach of valorizing this waste, leading to the production of high heating value biofuel (bio-oil). Extraction of polyphenolic compounds with bioactive properties from OMWWS was additionally explored in order to provide further added value to OMWWS, considered as a source of bioactively important polyphenolic compounds, prior its use as pyrolysis feedstock towards the production of green fuel. Pyrolysis of the treated OMWWS (after extraction) led to a considerable reduction of the bio-oil yield, however in both cases the bio-oil produced exhibits a very interesting composition (predominance of aliphatic hydrocarbons and small fractions of aromatic hydrocarbons and phenols) and sufficiently low oxygen content. Exploring the effect of either an acidic (ZSM-5) or a basic (MgO) catalyst on the yield and composition of the bio-oil produced during the catalytic pyrolysis of OMWWS we observed that yield and quality of the produced bio-oils strongly depended on the catalyst used. Thus, acidic ZSM-5 zeolite catalyzed cracking and aromatization reactions, resulting in a bio-oil enriched in aromatics, while basic MgO catalyzed decarboxylation of fatty acids yielding a bio-oil composed mostly of aliphatic hydrocarbons. In addition, Co-promoted catalysts (5% Co either on ZSM-5 or MgO) led to additional variation of bio-oil quality, mostly enhancing ketonization reactions. The effect of a series of Fe and Mn oxide catalysts, based on alumina, silica and magnesia supports, was also studied for the catalytic pyrolysis of OMWWS, mainly focusing on using low-cost catalytic materials. In addition, ferric oxide, aluminum oxide, magnesium oxide, and silicon oxide, are among the major components of red mud, an effective catalyst used in the pyrolysis of OMWWS. All of these Fe- or Mn- materials exhibit very promising in situ upgrading of pyrolysis vapors (retaining organics’ yield and improving produced bio-oil). Most of these materials also tend to favor ketonization reactions, a more or less preferred route among the studied catalysts, which seems to mainly relate with their multifunctional (both acidic and basic) character.

EXTRACTION OF POLYPHENOLIC COMPOUNDS FROM THE JUGLANS REGIA L. PELLICLES OF USING ULTRASOUND

The attention of Russian and foreign scientists is focused on obtaining secondary plant metabolites, including phenolic compounds, due to their pharmacological activity. The Juglans regia L. pellicles are a promising raw source for the production of alkaloids, naphthoquinones (juglone), tannins and organic acids. In modern practice of obtaining biologically active substances from plant raw materials, intensive extraction methods are of particular interest. In this extraction method ultrasonic treatment is used to increase the yield and intensify the process of extracting biologically significant substances. Technological parameters of ultrasonic treatment must be selected individually for each type of plant raw material. The aim of the work was to study the effect of ultrasonic treatment on the yield of polyphenolic substances during extraction from the pellicles of breeding varieties Juglans regia L. It was found that the content of tannins in the pellicle biomass of the studied varieties Juglans regia L. varies from 5.2 to 7.3 g/100 g, phenolic compounds – from 17 to 18.2 mg/100 g. The highest content of these compounds was recorded in the pellicle biomass of the Valentina's Gift variety. It was found that ultrasonic treatment with a power of 200 W for 10 min contributes to the highest yield of polyphenolic substances in the extract from the pellicle biomass of the Valentina's Gift variety. However, the spectral profiles of hydroalcoholic extracts indicate the opposite: 200 W ultrasound reduces the intensity of the extraction of polyphenolic compounds.

Development of natural deep eutectic solvent (NADES) based on choline chloride as a green solvent to extract phenolic compound from coffee husk waste

Natural deep eutectic solvent (NADES) has been successfully used as a green alternative for the extraction of polyphenolic compounds (phenolic) from coffee husk waste. The NADES was produced by combining b the choline chloride compound with glycerol, glucose, citric acid, and proline. Furthermore, it was characterized using FTIR with the appearance of a widening hydroxyl peak at a wave number of 3277–3364 cm−1, indicating the presence of hydrogen bond interactions. The results showed that the best composition of NADES solvent was choline chloride and proline ratio of 1:1, providing an extraction yield of 5.88 mg GAE g−1 with a polyphenol concentration in NADES of 294.02 mg/L. Optimum extraction conditions were carried out with the addition of 50 % water, extraction time of 30 min, and the ratio of sample weight to solvent volume (1:10), obtaining a yield of 6.16 mg GAE g−1 and the concentration of polyphenols in NADES of 307.81 mg/L. The effect of temperature on the extraction process can increase the extract yield under conditions at 80 °C with a yield of 10.07 mg GAE g−1 and a polyphenol concentration of 671.4 mg/L. The chlorogenic acid group of polyphenolic compounds was identified using HPLC at a retention time of 3.454 min with a concentration of 63 mg/L. Based on the results, NADES can be use as a green solvent for extracting active compounds from coffee husk waste. These extract can safely be applied to various medicinal and food products.

Ultrasonic assisted extraction of polyphenols from bayberry by deep eutectic supramolecular polymer and its application in bio-active film.

Ultrasound and deep eutectic supramolecular polymers (DESP) is a novel combination of green extraction method for phytochemicals. In this study, a new type of green extractant was developed: DESP. It is a derivative of deep eutectic solvent (DES) and was prepared by supramolecular polymer unit β-cyclodextrin (β-CD) as hydrogen bond acceptor (HBA) and organic acid as hydrogen bond donor (HBD). The current work focuses on the use of ultrasonic-assisted (UAE) DESP extraction of polyphenolic compounds (PCs) from bayberry. The experimental results showed that DESP synthesized with β-CD and lactic acid (LA) in a ratio of 1:1 (w/w %) had the best extraction effect. And by using a three-level factor experiment and the response surface method, the predicted TPC content is very close to the actual content (28.85±1.27mg GAE/g). The DESP extract including PCs were further used as plasticizer for chitosan (CS) to prepare highly active green biofilms (DESP-CS). It is possible to reduce the tedious procedures for separating biologically active substances from DESP. The experiment proved that the prepared films have good mechanical properties, plastic deformation resistance, thermal stability and antioxidant activity.

Bioactive Properties of Extracts from Plectranthus barbatus (Coleus forskohlii) Roots Received Using Various Extraction Methods.

The aim of this study was to verify various extraction methods: shaking water bath extraction (SWA), ultrasound-assisted extraction (UAE) and microwave assisted extraction (MAE), and their parameters to optimize the extraction yield as well as maximize the concentration of polyphenols in Plectranthus barbatus extracts. Extracts were obtained from dried roots of P. barbatus in various degrees of fragmentation and analyzed for content of polyphenols, antioxidant capacity and flavonoids. Additionally, phenolic compounds in extracts were analyzed using the UHPLC-DAD-ESI-MS/MS method. The conducted research showed that roots of P. barbatus are rich in polyphenolic compounds. A total of 15 phenolic compounds, belonging to the group of phenolic acids and their derivatives, were identified. The extraction yield was similar for all extraction methods and averaged 31%. Irrespective of the extraction method, the yield was the lowest in the case of using 80% ethanol as the solvent. The extracts obtained from the finer fraction were characterized by a higher antioxidant capacity as well as a higher concentration of polyphenolic compounds including flavonoids. UAE seems to be the most effective method for extraction of polyphenols from P. barbatus roots. Regardless of the extraction method, ethanol was a better extractant than distilled water. All ethanolic extracts were characterized by a high antioxidant capacity. The 80% ethanol solution was considered the best solvent for the extraction of flavonoids, while the 40% and 60% ethanol solutions were sufficient for the effective extraction of polyphenolic compounds in general.

Extraction of Polyphenolic and Volatile Compounds from Cistus creticus Using Deep Eutectic Solvents and Pulsed Electric Fields

To date, many studies have been published, aiming to extract bioactive compounds from plants. Lately, research focuses on maximizing the extraction yield, using environmentally friendly techniques and solvents. In this study, the extraction of polyphenolic compounds from Cistus creticus is discussed. Extraction of the compounds has been carried out with water and ethanol, employing the most common approach. To further enhance the extraction yield, the usage of four deep eutectic solvents (DESs) has also been examined. In an effort to further enhance the extraction yield, pulsed electric fields have also been employed. According to the results, it was evident that the use of DESs made of glycerol: choline chloride (2:1) increased the extraction yield by 75%, compared to extraction with water. Moreover, the use of pulsed electric fields enhanced the extraction yield of the common approach, by up to 70%. When pulsed electric fields and DESs were combined, the extraction yield increased by 14%, compared to the use of DESs only. Finally, the extract was analyzed for its content in volatile compounds, and it was found that new compounds could be extracted with the use of DESs.

Green electromembrane extraction procedure based on biodegradable chitosan films for determination of polyphenolic compounds in food samples: Greenness assessment of the sample preparation approach

A simple, rapid and environmentally friendly method for the electromembrane extraction of polyphenolic compounds has been developed using chitosan films (60% (w/w) chitosan, 40% (w/w)-Aliquat®336, 10–11 μm thickness) as biopolymeric membrane. In this work for the first time with this type of chitosan-based support, the use of organic solvents has been completely eliminated, which allows considering the proposed methodology as a green solvent-free procedure, as demonstrated by performing analytical greenness metric for sample preparation (AGREEprep). Under optimal experimental conditions (10 mL donor phase, pH 7; 50 μL acceptor phase, pH 9; 100 V applied voltage for 15 min) high enrichment factors (EF ≥ 60) were obtained for all the target analytes. Wide concentration ranges between 52.8 μg L−1 and 1000 μg L−1, good linearity (R2 ≥ 0.996), low limit of detection (15.9–37.1 μg L−1), and repeatability (relative standard deviation (RSD) values 4–10%) were achieved. Polyphenolic compounds have been successfully extracted from coffee- and tea-based dietary food supplements in different formats (pills and ampoules). For comparison purposes, target analytes have additionally been determined in green coffee beans and tea.

Optimization of Microwave-Assisted Extraction and Matrix Solid-Phase Dispersion for the Extraction of Polyphenolic Compounds from Grape Skin

Polyphenols are organic compounds that can be found in food, especially in fruits, vegetables, and their products. It was shown that their presence significantly affects the properties of food products and that the consumption of food rich in phenolic compounds has a beneficial effect on human health. The subjects of this research were polyphenols: anthocyanins, flavonols, and flavan-3-ols in the skin of grapevine variety Regent. Polyphenols from grape skins were extracted via microwave-assisted extraction (MAE) and matrix solid-phase dispersion (MSPD) as unconventional and green techniques. Therefore, the main aim of this work was to optimize the conditions for the extraction of polyphenolic compounds from grape skin using MAE and MSPD. The extracts were analyzed using high-performance liquid chromatography with a diode array detector and fluorescence detector. Analyses showed that MAE was a very effective method for extracting polyphenolic compounds from grape skin with 10 mL of 60% ethanol for 5 min at 40 °C. The best results for the MSPD extraction of polyphenolic compounds from grape skin were obtained with phenyl as an MSPD sorbent with 10 mL of acetonitrile:water 50:50 v/v as an elution solvent. This scientific research can be used for the better use of grapes as a basis for obtaining flavonoids for commercial purposes.

Determination of polyphenol compounds in medicinal plants of local habitat and their importance for health

Objective: Assess the possibility of using some medicinal plants containing polyphenolic compounds (tannins and gallic acid) in medicine. Materials and methods: The Folin-Ciocalteu reagent spectrophotometry method is used to determine the amount of polyphenolic compounds. The gallic acid solution was selected as the standard sample. The objects of the study were dry specimens of plants: Oak Bark (quercus cortex), Rhizomes of Bistorta officinalis (bistortae rhizomata), Galls of Oak leaves (gallae turcicae), Rhizomes of Potentilla erecta (tormentillae rhizomata). Experimental samples in the form of aqueous and alcoholic extracts are made from this dry raw material. Results: Studies have shown that all selected plants have sufficient tannin content to confirm their healing properties. The largest number was found in the galls of oak leaves. Alcohol extracts extracted polyphenolic compounds from plant raw materials better than aqueous ones, but the difference is relatively small. Therefore, aqueous extracts can be used as therapeutic drugs for those who are contraindicated alcohol extracts. Conclusions: The studied dry specimens of plants (oak bark (quercus cortex), rhizomes of snake mustard (bistortae rhizomata), galls of oak leaves (gallae turcicae), rhizomes of erect cinquefoil (tormentillae rhizomata)) contain polyphenolic compounds (tannin and gallic acid) in sufficient quantities to provide medicinal effect. It has been shown that the extraction of polyphenolic compounds from plant materials using alcohol solutions is more efficient than aqueous extracts. It is recommended to use herbal products with tannins in medicinal practice.