Individual Polyphenols Research Articles

Optimizing Extract Preparation from Laurel (Laurus nobilis L.) Leaves Using a Pulsed Electric Field

This study explores the bioactive compound extraction from laurel (Laurus nobilis L.) leaves using a pulsed electric field (PEF) as a standalone extraction technique. The primary parameters impacting the extraction process were optimized through response surface methodology. Specifically, solvent composition (ethanol and water mixtures) and liquid-to-solid ratio, along with other key PEF conditions (i.e., electric field intensity, pulse period, and pulse length) were examined. The antioxidant capacity was evaluated through DPPH and FRAP assays, whereas total polyphenol content was also measured. A comparison was also made between the extracts produced with and without PEF. The results showed that after 30 min of extraction, the best parameters were a pulse period of 355 μs, a pulse duration of 55 μs, and an electric field intensity of 0.6 kV/cm. A liquid-to-solid ratio of 10 mL/g was chosen, whereas the best solvent was determined to be 25% (v/v) ethanol/water mixture. The PEF-treated extract contained 77% more polyphenols compared to the untreated sample. In addition, PEF-treated samples had a rise of up to 288% for certain individual polyphenols. Correlation analyses also revealed interesting trends among bioactive compounds and the antioxidant capacity of the extracts. The effect of the investigated parameters on polyphenol recovery was demonstrated, indicating that comparable investigations should consider these parameters to optimize polyphenol extraction yield. Regarding green and non-thermal standalone techniques, PEF outshines other extraction techniques as it could also be used as a sustainable way to swiftly generate health-promoting extracts from medicinal plants.

Comparative Study of the Nutritional, Phytochemical, Sensory Characteristics and Glycemic Response of Cookies Enriched with Lupin Sprout Flour and Lupin Green Sprout.

This study aimed to compare the nutritional, phytochemical, and sensory characteristics of wheat flour (WF) cookies enriched with different proportions of lupin sprout flour (LSF) and those with different proportions of lupin green sprout (LGS). To achieve this, a control cookie (CC); three cookies with 10%, 20%, and 30% of LSF, respectively, CLSF1, CLSF2, and CLSF3; and three other cookies (CLGS1, CLGS2, and CLGS3) with 10%, 20%, and 30%, respectively, were produced. The proximate composition of each cookie was analyzed using AOAC methods. Also, the measurements of the total polyphenol content, antioxidant activity, individual polyphenols, glycemic index, and a sensory analysis were carried out using recent and accurate methods. The contribution of the main nutrients from 100 g of product to the required daily dose was also calculated. Data analysis revealed that cookies with LSF were richer than cookies with LGS in protein, fat, and energy values. CLGS3 was 35.12%, 1.45%, and 5.0% lower in protein, fat, and energy content than CLSF3, respectively. On the other hand, CLSF3 was lower than CLGS3, with 48.2% and 12.4% in moisture and mineral substances, respectively. Both cookies were lower in carbohydrates than the CC (65.20 g/100 g). Still on the subject of micro- and macronutrients, cookies with LSF were richer than those with LGS in all the minerals analyzed. The study also revealed improvements in phytochemical properties, such as total and individual polyphenols and antioxidant activity with the percentage of lupin sprout flour addition. The sensory analysis revealed that, for LSF and LGS cookies, the 10% samples were the most appreciated by consumers, irrespective of the sensory attributes studied. The glycemic index of the CLSF2 product was lower compared to the CC. This study shows that the LSF cookies have better nutritional, phytochemical, and sensory values than the LGS cookies. LSF is, therefore, better suited than LGS to the enrichment of bakery products in general and cookies in particular. The paper provides significant information to estimate the contribution of the consumption of functional products based on lupin sprouts to the required daily dose of food nutrients and the impact on the glycemic index of fortified products.

Optimization of Pulsed Electric Field-Based Extraction of Bioactive Compounds from Cannabis sativa Leaves

The current investigation examines the application of pulsed electric fields (PEFs) for isolating polyphenols from Cannabis sativa var. Futura 75 leaves. Firstly, the solvent composition, which included ethanol, water, and various mixtures of the two, was explored, along with the liquid-to-solid ratio. Subsequently, the primary parameters associated with PEFs (namely, pulse duration, pulse period, electric field intensity, and treatment duration) were optimized. The extracted samples were analyzed to determine their total polyphenol content (TPC), and individual polyphenols were also evaluated through high-performance liquid chromatography. In addition, the antioxidant activity of the extracts was assessed through ferric-reducing antioxidant power (FRAP) and DPPH assays. The extracts prepared utilizing PEFs were compared to the extracts obtained without PEFs in terms of their TPC, FRAP values, and DPPH activity. The results indicate that the most effective extraction parameters were a pulse duration of 10 μs, a pulse period of 1000 μs, and an electric field strength of 0.9 kV/cm after 25 min of extraction. The most efficient solvent was determined to be a 50% (v/v) mixture of ethanol and water in a 20:1 liquid-to-solid ratio. The extract obtained under the optimal conditions exhibited a ~75% increase in TPC compared to the extract obtained without any application of PEFs, while some individual polyphenols exhibited an increase of up to ~300%. Furthermore, significant increases of ~74% and ~71% were observed in FRAP and DPPH assays. From the information provided, it was observed that the tested variables had an impact on the recovery of polyphenols from C. sativa leaves.

Influence of various cooking treatments and extraction solvents on bioactive compounds and antioxidant capacities of bottle gourd (Lagenaria siceraria) fruit in India

Bottle gourd is a good source of health-beneficial bioactive substances. This research aimed at evaluating the effect of different cooking methods (pressure cooking, microwaving, and frying) and extraction solvents (methanol, ethanol and butanol) on bottle gourd fruit phenolic compounds and antioxidant capacity. The quantitative estimation of polyphenolic compounds, flavonoids and tannins was estimated by spectrophotometric methods. The antioxidative properties were evaluated using ferric thiocyanate (FTC), thiobarbituric acid (TBA), ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests using the standard methods. Moreover, quantification of individual polyphenols was carried out by high-performance thin layer chromatography (HPTLC) technique. Frying and pressure-cooking thermal treatments were observed to be the best methods for retaining bioactive molecules. When compared to the raw counterpart, the retention level of total phenol content (TPC) in pressure cooked and fried samples was 23.8% and 13.3%, respectively. Similarly, antioxidant capacity in terms of FRAP was observed to increase by 47.26% after pressure cooking and 28.50% after microwave cooking in respect to the raw sample. The HPTLC results showed that this fruit has high antioxidant capacity and is rich in phenolic acid [gallic(17.83 mg g−1dwb), p-coumaric (6.70 mg g−1dwb)and vanillic (60.66 mg g−1dwb] and flavonoids [quercetin (24.64 mg g−1dwb) and myrecetin (20.73 mg g−1dwb].The chromatography indicated destruction and transformation of new phenolic compounds due to heat treatments. The correlation analysis revealed that flavonoids were much more responsible for their antioxidant activity. Cooking methods and extraction solvents affected the retention and recovery of polyphenolic compounds available in bottle gourd fruit. These findings offer valuable information for optimizing cooking techniques to preserve and enhance the nutritional and antioxidant properties of bottle gourd, making it a valuable fruit for a healthy diet. Pressure cooking could be the most suitable cooking treatment as far as retention of bioactive compounds like phenolic acids is concerned.Graphical

High intraspecific variability and previous experience affect polyphenol metabolism in polyphagous Lymantria mathura caterpillars.

Polyphagous insect herbivores feed on multiple host-plant species and face a highly variable chemical landscape. Comparative studies of polyphagous herbivore metabolism across a range of plants is an ideal approach for exploring how intra- and interspecific chemical variation shapes species interactions. We used polyphagous caterpillars of Lymantria mathura (Erebidae, Lepidoptera) to explore mechanisms that may contribute to its ability to feed on various hosts. We focused on intraspecific variation in polyphenol metabolism, the fates of individual polyphenols, and the role of previous feeding experience on polyphenol metabolism and leaf consumption. We collected the caterpillars from Acer amoenum (Sapindaceae), Carpinus cordata (Betulaceae), and Quercus crispula (Fagaceae). We first fed the larvae with the leaves of their original host and characterized the polyphenol profiles in leaves and frass. We then transferred a subset of larvae to a different host species and quantified how host shifting affected their leaf consumption and polyphenol metabolism. There was high intraspecific variation in frass composition, even among caterpillars fed with one host. While polyphenols had various fates when ingested by the caterpillars, most of them were passively excreted. When we transferred the caterpillars to a new host, their previous experience influenced how they metabolized polyphenols. The one-host larvae metabolized a larger quantity of ingested polyphenols than two-host caterpillars. Some of these metabolites could have been sequestered, others were probably activated in the gut. One-host caterpillars retained more of the ingested leaf biomass than transferred caterpillars. The pronounced intraspecific variation in polyphenol metabolism, an ability to excrete ingested metabolites and potential dietary habituation are factors that may contribute to the ability of L. mathura to feed across multiple hosts. Further comparative studies can help identify if these mechanisms are related to differential host-choice and response to host-plant traits in specialist and generalist insect herbivores.

Polyphenols as Potential Geroprotectors.

Significance: Currently, a large amount of evidence of beneficial effects of diets enriched with polyphenols on various aspects of health has been accumulated. These phytochemicals have a geroprotective potential slowing down the pathological processes associated with aging and ensuring longevity. In this study, a comprehensive analysis was conducted to determine the adherence of individual polyphenols to geroprotector criteria. Data from experimental models, clinical trials, and epidemiological studies were analyzed. Recent Advances: Sixty-two polyphenols have been described to increase the life span and improve biomarkers of aging in animal models. They act via evolutionarily conserved molecular mechanisms, including hormesis and maintenance of redox homeostasis, epigenetic regulation, response to cellular damage, metabolic control, and anti-inflammatory and senolytic activity. Epidemiological and clinical studies suggest that certain polyphenols have a potential for prevention and treatment of various diseases, including cancer, metabolic disorders, and cardiovascular conditions in humans. Critical Issues: Among the reviewed phytochemicals, chlorogenic acid, quercetin, epicatechin, genistein, resveratrol, and curcumin were identified as compounds with the highest geroprotective potential. However, there is a lack of unambiguous information on the effectiveness and safety of polyphenols for increasing health span, preventing and treating aging-associated diseases in humans. Future Directions: Further research is needed to fully understand the effects of polyphenols considering their long-term consumption, metabolic modification and bioavailability, complex interactions between different groups of polyphenols and with other phytochemicals, as well as their effects on individuals with different health status. Antioxid. Redox Signal. 40, 564-593.

Effect of structurally different pectin combined with polyphenol on water distribution, protein oxidation and heterocyclic amines formation in meat-based snacks

This research studied the effect of structurally different pectin combined with polyphenol (PP) on the physicochemical properties, inhibition of protein oxidation and heterocyclic amines (HAs) formation in fish meat snacks. The findings demonstrated that pectin with a high degree of esterification (DE) and average chain length (ACL) significantly reduced cooking loss, improved zeta potential values, and reduced particle size when combined with polyphenols, indicating an inhibition of protein aggregation and crosslinking. The addition of PP decreased the carbonyl formation as compared to individual polyphenol and control. Low Field Nuclear Magnetic Resonance (LF-NMR) analysis publicized that PP combination increased the water binding capacity, which resulted in less free water (T22 and T23) in those samples. Furthermore, LC/MS analysis revealed that PP combination, retained the water inside the macromolecules and prevented the relocation of water to the surface, which resulted in the less HAs formation as compared to control. The scanning electron microscopy (SEM) revealed that combination of PP samples formed a compact structure evidenced by less wide holes while control sample revealed loose structure. The findings suggest that 201 and 601 pectin combined with catechin have potential to improve the physicochemical properties and inhibition of hazardous compound formation.

Partitioning and in vitro bioaccessibility of apple polyphenols during mechanical and physiological extraction: A hierarchical clustering analysis with LC-ESI-QTOF-MS/MS

Polyphenol partitioning during mechanical (cold-pressing) and physiological (digestion) extraction at the individual polyphenol and subclass level was investigated. UHPLC-ESI-QTOF-MS/MS analysis yielded a comprehensive identification of 45 polyphenols whose semi-quantification revealed a hierarchical clustering strongly determined by polyphenol structure and their location within the apple tissue. For instance, pomace retained most flavonols and flavanols (degree of polymerization DP 5–7), which were highly hydrophobic, hydroxylated, or large (>434 Da), and more abundant in peel. In vitro digestion UHPLC-ESI-QTOF-MS/MS analysis of whole apple (and its corresponding matrix-free extract) clustered polyphenols into five main groups according to their interaction with plant cell walls (PCWs) during each digestion phase. This grouping was not reproduced in pomace, which exhibited a greater matrix effect than whole apple during oral and gastric digestion. Nevertheless, the interaction between most polyphenol groups, including dihydrochalcones, flavanols (DP 1–4) and hydroxycinnamic acid derivatives, and pomace PCWs was lost during intestinal digestion.

How Does In Vitro Digestion Change the Amount of Phenolics in Morus alba L. Leaf? Analysis of Preparations and Infusions.

The application of Morus alba L. in traditional oriental medicine and cuisine has resulted in numerous studies on its health-promoting effects. However, if the process is not monitored by the manufacturers, the processing of the leaves alters the obtained health-promoting properties and results in different health qualities in the final composition of dietary supplements. This article aims to analyze changes (using the HPLC/DAD method) in the proposed conditioned mulberry leaves in terms of key compounds (phenolic acids and flavonols) responsible for antioxidant activity after being digested in in vitro conditions. The analyzed material was leaves of white mulberry (Morus alba L.) cv. Żółwińska wielkolistna, conditioned (1-4 h) and non-conditioned. The conditioning process of mulberry proposed here, e.g., for industry production, resulted in variable transformations of polyphenols during in vitro digestion. For many polyphenols, especially those shown in the highest amounts, significant correlations were found between their content and conditioning, as well as the stage of digestion. In the case of mulberry infusions, the amounts of individual polyphenols were several times lower than in the preparations, which was due to the degree of dilution. Their amounts tended to decrease in the course of digestion. Taking this into account, it seems justified to continue research on the in vivo bioavailability of bioactive components from conditioned Morus alba L. leaves.

Production of cornelian cherry (Cornus mas L.) pulp powder by foam-mat drying: analysis of physicochemical and antioxidant properties

AbstractCornelian cherry (Cornus mas L.) is a rich source of (poly)phenols such as phenolic acids, flavonoids, and anthocyanins that are known for their bioactivity. This study aimed to enhance the industrial applications of this cherry’s pulp as a potential functional food ingredient. Foam-mat drying was used to produce cherry powder from cherry pulp. The convective drying process was performed at different temperatures (50, 60, 70, and 80°C) to study the effect of drying temperature on the physical properties, flow properties, microstructure, (poly)phenol content, antioxidant properties, and bioaccessibility of foam-dried cherry pulp, in comparison to freeze-dried sample. Different drying temperatures did not affect color properties. The highest gloss was determined at high temperatures (70–80°C). According to the Carr index, the fluidity increased between 18 and 22% as the temperature increased. The total phenolic content was higher at elevated temperatures (70–80°C), yet the anthocyanin content was the highest at 60°C. The flavonoid content was not affected by different drying temperatures, as well as compared to lyophilized samples. The antioxidant activity was higher in samples dried at elevated temperatures, with no significant difference in comparison to lyophilized samples. The bioaccessibility experiment showed that the lyophilized samples had significantly greater bioaccessibility in comparison to the convective dried samples, yet further investigation is required to understand the differences in bioaccessibility and bioavailability of individual polyphenols. Overall, foam-mat drying using a convective drying system could be an economic choice to preserve acceptable amounts of phenolics and antioxidants.

Bioactive Properties of Tagetes erecta Edible Flowers: Polyphenol and Antioxidant Characterization and Therapeutic Activity against Ovarian Tumoral Cells and Caenorhabditis elegans Tauopathy.

Tagetes erecta is an edible flower deeply rooted in traditional Mexican culture. It holds a central role in the most popular and iconic Mexican celebration, "the Day of the Dead". Furthermore, it is currently receiving interest as a potential therapeutic agent, motivated mainly by its polyphenol content. The present study aims to evaluate the biological activity of an extract synthesized from the petals of the edible flower T. erecta. This extract showed significant antioxidant scores measured by the most common in vitro methodologies (FRAP, ABTS, and DPPH), with values of 1475.3 μM trolox/g extr, 1950.3 μM trolox/g extr, and 977.7 μM trolox/g extr, respectively. In addition, up to 36 individual polyphenols were identified by chromatography. Regarding the biomedical aspects of the petal extract, it exhibited antitumoral activity against ovarian carcinoma cells evaluated by the MTS assay, revealing a lower value of IC50 compared to other flower extracts. For example, the extract from T. erecta reported an IC50 value half as low as an extract from Rosa × hybrida and six times lower than another extract from Tulbaghia violacea. This antitumoral effect of T. erecta arises from the induction of the apoptotic process; thus, incubating ovarian carcinoma cells with the petal extract increased the rate of apoptotic cells measured by flow cytometry. Moreover, the extract also demonstrated efficacy as a therapeutic agent against tauopathy, a feature of Alzheimer's disease (AD) in the Caenorhabditis elegans experimental model. Treating worms with the experimental extract prevented disfunction in several motility parameters such as wavelength and swimming speed. Furthermore, the T. erecta petal extract prevented the release of Reactive Oxygen Species (ROS), which are associated with the progression of AD. Thus, treatment with the extract resulted in an approximate 20% reduction in ROS production. These findings suggest that these petals could serve as a suitable source of polyphenols for biomedical applications.

Influence of Extraction Methods on the Phytochemical Profile of Sambucus nigra L.

The aim of this work is to evaluate the influence of drying methods, extraction solvent, and extraction methods on the phytochemical profile of Sambucus nigra L. flowers harvested from the western region of Romania. Two drying methods for plant conditioning (room temperature and lyophilization), two extraction solvents (70% ethyl alcohol and water), and three extraction methods (conventional extraction (C), ultrasound-assisted extraction, and microwave extraction) were used. For the evaluation of the phytochemical profile, the following spectrophotometric methods were investigated: total polyphenol content, total antioxidant activity using the DPPH and FRAP methods, and flavonoid content. In addition to the spectrophotometric methods, the individual polyphenols were evaluated using the LC/MS method. Using atomic absorption spectrometry, the macro and microelement content of Sambucus nigra L. flowers was assessed. The results showed that the drying method, the solvent used for extraction, and the extraction method influenced the phytocompound content. The analyses showed that in terms of polyphenols, flavonoid content, and antioxidant activity, high values were recorded for lyophilization-dried samples compared to samples dried at room temperature. Also, higher values were recorded for alcoholic extracts compared to aqueous extracts, but also for extracts obtained by the ultrasound-assisted method, followed by extracts obtained via microwave compared to extracts obtained by conventional extraction.

Effect of Postharvest UVB Irradiation on the Fruit of cv. Dottato (Ficus carica L.)

Exposing fruits and vegetables to UVB radiation post-harvest is a technique used to modify secondary metabolites and prolong their shelf life. The aim of the present study was to evaluate the effects of UVB irradiation on the chemical and physical characteristics of fig cv. Dottato fruits. The UVB irradiation was 2.26 Wm−2. Two exposure times were carried out: 10 and 60 min resulting in a UVB dose of 1.4 and 8.1 kJm−2, respectively. In the control, the UVB was eliminated by a polyester film (control −UVB). After treatment, the fig fruits were stored and analyzed at different times until decay. Quality parameters (decay, weight loss, color, chlorophyll, and firmness) and physicochemical parameters (soluble solids content, pH parameters, and titratable acidity) were positively influenced by irradiation. Total and individual sugars increased gradually during the storage period in both the skin and the flesh, with glucose being higher after 10 days in the UVB treated samples. Total carotenoid content increased gradually during the storage period, with a marked increase in the +UVB fruit. The content of total and individual polyphenols was positively influenced by UVB treatment, with the UVB treated samples showing the highest values at both 7 and 10 days. The study showed an increase in by-products in both the skin and the flesh. This research confirms the effectiveness of UVB radiation in improving the nutritional qualities and shelf life of Ficus carica fruits.

An opportunity for acerola pulp (Malpighia emarginata DC) valorization evaluating its performance during the block cryoconcentration by physicochemical, bioactive compounds, HPLC–ESI-MS/MS, and multi-elemental profile analysis

The present study evaluated the effect of cryoconcentration of pulp blocks of acerola (Malpighia emarginata DC). The study evaluated cryoconcentration in three stages. The cryoconcentrated samples, the ice fractions, and the initial pulp were evaluated for physicochemical composition, bioactive composition, and multielement profile. The cryoconcentrated sample obtained in the third stage of cryoconcentration showed the best results for the concentration factor, process efficiency, total soluble solids content, red color intensity, and increasing of the macro and micronutrients: Cu, Ca, S, Sr, K, Mn, Na, P, Mg, Fe. All stages presented good performance in the total soluble solids content, increase in the titratable acidity of the concentrates, and progressive increase in the intensity of the red color. Generally, higher levels of total phenolic and antioxidant activity were found for the 2nd and 3rd concentrates. The phenolic activity showed an increase of 166.90% in the 3rd stage concentrate compared to fresh pulp, and the antioxidant activity was 112.10% by the ABTS method and 131.60% by the DPPH method, both in the 3rd stage concentrate. The major individual polyphenols were Ferulic acid, Protocatechuic acid, and Taxifolin, with significant increases in the concentration of the compounds in the 2nd and 3rd stage concentrates. In addition, the contents of potentially toxic metals were below detection limits. During the cryoconcentration process, there was a decrease in the values ​​of vitamin C content, moisture content, density, and elements Cu, Sr, and Zn.

Study of polyphenolic compounds in wines and different parts of the grapevine

ABSTRACT This paper describes research conducted on the polyphenolic compounds found in wine and different parts of the grapevine. The research consisted of two experiments. In the first, extracts of polyphenols from the leaves, stems, skins and seeds were measured. In the second, these parts were macerated and left in the must during fermentation. For this experiment, the Souvignier gris wine grape variety was used. In both cases, 33 polyphenolic compounds were measured. These measurements were made using the liquid chromatography–mass spectrometry (LC-MS) method. Based on the results, the individual concentrations of all the polyphenolic compounds in different parts of the plant were measured. Addition of the individual parts of the grapevine to the must during fermentation was shown to increase the concentration of the individual polyphenols in the wine. It is therefore important not to forget the importance of the stems and the maceration of the grapes during the winemaking process.

Accumulation of Polyphenols and Naphthoquinones in Morphogenic Cultures of Two Drosera Species

A rhizogenic culture of Drosera capensis L. was obtained. An HPLC method with UV and mass-spectrometric detection was applied to analyze the effect of different drying protocols on the yield of individual polyphenols and 1,4-naphthoquinones from the rhizogenic culture of D. capensis L. The results of this analysis were compared with similar data obtained on the previously established morphogenic culture of D. rotundifolia L. that has been maintained for more than 15 years. In the rhizogenic culture of D. capensis L., six compounds were identified for the first time (myricetin-3-O-β-glucopyranoside, rossoliside, 3,3'-di-O-methylellagic acid 4-O-β-D-glycopyranoside, myricetin, 3,3'-di-O-methylellagic acid, and plumbagin).

Designing New Sport Supplements Based on Aronia melanocarpa and Bee Pollen to Enhance Antioxidant Capacity and Nutritional Value.

With a high number of athletes using sport supplements targeting different results, the need for complex, natural and effective formulations represents an actual reality, while nutrition dosing regimens aiming to sustain the health and performance of athletes are always challenging. In this context, the main goal of this study was to elaborate a novel and complex nutraceutical supplement based on multiple bioactive compounds extracted from Aronia melanocarpa and bee pollen, aiming to support physiological adaptations and to minimize the stress generated by intense physical activity in the case of professional or amateur athletes. Our proposed formulations are based on different combinations of Aronia and bee pollen (A1:P1, A1:P2 and A2:P1), offering personalized supplements designed to fulfill the individual requirements of different categories of athletes. The approximate composition, fatty acid profile, identification and quantification of individual polyphenols, along with the antioxidant capacity of raw biological materials and different formulations, was performed using spectrophotometric methods, GS-MS and HPLC-DAD-MS-ESI+. In terms of antioxidant capacity, our formulations based on different ratios of bee pollen and Aronia were able to act as complex and powerful antioxidant products, highlighted by the synergic or additional effect of the combinations. Overall, the most powerful synergism was obtained for the A1:P2 formulation.

From Waste to Green: Water-Based Extraction of Polyphenols from Onion Peel and Their Adsorption on Biochar from Grapevine Pruning Residues.

Onion peels (OP) are rich in bioactive compounds with a plethora of benefits for human health, but this valuable material is often wasted and underutilized due to its inedibility. Likewise, grapevine pruning residues are commonly treated as agricultural waste, but biochar (BC) obtained from this material has favorable characteristics as an adsorbent. This study investigated the potential of BC in removal of targeted polyphenolic compounds from OP extracts. The OP extracts were obtained adhering to green chemistry principles using deionized water amplified by three methods: maceration (MAC), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). The extraction efficiency on the polyphenolic profile and antioxidant capacity was investigated with different extraction temperatures and solid-to-liquid (s/l) ratios. For further analysis, UAE at 90 °C with an s/l ratio of 1:100 was used due to higher polyphenolic compound yield. The BC adsorption capacity of individual polyphenols was fitted with the Langmuir and Freundlich isotherm models. Quercetin-3,4'-diglucoside obtained the highest R2 coefficient in both models, and the highest qmax value. The optimum conditions in the dosage experiment suggested an amount of 0.5 g of BC using 3 g/L extracts. The studied BC showed a high affinity for targeted phytochemicals from OP extracts, indicating its potential to be applied for the green adsorption of valuable polyphenolic compounds.

Ultrasound-Assisted Extraction of Applewood Polyphenols at Lab and Pilot Scales.

This study focused on the extraction of polyphenols from applewood using ultrasonic-assisted extraction (UAE). First, the influence of solvent composition and mass-volume (m:v) ratio on the extraction yield was studied at a lab scale (200 mL). Overall, a ratio of 1:33 (m:v) resulted in a higher yield of polyphenols. Furthermore, both a higher yield of polyphenols and higher antioxidant capacity were detected in the extracts produced in the presence of a 30 v/v % ethanol mixture compared to pure water; a further increase in ethanol did not improve the extraction yield. Second, under the optimal conditions (30 v/v % ethanol-water; 1:33 and 1:20 (m:v)), the UAE technique was applied at a pilot scale (100 L). At 1:33 (m:v), the polyphenol yield was lower at the pilot scale compared to the lab scale; by contrast, at 1:20 (m:v), production at the pilot scale resulted in a higher yield compared to the lab scale. To identify and quantify individual polyphenols, HPLC-PDA analyses were performed. Phloridzin appears to be the major identified compound. Finally, the UAE process was compared to a conventional solid-liquid extraction technique, showing that a significantly higher yield could be obtained with UAE.

Effect of different processing practices on physicochemical parameters, phenolic compounds, and antioxidant properties of chia seed oils

AbstractAlpha‐linolenic acid and antioxidant substances (such as tocopherols and polyphenols) are abundant in chia seed oil, which may prevent certain chronic diseases. This study compared the physicochemical parameters, chemical composition and antioxidant properties of black and white chia seed oil extracted by solvent extraction, pressing and supercritical CO2 extraction. Chia seed oil contained higher levels of polyunsaturated fatty acids, including linoleic acid (18.68%–20.15%) and α‐linolenic acid (60.47%–63.68%). Black and white chia seeds and processing methods had significant effects on minor components (tocopherols, total phenols, phytosterols and squalene), oxidative stability and free radical scavenging ability. Compared with other methods, the contents of tocopherols (512.72–603.04 mg/kg), total phenols (35.21–57.75 mgGAE/kg) and phytosterols (5536.69–5956.65 mg/kg) were higher in the pressing method. In addition, 17 individual polyphenols were identified and quantified, among which genistein and gallic acid had higher contents, which were significantly affected by varieties and processing methods. In general, the pressing process may be the best processing method to improve minor components and antioxidant capacity. This study can provide a valuable reference for producing functional foods supplemented with α‐linolenic acid.