Natural Source Of Phenolic Compounds Research Articles

Abstract 4748: Aronia berry overcomes gemcitabine resistance by regulating the MYD88/NF-kB/P-glycoprotein pathway in pancreatic ductal adenocarcinoma

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is lethal, which is partly due to the limited efficacy of Gemcitabine (Gem)-based chemotherapy, resulting from the development of acquired resistance to this regimen. Aronia berry extract (ABE) is a natural source of phenolic compounds known for its anti-cancer properties. Previous research has highlighted the ability of ABE to help overcome chemoresistance to conventional chemotherapies in various cancers. In this study, we interrogated the ability of ABE to overcome Gem-resistance (Gem-R) in PDAC and identify specific pathway(s) responsible for this anti-cancer efficacy. Methods: We performed a series of in-vitro experiments in Gem-R cells to evaluate the synergistic effect of combined treatment with Gem and ABE. Furthermore, we conducted a genomewide transcriptomic analysis to identify the critical regulatory pathways associated with chemoresistance and potential therapeutic targets of ABE in Gem-R PDAC cells. The cell culture findings were validated in patient-derived 3D organoids. Results: The combined treatment with ABE and Gem in Gem-R cells exhibited significant synergistic anticancer effects on cell viability, proliferation, migration, and invasion. The transcriptomic analysis revealed that the NF-κB signaling pathway was associated with Gem-R (p<0.05), with a significant upregulation of MYD88. Additionally, MYD88 was significantly associated with overall survival in PDAC patients in the TCGA cohort (HR=1.58, P=0.045). The MYD88/NF-κB signaling is associated with chemoresistance as it can upregulate the efflux transporters like P-glycoprotein (P-gp). Our results confirmed that combined treatment inhibited the NF-κB signaling pathway by suppressing MYD88 and downregulating P-gp expression to overcome Gem-R. Finally, the combined treatment demonstrated superior anti-cancer activity in 3D organoids by reducing both their number and size (P<0.05). Conclusion: We provide novel insights into the potential of ABE in overcoming Gem-R in PDAC cells by targeting the MYD88/NF-κb/P-gp axis, which offers a safe and inexpensive approach for improving therapeutic outcomes in this fatal malignancy. Citation Format: Yuan Li, Caiming Xu, Haiyong Han, Ajay Goel. Aronia berry overcomes gemcitabine resistance by regulating the MYD88/NF-kB/P-glycoprotein pathway in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4748.

Effects of grape variety and roasting on the proanthocyanidin oligomers distribution, cyclic proanthocyanidins, and total polyphenol content in grape seed powders

Grape seeds are a valuable source of natural phenolic compounds, particularly flavan-3-ol derivatives such as condensed tannins. Recent studies have shown that grape seed powder can be applied to reduce the undesirable effects of protein instability in wine. One pretreatment method applied to grape seeds is roasting. Roasting causes the heavier proanthocyanidins (PAC) oligomers to break down, thereby increasing the concentration of smaller oligomers available for interaction with proteins. In addition, roasting can prolong grape seed storage. Among the subclasses of proanthocyanidins, oligomeric macrocyclic proanthocyanidins have also shown potential effects in terms of wine stabilization, particularly by presenting selective interactions with metal cations such as potassium and calcium. However, their composition in grape seed extracts has never been studied. Here, the characterization of condensed tannins according to the degree of polymerization in grape seeds, the profile of cyclic proanthocyanidins and the total polyphenol content were characterized in relation to different grape varieties and the application of roasting. Roasting greatly influenced the distribution of PAC according to the degree of polymerization, increasing the abundance of almost all classes of PAC. However, the overall effect of roasting was highly dependent on grape variety. PAC were analyzed according to the degree of polymerization. Grape seed roasting of red varieties (Croatina and Sangiovese) showed an increase in all classes of PAC except trimers. The white variety (Ortrugo) and the mix of Nebbiolo and Barbera varieties (80% and 20% w/w, respectively) showed no clear effect on the profile of PAC upon roasting. Notably, cyclic procyanidins were identified for the first time in grape seeds: a cyclic tetrameric procyanidin (ESI + m/z 1153) and cyclic pentameric procyanidin (ESI + m/z 1441) were found. The abundances of these cyclic PAC were found to be completely stable upon roasting, also in agreement with the already known stability of these compounds against depolymerizing conditions. Interestingly, the cyclic pentameric procyanidin was significantly more abundant in Ortrugo (white variety), than in Sangiovese and Croatina (red varieties). Besides, no effect of roasting occurred on the profile of cyclic procyanidins in grape seed powder. Finally, the total polyphenol content was evaluated, showing that roasting caused an increase of polyphenolic molecular species potentially available for protein stabilization, but only in GSP of red varieties. Overall, the grape variety was found to be a significant factor in determining how much the roasting would change the PAC profile, providing valuable information for future applications of GSP in enology.

Advances in Nanomaterials Based on Cashew Nut Shell Liquid.

Cashew nut shell liquid (CNSL), obtained as a byproduct of the cashew industry, represents an important natural source of phenolic compounds, with important environmental benefits due to the large availability and low cost of the unique renewable starting material, that can be used as an alternative to synthetic substances in many industrial applications. The peculiarity of the functional groups of CNSL components, such as phenolic hydroxyl, the aromatic ring, acid functionality, and unsaturation(s) in the C15 alkyl side chain, permitted the design of interesting nanostructures. Cardanol (CA), anacardic acid (AA), and cardol (CD), opportunely isolated from CNSL, served as building blocks for generating an amazing class of nanomaterials with chemical, physical, and morphological properties that can be tuned in view of their applications, particularly focused on their bioactive properties.

Evaluation of the antioxidant potential of brown seaweeds extracted by different solvents and characterization of their phenolic compounds by LC-ESI-QTOF-MS/MS.

Seaweeds, serving as valuable natural sources of phenolic compounds (PCs), offer various health benefits like antioxidant, anti-inflammatory properties, and potential anticancer effects. The efficient extraction of PCs from seaweed is essential to harness their further applications. This study compares the effectiveness of different solvents (ethanol, methanol, water, acetone, and ethyl acetate) for extracting PCs from four seaweed species: Ascophyllum sp., Fucus sp., Ecklonia sp., and Sargassum sp. Among them, the ethanol extract of Sargassum sp. had the highest content of total phenolics (25.33±1.45mgGAE/g) and demonstrated potent scavenging activity against the 2,2-diphenyl-1-picrylhydrazyl radical (33.65±0.03mgTE/g) and phosphomolybdate reduction (52.98±0.47mgTE/g). Ecklonia sp. had the highest content of total flavonoids (0.40±0.02mgQE/g) in its methanol extract, whereas its ethyl acetate extract contained the highest content of total condensed tannins (8.09±0.12mgCE/g). Fucus sp. demonstrated relatively strong antioxidant activity, with methanolic extracts exhibiting a scavenging ability against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (54.41±0.24mgTE/g) and water extracts showing ferric-reducing antioxidant power of 36.24±0.06mgTE/g. Likewise, liquid chromatography-mass spectrometry identified 61 individual PCs, including 17 phenolic acids, 32 flavonoids, and 12 other polyphenols. Ecklonia sp., particularly in the ethanol extract, exhibited the most diverse composition. These findings underscore the importance of selecting appropriate solvents based on the specific seaweed species and desired compounds, further providing valuable guidance in the pharmaceutical, nutraceutical, and cosmetic industries. PRACTICAL APPLICATION: The PCs, which are secondary metabolites present in terrestrial plants and marine organisms, have garnered considerable attention due to their potential health advantages and diverse biological effects. Using various organic/inorganic solvents during the extraction process makes it possible to selectively isolate different types of PCs from seaweed species. The distinct polarity and solubility properties of each solvent enable the extraction of specific compounds, facilitating a comprehensive assessment of the phenolic composition found in the seaweed samples and guiding industrial production.

Dual Emerging Applications of Solid-State Fermentation (SSF) with Aspergillus niger and Ultrasonic-Assisted Extraction (UAE) for the Obtention of Antimicrobial Polyphenols from Pineapple Waste

The exploration of natural antimicrobial compounds is necessary due to the current bacterial resistance to synthetic antibiotics. For this reason, pineapple residues were evaluated as a natural source of phenolic compounds with antimicrobial capacity. Pineapple residues were fermented with A. niger GH1 and subjected to ultrasound for the extraction of phenolic compounds. In the solid-state fermentation (SSF), the peel and the core (70:30) were fermented for 32 h. Ultrasonic-assisted extraction (UAE) was optimized. The factors solid–liquid ratio (X1), ethanol concentration (X2), and extraction cycle (X3) were optimized through a Box–Behnken statistical design, using the total phenol content (TPC) as a response variable. The optimized and pre-purified extract with amberlite was characterized using HPLC-MS and we measured the antimicrobial activity against Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli. The optimal values for X1, X2, and X3 were 82 mg/mL, 26%, and two cycles, respectively. The extract was effective as an antimicrobial agent against S. aureus and L. monocytogenes, with MICs of 50 mg/mL and 12.5 mg/mL, respectively; the bacterial growth curve and transmission electron microscopy (TEM) confirmed the antimicrobial activity. The main compounds identified in the antimicrobial extract were 3,4-DHPEA-EA, Phloretin 2′-O-xylosyl-glucoside, and Feruloyl tartaric acid. Overall, the combination SSF-UAE showed to be a promising strategy to recover phenolic compounds from pineapple residues, exhibiting great potential as a natural antimicrobial agent.

Phenolic composition, antioxidant, and cytotoxic effects on HeLa and HepG2 cancer cell lines of Mespilus germanica grown in Turkey

This study screened flavonoids and phenolic acids, antioxidant and cytotoxic effects of Mespilus germanica leaf and fruit samples. The RP-HPLC-DAD analysis allowed the identification of hesperidin, epicatechin, epigallocatechin, benzoic, p-hydroxybenzoic, vanillic, protocatechuic, syringic, caffeic, ferulic, sinapic and p-coumaric acids in various extracts. Fruit alkaline-hydrolysable phenolic acids extract (BHPA), leaf bound phenolic acids from basic hydrolysis-2 extract (BPBH2) and leaf free flavan-3-ol extract exhibited the largest DPPH, OH and NO radicals scavenging activity, respectively. Leaf flavone extract showed strong cytotoxicity on the HepG2 cell line (IC50 = 36.49 ± 1.12 μg/mL) as well as good •OH scavenging and Fe2+ chelation activities. Additionally, leaf bound phenolic acids from acid hydrolysis-1 extract (BPAH1) demonstrated strong cytotoxicity on the HeLa cell line (IC50 = 36.24 ± 1.89 μg/mL). This study suggests Turkish medlar as a natural source of phenolic compounds with potential application in food and pharmaceutical industries as anticancer/antioxidant agents.

Coastal Halophytes: Potent Source of Bioactive Molecules from Saline Environment.

This study represents a comparative analysis of secondary metabolites content, antioxidant, and antimicrobial activity of 24 halophytes from coastal saline habitats of the Balkan Peninsula (Montenegro, Albania, and Greece). Total content of phenolics, flavonoids, tannins, anthocyanins, antioxidant, and antimicrobial activity was determined for dry methanolic (DME) and crude water extracts (CWE) and compared with well-known medicinal plants. The total phenolic content ranged from 13.23 to 376.08 mg of GA/g of DME, and from 33.68 to 511.10 mg/mL of CWE. The content of flavonoids ranged from 12.63 to 77.36 mg of RU/g of DME, and from 12.13 to 26.35 mg/mL of CWE. Total tannins and anthocyanins varied from 0.05 to 2.44 mg/mL, and from 1.31 to 39.81 µg/L, respectively. The antioxidant activity ranged from 1147.68 to 15.02 µg/mL for DME and from 1613.05 to 21.96 µg/mL for CWE. The best antioxidant properties, and the highest content of phenolic compounds, were determined for Polygonum maritimum and Limonium vulgare with values similar to or higher compared to the medicinal plants. Halophytes with significant antimicrobial potential were Limonium vulgare, L. angustifolium, and Artemisia maritima. Some of the analyzed coastal halophytes can be considered rich natural sources of phenolic compounds, with favorable antioxidative and antimicrobial properties.

Topical formulation of Pistacia vera L. pericarp on knee osteoarthritis: A randomized placebo controlled clinical trial

The pericarp of Pistacia vera L. is considered a rich source of natural phenolic compounds. Recent studies have examined the anti-inflammatory and painkiller properties of pistachio pericarp. In this randomized placebo-controlled clinical trial, the impact of a topical formulation of pistachio pericarp (TFPP) was investigated on knee osteoarthritis (OA). This was a randomized, double-blind clinical trial with three groups of 25 patients with OA. The diagnosis was made according to the American College of Rheumatology (ACR) criteria and approved by a rheumatologist. Subjects were randomly divided into three groups: piroxicam, TFPP, and placebo. Over eight weeks, patients were treated twice daily. Finally, knee pain and severe pain, stiffness, and physical function were assessed using the visual analogue scale (VAS) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) criteria at baseline, one and two months after the intervention, respectively. The patients (n=75) were middle-aged and older adults with a BMI>25 kg/m2. Compared to the placebo, the mean VAS (VAS two-months intervention = -1.7; 95%CI; -2.38,-1.08), total WOMAC (Total WOMAC two-months intervention =-2.2; 95%CI: -2.97,-1.55), pain intensity (Pain two-months intervention =-1.7; 95% CI: -2.42,-1.11), stiffness (Stiffness two-months intervention = -1.8; 95%CI: -2.47,-1.15), and physical performance (Physical performance two-months intervention =-1.8; 95%CI: -2.55,-1.21) significantly improved, indicating the potential efficacy of pistachio pericarp compounds in alleviating OA symptoms. The results of this study demonstrated that TFPP is effective at relieving pain and could be used as a safe supplement to treat OA-related pain. IRCT20210912052445N1

Grape Pomace as a Natural Source of Phenolic Compounds: Solvent Screening and Extraction Optimization.

The optimization of extraction by using solvents of phenolic compounds (TPh) of grape pomace (GP) based on a central composite design was investigated. The GP was characterized, and preliminary assays were conducted with five different solvents (water, ethanol, acetone, methanol, and butanol) and the aqueous mixtures thereof. Ethanol and acetone were revealed to be the best solvents for TPh extraction. The main extraction parameters (temperature-T, time-t, solvent concentration, and liquid-solid ratio-L/S) were optimized by using a central composite design. The optimized conditions for the ethanol extraction (T = 60 °C, t = 1.5 h, L/S = 25 mL/gdryGP) and for acetone (T = 50 °C, t = 1.5 h, L/S = 25 mL/gdryGP) were determined. Single-stage extraction revealed a TPh of 45.18 ± 9.51 mgGAE/gdryGP for acetone and a TPh of 38.70 ± 3.64 mgGAE/gdryGP for ethanol. The characterization of the extracts revealed the presence of gallic acid, caffeic acid, syringic acid, vanillic acid, chlorogenic acid, and p-coumaric acid, where the concentration of the first three compounds stands out in all extracts. A three-stage extraction increased the yield of ethanol to 63.3 mg GAE/gdryGP and the yield of acetone to 59.2 mg GAE/gdryGP. Overall, both solvents allow the extraction of phenolic compounds of grape pomace, but ethanol is commonly considered a greener solvent for this purpose.

Bioprospecting of Targeted Phenolic Compounds of Dictyota dichotoma, Gongolaria barbata, Ericaria amentacea, Sargassum hornschuchii and Ellisolandia elongata from the Adriatic Sea Extracted by Two Green Methods.

The content of bioactive compounds in four brown and one red algae from the Adriatic Sea (Dictyota dichotoma, Gongolaria barbata, Ericaria amentacea, Sargassum hornschuchii and Ellisolandia elongata) is explored. The efficiency of two different extraction methods viz. ultrasound-assisted extraction (UAE) and matrix solid-phase dispersion (MSPD) to obtain the extracts rich in phenolic compounds was compared. The effect of the extraction solvent to modulate the phenolic profile was assessed. In general, the mixture ethanol/water in an isovolumetric proportion showed the best results. The total phenolic content (TPC) and antioxidant activity (AA), as well as the individual polyphenolic profile, were evaluated for five target algae. TPC values ranged between 0.2 mg GAE/g (for E. elongata) and 38 mg GAE/g (for S. hornschuchii). Regarding the quantification of individual polyphenols by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, the presence of a high number of hydroxybenzoic acid derivatives (mainly of 3- and 4-hydroxybenzoic acids) in all species was noted. In G. barbata their concentrations reached up to 500 mg/kg. IC50 values (ABTS assay) ranged between 44 mg/L (for S. hornschuchii) and 11,040 mg/L (for E. elongata). This work contributes to the in-depth characterization of these little-explored algae, showing their potential as a natural source of phenolic compounds.

Phenolic Compounds from onion husk (Allium cepa L.): Mode of Extraction

Phenolic compounds contained in plants can prevent cardiovascular and oncological diseases that pose a serious threat to human health and life. Onion Allium cepa L. is a source of natural phenolic compounds This study investigates the effect of extraction temperature and duration on the total content of phenolic compounds in aqueous extracts of onion husk Allium cepa L. The total content of phenolic compounds in extracts has been measured. The prospects of using onion husk as a source of substances of phenolic nature are analyzed in the article.

Antileishmania and immunomodulatory potential of cashew nut shell liquid and cardanol

Conventional treatments for leishmaniasis have caused serious adverse effects, poor tolerance, development of resistant strains. Natural products have been investigated as potential therapeutic alternatives. The cashew nut shell liquid (CNSL) is a natural source of phenolic compounds with several biological activities, where cardanol (CN) is considered one of the most important and promising compounds. This study aimed to evaluate antileishmanial, cytotoxic and immunomodulatory activities of CNSL and CN. Both showed antileishmanial potential, with IC50 for CNSL and CN against Leishmania infantum: 148.12 and 56.74 μg/mL; against Leishmania braziliensis: 85.71 and 64.28 μg/mL; against Leishmania major: 153.56 and 122.31 μg/mL, respectively. The mean cytotoxic concentrations (CC50) of CNSL and CN were 37.51 and 31.44 μg/mL, respectively. CNSL and CN significantly reduced the percentage of infected macrophages, with a selectivity index (SI) >20 for CN. CNSL and cardanol caused an increase in phagocytic capacity and lysosomal volume. Survival rates of Zophobas morio larvae at doses of 3; 30 and 300 mg/kg were: 85%, 75% and 60% in contact with CNSL and 85%, 60% and 40% in contact with CN, respectively. There was a significant difference between the survival curves of larvae when treated with CN, demonstrating a significant acute toxicity for this substance. Additional investigations are needed to evaluate these substances in the in vivo experimental infection model.

Maceration and liquid-liquid extractions of phenolic compounds and antioxidants from Algerian olive oil mill wastewater.

Olive oil mill wastewater (OMW) is a major waste stream generated in olive oil industry. It is highly polluted due to phenolic compounds. The present study focused on the physicochemical properties of OMW as well as the quantitative and qualitative effects of two extraction methods of phenolic compounds which were liquid-liquid and maceration methods. Spectrophotometry and high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) were adopted to quantify the phytochemical contents and the phenolic compounds. The extract obtained by the maceration method showed the highest yields of total polyphenol, flavonoid, and tannin contents. The LC-MS results revealed the presence of 16 phenolic compounds in the macerated, and only 12 phenolic compounds were found in the extract of the second method. Quinic acid was identified as the most abundant compound. Moreover, the macerated extracts possessed the highest antioxidant potential as evidenced by their strong ferric reducing antioxidant power (FRAP) and their 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging activities. The phytochemical contents, as well as the antioxidant potentials of OMW after extraction using maceration, were significantly greater than using liquid-liquid method. Therefore, maceration seemed to be the most effective method for extracting phenolic compounds from OMW. The OMW constitute a rich source of natural phenolic compounds that could be used as a potential source of natural antioxidants.

Impact of Solvent Type on Total Phenol and Flavonoid Content and Sun Protection Factor of Crude Cashew Nutshell Liquid

Cashew nutshell liquid (CNSL) is a cheap source of natural phenolic compounds that have numerous applications. These phenolic compounds have chemical structures with chromophores similar to those found in synthetic chemical UV-filters, which are present in commercial sunscreen products (SSPs). Thus, this study investigated the impact of solvents on the yield, total phenol content (TPC), total flavonoid content (TFC), and the sun protection factor (SPF) of crude CNSL. The percent yield ranged from (30.4 ± 0.7% to 49.3 ± 3.2%); hexane recorded the lowest yield, while ethanol recorded the highest. Acetone (101.2 ± 2.5 mg GA/g), methanol (99.5 ± 0.10), and chloroform (95.4 ± 3.7 mg GAE/g), recorded the highest TPC respectively, while hexane (33.3 ± 0.7 mg QE/g) recorded the highest TFC. The SPFs ranged from (22.1 ± 1.1 to 16.4 ± 0.8), chloroform (22.1 ± 1.1), acetone (21.5 ± 1.1), and methanol (19.3 ± 1.0) again recorded the highest values respectively, while hexane (16.4 ± 0.8) recorded the lowest. Our results revealed that extracting solvents has a significant impact on the yield and SPF of CNSL. Therefore, we propose that acetone, chloroform, and methanol, either alone or as mixtures, could be the best solvents for extracting CNSL with a good TPC and SPF.

Biological activities and phenolic compounds of olive oil mill wastewater from Abani, endemic Algerian variety

The current study aimed to determination of cytotoxicity, antioxidant, anti-inflammatory, anti-hemolytic, and anticoagulant activities of phenolic compounds extracted from olive oil mill wastewater (OMW) issue from the cold extraction of olive oil from Khenchela eastern in Algeria. The LC–MS (liquid chromatography–mass spectrometry) results were revealed the presence of 20 phenolic compounds in the extract of OMW and mostly consisted of Kaempferol, 4,5-di-O-caffeoyquinic acid, quinic acid, and caffeic acid. The extracts possessed effective reducing power (FRAP) and high radical scavenging activity against DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS + (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) free radicals, and it inhibited cytochrome c reduction in a dose-dependent manner. They exert a protective effect on red blood cells, and they were found to exhibit the highest inhibitory effect anti-inflammatory activity using inhibition of protein denaturation (IPD) and membrane stabilizing potential (MSP) tests (80.46 ± 3.81 µg/mL and 87.43 ± 0.66 µg/mL) more than the standard used. The extract also showed the greatest anticoagulant activity in both the endogenous and exogenous routes (44.77 ± 0.25 s and 15.84 ± 0.12 s, respectively). Based on these findings, it is reasonable to infer that OMW is a good source of natural phenolic compounds with potential antioxidant, anti-inflammatory, and anticoagulant properties.

Phenolic composition, antioxidant and antiacetylcholinesterase activities of Opuntia ficus‐indica peel and flower teas after in vitro gastrointestinal digestion

The flowers and peels of cactus Opuntia ficus-indica (OFI) are by-products generally discarded. Their beneficial properties have been linked to the chemical composition without taking into account its transformations during digestion. This study evaluated and compared the phenolic composition, antioxidant and antiacetylcholinesterase activities of OFI peel and flower teas before and after in vitro gastrointestinal digestion. Results showed that OFI peel tea was a source of natural phenolic compounds and carotenoids, while OFI flower tea was a source of flavonoids. Both OFI peel and flower teas exhibited high antioxidant activities (AAs) measured by several tests [1,1-diphenyl-2-picrylhydrazyl radical (DPPH• ), reducing power (RP), hydrogen peroxide scavenging activity (HPSA)]. Flower teas presented a higher antiacetylcholinesterase inhibition percentage than peel teas. Significant decreases of acetylcholinesterase and AAs were obtained under in vitro gastrointestinal digestion. Fourteen phenolic compounds typical of phenolic acids and flavonoids were identified in both teas. These compounds seemed to be more affected by pancreatic than by the gastric conditions. OFI peel tea has been found as a source of natural phenolic compounds and carotenoids, while OFI dry flower tea as a source of flavonoids. The OFI flower tea phytochemicals were more stable than peel tea during the digestive process. These findings suggest that peels and flowers of OFI should be considered as sources of healthy ingredients. © 2022 Society of Chemical Industry.

Effect of Storage Conditions on Biologically Active Compounds in Purple-Fleshed Potatoes

Abstract Potatoes (Solanum tuberosum L.) are an important crop. They are a source of natural phenolic compounds with high biological activity. Stress factors may decrease phenolic concentration and increase concentration of the toxin glycoalkaloid as a result of plant self-protection against stress. The aim of the current study was to evaluate the effect of storage under light on the concentration of biologically active compounds in purple-fleshed potatoes. The purple-fleshed potato variety ‘Blue Congo’ was harvested from test fields of the Institute of Agricultural Resources and Economics in Latvia. Storage under light was performed in a climate chamber ICH110 (Memmert GmbH + Co. KG, Germany) with constant pre-set relative air humidity 85%, temperature +22 °C, and full-spectrum light (Eecoo, 1200 W, LED) intensity of 2000 lux and total time seven days. Total phenolic concentration, antioxidant activity and total glycoalkaloid concentration was measured using spectrophotometry, and moisture was determined according to standard LVS 272:2000. Storage under artificial light of purple-fleshed variety ‘Blue Congo’ potatoes caused decrease of total phenolic concentration and antioxidant activity, no change in moisture level, and increase of total glycoalkaloid concentration.

Solid-state bioprocessing of sugarcane bagasse with Auricularia fuscosuccinea for phenolic compounds extraction

Sugarcane bagasse is a natural source of phenolic compounds. However, these compounds are bound to lignocellulose components, reducing their ability to function as good antioxidants. These linkages are hydrolyzed by enzymes like β-glucosidases, increasing free phenolics. Auricularia is a food-grade genus capable of producing β-glucosidases. The aim of this work was (I) to determine naturally occurring species of Auricularia and (II) to obtain phenolic compounds through the solid-state bioprocessing of sugarcane bagasse. We have successfully isolated five strains that were assigned to the taxon A. fuscosuccinea. We determined β-glucosidase activity by fluorescence plate assay of the five isolated strains and adjusted an optimal temperature for mycelial growth at 30 °C. A. fuscosuccinea LBM 243 was chosen for solid-state bioprocessing of sugarcane bagasse. β-glucosidase activity (12.2 ± 0.62 U l−1) and protein content (51.58 ± 6.26 mg l−1) were highest on day 20 of culture. The maximum value of total phenolic content (507.5 ± 9.05 mg l−1) was obtained at day 20 and antioxidant capacity (34.44% ± 11.20) was highest at day 10, both in ethanolic extracts. The best performance of ethanol against methanol extraction in this work is highlighted considering ethanol to be a safe, efficient, and low-cost solvent.

Bioavailability and radical scavenging power of phenolic compounds of cocoa and coffee mixtures.

Cocoa and coffee are natural sources of phenolic compounds, which are degraded during beans processing of both. For this reason, there is an interest in obtaining extracts of these bio compounds. The aim of this study was uncovering the radical scavenging activity (AC) of mixtures of cocoa and coffee extracts, and the bioavailability of their phenolic compounds, resorting to in vitro models: DPPH and ORAC antioxidant methods, and the characterization of the trans-epithelial transport of cocoa and coffee phenolics through Caco-2 cells monolayer model of the intestinal barrier. The cocoa displayed a higher AC than the coffee regarding both DPPH and ORAC assays, while the mixtures increased in parallel with the percentage of cocoa in the blends. The combination index was calculated to set up the type of interaction in the cocoa-coffee mixtures, obtaining that the mixture 25:75 was moderately antagonistic, 50:50 nearly additive, and 75:25 slightly synergistic. The absorption efficiency of the cocoa phenolic compounds was between 87.9%-97.4%, in the coffee compounds was 100%. The mixtures varied according to the proportion of cocoa and coffee. The results obtained allowed concluding that the phenolic compounds present in cocoa and coffee, respectively, are featured by high bioavailability and a valuable antioxidant capacity, while no pattern was found in the mixtures concerning the real benefit of using them combined.

Artichoke By-Products as Natural Source of Phenolic Food Ingredient

Nowadays, the transformation activity of the food industry results in the generation of a huge amount of daily discarded vegetables wastes. One of those undervalued by-products are produced during the post-harvesting and processing process of artichokes. In the present research, the potential of artichokes’ bracts and stalks have been evaluated as a natural source of phenolic compounds which could be used as bioactive food ingredients, among others. In this study, the bioactive composition of those wastes has been evaluated using recent advances in extraction and analytical technologies, concretely, pressurized liquid extraction (PLE) followed by high-performance liquid chromatography (HPLC) coupled to electrospray time-of flight mass spectrometry (ESI-TOF/MS) analysis. To achieve this goal, first, the extraction process was evaluated by a comparative study using GRAS (Generally Recognized As Safe) solvents (mixtures of ethanol and water) at different temperatures (40–200 °C). The second step was to deeply characterize the composition of individual polyphenols by HPLC-ESI-TOF/MS in order to establish a comparison among the different PLE conditions applied to extract the phenolic fraction. The analysis revealed a wide variety of phenolic-composition, mainly phenolic acids and flavonoids. The results also highlighted that high percentages of ethanol and medium-high temperatures pointed out to be useful PLE conditions for recovering this kind of phytochemicals, which could be used in different applications, such as functional food ingredients, cosmetics, or nutraceuticals.