Natural Source Of Phenolic Compounds Research Articles

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.

Comprehensive Mass Spectrometric Analysis of Snake Fruit: Salak (Salacca zalacca)

Snake fruit (Salacca zalacca (Gaert.) Voss) is a fruit species traditionally cultivated in Indonesia and other Southeast Asian countries. The edible parts of the fruits contain a certain amount of total phenolic, flavonoid, and monoterpenoid compounds, proving them to be their perfect sources. The main goal of this work was to detect, quantify, and identify various phenolic compounds present in snake fruit pulp. Ultrahigh performance liquid chromatography coupled to a Q-Orbitrap tandem mass spectrometer was able to detect 19 phenolic compounds in the salak pulp, including 5 flavanols, 6 phenolic acids, 2 flavonols, 1 flavone, and also 5 presumably new phenolic compounds. Among the detected compounds, 11 were reported and quantified for the first time in salak pulp. Chlorogenic acid was by far the most predominant phenolic compound. The next relatively abundant compounds in snake fruit were epicatechin, isoquercetin, neochlorogenic acid, ferulic acid, gallic acid and procyanidine B2 (levels at ca 5–10 μg/g in MeOH extract), syringic acid, and caffeic acid (levels at ca 1 μg/g in H2O extract). A significant total phenolic content (257.17 μL/mL) and antioxidant activities (10.56 μM TE/g of fruit pulp) were determined. In conclusion, S. zalacca fruit has potential to serve as a natural source of phenolic compounds with antioxidative activities which may be associated with their health benefits.

Effects of high-temperature drying on the polyphenolic composition of skins and seeds from red grape pomace

The management and disposal of large amounts of grape pomace (GP) annually generated by the wine industry represent a serious economic and environmental problem. On the other hand, GP can be profitably exploited for many possible purposes as a source of natural phenolic compounds. GP is highly perishable, and it is produced in large amounts during a short period of time: a rapid stabilization by drying is needed to prolong its availability for any further processing. In the case of large amounts of GP to be dried at an industrial level, the balance between costs and final quality of the dried product must be considered. The effect of high-temperature treatments (160–200 °C) for short duration on the polyphenolic composition of GP, and on its stability over time during storage, were studied separately for skins and seeds. The high-temperature treatments caused the enrichment of the polyphenolic content of the skins and the contemporary decrease in that of the seeds. Overall, the dried GP retained over time the polyphenolic composition and the anti-radical properties determined at the end of the drying process. This result is of particular interest in view of the use of dried GP throughout the year for any further processing.

HPTLC Phytochemical Screening and Hydrophilic Antioxidant Activities of <i>Apium graveolens</i> L., <i>Cleome gynandra</i> L., and <i>Hibiscus sabdariffa</i> L. Used for Diabetes Management

Diabetes mellitus is a socially significant disease characterized by chronic hyperglycemia and metabolic disorders of proteins, carbohydrates, and lipids due to reduced function of insulin. Medicinal plants, rich in bioactive components that promote prevention and treatment, are inexpensive and no side effects. Apium graveolens, Cleome gynandra, and Hibiscus sabdariffa from Burkina Faso were investigated for their phytochemical profile and antioxidant activities. The high-performance thin-layer chromatography profile revealed flavonoids, tannins, and sterols in these herbaceous. The Hibiscus sabdariffa methanolic extract exhibited the highest total phenolic (138.4 ± 0.5 mg GAE/g DW) and flavonoid (52.8 ± 0.6 mg RuE/g DW) contents comparatively to Cleome gynandra and Apium graveolens. Hibiscus sabdariffa methanolic extract also presented the highest antioxidant activity (IC50 = 0.31 ± 0.002 mg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay. A high correlation between flavonoid contents and hydrophilic antioxidant activities (r = 0.99) was observed, indicating that flavonoids contribute significatively to these herbaceous antioxidant properties. Apium graveolens, Cleome gynandra, and Hibiscus sabdariffa constitute a natural source of phenolic compounds that could be exploited in diabetes mellitus management.

Phenolic Composition of Dipteryx alata Vogel Pulp + Peel and Its Antioxidant and Cytotoxic Properties

Dipteryx alata Vogel is a native fruit from Brazil, which has been poorly investigated concerning its phenolic composition and the biological effects of its pulp + peel. Thus, in this study we evaluated the antioxidant activity and total phenolic content of the D. alata pulp + peel extracts obtained with different solvents, as well as determined the phenolic compounds by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis. In addition, cytotoxic effects of D. alata pulp + peel extract on non-tumor and cancer cell lines were investigated for the first time. The results showed that phenolic compounds can be efficiently extracted from pulp + peel of D. alata by organic solvent-water mixtures as an extraction system. The developed UHPLC-MS/MS method allowed the quantification of eighteen phenolic compounds in D. alata pulp + peel extract for the first time, which luteolin and trans-cinnamic acid were predominant. In addition, D. alata pulp + peel extract exhibited better cytotoxity against SiHa and C33A cervical cancer cell lines, while weak cytotoxicity was noticed against non-tumor HaCaT and L929 cell lines, pointing out its safety and providing preliminary evidence of its anticancer potential. Our findings indicate that D. alata pulp + peel can be explored as a natural source of phenolic compounds with promising antioxidant and cytotoxic properties.

Ultrasound-Assisted Extraction of Polyphenolic Contents and Acid Hydrolysis of Flavonoid Glycosides from Oil Palm (Elaeis guineensis Jacq.) Leaf: Optimization and Correlation with Free Radical Scavenging Activity

Malaysia is ranked as the second largest oil palm producer in the world after Indonesia. This leads to the generation of large quantities of oil palm (Elaeis guineensis Jacq.) leaves (OPLs) annually, considered an underutilized oil palm biomass with low economical value. The present study aimed to study the effects of several parameters of ultrasound-assisted extraction (UAE) and the acid hydrolysis of phenolic compounds from OPLs using the single factor experimental approach. The effects of different solvents (hexane, ethyl acetate, 1:1 methanol–ethyl acetate, absolute methanol, and 4:1 methanol–water), solid–liquid ratios (1:20, 1:40, 1:50, 1:60, and 1:70), times (0.5, 1, 2, 3, and 5 h), and temperatures (25, 30, 40, 60, and 70 °C) were investigated for UAE. Moreover, the effects of acid concentration (0.2, 1, 2, 4, 6, and 12 M), incubation time (10, 30, 45, 60, and 90 min), and incubation temperature (65, 75, 85, 90, and 95 °C) on the acid hydrolysis of flavonoid glycosides were also determined. The results revealed that some of the tested parameters had prominent effects on the total phenolic (TPC) and total flavonoid (TFC) contents, as well as the DPPH free radical scavenging activity recovered from the OPLs. The optimal UAE conditions were determined to be 0.5 h at 25 °C using 4:1 methanol–water and 1:50 solid–liquid ratio, producing OPL extracts with TPC and TFC at 335.30 and 60.67 milligrams quercetin equivalents per gram of extract (mg QCE/g extract), respectively, and DPPH free radical scavenging activity at 94.06%. The phenolics present in OPLs were optimally hydrolysed using 6 M hydrochloric acid with an incubation period of 45 min at 95 °C with TPC, TFC, and DPPH free radical scavenging activity at 126.33 milligrams gallic acid equivalents per gram of extract (mg GAE/g extract), 36.08 mg QCE/g, and 54.88%, respectively. Moreover, acid hydrolysis managed to optimally recover the total apigenin content (TAC), total luteolin content (TLC), and total flavonoid C-glycoside content (TFCGC) with values of 79.12 micrograms vitexin equivalents per milligram of extract (µg VE/mg extract), 20.97 micrograms orientin equivalents per milligram of extract (µg OE/mg extract), and 100.09 µg/mg, respectively. Additionally, there were significant correlations between the polyphenolic compounds, flavonoid C-glycosides, and antioxidant activity for all parameters based on the Pearson correlation analysis. This indicates that OPLs have potential as a natural source of phenolic compounds, especially flavonoid C-glycosides, with beneficial free radical scavenging activity that can be incorporated in food and pharmaceutical products.

Transformed Shoots of Dracocephalum forrestii W.W. Smith from Different Bioreactor Systems as a Rich Source of Natural Phenolic Compounds.

Transformed shoots of the Tibetan medicinal plant Dracocephalum forrestii were cultured in temporary immersion bioreactors (RITA and Plantform) and in nutrient sprinkle bioreactor (NSB) for 3 weeks in MS (Murashige and Skoog) liquid medium with 0.5 mg/L BPA (N-benzyl-9-(2-tetrahydropyranyl)-adenine) and 0.2 mg/L IAA (indole-3-acetic acid). The greatest biomass growth index (GI = 52.06 fresh weight (FW) and 55.67 dry weight (DW)) was observed for shoots in the RITA bioreactor, while the highest multiplication rate was found in the NSB (838 shoots per bioreactor). The levels of three phenolic acids and five flavonoid derivatives in the shoot hydromethanolic extract were evaluated using UHPLC (ultra-high performance liquid chromatography). The predominant metabolite was rosmarinic acid (RA)—the highest RA level (18.35 mg/g DW) and total evaluated phenol content (24.15 mg/g DW) were observed in shoots grown in NSB. The NSB culture, i.e., the most productive one, was evaluated for its antioxidant activity on the basis of reduction of ferric ions (ferric reducing antioxidant power, FRAP) and two scavenging radical (O2•– and DPPH, 1,1-diphenyl-2-picrylhydrazyl radical) assays; its antibacterial, antifungal, and antiproliative potential against L929 cells was also tested (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test). The plant material revealed moderate antioxidant and antimicrobial activities and demonstrated high safety in the MTT test—no cytotoxicity at concentrations up to 50 mg/mL was found, and less than a 20% decrease in L929 cell viability was observed at this concentration.

Variety and Year Impact on Phenolic Content of Arkansas-Grown Sweetpotato Leaves

Abstract Objectives Sweetpotato leaf (SPL) is a natural source of phenolic compounds with potential utility as an antioxidant. The study aimed to measure the impacts of the years on SPL total phenolic content and antioxidant capacity and to identify and quantify the individual phenolic compounds. Methods Sweetpotato leaves in 2018 (27 varieties) and 2019 (24 varieties) were grinded and lyophilized. Phenolic compounds were extracted with 70% ethanol from SPLs. Total phenolic content was determined by Folin-Ciocalteu method and antioxidant potential was determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. Five SPL samples with statistically highest antioxidant capacity were identified and quantified by HPLC. All statistical analyses were carried out by SAS software using ANOVA. Statistical significance was accepted at P < 0.05. Results The average of total phenolic contents in 2018 SPL samples was 43 ± 13 mg gallic acid equivalent (GAE)/g dry weight (DW) SPL whereas in 2019, it was 53 ± 9 mg GAE/g dry weight SPL. Antioxidant capacity in 2018 was 110 ± 75 µmol Trolox equivalent (TE)/g dry weight SPL whereas in 2019, it was 132 ± 32 µmol TE/g dry weight SPL. SPL1 had the highest antioxidant potential, followed by SPL9, SPL3, SPL28, and SPL11 (P < 0.05). The concentrations of major identified phenolics from the five SPL samples (#1, 9, 3, 28, and 11) in dry weight of SPL were: chlorogenic acid at 3.05 ± 0.35 mg/g, 5-monocaffeoylquinic acid (CQA) at 0.71 ± 0.06 mg chlorogenic acid equivalent (ChAE)/g, 4-CQA at 0.99 ± 0.07 mg ChAE/g, 3,4-diCQA at 1.22 ± 0.18 mg ChAE/g, 3,4,5-triCQA at 1.2 ± 0.18 mg ChAE/g, and 3,5-diCQA at 15.5 ± 4.05 mg ChAE/g. 3,5-diCQA, the predominant phenolic, was present in the highest amounts in SPL1. Conclusions The results showed that sweetpotato leaves collected in 2019 contained higher total phenolics and antioxidant capacity than the ones collected in 2018. Phenolic compounds have strong antioxidant activity in Arkansas-grown sweetpotato leaves. This study warrants further investigation of sweetpotato leaves to be utilized as an antioxidant. Funding Sources The work was supported by USDA-NIFA.

A Reference List of Phenolic Compounds (Including Stilbenes) in Grapevine (Vitis vinifera L.) Roots, Woods, Canes, Stems, and Leaves.

Due to their biological activities, both in plants and in humans, there is a great interest in finding natural sources of phenolic compounds or ways to artificially manipulate their levels. During the last decade, a significant amount of these compounds has been reported in the vegetative organs of the vine plant. In the roots, woods, canes, stems, and leaves, at least 183 phenolic compounds have been identified, including 78 stilbenes (23 monomers, 30 dimers, 8 trimers, 16 tetramers, and 1 hexamer), 15 hydroxycinnamic acids, 9 hydroxybenzoic acids, 17 flavan-3-ols (of which 9 are proanthocyanidins), 14 anthocyanins, 8 flavanones, 35 flavonols, 2 flavones, and 5 coumarins. There is great variability in the distribution of these chemicals along the vine plant, with leaves and stems/canes having flavonols (83.43% of total phenolic levels) and flavan-3-ols (61.63%) as their main compounds, respectively. In light of the pattern described from the same organs, quercetin-3-O-glucuronide, quercetin-3-O-galactoside, quercetin-3-O-glucoside, and caftaric acid are the main flavonols and hydroxycinnamic acids in the leaves; the most commonly represented flavan-3-ols and flavonols in the stems and canes are catechin, epicatechin, procyanidin B1, and quercetin-3-O-galactoside. The main stilbenes (trans-ε-viniferin, trans-resveratrol, isohopeaphenol/hopeaphenol, vitisin B, and ampelopsins) accumulate primarily in the woods, followed by the roots, the canes, and the stems, whereas the leaves, which are more exposed to environmental stresses, have a low concentration of these compounds. Data provided in this review could be used as (i) a metabolomic tool for screening in targeted and untargeted analyses and (ii) a reference list in studies aimed at finding ways to induce naturally occurring polyphenols on an industrial scale for pant and human disease control.

In vitro hypoglycemic, antioxidant and antineurodegenerative activity of chokeberry (Aronia melanocarpa) leaves

Chokeberries (Aronia melanocarpa (Michx.) Elliot have recently become one of the most popular and widely used berry fruits, and there are numerous studies dealing with the investigation of their chemical composition and biological activities. Unlike berries, chokeberry leaves were far less investigated. Therefore, the aim of this study was to conduct a bioactivity-based analysis of chokeberry leaves collected after berries were harvested. Chemical analysis of hydroethanolic chokeberry extract and its ethyl acetate, n-butanol, and water fractions was performed. Antioxidant, hypoglycemic, and antineurodegenerative activities of the obtained samples were assessed by in vitro tests. The highest total phenolics content was found in n-butanol fraction (221.5 mg gallic acid equivalents/g dw). Fourteen compounds (six phenolic acids and eight flavonoids) were identified in the samples. Caffeoylquinic acid derivatives and quercetin glycosides were dominant phenolic compounds. The highest content of phenolic acids, as well as flavonoids, was recorded in n-butanol fraction (80.75 mg/g dw and 47.79 mg/g dw, respectively). This fraction was the most active in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Also, the n-butanol fraction was the most effective inhibitor of acetylcholinesterase (AChE) and tyrosinase (TYR) enzymes. All samples showed a better inhibitory effect on α-glucosidase enzyme with inhibition concentrations IC50 = 4.21 - 9.22 μg/mL, than α-amylase enzymes (IC50 = 14.36 - 88.61 μg/mL). Pearson’s correlation between the content of individual phenolics and the results of biological tests was performed. Thus, hyperoside and isoquercitrin showed a significant correlation with DPPH and ABTS tests, caffeoylquinic acids with FRAP test, quercetin 3-O-vicianoside with β-carotene assay, hyperoside and isoquercitrin with α-amylase inhibition activity, and isorhamnetin 3-O-rutinoside with α-glucosidase inhibition assay. Considering the obtained results, chokeberry leaves represent a valuable natural source of phenolic compounds with promising potential for the development of new products with beneficial effects on human health.

Physicochemical Properties of White Soft Cheese Supplemented With Encapsulated Olive Phenolic Compounds

Background and Objective: White soft cheese is one of the most popular, high nutritional and healthy dairy products in Egypt. The Olive cake and mill waste-water are natural sources of phenolic compounds enriched with natural antioxidants. The aim of this work was the use of milk proteins as carriers for olive polyphenolic extract and its use it in the production of white soft cheese. Materials and Methods: polyphenols were extracted from olive mill waste. Maltodextrin (MD) with whey protein isolate (WPI) and skim milk powder (SMP) were used to entrap olive polyphenols extract. Encapsulation efficiency (EE), particle size, Zeta potential and electron microscopy for the prepared capsules were assessed. White soft cheese fortified with polyphenol capsules was made. The polyphenols content, antioxidant activity, texture profiles and sensory properties of cheese were followed. Results: The SMP/MD mixture gives better encapsulation efficiency of 90.08%, while the combination between MD with WPI at ratio 50:50 improved the encapsulation efficiency up to 88.42%. Capsules prepared with the use of SMP/MD mixture less mean diameter of 189 nm compared with using WPI: MD 50:50 which recorded 270.3 nm. Also, capsules prepared with SMP/MD mixture showed zeta potential of -39.75 mV while that prepared using WPI with MD showed -13.7 mV. Electron microscopy revealed that SMP capsules had diameter of 122.04 nm compared to 262.07 nm for WPI capsules. White soft cheese with fortification by olive polyphenols capsules had high total solids and protein contents and almost constant antioxidant activity during 30 days of cold storage. Hardness, gumminess, and chewiness of cheese fortified with polyphenols capsules increased significantly (P˂ 0.05) compared to control samples. Also, it gained higher total acceptability scores compared to control. Conclusion: Milk proteins can be used successfully to encapsulate olive polyphenols and polyphenols capsules can be used in the production of healthy white soft cheese.

Characterisation and valorisation of the bark ofMyrcia eximiaDC. trees from the Amazon rainforest as a source of phenolic compounds

AbstractThe bark of the tree speciesMyrcia eximiaDC., which occurs in secondary forests in the Brazilian Amazon, is described for the first time. The aim was to provide a broad knowledge of its composition, to add value, and to direct uses to the bark of this species based on its polyphenolic content and antioxidant capacity. The bark is formed by conducting phloem, nonconducting phloem, and rhytidome. In addition, dead phloem occurs between the periderms. The average chemical composition of the bark was 45.6% total extractives, 1.4% suberin, 1.7% ash, and 21.1% lignin. The ethanol-water extract had a high content of flavonoids and condensed tannins [300.8 and 877.3 mg catechin equivalents (CE) g−1of the extract, respectively]. High-performance liquid chromatography (HPLC) was used to quantify the presence of rutin, quercetin, and gallic, ferulic, and o-coumaric acids. The bark extract showed strong 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging activity, which was superior to that of the commercial antioxidant butylated hydroxytoluene (BHT), with an IC50of 85.2 μg mL−1. Based on these results, it is evident that the bark ofM. eximiafrom the Brazilian Amazon rainforest is a new and potential natural source of phenolic compounds and antioxidants, and its extracts can be used in the food and pharmaceutical industry and in various condensed tannin-based products.

Extra virgin olive oil and related by-products (Olea europaea L.) as natural sources of phenolic compounds for abdominal pain relief in gastrointestinal disorders in rats.

Management of abdominal pain, a common symptom of IBDs and IBS, is still a clinical problem. Extra virgin olive oil (EVOO), a main component of the Mediterranean diet, shows positive effects on chronic inflammation in IBDs. In this study, the effect of the oral administration of EVOO (3 mL) and two olive milling by-products, DPA (300 mg kg-1) and DRF (300 mg kg-1), on preventing the development of abdominal pain in a DNBS-induced colitis model in rats was evaluated. The doses were chosen with the aim of simulating a plausible daily intake in humans. DPA and EVOO treatments significantly reduced the abdominal viscero-motor response to colon-rectal distension at 2 and 3 mL of balloon distension volume, both 7 and 14 days after the DNBS-injection. DRF showed efficacy in the reduction of visceral hypersensitivity only with 3 mL balloon inflation. In awake animals, DPA and DRF reduced pain perception (evaluated as abdominal withdrawal reflex) with all balloon distension volumes, while EVOO was effective only with higher distension volumes. Fourteen days after the DNBS-injection, all samples reduced the macroscopic intestinal damage (quantified as the macroscopic damage score) also showing, at the microscopic level, a reduction of the inflammatory infiltrate (quantified by hematoxylin and eosin analysis), fibrosis (highlighted by picrosirius red staining), the increase in mast cells and their degranulation (analyzed by triptase immunohistochemistry). This is the first report on the promotion of abdominal pain relief in a rat model obtained administering EVOO and two derived by-products. Our results suggest a protective role of phenol-rich EVOO and milling by-products, which may be proposed as food ingredients for novel functional foods.

Chemical Characterization and Antioxidant Properties of Ethanolic Extract and Its Fractions from Sweet Potato (Ipomoea batatas L.) Leaves.

Sweet potato (Ipomoea batatas L.) leaf is a natural source of phenolic compounds with strong antioxidant activity and potential utility as an antioxidant. The aim of this study was to evaluate the polyphenol composition and antioxidant activities of ethanol extracts and their various solvent-partitioned fractions (petroleum ether, ethyl acetate, and aqueous fraction) from sweet potato leaves and petioles. Seven caffeoylquinic acid (CQA) derivatives and four flavonoids were detected in sweet potato leaves by HPLC-ESI-MS. The total phenolic content (TPC) and total flavonoid content (TFC) in leaf (112.98 ± 4.14 mg gallic acid equivalent (GAE)/g of dried extract, 56.87 ± 5.69 mg rutin equivalent (RE)/g of dried extract) was more than ten times higher than in petiole (9.22 ± 2.67 mg GAE/g of dried extract, 3.81 ± 0.52 mg RE/g of dried extract). The antioxidant contents of ethyl acetate fractions increased dramatically relative to those of crude extracts for both leaves and petioles. Purification using solvent partition with ethyl acetate increased TPC and TFC of crude extracts, especially the CQA derivatives including 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, and 3,4,5-tricaffeoylquinic acid. Meanwhile, the ethyl acetate fractions with the highest CQA content were associated with the highest scavenging activities towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) and higher ferric ion reducing antioxidant power (FRAP)-reducing power.

Effect of different coating materials on freeze‐drying encapsulation of bioactive compounds from fermented tea leaf wastewater

Bioactive compounds present in concentrated fermented Miang wastewater (CFMW) were encapsulated by freeze drying using various coating materials (maltodextrin, gum arabic, and modified starch) and CFMW‐to‐coating material ratios. The highest encapsulation efficiency of 98.05% was produced with gum arabic coating and 10:1 CFMW‐to‐coating ratio. The encapsulated Miang powder contained gallocatechin, epigallocatechin, catechin, epicatechin, gallic acid, and caffeine content of approximately 8.33, 27.81, 76.53, 8.01, 4.44, and 257.47 mg/100 g dry Miang powder (DMP), respectively. The antioxidant values (IC₅₀) of the Miang powder were 22.44 µg/ml against DPPH radicals and 334.33 µg/mL against ABTS radicals. Similarly to the freeze‐dried sample, spray‐dried Miang powder formulated with gum arabic coating, which were prepared for comparison, achieved the encapsulation efficiency 85.18%, total catechins 105.22 mg/100 g DMP, DPPH IC₅₀ value 21.88 µg/ml and ABTS IC₅₀ value 366.32 µg/ml. Additionally, the encapsulated Miang powder could be utilized to enhance the value of low‐quality tea drink. PRACTICAL APPLICATIONS: The wastewater from fermented tea leaf (Miang) production is an interesting natural source of phenolic compounds, including the antioxidants gallocatechin, epigallocatechin, catechin, epicatechin, and gallocatechin gallate. Freeze drying with gum arabic as a coating material can be utilized to encapsulate these bioactive compounds present in the wastewater of fermented Miang with high encapsulation efficiency. Encapsulated Miang powder could be used to enhance the value of low‐quality tea drink. Therefore, encapsulated Miang powder is a natural bioactive compound source with the potential as an ingredient in food and beverage production.

Wine Lees as a Source of Antioxidant Compounds.

The winemaking industry produces large amount of byproducts, including grape pomace, stalks, and lees. Wine lees are a natural source of phenolic compounds, which have important antioxidant and biological properties. Due to the high quantities produced worldwide, this byproduct can be an ideal raw material for obtaining phenolic compounds that could be of interest in the food and pharmaceutical industries. In this mini review, the main characteristics of wine lees as well as their phenolic composition and antioxidant activity have been summarized from the information in the literature.

Tailoring bilberry powder functionality through processing: Effects of drying and fractionation on the stability of total polyphenols and anthocyanins.

Bilberries are a rich natural source of phenolic compounds, especially anthocyanins. The press cake obtained during the processing of bilberry juice is a potential source of phytochemicals. The objective of this study was to evaluate different drying techniques and the fractionation of bilberry press cake powder toward obtaining phenolic‐rich ingredients for incorporation into value‐added food products. The derived powders were dispersed in water and dairy cream, to investigate the effects of drying and fractionation on the dispersibility and solubility of phenolic compounds. The drying techniques, hot air drying and microwave drying, applied on bilberry press cake reduced the content of total phenolics and anthocyanins. The degradation was, however, consistently small and similar for both techniques. The major anthocyanins detected in the samples were stable during drying and fractionation treatments. Fractionation of the press cake powder affected the total apparent phenolic content and composition of the different fractions. The highest phenolic content (55.33 ± 0.06 mg g−1 DW) and highest anthocyanin content (28.15 ± 0.47 mg g−1 DW) were found in the fractions with the smallest particle size (<500 μm), with delphinidin‐3‐O‐galactoside being the most abundant anthocyanin. Dispersibility of all dried powder samples was higher in dairy cream than water, and the highest level of anthocyanins was measured in samples from the powder with the smallest particle size (<500 μm), dispersed in cream. The application of drying, milling and fractionation was found to be a promising approach to transform bilberry press cake into stable and deliverable ingredients that can be used for fortification of food products with high levels of phenolic compounds.

In Vitro Antioxidant Activity and Total Phenolic Content of Root Extracts from Phragmanthera glaucocarpa (Peyr.) Balle

Background: Africa has a rich diversity of plant species, which can be considered important sources of new chemical compounds that can be used in the development of novel therapeutic drugs. Objectives: The present study aimed at investigating the antioxidant activity and total phenolic content of extracts obtained from the roots of Phragmanthera glaucocarpa (Peyr.) Balle, a plant used in Angola folk medicine. Methods: The prepared extracts were tested for their antioxidant activity using ABTS (2,2’-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid), DPPH (1’,1’-diphenyl-2-picrylhydrazyl), and peroxide value methods. Total phenolics were evaluated by the Folin-Ciocalteu method. Results: For ABTS, the best EC50 result was obtained with the ethyl acetate fraction (1.06 ± 0.30 mg/mL). For the DPPH method, the methanol extract and aqueous fraction presented the best EC50 results, 0.10 ± 0.01 mg/mL and 0.10 ± 0.00 mg/mL, respectively. The ethyl acetate fraction had the highest phenolic content (280.42 ± 0.15 mg G.A.E. /g of dry extract). The best result for the peroxide reduction value on the eighth day of sunflower oil oxidation was obtained for the aqueous fraction, with 131.40 ± 1.05 meq O2/g of lipid sample. Conclusions: The results of the present study demonstrate that the roots of the medicinal plant Phragmanthera glaucocarpa (Peyr.) Balle represent a promising source of natural phenolic compounds with antioxidant activity.

Phenolic profile and antioxidative properties of pulp and seeds of Randia monantha Benth

Randia monantha is a non-food fruit traditionally used in the prevention and treatment of various diseases such as cancer, diabetes hypertension and snake bite poisoning, among others. The main goal of this work was to identify and quantify phenolic compounds and to determine the antioxidative properties of extracts prepared in different solvents of the pulp and seeds of this fruit. The UPLC-MS-MS analysis detected 15 phenolic compounds, including, predominantly, chlorogenic acid, rutin and 4-coumaric acid. The aqueous extract of R. monantha pulp and seed exhibited the highest antioxidant activity. The seeds are rich in fiber (28.59 g/100 g) and the major polyunsaturated fatty acids found in seed oil were linoleic (ω-6, 46.56%), oleic (ω-9, 26.12%) and palmitic (21.78%). In conclusion, R. monantha fruit have potential as a natural source of phenolic compounds with antioxidative activities which may be associated to their health benefits so it could help in the development of pharmaceutical products.