Hydrolyzable vs. Condensed Wood Tannins for Bio-based Antioxidant Coatings: Superior Properties of Quebracho Tannins

Tannins have always been the subject of great interest for their countless properties, first of all their ability to produce functional coatings on a variety of materials. We report herein a comparative evaluation of the antioxidant properties of wood tannin-based coated substrates. In particular, nylon membrane filters were functionalized with chestnut (hydrolyzable) or quebracho (condensed) tannins by dip coating under different conditions. The efficiency of functionalization was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays, which invariably highlighted the superior ability of condensed tannins to induce the formation of a functional and robust coating. The results of the antioxidant assays revealed also the deleterious effects of aerial or enzymatic oxidation conditions on substrate functionalization, being more significant in the case of hydrolyzable tannins. On the other hand, the use of oxidizing conditions allowed to obtain more stable coatings, still exhibiting good antioxidant properties, in the case of condensed tannins. The presence of iron ions did not lead to a significant improvement of the coating efficiency for either tannins. The systematic approach used in this work provides novel and useful information for the optimal exploitation of tannins in antioxidant functional coatings.

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Acid Treatment Enhances the Antioxidant Activity of Enzymatically Synthesized Phenolic Polymers

Polymers ◽

10.3390/polym12112544 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2544

Author(s):

Maria Laura Alfieri ◽

Federica Moccia ◽

Gerardino D’Errico ◽

Lucia Panzella ◽

Marco d’Ischia ◽

...

Keyword(s):

Phenolic Compounds ◽

Acid Treatment ◽

Antioxidant Properties ◽

Fold Increase ◽

Enzymatic Oxidation ◽

Antioxidant Power ◽

Structural Modifications ◽

Ferric Reducing Antioxidant Power ◽

Natural Phenolic Compounds ◽

Electron Transfer Properties

Phenolic polymers produced by enzymatic oxidation under biomimetic and eco-friendly reaction conditions are usually endowed with potent antioxidant properties. These properties, coupled with the higher biocompatibility, stability and processability compared to low-molecular weight phenolic compounds, open important perspectives for various applications. Herein, we report the marked boosting effect of acid treatment on the antioxidant properties of a series of polymers obtained by peroxidase-catalyzed oxidation of natural phenolic compounds. Both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays indicated a remarkable increase in the antioxidant properties for most phenolic polymers further to the acid treatment. In particular, up to a ca. 60% decrease in the EC50 value in the DPPH assay and a 5-fold increase in the Trolox equivalents were observed. Nitric oxide- and superoxide-scavenging assays also indicated highly specific boosting effects of the acid treatment. Spectroscopic evidence suggested, in most cases, that the occurrence of structural modifications induced by the acid treatment led to more extended π-electron-conjugated species endowed with more efficient electron transfer properties. These results open new perspectives toward the design of new bioinspired antioxidants for application in food, biomedicine and material sciences.

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Antioxidant Capacity and Phenolic and Sugar Profiles of Date Fruits Extracts from Six Different Algerian Cultivars as Influenced by Ripening Stages and Extraction Systems

Foods ◽

10.3390/foods10030503 ◽

2021 ◽

Vol 10 (3) ◽

pp. 503

Author(s):

Malika Tassoult ◽

Djamel Edine Kati ◽

María África Fernández-Prior ◽

Alejandra Bermúdez-Oria ◽

Juan Fernandez-Bolanos ◽

...

Keyword(s):

Sugar Content ◽

Antioxidant Properties ◽

Dry Weight ◽

Natural Antioxidants ◽

Antioxidant Power ◽

Fruit Extracts ◽

Ripening Stages ◽

Date Fruit ◽

Ferric Reducing Antioxidant Power ◽

First Time

The study investigated the phenols, sugar and the antioxidant capacities of date fruit extracts obtained by organic solvents and by hydrothermal treatment from six different Algerian cultivars at two ripening stages for the first time. The analyzed cultivars exhibited potent antioxidant properties (ferric reducing antioxidant power (FRAP), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacities) and different phenols regardless of the solvents and the maturity stages. About 18 phenols were identified and quantified, mainly in the hydrothermal extracts. The earlier stages were characterized by high amounts of o-coumaric acid, cinnamic acid and luteolin, with a noticeable absence of quercetin. The tamr stage presented the highest sugar content (78.15–86.85 mg/100 mg dry weight (DW)) with an abundance of glucose. Galactose was present only in some cultivars from the kimri stage (tamjouhert). Uronic acids were mostly detected at the tamr stage (4.02–8.82 mg gallic acid equivalent/100 mg dried weight). The obtained results highlight the potential of using date fruit extracts as natural antioxidants, especially at industrial scales that tend use hydrothermal extraction.

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Synthesis and antioxidant properties of 2-(3-(hydroxyimino)methyl)-1H-indol-1-yl)acetamide derivatives

Future Journal of Pharmaceutical Sciences ◽

10.1186/s43094-020-00090-6 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Chandravadivelu Gopi ◽

Magharla Dasaratha Dhanaraju

Keyword(s):

Antioxidant Activity ◽

Condensation Reaction ◽

Antioxidant Properties ◽

Side Chain ◽

Antioxidant Power ◽

H Nmr ◽

Antioxidant Agents ◽

Phenyl Rings ◽

Ferric Reducing Antioxidant Power ◽

Ft Ir

Abstract Background The main aim of this work was to synthesise a novel N-(substituted phenyl)-2-(3-(hydroxyimino) methyl)-1H-indol-1-yl) acetamide derivatives and evaluate their antioxidant activity. These compounds were prepared by a condensation reaction between 1H-indole carbaldehyde oxime and 2-chloro acetamide derivatives. The newly synthesised compound structures were characterised by FT-IR, 1H-NMR, mass spectroscopy and elemental analysis. Furthermore, the above-mentioned compounds were screened for antioxidant activity by using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods. Result The antioxidant activity result reveals that most of the compounds were exhibiting considerable activity in both methods and the values are very closer to the standards. Among the synthesised compounds, compound 3j, 3a and 3k were shown remarkable activity at low concentration. Conclusion Compounds 3j, 3a and 3k were shown highest activity among the prepared analogues due to the attachment of halogens connected at the appropriate place in the phenyl ring. Hence, these substituted phenyl rings considered as a perfect side chain for the indole nucleus for the development of the new antioxidant agents.

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Effect of Parinari curatellifolia Peel Flour on the Nutritional, Physical and Antioxidant Properties of Biscuits

Processes ◽

10.3390/pr9081262 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1262

Author(s):

Shonisani Eugenia Ramashia ◽

Felicia Matshepho Mamadisa ◽

Mpho Edward Mashau

Keyword(s):

Antioxidant Activity ◽

Antioxidant Properties ◽

Polyphenolic Compounds ◽

Total Phenolic ◽

Crude Fibre ◽

Yellowness Index ◽

Antioxidant Power ◽

Parinari Curatellifolia ◽

Ferric Reducing Antioxidant Power ◽

The Impact

This study investigated the impact of Parinari curatellifolia peel flour on the nutritional, physical and antioxidant properties of formulated biscuits. Biscuits enriched with 5%, 10%, 15% and 20% of Parinari (P). curatellifolia peel flour were formulated and characterised. Thermal, physicochemical, polyphenolic compounds and antioxidant properties of flour and biscuits were determined. The incorporation of P. curatellifolia peel flour significantly increased (p < 0.05) thermal properties (onset, peak and conclusion temperatures) of flour. However, enthalpy of gelatinisation, viscosity and pH of flour samples decreased. Nutritional analysis revealed an increase in ash (0.74% to 2.23%) and crude fibre contents (0.39% to 2.95%) along with an increase of P. curatellifolia peel flour levels. Protein content and carbohydrates decreased while moisture content was insignificantly affected by the addition of P. curatellifolia peel flour. The L*, b* values and whiteness index of formulated biscuits decreased while parameter a* value (10.76 to 21.89) and yellowness index (69.84 to 102.71) decreased. Physical properties such as diameter (3.57 mm to 3.97 mm), spread ratio (2.67 to 3.45) and hardness (1188.13 g to 2432.60 g) increased with the inclusion levels of peel flour while weight and thickness decreased. The inclusion of P. curatellifolia improved the polyphenolic compounds and antioxidant activity of biscuits with values of total flavonoids content ranging from 0.028 to 0.104 mg CE/g, total phenolic content increasing from 20.01 mg to 48.51 mg GAE/g, ferric reducing antioxidant power (FRAP) increasing from 108.33 mg to 162.67 mg GAE/g and DPPH (2,2-diphenyl-1-picrylhydrazyl) from 48.70% to 94.72%. These results lead to the recommendation of the utilisation of P. curatellifolia peel flour to enhance the nutritional value, polyphenolic compounds and antioxidant activity of bakery products such as biscuits.

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UPLC-QTOF-MS/MS and GC-MS Characterization of Phytochemicals in Vegetable Juice Fermented Using Lactic Acid Bacteria from Kimchi and Their Antioxidant Potential

Antioxidants ◽

10.3390/antiox10111761 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1761

Author(s):

Moeun Lee ◽

Jung Hee Song ◽

Eun Ji Choi ◽

Ye-Rang Yun ◽

Ki Won Lee ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Antioxidant Activities ◽

Antioxidant Properties ◽

Total Phenolic ◽

Phenyllactic Acid ◽

Antioxidant Power ◽

Vegetable Juice ◽

Daucus Carota L ◽

Ferric Reducing Antioxidant Power

This study aims to investigate fermentative metabolites in probiotic vegetable juice from four crop varieties (Brassica oleracea var. capitata, B. oleracea var. italica, Daucus carota L., and Beta vulgaris) and their antioxidant properties. Vegetable juice was inoculated with two lactic acid bacteria (LAB) (Companilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124) isolated from kimchi and their properties were evaluated using untargeted UPLC-QTOF-MS/MS and GC-MS. The samples were also evaluated for radical (DPPH• and OH•) scavenging activities, lipid peroxidation, and ferric-reducing antioxidant power. The fermented vegetable juices exhibited high antioxidant activities and increased amounts of total phenolic compounds. Fifteen compounds and thirty-two volatiles were identified using UPLC-QTOF-MS/MS and GC-MS, respectively. LAB fermentation significantly increased the contents of d-leucic acid, indole-3-lactic acid, 3-phenyllactic acid, pyroglutamic acid, γ-aminobutyric acid, and gluconic acid. These six metabolites showed a positive correlation with antioxidant properties. Thus, vegetable juices fermented with WiKim39 and WiKim0124 can be considered as novel bioactive health-promoting sources.

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Antioxidant Activities and Volatile Flavor Components of Selected Single-Origin and Blend Chocolates

Molecules ◽

10.3390/molecules25163648 ◽

2020 ◽

Vol 25 (16) ◽

pp. 3648

Author(s):

Lucia Godočiková ◽

Eva Ivanišová ◽

Grzegorz Zaguła ◽

Luis Noguera-Artiaga ◽

Ángel A. Carbonell-Barrachina ◽

...

Keyword(s):

Antioxidant Activity ◽

Phenolic Acids ◽

Antioxidant Activities ◽

Antioxidant Properties ◽

Total Content ◽

Composition Analysis ◽

High Positive Correlation ◽

Antioxidant Power ◽

Single Origin ◽

Ferric Reducing Antioxidant Power

The biological activity of chocolates gains more and more attention of consumers. Its antioxidant properties depend, among other factors, mainly on the origin of cocoa and the characteristics that this origin gives to the final product. Therefore, the aim of the study was to measure and compare the total content of polyphenols, antioxidant activity, and key odorants of commercial chocolates made from blend cocoa with single-origin ones. The highest content of polyphenols was found in 90% blend cocoa chocolate and single-origin samples, while the lowest content was exhibited by 100% chocolate from blend cocoa mass. The highest antioxidant activity measured by 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) assays was observed in the sample of chocolate with 90% cocoa solids from blend mass, followed by single-origin chocolates. A high positive correlation between ABTS assay and the total polyphenol and phenolic acids’ content, as well as among the total content of polyphenols, flavonoids, and phenolic acids was found. Mineral composition analysis showed that dark chocolate is a valuable source of some elements, especially Mg, Fe, and Zn. Potentially toxic elements were not detected or below permitted limits. Moreover, it was noticed that the main volatile compound in all tested samples was acetic acid, but pyrazines were considered the most important group of chocolate odorants.

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Zn(II) Complex of Plant Phenolic Chlorogenic Acid: Antioxidant, Antimicrobial and Structural Studies

Materials ◽

10.3390/ma13173745 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3745

Author(s):

Monika Kalinowska ◽

Justyna Sienkiewicz-Gromiuk ◽

Grzegorz Świderski ◽

Anna Pietryczuk ◽

Adam Cudowski ◽

...

Keyword(s):

Antioxidant Activity ◽

Chlorogenic Acid ◽

Density Functional ◽

Salmonella Enteritidis ◽

Antioxidant Properties ◽

Antimicrobial Activities ◽

Butylated Hydroxytoluene ◽

Antioxidant Power ◽

Ferric Reducing Antioxidant Power ◽

Thermochemical Parameters

The structure of the Zn(II) complex of 5-caffeoylquinic acid (chlorogenic acid, 5-CQA) and the type of interaction between the Zn(II) cation and the ligand were studied by means of various experimental and theoretical methods, i.e., electronic absorption spectroscopy UV/Vis, infrared spectroscopy FT-IR, elemental, thermogravimetric and density functional theory (DFT) calculations at B3LYP/6-31G(d) level. DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), FRAP (ferric reducing antioxidant power), CUPRAC (cupric reducing antioxidant power) and trolox oxidation assays were applied in study of the anti-/pro-oxidant properties of Zn(II) 5-CQA and 5-CQA. The antimicrobial activity of these compounds against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Salmonella enteritidis and Candida albicans was tested. An effect of Zn(II) chelation by chlorogenic acid on the anti-/pro-oxidant and antimicrobial activities of the ligand was discussed. Moreover, the mechanism of the antioxidant properties of Zn(II) 5-CQA and 5-CQA were studied on the basis of the theoretical energy descriptors and thermochemical parameters. Zn(II) chlorogenate showed better antioxidant activity than chlorogenic acid and commonly applied natural (L-ascorbic acid) and synthetic antioxidants (butylated hydroxyanisol (BHA) and butylated hydroxytoluene (BHT)). The pro-oxidant activity of Zn(II) 5-CQA was higher than the ligand and increased with the rise of the compound concentration The type of Zn(II) coordination by the chlorogenate ligand strongly affected the antioxidant activity of the complex.

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Antioxidant, Antimutagenic and Cytoprotective Properties of Hydrosos Pistachio Nuts

Molecules ◽

10.3390/molecules24234362 ◽

2019 ◽

Vol 24 (23) ◽

pp. 4362 ◽

Cited By ~ 2

Author(s):

Luis Noguera-Artiaga ◽

Joel Said García-Romo ◽

Ema C. Rosas-Burgos ◽

Francisco Javier Cinco-Moroyoqui ◽

Reyna Luz Vidal-Quintanar ◽

...

Keyword(s):

Antioxidant Activity ◽

Deficit Irrigation ◽

Ames Test ◽

Antioxidant Properties ◽

Human Cell Lines ◽

Regulated Deficit Irrigation ◽

Antioxidant Power ◽

Pistachio Nuts ◽

Ferric Reducing Antioxidant Power ◽

Cancerous Cells

Pistachio nuts are included among the foods with the highest antioxidant capacity. Stressed cultivating conditions, such as the use of regulated deficit irrigation (RDI), are expected to create a plant response that might increase the production of secondary metabolites. Fruits that are obtained under RDI treatments are commonly called hydroSOS products. The aim of this work was to study the influence of using different rootstocks (P. atlantica, P. integerrima, and P. terebinthus) and two RDI treatments on the antioxidant (ABTS, ferric reducing antioxidant power (FRAP), and DPPH), antimutagenic (Ames test), and cytotoxicity (MTT assay in five human cell lines) activities of pistachios. P. terebinthus showed the best antioxidant activity, and the RDI treatments maintained and improved the antioxidant properties of pistachios. Neither the rootstock nor the RDI had significant impact on the antimutagenic potential of pistachios. The nut extracts had no toxic effect on non-cancerous cells and the application of RDI did not reduce their cytoprotective capacity. Furthermore, neither rootstock nor RDI treatments affected the ability of the pistachio extracts of preventing the oxidative damage by H2O2. The application of RDI strategies, in addition to allowing irrigation water saving, led to obtaining pistachios with the same or even better biofunctional characteristics as compared to fully irrigated pistachios.

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Effect οf Genotype and Growing Year on the Nutritional, Phytochemical, and Antioxidant Properties of Industrial Hemp (Cannabis sativa L.) Seeds

Antioxidants ◽

10.3390/antiox8100491 ◽

2019 ◽

Vol 8 (10) ◽

pp. 491 ◽

Cited By ~ 14

Author(s):

Maria Irakli ◽

Eleni Tsaliki ◽

Apostolos Kalivas ◽

Fotios Kleisiaris ◽

Eirini Sarrou ◽

...

Keyword(s):

High Performance ◽

Cannabis Sativa ◽

Antioxidant Properties ◽

Major Effect ◽

Total Carotenoids ◽

Antioxidant Power ◽

Phenolic Profiles ◽

Ferric Reducing Antioxidant Power ◽

Industrial Hemp ◽

Phytochemical Components

Cannabis sativa L. seeds have been an important source of protein, oil, and dietary fiber for human and animals. Currently, there is a growing interest in the commercial products of these seeds, which are recognized as a legitimate source of medicaments, cosmeceuticals, and nutraceuticals. The objective of this study was to investigate the nutritional, phytochemical composition, and antioxidant properties of seeds from seven hemp cultivars grown in Greece for three consecutive years. All the measured parameters strongly varied under the influence of growing year and genotype. In particular, protein, oil, and carbohydrates’ content of hemp seeds as well as fatty acids’ composition were mainly affected by genotype, whereas the growing year had a major effect on phytochemical components and antioxidant activity, which was determined by the 2,2′-azino-bis (3-ethylbenzthiazoline sulfonate) (ABTS) and ferric-reducing antioxidant power (FRAP) assays. Moreover, a predominant effect of the year was observed for phenolic profiles as determined by high-performance liquid chromatography and total carotenoids’ content. This study suggests that hemp seeds could be a promising food crop as a result of their high nutritive traits and antioxidant potential. A comparison of the studied cultivars, showed that Finola seeds had the highest oil and protein contents and, thus, appeared to be the most promising cultivar for cultivation in Greece.

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Impact of Sodium Nitrite Reduction on Lipid Oxidation and Antioxidant Properties of Cooked Meat Products

Antioxidants ◽

10.3390/antiox9010009 ◽

2019 ◽

Vol 9 (1) ◽

pp. 9 ◽

Cited By ~ 4

Author(s):

Małgorzata Karwowska ◽

Anna Kononiuk ◽

Karolina M. Wójciak

Keyword(s):

Lipid Oxidation ◽

Sodium Nitrite ◽

Antioxidant Properties ◽

Meat Products ◽

Thiobarbituric Acid ◽

Nitrite Reduction ◽

Antioxidant Power ◽

Ferric Reducing Antioxidant Power ◽

Cooked Meat ◽

Cooked Meat Products

Oxidation processes are responsible for reduction of the sensory and nutritional quality of meat and meat products, thus affecting consumer acceptance. The use of sodium nitrite in meat processing is an important factor limiting these changes. Therefore, eliminating this substance from the recipe of meat products to increase their nutritional value is not an easy challenge. The aim of this study was to determine the effect of sodium nitrite reduction on the lipid oxidation (peroxide value, thiobarbituric acid reactive substances), and color parameters (CIE L*a*b*, total heme pigment and heme iron, nitrosylmyoglobin) in cooked meat products during 15 days of vacuum storage. The antioxidant properties of products and isolated peptides (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS•), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric-reducing antioxidant power) were also evaluated. Experimental material included four different sample groups of cooked meat products produced with various percentages of sodium nitrite (0, 50, 100, and 150 mg kg−1). It was shown that the sodium nitrite dose had no statistically significant effect on lightness (L*) and redness (a*) values, as well as nitrosylmyoglobin content. Along with decreasing the share of sodium nitrite in the samples, the thiobarbituric acid reactive substances (TBARS) value increased from 0.43 mg kg−1 for samples with 150 mg kg−1 at day 0 to 3.14 mg kg−1 for samples without nitrite at day 15. The total ABTS scavenging capacity of the cooked meat samples was in the range 2.48 to 4.31 eqv. mM Trolox per g of product throughout the entire storage period. During storage, the ferric-reducing antioxidant power of samples with nitrite increased from 0.25 to 0.38 eqv. mg/mL ascorbic acid per g of product. In conclusion, reduction of nitrite to the level of 50 mg kg−1 seemed to be comparable with the traditional use of nitrite in meat products in terms of the physicochemical properties and properties related to lipid oxidation, as well as total antioxidant capacity and peptide antioxidant capacity.

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