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Artigos de revistas sobre o assunto "Phenolics and antioxidant capacity"
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Gan, Ren-You, Wing-Yee Lui, Ming-Fu Wang, Harold Corke e Zhong-Quan Sui. "Accumulation of solvent-soluble and solvent-insoluble antioxidant phenolics in edible bean sprouts: implication of germination". Functional Foods in Health and Disease 6, n.º 8 (30 de agosto de 2016): 519. http://dx.doi.org/10.31989/ffhd.v6i8.273.
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Background: Edible bean sprouts are popular fresh vegetables widely recognized for their nutritional quality. However, while their antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble extracts has not been systematically evaluated. Methods: The antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble fractions of 12 cultivars of edible bean sprouts were evaluated, and relationships of antioxidant capacity and total phenolic content were also analyzed. Results: Sprouts demonstrated a wide range of antioxidant capacity and total phenolic content, with lower but substantial antioxidant capacity and total phenolic content in the solvent-insoluble fractions. Highest levels were found in the green mung bean sprout. Phenolic compounds, such as catechin, ellagic acid, ferulic acid, gallic acid and p-coumaric acid were widely detected in these sprouts. Additionally, a positive correlation was discovered between antioxidant capacity and total phenolic content in these edible bean sprouts. Conclusions: Germination generally resulted in the accumulation of antioxidant phenolics in the most edible bean sprouts. Edible bean sprouts with high antioxidant phenolics can be valuable natural sources of dietary antioxidants for the prevention of oxidative stress-related chronic diseases. Keywords: Bean sprout, Germination, Antioxidant capacity, Radical scavenging capacity, Phenolic composition, Solvent-insoluble phenolics
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Tuyen, Phung Thi, Do Tan Khang, Pham Thi Thu Ha, Tran Ngoc Hai, Abdelnaser Abdelghany Elzaawely e Tran Dang Xuan. "Antioxidant Capacity and Phenolic Contents of Three Quercus Species". International Letters of Natural Sciences 54 (maio de 2016): 85–99. http://dx.doi.org/10.18052/www.scipress.com/ilns.54.85.
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The antioxidant capability and phenolic contents of ethanol extracts (free phenolics) and ethyl acetate extracts (bound phenolics) of three Quercus species were estimated in this work. The antioxidant activities were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical, reducing power and b-carotene bleaching methods. HPLC was employed to detect major phenolic acids. The leaf extract of Q. salicina contained maximum total phenolics while the highest total flavonoid content was found in the leaf extract of Q. serrata. The antioxidant activities varied among three species. Bark extract of Q. salicina was the most potential and it was closed to levels of the standard antioxidative dibutyl hydroxytoluene (BHT). The bark extract of Q. serrata also showed promising antioxidant activities despite their eminence was negligibly lower than Q. salicina. Stronger antioxidant activities of free phenolics than those of the bound phenolics may be attributed to higher quantities of free phenolics in the barks of Quercus species, however total flavonoids may not contribute a critical role. By HPLC analysis, thirteen phenolic acids were detected in the leaf and bark extracts. Of them, Q. salicina showed maximum in number (ten compounds) and quantities of detected phenolic acids. Ellagic, chlorogenic and benzoic acids were dominant in Quercus species. Findings of this study revealed that leaves and barks of three Quercus species are rich source of antioxidants, and Q.salicina is the most promising and should be elaborated to exploit its pharmaceutical properties.
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Howell, A., W. Kalt, J. C. Duy, C. F. Forney e J. E. McDonald. "Horticultural Factors Affecting Antioxidant Capacity of Blueberries and other Small Fruit". HortTechnology 11, n.º 4 (janeiro de 2001): 523–28. http://dx.doi.org/10.21273/horttech.11.4.523.
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It is now widely held that the antioxidants contained in fruit and vegetables can provide protection against certain human degenerative conditions that are associated with oxygen free radical damage. This view is supported by epidemiological, in vitro, and more recently, in vivo evidence. Phenolics (polyphenolics) contribute substantially to the antioxidant complement of many small fruit species whose ripe fruit are red, purple or blue in color. Fruit containing high levels of phenolic antioxidants would be attractive to health conscious consumers, therefore optimization of production and processing factors affecting small fruit antioxidant capacity is desirable. In many small fruit crops, antioxidant activity [measured as oxygen radical absorbing capacity (ORAC)] is positively correlated with their content of anthocyanins and total phenolics. Genera, species, and genotypes vary with respect to phenolic content. Both annual and geographical factors appear to influence ORAC, although many years of study are needed to distinguish these effects from other biotic and abiotic factors that influence fruit phenolic content. Antioxidant capacity due to phenolics is decreased by food processing practices, such as heat or aeration.
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Ye, Lingxu, Sumei Zhou, Liya Liu, Lei Liu, Daniel L. E. Waters, Kui Zhong, Xianrong Zhou, Xiaojun Ma e Xingxun Liu. "Phenolic Compounds and Antioxidant Capacity of Brown Rice in China". International Journal of Food Engineering 12, n.º 6 (1 de agosto de 2016): 537–46. http://dx.doi.org/10.1515/ijfe-2015-0346.
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Abstract The phenolic compounds and antioxidant activity of brown rice are well known but the extent to which phenolics and antioxidant activity varies within rice (Oryza sativa) is not known. This study evaluated the natural variation of phenolic compounds in brown rice of the major cultivars currently grown in China. Free phenolics were extracted with chilled methanol, while bound phenolics were released and extracted by alkaline hydrolysis. There were significant differences in phenolic and flavonoid content between these cultivars and significant differences in bound and total phenolics between japonica and indica samples. Ferulic and p-coumaric acids were the major phenolic acids and existed in both free and bound forms, with the bound form of ferulic acid being a dominant phenolic compound in brown rice. Phenolic compounds were the major contributor to the antioxidant capacity of brown rice and bound phenolics contributed more than free phenolics as estimated using ABTS+ radical scavenging method. This study provides additional information on brown rice from japonica and indica subspecies and may assist in retaining or increasing phenolics and antioxidant activity in rice.
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Tuyen, Phung Thi, Do Tan Khang, Pham Thi Thu Ha, Tran Ngoc Hai, Abdelnaser Abdelghany Elzaawely e Tran Dang Xuan. "Antioxidant Capacity and Phenolic Contents of Three <i>Quercus</i> Species". International Letters of Natural Sciences 54 (11 de maio de 2016): 85–99. http://dx.doi.org/10.56431/p-u66fhw.
Texto completo da fonteResumo:
The antioxidant capability and phenolic contents of ethanol extracts (free phenolics) and ethyl acetate extracts (bound phenolics) of three Quercus species were estimated in this work. The antioxidant activities were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical, reducing power and b-carotene bleaching methods. HPLC was employed to detect major phenolic acids. The leaf extract of Q. salicina contained maximum total phenolics while the highest total flavonoid content was found in the leaf extract of Q. serrata. The antioxidant activities varied among three species. Bark extract of Q. salicina was the most potential and it was closed to levels of the standard antioxidative dibutyl hydroxytoluene (BHT). The bark extract of Q. serrata also showed promising antioxidant activities despite their eminence was negligibly lower than Q. salicina. Stronger antioxidant activities of free phenolics than those of the bound phenolics may be attributed to higher quantities of free phenolics in the barks of Quercus species, however total flavonoids may not contribute a critical role. By HPLC analysis, thirteen phenolic acids were detected in the leaf and bark extracts. Of them, Q. salicina showed maximum in number (ten compounds) and quantities of detected phenolic acids. Ellagic, chlorogenic and benzoic acids were dominant in Quercus species. Findings of this study revealed that leaves and barks of three Quercus species are rich source of antioxidants, and Q.salicina is the most promising and should be elaborated to exploit its pharmaceutical properties.
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Wu, Shutian, Runhong Mo, Ruohui Wang, Qingyang Li, Danyu Shen e Yihua Liu. "Identification of Key Antioxidants of Free, Esterified, and Bound Phenolics in Walnut Kernel and Skin". Foods 12, n.º 4 (15 de fevereiro de 2023): 825. http://dx.doi.org/10.3390/foods12040825.
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Walnut is a natural source of antioxidants. Its antioxidant capacity is determined by the distribution and composition of phenolics. The key phenolic antioxidants in various forms (free, esterified, and bound) in walnut kernel (particularly seed skin) are unknown. The phenolic compounds in twelve walnut cultivars were analyzed using ultra-performance liquid chromatography coupled with a triple quadrupole mass spectrometer in this study. A boosted regression tree analysis was used to identify the key antioxidants. Ellagic acid, gallic acid, catechin, ferulic acid, and epicatechin were abundant in the kernel and skin. The majority of phenolic acids were widely distributed in the free, esterified, and bound forms in the kernel but more concentrated in bound phenolics in the skin. The total phenolic levels of the three forms were positively correlated with antioxidant activities (R = 0.76–0.94, p < 0.05). Ellagic acid was the most important antioxidant in the kernel, accounting for more than 20%, 40%, and 15% of antioxidants, respectively. Caffeic acid was responsible for up to 25% of free phenolics and 40% of esterified phenolics in the skin. The differences in the antioxidant activity between the cultivars were explained by the total phenolics and key antioxidants. The identification of key antioxidants is critical for new walnut industrial applications and functional food design in food chemistry.
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Tusevski, Oliver, Aneta Kostovska, Ana Iloska, Ljubica Trajkovska e Sonja Simic. "Phenolic production and antioxidant properties of some Macedonian medicinal plants". Open Life Sciences 9, n.º 9 (1 de setembro de 2014): 888–900. http://dx.doi.org/10.2478/s11535-014-0322-1.
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AbstractInvestigations have been made to study the production of phenolic compounds (total phenolics, flavonoids and phenylpropanoids) and total antioxidant capacity in 27 Macedonian traditional medicinal plants to improve its potential as a source of natural antioxidants. Antioxidant potential of plant extracts was analyzed by five different assays: cupric reducing antioxidant capacity (CUPRAC), phosphomolybdenum method (PM), reducing power (RP), 2,2-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS·+) radical scavenging activity. Origanum vulgare extract consistently exhibited the highest content of phenolic compounds and the strongest antioxidant capacity based on the tests performed, and can be proposed as a promising source of natural antioxidants. Melissa officinalis and Salvia ringens were also identified as valuable sources of antioxidant compounds. A positive linear correlation between antioxidant activity and total phenolics, flavonoids and phenylpropanoids indicates that these compounds are likely to be the main antioxidants contributing to the observed activities of evaluated plants. These findings suggest that the medicinal plants studied in this paper are good sources of bioactive compounds for the food and pharmaceutical industries.
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Orphanides, A., V. Goulas e V. Gekas. "Effect of drying method on the phenolic content and antioxidant capacity of spearmint". Czech Journal of Food Sciences 31, No. 5 (9 de setembro de 2013): 509–13. http://dx.doi.org/10.17221/526/2012-cjfs.
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The changes in total phenolics, hydroxycinammic acid derivatives, and antioxidant properties of spearmint after five drying treatments (convection oven drying, freeze-drying, microwave drying, and air drying with the sun exposure and without the sun exposure) were investigated. Phenolic composition of dried spearmint was analysed by spectrophotometric assays, while DPPH radical scavenging activity and Ferric reducing/Antioxidant power (FRAP) assay was used to measure the antioxidant properties. The results showed that freeze drying produced dried spearmint that had the highest total phenolics (34.6 ± 1.9 mg/g) content and the most potent antioxidant capacity (126.2 ± 0.4 mg/g for FRAP and 88.1 ± 5.9 mg/g for DPPH, respectively). On the other hand, spearmint that was dried by convection oven and microwave drying presented the lowest amount of phenolic compounds (12.0 ± 0.5 mg/g) and antioxidant potency (49.3 ± 0.7 mg/g for FRAP and 26.9 ± 1.6 mg/g for DPPH, respectively). This might be attributed to the fact that heat-sensitive phenolics were degraded or biotransformed at high temperatures. The loss of phenolic compounds and antioxidant activity reached up to 60% compared to freeze drying.
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Miletić, N., B. Popović, O. Mitrović, M. Kandić e A. Leposavić. "Phenolic compounds and antioxidant capacity of dried and candied fruits commonly consumed in Serbia ". Czech Journal of Food Sciences 32, No. 4 (29 de julho de 2014): 360–98. http://dx.doi.org/10.17221/166/2013-cjfs.
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Dried fruits (plums, apricots, figs, grapes (amber light and amber dark), chokeberries, and bilberries), and candied fruits (cranberries, cherries, and dates), commercially available and commonly consumed in Serbia, were purchased on the same day in local groceries, and analysed for total phenolics and antioxidant capacity. Total phenolics contents of dried and candied fruits were as follows: dried chokeberries > dried bilberries > dried plums > candied cherries, dried apricot > dried grapes (amber light) > candied cranberries, dried figs, dried grapes (amber dark), candied dates. The order of antioxidant capacity showed a very similar trend as the total phenolics content. Significant correlation between total phenolics content and antioxidant capacity (R = 0.9931, P < 0.001) was observed. Using HPLC, the identification of selected phenolic compounds was carried out. Most of these compounds were the most abundant in dried chokeberries and dried bilberries, and consequently the highest antioxidant capacity was found in these dried fruit species.
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Sawicki, Tomasz, Monika Jabłońska, Anna Danielewicz e Katarzyna E. Przybyłowicz. "Phenolic Compounds Profile and Antioxidant Capacity of Plant-Based Protein Supplements". Molecules 29, n.º 9 (2 de maio de 2024): 2101. http://dx.doi.org/10.3390/molecules29092101.
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The study aimed to determine the phenolic content and antioxidant capacity of five protein supplements of plant origin. The content and profile of phenolics were determined using the UHPLC-DAD-MS method, while antioxidant capacity (ABTS and DPPH assays) and total phenolic content (TPC) were evaluated using spectrophotometric tests. In the analyzed proteins, twenty-five polyphenols were detected, including eleven phenolic acids, thirteen flavonoids, and one ellagitannin. Hemp protein revealed the highest individual phenolics content and TPC value (1620 μg/g and 1.79 mg GAE/g, respectively). Also, hemp protein showed the highest antioxidant activity determined via ABTS (9.37 μmol TE/g) and DPPH (9.01 μmol TE/g) assays. The contents of p-coumaric acid, m-coumaric acid, kaempferol, rutin, isorhamnetin-3-O-rutinoside, kaempferol-3-O-rutinoside, and TPC value were significantly correlated with antioxidant activity assays. Our findings indicate that plant-based protein supplements are a valuable source of phenols and can also be used in research related to precision medicine, nutrigenetics, and nutrigenomics. This will benefit future health promotion and personalized nutrition in the prevention of chronic diseases.
Teses / dissertações sobre o assunto "Phenolics and antioxidant capacity"
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Rózek, Aleksandra. "Direct formulation of solid foods with grape phenolics: studies on mass transfer and antioxidant capacity". Doctoral thesis, Universitat Rovira i Virgili, 2009. http://hdl.handle.net/10803/8568.
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El enriquecimiento de frutas y verduras con minerales, vitaminas o compuestos fisiológicamente activos de los que se deriven efectos potencialmente beneficiosos para la salud y la prevención de enfermedades, puede resultar crucial en el desarrollo de nuevos alimentos funcionales. Recientemente, los extractos de semillas y piel de uva se han convertido en un complemento nutricional muy extendido debido a su elevado contenido en compuestos fenólicos. Estos compuestos han mostrado ser altamente biodisponibles además de conferir excelentes beneficios para la salud. En los últimos años, la aplicación del tratamiento osmótico (TO) se ha propuesto como un método eficaz de introducir en el alimento cantidades controladas de los solutos presentes en la solución osmótica, deshidratándolo parcialmente.Un rango de alimentos sólidos enriquecidos con compuestos fenólicos de uva de diferentes fuentes fueron formulados mediante TO. Parámetros de proceso como la fuente y concentración de los compuestos fenólicos, la naturaleza y concentración de soluto osmo-activo en la solución osmótica, y la estructura del alimento fueron investigados. Además el efecto de un post-tratamiento tal como el secado convectivo en la estabilidad y la capacidad antioxidante de fenólicos de uva impregnados en el alimento tratado osmóticamente fue estudiado.
Los resultados confirman que TO es la tecnología adecuada para explotación de geles alimenticios, frutas y verduras como matrices en las cuales los ingredientes funcionales pueden ser incorporados con éxito para proporcionar productos funcionales de humedad intermedia. El mosto concentrado de uva y extractos comerciales de semilla de uva y orujo de uva blanca fueron utilizados como suplementos nutricionales. Su alto contenido en compuestos fenólicos los hacen una fuente ideal de antioxidantes naturales.
The enrichment of fruits and vegetables with minerals, vitamins or physiologically active compounds that have potential benefits in terms of health maintenance and disease prevention may be a crucial way of developing new functional foods. Recently, extracts from grape seeds and skins have become a widespread nutritional supplement, because of their high content of phenolic compounds. These compounds have been shown to be highly bioavailable and to provide excellent health benefits. In the last few years, it has been suggested that osmotic treatment (OT) is a useful way of introducing controlled quantities of solution solutes into food and partially dehydrating it at the same time.
A range of solid foods enriched with grape phenolics from several sources were formulated using OT. Process parameters such as the source and concentration of the phenolic compounds, the nature and concentration of the osmo-active solute in the osmotic solution, and the food structure were investigated. Moreover the effect of a post treatment such as convective air drying on the stability and antioxidant properties of the grape phenolics infused in the osmo-treated food was studied.
The results confirm that OT is a suitable technology for the exploitation of jelly foods, fruits and vegetables as matrices into which functional ingredients can be successfully incorporated to provide novel functional products of intermediate moisture. Concentrated red grape must and commercial grape seed and white grape marc extracts were successfully used as nutritional supplements. Their high content in phenolic compounds makes them ideal sources of natural antioxidants.
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Jelénková, Zuzana. "Stanovení aktivních látek v medu". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216227.
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This diploma thesis was focused on biologically active compounds determination. 26 samples of honey, one sample of propolis and one sample of royal jelly were analyzed. Honey were harvested in year 2006 and 2007 and bought in retail chain, special shops and directly from bee-keeper. Samples were analyzed by titration, spectrofotometry, LC/MS and RP-HPLC methods. The study was focused on analysis of antioxidants. Followed groups of antioxidants were determined: flavonoids, catechins, carotenoids, vitamins E, C, A. Authenticity of quality was determined by hydroxymethylfurfural analysis. Average values of total antioxidant capacity ranged (12.75-137.49) mmol .100 g-1. Average values of total phenolic ranged (8.51-61.34) mg .100 g-1 and average values of total flavonoids ranged (0.75-6.04) mg .100 g-1. Honey samples contained (41.83-585.10) g .100 g-1 of rutin, (9.30-313.40) g .100 g-1 of myricetin, (6.5-171.90) g .100 g-1 of luteolin, (3.19-436.37) g .100 g-1 of quercetin, (2.10-242.66) g .100 g-1 of apigenin, (0.15-105.12) g .100 g-1 of caempferol and (0.07-17.52) mg .100 g-1 of naringenin. From group of catechins there were measured (5.98-310) g .100 g-1 of catechin, (17.77-486.29) g .100 g-1 of epicatechin, (0.18-64.90) g .100 g-1 of catechin gallate and (0.59-140.56) g .100 g-1 of epicatechin gallate. From lipophilic compounds the most abundant in honey samples was tocopherol, its value ranged (29.20-8531.17) g .100 g-1. Content of ascorbic acid ranged (0.65-4.65) mg .100 g-1. Content of hydroxymethyl.furfural. ranged (0.26-4.06) mg .100 g-1. By LC/MS method luteolin, naringenin, protocatechin acid, coffee acid and p-cumaric acid in honeydew were detected and, furthermore, kyanidin and pinocembrin in floral honey were found. Mono-floral honey contained biologically active compounds the most, imperceptibly less contained multi-floral honey and honeydew honey. Acacia honey contained the lowest amount of biologically active compounds.
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Konda, Paula Becker Pertuzatti 1984. "Phenolic compounds and antioxidant capacity in blueberry species produced in Brazil = Compostos fenólicos e capacidade antioxidante em espécies de mirtilo produzidas no Brasil". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254319.
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Orientadores: Helena Teixeira Godoy, Isidro Hermosín-GutiérrezTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-25T09:19:08Z (GMT). No. of bitstreams: 1 Konda_PaulaBeckerPertuzatti_D.pdf: 1709064 bytes, checksum: 32eff0f96e85c62585e501c2d1fa6158 (MD5) Previous issue date: 2014
Resumo: A produção de mirtilos iniciou-se no Brasil na década de 80 e a comercialização da fruta na década de 90. Apesar de ser um cultivo novo no país, observa-se que a cada dia o fruto tem ganhado mais espaço, o que fez com que aumentasse o número de produtores e cultivares comercializadas. Deste modo, o presente trabalho teve por objetivo analisar cultivares comercializadas por diferentes produtores, quanto a sua capacidade antioxidante e teor de antocianinas, flavonóis e ácido clorogênico. Foram elaborados um extrato hidrofílico e um extrato lipofílico para as trinta amostras, pertencentes a 10 cultivares de mirtilo da safra de 2010/2011 e 2011/2012 de quatro diferentes produtores e sua capacidade antioxidante foi medida pelos métodos de ABTS, FRAP, ORAC e ?-caroteno/ácido linoleico e correlacionadas com o teor de antocianinas, compostos fenólicos e carotenoides totais. Os extratos hidrofílicos apresentaram uma maior correlação positiva, entre o teor de compostos bioativos e os métodos de capacidade antioxidante, do que os extratos lipofílicos, os quais se diferenciaram na análise de componentes principais de acordo com o grupo que pertenciam, Rabbiteye ou Highbush. Enquanto, nos extratos hidrofílicos houve uma separação quanto aos produtores e safras analisados. Através de HPLC-DAD-ESI-MSn, foi determinado o conteúdo de flavonóis, ácido clorogênico e antocianinas nos mirtilos e observou-se que todas as cultivares apresentam grandes quantidades de ácido clorogênico. Em média os valores oscilaram entre 0,2 e 4,0 g / kg de fruta seca, também foram encontrados quarenta e quatro flavonóis, sendo os majoritários no grupo Highbush, quercetina 3-galactosídeo, enquanto os frutos do grupo Rabbiteye apresentam em maior quantidade quercetina 3-rhamnosídeo e quercetina 3-glucuronídeo. Dentre os flavonóis identificados, encontrou-se quercetina-3-O-[4¿¿-(3-hidroxi-3-metilglutaroil)]-?-rhamnose, pela primeira vez em mirtilos, sendo este composto exclusivo das cultivares Florida e Powderblue. Além deste composto, derivados da isorhamnetina, siringetina e laricitrina, foram encontrados pela primeira vez no mirtilo. Quanto as antocianinas foram encontradas trinta e seis, havendo também um diferenciação na antocianina majoritária, de acordo com o grupo de mirtilo. As cultivares do grupo Rabbiteye apresentaram maiores quantidades de cianidina 3-galactosídeo, enquanto as cultivares do grupo Highbush possuem maiores quantidades de arabinosídeos de delfinidina e malvidina
Abstract: The blueberry production began in Brazil at 80¿s and your commercialization at 90¿s, despite being a new crop in the country, it is observed that each day the fruit has been gaining ground, which led to an increase the number of producers and cultivars marketed. Due to this, the objective of this study was to analyze different cultivars produced by different producers, for antioxidant capacity and anthocyanins, flavonols and chlorogenic acid levels. Hydrophilic and lipophilic extracts were prepared for thirty samples from 10 blueberry cultivars in two harvests, 2010/2011 and 2011/2012, and four different producers. Antioxidant capacity was measured by the ABTS, FRAP, ORAC and ?-carotene/linoleate methods and correlated to the amounts of carotenoids, total phenolics and anthocyanins. The hydrophilic extracts showed a higher positive correlation, between the amounts of bioactive compounds and the antioxidant capacity, compared to lipophilic extracts, which differentiated by principal component analysis according to whether they were Rabbiteye or Highbush. Already, in the hydrophilic extracts there was a separation by producers and harvest seasons. The flavonols, chlorogenic acid and anthocyanins content of blueberries were determined by HPLC-DAD-ESI-MSn and we observed that all cultivars showed high concentration of chlorogenic acid, average values ranged between 0.2 e 4.0 g / kg dry matter, were also found forty four flavonols, and the main in Highbush blueberry was quercetin 3-galactosídeo, while the fruits of Rabbiteye group presented in high proportions quercetin 3-ramnosídeo and quercetin 3-glucuronide. Amoung the flavonols identified, quercetin-3-O-[4¿¿-(3-hydroxy-3-methylglutaroyl)]-?-rhamnose was found, for the first time in blueberries, it was detected only in Florida and Powderblue cultivars, where was a major flavonol. Apart from this compound, isorhamnetin, siringetin and laricitrin derivatives, were also reported for the first time in blueberries. Were identified 36 anthocyanins, there were also differentiation in the majority anthocyanin according to the blueberry group. The cultivars of Rabbiteye group showed higher amounts of cyanidin 3-galactoside than cultivars of Highbush group, while Highbush cultivars have more 3-O-arabinoside of delphinidin and malvidin
Doutorado
Ciência de Alimentos
Doutora em Ciência de Alimentos
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Soyler, Ulviye Betul. "Characterization And Analysis Of The Antioxidant Capacity Of Functional Phenolics Oxidized By Scytalidium Thermophilum Catalase Phenol Oxidase (catpo)". Thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615049/index.pdf.
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Scytalidium thermophilum is a termophilic fungus that effectively produces the
extracellular enzyme catalase phenol oxidase (CATPO). The enzyme is distinct
among catalases with its bifunctionality of oxidising phenolic compounds in the
absence of H2O2. CATPO is capable of oxidizing catechol, chlorogenic acid,
caffeic acid and catechin which are ortho &ndashdiphenolic compounds. Diphenolic compounds are known as strong antioxidants. Catalase is one of the important antioxidant enzymes. Therefore, in this thesis the effect of CATPO on the final antioxidant capacity of the oxidized products was analysed. Antioxidant capacity measurements of oxidized and unreacted phenolic compounds were done using the two widely used methods TEAC and FRAP. CATPO oxidized catechol showed 2.4 fold increase when compared to its nonoxidized form, which was highest among others. Catechol was followed by caffeic acid, chlorogenic acid, and catechin. This finding is new to the literature and may be of importance to the antioxidant mechanism of organisms. Results have also shown that the most well known phenol oxidases, laccase and tyrosinase, do not result in such high increases in antioxidant capacity upon oxidation of the substrates tested. Due to this finding, as a possible means of applying CATPO to increase the antioxidant capacity of products daily consumed, tea was selected. Tea is the second most consumed beverage after water and it is known to possess high amounts of flavanols. Green tea is rich in catechins whereas black tea is a rich source of theaflavins and thearubigins. Fermentation is a critical process for production of good quality tea and is the key step differing between green and black tea production. During this process phenol oxidases catalyze the oxidation of polyphenolic compounds present in tea leaves to their corresponding o-quinones. Utilization of CATPO in tea samples resulted in an increase in antioxidant capacity and its effect was enhanced by an increase in brewing time. Interestingly, the addition of sugar decreased antioxidant capacity. Laccase and tyrosinase were ineffective in increasing the antioxidant capacity of tea samples.
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Salabak, Dane E. "Determination of Sensory Characteristics and Antioxidant Capacity of Pawpaw Pulp During Frozen Storage". Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1353528036.
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Vicente, Silvio José Valadão. "Caracterização antioxidante do café (Coffea arabica, L.) e efeitos da sua administração oral em ratos". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/6/6133/tde-10092009-092017/.
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Introdução: Um dos fatores de risco para doenças crônicas não-transmissíveis é o excesso de espécies reativas causado pelo estresse oxidativo. Ácidos fenólicos atuam na defesa contra estas espécies, agindo como antioxidantes e como fatores de transcrição para as enzimas antioxidantes fase II (superóxido dismutase, catalase e glutationa peroxidase). Vários alimentos possuem ácidos fenólicos na composição porém o café se destaca pelo alto conteúdo dos mesmos e por ser consumido mundialmente. Objetivos: a) Comparar a capacidade antioxidante e a estabilidade dos cafés regular e descafeinado ao longo de seis meses; b) Verificar o tempo de resposta e possíveis correlações dose-resposta do efeito antioxidante em ratos após dose única de café; c) Avaliar o efeito antioxidante e possíveis danos hepáticos em ratos submetidos a doses repetidas de café durante 30 dias. Métodos: na etapa in vitro, foram analisados os compostos fenólicos totais, os principais ácidos fenólicos, a capacidade antioxidante (ORAC e DPPH) e a estabilidade destes parâmetros nos cafés regular e descafeinado durante seis meses. Na etapa in vivo, foram utilizados ratos machos Wistar, sendo dosadas as enzimas fase II e o ORAC, além do exame histopatológico e biomarcadores. Resultados: o café regular apresentou capacidade antioxidante inicial superior ao descafeinado com compostos fenólicos totais iguais e maiores teores de ácido fenólicos (15,3% cafêico, 17,0% p-cumárico e 38,1% ferúlico), ORAC (20,8%) e DPPH (3,9%). Após 6 meses, as amostras fechadas à vácuo praticamente não sofreram perdas, as abertas mantidas a 4oC apresentaram perdas medianas (9,6% fenólicos totais, 4,5-8,2% ácidos fenólicos, 21,3-21,6% ORAC e 2,8-3,2% DPPH) e as mantidas abertas a 20oC exibiram perdas elevadas (14,4-19,8% fenólicos totais, 11,9-19,6% ácidos fenólicos, 38,8-49,9% ORAC e 2,1- 3,8% DPPH). Após dose única de café para os ratos, o tempo de resposta máxima para as enzimas fase II e ORAC foi de 1 hora, com significância estatística para as enzimas (p=0,015 SOD e Cat, p=0,007 GPx e p=0,403 ORAC). Após diferentes doses, foram obtidas correlações dose-resposta positivas e com significância estatística para as enzimas (p=0,050 SOD, p=0,033 Cat, p=0,008 GPx e p=0,113 ORAC). Após doses repetidas (30 dias), a atividade das enzimas antioxidantes e o ORAC apresentaram grandes aumentos (74,8% SOD, 59,4% Cat, 135,2% GPx e 25,1% ORAC), todos estatisticamente significativos (p<0,001 para todos). O tecido hepático e os biomarcadores não apresentaram alterações em relação ao grupo controle. Conclusões: o café regular apresentou capacidade antioxidante superior ao descafeinado, os dois cafés não apresentaram perdas das características antioxidantes após seis meses se mantidos selados à vácuo e a administração oral de café regular aumentou a condição antioxidante dos ratos de maneira significativa, sem causar danos hepáticos.Introduction: A risk factor for several degenerative diseases is the excess of reactive species caused by oxidative stress. Phenolic acids share in the defense against those species, acting as antioxidants and as transcriptional factors for the phase II antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase). Several foods have phenolic acids in their composition but coffee stands out by the high contend of them and to be consumed worldwide. Objectives: a) Compare the antioxidant capacity and the stability of regular and decaffeinated coffees along six months; b) Verify the time of response and possible dose-response correlations of antioxidant effect in rats after a single dose of coffee; c) Evaluate the antioxidant effect and possible hepatic damages in rats submitted to repetitive doses along 30 days. Methods: in the in vitro step, it was analyzed the total phenolic compounds, main phenolic acids, antioxidant capacity (ORAC and DPPH) and the stability of these parameters in regular and decaffeinated coffees along six months. In the in vivo step, it was used male Wistar rats, being analyzed phase II enzymes and ORAC, besides histopathologic examination and biomarkers. Results: regular coffee presented a higher initial antioxidant capacity than decaffeinated coffee with equal total phenolic compounds and higher contend of phenolic acids (15.3% caffeic, 17.0% p-coumaric and 38.1% ferulic), ORAC (20.8%) and DPPH (3.9%). After six months, closed samples kept under vacuum practically did not show any losses, opened samples kept at 4oC presented regular losses (9.6% total phenolic compounds, 4.5-8.2% phenolic acids, 21.3-21.6% ORAC and 2.8-3.2% DPPH) and opened samples kept at 20oC exhibited big losses (14.4-19.8% total phenolic compounds, 11.9-19.6% phenolic acids, 38.8-49.9% ORAC and 2.1-3.8% DPPH). After a single dose of coffee for rats, time for maximum response of phase II enzymes and ORAC was 1 hour, with statistic significance for enzymes (p=0.015 SOD and Cat, p=0.007 GPx and p=0.403 ORAC). After different doses, it was obtained positive dose-response correlations, with statistic significance for enzymes (p=0.050 SOD, p=0.033 Cat, p=0.008 GPx and p=0.113 ORAC). After repetitive doses (30 days), the activity of antioxidant enzymes and ORAC showed big increases (74.8% SOD, 59.4% Cat, 135.2% GPx and 25.1% ORAC), all with statistic significance (p<0.001 for all). Hepatic tissue and biomarkers did not show any change compared to control group. Conclusions: regular coffee presented higher antioxidant capacity than decaffeinated coffee, both coffees did not show any antioxidant losses after six months if kept sealed under vacuum and the oral administration of regular coffee increased significantly the antioxidant condition of rats, without any hepatic damages.
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Venter, Alet. "Phenolic composition and in vitro antioxidant capacity of South African plums (Prunus salicina Lindl.)". Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80199.
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Thesis (MSc Food Sc)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Phenolic compounds of the types present in plums have been found to exhibit health-promoting properties associated with their antioxidant capacity. Fruits with red peel and/or flesh are thus sought-after for their high antioxidant levels. In the current study South African plum (Prunus salicina Lindl.) cultivars and selections, harvested during two consecutive fruit seasons, were compared in terms of general fruit attributes (colour, firmness, °Brix, pH, titratable acidity), phenolic composition and antioxidant capacity. The effect of season and a commercial cold storage and ripening regime was also investigated. A reversed-phase high-performance liquid chromatography-diode-array-fluorescence detection (HPLC-DAD-FLD) method suitable for use with mass spectrometry (MS) detection, was optimised for separation and identification of phenolic compounds from four phenolic groups (phenolic acids, anthocyanins, flavan-3-ols and flavonols) in six South African plum cultivars and five selections. Parameters that were optimised include the mobile phases, analysis temperature and gradient program. Good stability, linearity and inter- and intra-day precision were obtained. Identification of compounds was based on comparison of retention times, UV-Vis spectra and mass fragments with available authentic phenolic standards and/or literature data. The optimised method allowed identification or tentative identification of twenty-four phenolic compounds, including cyanidin-3-O-glycosides, quercetin glycosides, monomeric, dimeric and trimeric flavan-3-ols, and hydroxycinnamic acids. An on-line ABTS•+ (2,2ʹ-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid)) antioxidant assay, performed for qualitative evaluation of the antioxidant response of individual phenolic compounds, indicated the flavan-3-ols as major antioxidants in plums. Eighteen phenolic compounds were quantified, including anthocyanins and flavonol glycosides, flavan-3-ols (monomers and dimers) and hydroxycinnamic acids. Phenolic composition differed greatly between cultivars and selections. Cyanidin-3-O-glucoside was the predominant anthocyanin in plums with red peel and/or flesh, followed by cyanidin-3-O-rutinoside. Cyanidin-3-O-galactoside was present only in the cultivar Laetitia (red peel, yellow flesh). The ripe fruit of Ruby Red and PR04-19, both with red peel and flesh, had the highest anthocyanin content for the first and second harvest season, respectively. Neochlorogenic acid and quercetin-3-O-glucoside were the major phenolic acid and flavonol, respectively. Chlorogenic acid, 3-O-p-coumaroylquinic acid and several quercetin-glycosides and -diglycosides were also present in some cultivars and selections. Procyanidin B1 was the flavan-3-ol present in the highest concentration in the majority of cultivars and selections and its content correlated with the (+)-catechin content, while the same was observed for procyanidin B2 and (-)-epicatechin. The effect of cold storage and ripening on fruit attributes differed greatly between cultivars and selections. The increase and decrease in pH and titratable acidity, respectively, were as expected for ripe fruit as opposed to unripe fruit. Ripe fruit had higher a*-values and lower L*-values. The cold storage and ripening regime had no significant effect on total polyphenol and total flavan-3-ol content of the cultivars and selections, but the anthocyanin content increased in some cases. In terms of in vitro antioxidant capacity, the selections PR04-32 and PR04-35, both with red peel and flesh, had the highest antioxidant capacity, irrespective of assay. Sapphire (red peel, yellow flesh), with the lowest total polyphenol content, also had the lowest antioxidant capacity in the ORAC and FRAP assays. Both the total polyphenol and flavan-3-ol contents correlated significantly to antioxidant capacity, irrespective of assay.
AFRIKAANSE OPSOMMING: Fenoliese verbindings, soos teenwoordig in pruime, is bekend vir hul gesondheidsbevorderende eienskappe wat geassosieer word met antioksidant kapasiteit. Vrugte met ‘n rooi skil en/of vleis is veral gesog as gevolg van hul hoë antioksidant aktiwiteit. Met hierdie studie is Suid-Afrikaanse pruim (Prunus salicina Lindl.) kultivars en seleksies, geoes tydens twee opeenvolgende seisoene, vergelyk in terme van algemene vrug einskappe (kleur, fermheid, °Brix, pH en titreerbare suurheid), fenoliese samestelling en antioksidant kapasiteit. Die effek van ‘n kommersiële koelopberging en rypwording prosedure is ook ondersoek. ‘n Omgekeerde-fase hoë-druk vloeistof chromatografie (HPLC) metode met diode-opstelling en fluoressensie deteksie, maar wat ook geskik is vir massa spektrometrie (MS), is geoptimiseer om fenoliese verbindings te skei en te identifiseer in Suid-Afrikaanse pruime. Verbindings van vier fenoliese groepe (fenoliese sure, antosianiene, flavan-3-ole en flavonole) wat in ses kultivars en vyf seleksies voorgekom het, is ondersoek. Die vloeistof fases, skeidingstemperatuur en gradiënt van die metode is geoptimiseer. Goeie resultate vir stabiliteit, lineariteit en inter- en intra-dag akkuraatheid is verkry. Verbindings is geïdentifiseer deur vergelyking van retensie tye, UV-Vis spektra en massa fragmente met dié van egte fenoliese standaarde en/of met literatuur data. Vier-en-twintig fenoliese verbindings is geïdentifiseer of voorlopig geïdentifiseer, insluitende sianidien- en kwersetien glikosiede, flavan-3-ol monomere, dimere en trimere, en hidroksikaneelsure. ‘n Aanlyn ABTS•+ (2,2 ʹ-azino-di-(3-etielbensotialosien-sulfoon suur) radikaal katioon blussingstoets is gebruik om die antioksidant reaksie van individuele polifenole op ‘n kwalitatiewe wyse te evalueer en flavan-3-ole is as hoof antioksidante in pruime aangetoon. Kwantifisering van agtien verbindings, insluitende antosianiene, flavonol glikosiede, flavan-3-ole (monomere en dimere) en hidroksikaneelsure, was moontlik met hierdie geoptimiseerde metode. Die fenoliese samestelling het aansienlik verskil tussen kultivars en seleksies. Sianidien-3-O-glukosied was die hoof antosianien in pruime met ‘n rooi skil en/of vleis, gevolg deur sianidien-3-O-rutinosied. Sianidien-3-O-galaktosied het slegs in Laetitia (rooi skil en geel vleis) voorgekom. Ryp vrugte van Ruby Red en PR04-19, beide met rooi skil en vleis, het onderskeidelik die hoogste antosianieninhoud gehad met die eerste en tweede seisoen se oeste. Neochlorogeniese suur en kwersetien-3-O-glukosied was die hoof fenoliese suur en flavon-3-ol, onderskeidelik. Chlorogeniese suur, 3-O-p-kumarienkwiniensuur en verskeie kwersetien glikosiede en diglikosiede was teenwoordig in sekere kultivars/seleksies. Die flavan-3-ol, prosianidien B1, was teenwoordig in die hoogste konsentrasie in die meerderheid kultivars/seleksies. Die prosianidien B1 inhoud het met die (+)-katekien inhoud gekorreleer, terwyl dieselfde gevind is vir prosianidien B2 en (-)-epikatekien. Die effek van koelopberging en rypwording op die algemene vrug einskappe het tussen kultivars en seleksies verskil. Die pH en titreerbare suurheid het onderskeidelik toegeneem en afgeneem, soos verwag is vir ryp vrugte teenoor onryp vrugte. Ryp vrugte het hoër a*-waardes en laer L*-waardes getoon. Koelopberging en rypwording het geen beduidende effek op die totale polifenol- en totale flavan-3-ol inhoud gehad nie, maar die antosianieninhoud het vir sommige kultivars en seleksies toegeneem. In terme van in vitro antioksidant kapasiteit het die seleksies PR04-32 en PR04-35, beide met rooi skil en vleis, die hoogste antioksidant kapasiteit getoon, ongeag die antioksidant toets wat gebruik is. Sapphire (rooi skil en geel vleis) het die laagste totale polifenolinhoud gehad, asook die laagste antioksidant kapasiteit soos bepaal deur die ORAC en FRAP toetse. Beide die totale polifenol- en flavan-3-ol inhoud het beduidend met die antioksidant kapasiteit korreleer, ongeag van die toets wat gebruik is.
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Kucich, Daniela Amalia. "Total phenolic content and antioxidant capacity of a selection of South African indigenous fruits". Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2322.
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Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2015.It has recently been confirmed that people consuming 7+ portions of fruit and vegetables daily have a lower risk of mortality from any cause. With a fifth of the population of South Africa falling below the poverty line, it has been found that rural adults have a very low daily intake of fruit and vegetables; at the same time rural children are consuming a primarily maize-based diet. This low dietary diversity translates into a higher level of infectious diseases in children younger than five years. Interventions at national level included promoting the growing of underexploited traditional indigenous vegetables and fruits in home gardens, in the hope that rural households would help themselves in diversifying their cereal-based diet, while using crops they are accustomed to in their environment. Ten indigenous South African fruits found in the Western Cape were evaluated for their potential to make a positive contribution to the diet of rural communities and were compared with Blueberry and Cranberry, the North American ‘gold standards’. The following determinations were carried out on 12 samples: Total Phenolic Content, Total Flavanols and Total Monomeric Anthocyanins were analysed using the Folin-Ciocalteu, Mazza and pH Differential methods. Total Antioxidant Capacity was assessed using the Trolox Equivalent Antioxidant Capacity (TEAC), DPPH and Molybdenum Reduction assays. The Oxygen Radical Absorbance Capacity (ORACFL) was also determined. Iron Chelating Activity, one of the methods recommended to reflect other antioxidant mechanisms, was also investigated. The fruits possessing the highest concentration of Total Phenolic Content (Mazza) were Christmas berry, Bietou, Wild Olive and Wild Plum, at levels significantly higher than those of the two control berries, Blueberry and Cranberry. The fruits yielding the highest results for the TEAC assay were Wild Plum, Wild Olive, Tortoise berry, Christmas berry and Colpoon. The fruits giving the highest results for the DPPH assay were Wild Plum, Colpoon, Wild Olive, and Christmas berry. The fruits showing the highest results for the Molybdenum Reduction assay were Wild Olive, Wild Plum, Christmas berry, and Tortoise berry. The fruits yielding the highest results for the ORAC Total Antioxidant Capacity assay were Colpoon, Christmas berry, Wild Olive, Crossberry, Wild Plum, Waterberry followed by Blueberry and Cranberry. The results from the Iron Chelating Activity assay revealed a ranking of Christmas berry, Blueberry, followed by Num-num. On combining the results of eight assays, namely TPC (Mazza), TF, TA, TEAC, DPPH, TAC, TPC (FCR), ICA to give an Antioxidant Potency Composite Index, the fruits with the highest iv rankings were (1) Wild Plum, (2) Wild Olive, (3) Colpoon, and (4) Christmas berry. By comparison the northern hemisphere control berries ranked (5) Blueberry and (9) Cranberry. These findings show that by introducing even small servings of indigenous fruits into the diet, an important and inexpensive source of natural antioxidants could be accessed and the mean daily ORAC intake could thereby be boosted significantly by about 4,000 µmol Trolox Equivalents to bring the Total ORAC consumed to within optimum levels (6,000 µmol Trolox Equivalents and above). These bioactive plant compounds have the potential to deliver immense benefits to health to impoverished South African adults, as well as rural children, well beyond basic nutrition.
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Brum, Thiele Faccim de. "METABÓLITOS SECUNDÁRIOS, COMPOSIÇÃO QUÍMICA E ATIVIDADE ANTIOXIDANTE DO ÓLEO ESSENCIAL E DAS FOLHAS DE Vitex megapotamica (SPRENGEL) MOLDENKE". Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/6006.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe Verbenaceae family consists of about 2600 species, of which the genera Vitex has 250 species. Vitex megapotamica is distributed in northeastern Argentina, eastern Paraguay, in Uruguay and commonly found in southern Brazil. The present work aims to perform a phytochemical study, the chemical composition and antioxidant activity of essential oil and extracts of leaves of V. megapotamica. Leaves of V. megapotamica were collected in Santa Maria, RS, Brazil, in december of 2010. A dried voucher specimen is preserved in the herbarium of the Department of Biology at Federal University of Santa Maria by register number SMBD 13071. The material was macerated in ethanol (70%) and filtered, after a part of the ethanol extract was reserved and the other evaporated in rotary evaporator to remove ethanol (aqueous extract). This was partitioned in ampoules of separation using increasingly polar solvents: dichloromethane, ethyl acetate and butanol, and the crude extract was obtained by drying the aqueous extract. The phytochemical study revealed the presence of anthocyanins, phenols, tannins, catechins, flavonols, flavanones, flavanonóis, xanthones, triterpenoids, steroids, cardioactive glycosides, phenols with ortho and meta position free, coumarins and organic acids. The crude extract and fractions were investigated for antioxidant activity by the method of DPPH, TBARS and protein carbonyls, the content of phenolic compounds (flavonoids, polyphenols and tannins) was determined, and was performed to identification and quantification of phenolic acids by HPLC. The phenolics compounds were higher in the ethyl acetate fraction, being 522.4 ± 12.1 mg/g for polyphenols and 220.48 ± 0.30 mg/g for flavonoids, only this fraction showed condensed tannins, though in small quantity. The assays with DPPH revealed high radical scavenging capacity, showed IC50 ranged from 14.17 ± 0.76 μg/ml to 37.63 ± 0.98 μg/ml. The crude extract and fractions inhibited the TBARS production, with IC50 ranging from 16.36 ± 5.09 μg/ml to 72.72 ± 7.22 μg/ml, where as ethyl acetate fraction was showed the best result. The extracts were effective in inhibiting protein carbonyls at concentrations of 50, 100 and 200 mg/ml, therefore have a higher amount of phenolic compounds. HPLC analysis revealed the presence of chlorogenic and rosmarinic acids and the second in the greatest quantity. Through the extracting the essential oil of the leaves, it was obtained the chemical composition and antioxidant capacity by DPPH method. The main components in the oil were BHT (34.17%), phytol (12.66%), α-caryophyllene (11.84%), δ-elemene (10.65%), β-caryophyllene (7.82%), γ-elemene (4.24%) and germacrene D (2.82%). The oil showed percentage inhibition of 35.62% and 75.25% at concentrations of 76 and 101.6 mg/ml, respectively. Probably, the antioxidant activity reported is due to the major component of BHT. Through this study it was possible identify the chemical composition of essential oil, as well as know the major groups of substances present in extracts from leaves of V. megapotamica who obtained a good antioxidant activity.
A família Verbenaceae consiste de aproximadamente 2600 espécies, sendo que o gênero Vitex apresenta 250 espécies. Vitex megapotamica distribui-se no nordeste da Argentina, no leste do Paraguai, no Uruguai e comumente encontrada no sul do Brasil. O presente trabalho teve como objetivo realizar um estudo fitoquímico, a constituição química e a atividade antioxidante do óleo essencial e dos extratos das folhas de V. megapotamica. As folhas da planta foram coletadas no município de Santa Maria, RS, Brasil, em dezembro de 2010. O material está depositado no herbário do Departamento de Biologia da UFSM catalogado sob o número de registro SMBD 13.071. O material macerado com etanol (70%) e filtrado, após uma parte do extrato etanólico foi reservada e a outra evaporada em evaporador rotatório para remoção do etanol (extrato aquoso). Este foi particionado em ampolas de separação, utilizando solventes de polaridade crescente: diclorometano, acetato de etila e butanol, sendo que o extrato bruto foi obtido pela secura do extrato aquoso. O estudo fitoquímico revelou a presença de heterosídeos antociânicos, fenóis, taninos, catequinas, flavonóis, flavanonas, flavanonóis, xantonas, esteroides, triterpenoides, heterosídeos cardioativos, fenóis com posição orto e meta livres, cumarinas, e ácidos orgânicos. O extrato bruto e as frações foram investigados quanto à capacidade antioxidante através do método do DPPH, TBARS e carbonilação de proteínas, o teor de compostos fenólicos (flavonoides, polifenóis e taninos) foi determinado, e foi realizada a identificação e quantificação de ácidos fenólicos por CLAE. Os teores de compostos fenólicos foram maiores na fração acetato de etila, sendo de 522,4 ± 1,12 mg/g para polifenóis e 220,48 ± 0,30 mg/g para flavonoides, esta fração foi a única que apresentou taninos condensados, embora em pequena quantidade. Os ensaios com DPPH revelaram alta capacidade seqüestradora de radicais livres, apresentando IC50 que variaram de 14,17 ± 0,76 μg/ml a 37,63 ± 0,98 μg/ml. As frações e o extrato bruto inibiram a produção de TBARS, com IC50 que variou de 16,36 ± 5,09 μg/ml a 72,72 ± 7,22 μg/ml, sendo que a fração acetato de etila foi a que apresentou o melhor resultado. Os extratos foram eficazes na inibição da carbonilação de proteinas em concentrações de 50, 100 e 200 mg/ml, por possuírem maior quantidade de compostos fenólicos. A análise por CLAE revelou a presença de ácido clorogênico e rosmarínico, sendo o segundo encontrado em maior quantidade. Através da extração do óleo essencial das folhas, foi possível obter a composição química e a capacidade antioxidante pelo método do DPPH. Os componentes majoritários obtidos foram BHT (34,17%), fitol (12,66%), α-cariofileno (11,84%), δ-elemeno (10,65%), β-cariofileno (7,82%), γ-elemeno (4,24%) e germacreno D (2,82%). O óleo mostrou inibição percentual de 35,62% e 75,25% em concentrações de 76 e 101,6 mg/ml, respectivamente. Provavelmente, a atividade antioxidante relatada se deve ao componente majoritário BHT. Através deste estudo, foi possível identificar a composição química do óleo essencial bem como reconhecer os principais grupos de substâncias presentes nos extratos das folhas de V. megapotamica os quais obtiveram uma boa atividade antioxidante.
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Duy, Joanna Catherine. "A survey of the quantitative intraspecific variation of anthocyanins, phenolics and antioxidant capacity in leaves and fruit of Vaccinium angustifolium Aiton clones in Nova Scotia". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37796.pdf.
Texto completo da fonteLivros sobre o assunto "Phenolics and antioxidant capacity"
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Apak, Resat, Esra Capanoglu e Fereidoon Shahidi, eds. Measurement of Antioxidant Activity & Capacity. Chichester, UK: John Wiley & Sons, Ltd, 2018. http://dx.doi.org/10.1002/9781119135388.
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King, Caitriona Maria. An investigation of antioxidant status DNA repair capacity and mutation as a function of age inhumans. [S.l: The Author], 1995.
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Francisco de Assis Avelino de Sobrinho. Antioxidant Methods: A Guideline for Understanding and Determining Antioxidant Capacity. Elsevier Science & Technology Books, 2024.
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Francisco de Assis Avelino de Sobrinho. Antioxidant Methods: A Guideline for Understanding and Determining Antioxidant Capacity. Elsevier Science & Technology, 2024.
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Niu, Li, e Dongxue Han. Chemical Analysis of Antioxidant Capacity: Mechanisms and Techniques. de Gruyter GmbH, Walter, 2020.
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Chemical Analysis of Antioxidant Capacity: Mechanisms and Techniques. De Gruyter, Inc., 2020.
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Niu, Li, e Dongxue Han. Chemical Analysis of Antioxidant Capacity: Mechanisms and Techniques. de Gruyter GmbH, Walter, 2020.
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Shahidi, Fereidoon, Resat Apak e Esra Capanoglu. Measurement of Antioxidant Activity and Capacity: Recent Trends and Applications. Wiley & Sons, Incorporated, John, 2017.
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Shahidi, Fereidoon, Resat Apak e Esra Capanoglu. Measurement of Antioxidant Activity and Capacity: Recent Trends and Applications. Wiley & Sons, Incorporated, John, 2017.
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Shahidi, Fereidoon, Resat Apak e Esra Capanoglu. Measurement of Antioxidant Activity and Capacity: Recent Trends and Applications. Wiley & Sons, Limited, John, 2018.
Encontre o texto completo da fonteCapítulos de livros sobre o assunto "Phenolics and antioxidant capacity"
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Bunzel, Mirko, e Rachel R. Schendel. "Determination of (Total) Phenolics and Antioxidant Capacity in Food and Ingredients". In Food Science Text Series, 455–68. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-45776-5_25.
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Naczk, M., R. Amarowicz, R. Zadernowski e F. Shahidi. "Antioxidant Capacity of Phenolics from Canola Hulls as Affected by Different Solvents". In ACS Symposium Series, 57–66. Washington, DC: American Chemical Society, 2005. http://dx.doi.org/10.1021/bk-2005-0909.ch006.
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Nackz, M., R. Zadernowski e F. Shahidi. "Antioxidant Capacity of Phenolic Extracts from Selected Food By-Products". In Antioxidant Measurement and Applications, 184–94. Washington, DC: American Chemical Society, 2007. http://dx.doi.org/10.1021/bk-2007-0956.ch013.
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Lamuela-Raventós, Rosa M. "Folin-Ciocalteu method for the measurement of total phenolic content and antioxidant capacity". In Measurement of Antioxidant Activity & Capacity, 107–15. Chichester, UK: John Wiley & Sons, Ltd, 2017. http://dx.doi.org/10.1002/9781119135388.ch6.
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Yilmaz, Mustafa Abdullah, e Oguz Cakir. "Salvia (Sage) Species, a Game-Changer Bioactive Plant: Focus on Antioxidant Properties". In Natural Antioxidants and in Vitro Antioxidant Assays, 71–98. Istanbul: Nobel Tip Kitabevleri, 2024. http://dx.doi.org/10.69860/nobel.9786053359333.4.
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The demand for natural, health-oriented food additives and components has increased, with plant-based foods rich in phytochemicals like phenolic compounds being beneficial for human health. Salvia species, the largest plant family in the Lamiaceae, contain over nine hundred species, including sage, which has numerous beneficial uses and biological properties. Sage extracts have shown antioxidant, hypoglycemic, hypolipidemic, antitumor, anticholinesterase, antimicrobial, and liver-protective properties. S. officinalis L. has been suggested to have an anti-radical effect against uranium toxicity. Sage essential oil (EO) has antibacterial, antifungal, and free radical scavenging properties. S. miltiorrhiza has been given special attention for treating viral illnesses, with quinoone diterpenes being the most intriguing. Antioxidant activity evaluation techniques have evolved over the past decade, with chemical assays and novel detection technologies replacing earlier approaches. In vitro chemical tests, such as hydrogen atom transfer (HAT) and single electron transfer (SET) procedures, are used to assess antioxidant capacity. Electron transfer (ET) assays measure antioxidant activity by transferring electrons and lower metallic ions, carbonyl groups, and free radicals. Mixed tests (HAT/SET) determine the total antioxidant capacity (TAC) of a compound or extract. In vivo animal experiments are used to assess the antioxidant activity of natural extracts. Future research should focus on sage’s antioxidant properties, its mode of action, and the varying compositions of different species.
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Karagecili, Hasan. "Grape Seeds Using As Natural Antioxidant Sources". In Natural Antioxidants and in Vitro Antioxidant Assays, 233–47. Istanbul: Nobel Tip Kitabevleri, 2024. http://dx.doi.org/10.69860/nobel.9786053359333.11.
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Grape seeds (GS) are waste products from the manufacturing of wine, molasses, and fruit juice. They are the portion of grapes that have the highest concentration of phenolic and antioxidant chemicals, second only to the fruits. In addition to highly polymerized procyanidins, the GS contains catechin, epicatechin, gallocatechin, epigallocatechin, and gallic acid. GS may be a good substitute for being used in the creation of new goods with a high added value, such as antioxidant-rich smart foods that are extremely concentrated. Because of its strong antioxidant, anticancer, antibacterial, anti-aging, antidiabetic and anti-inflammatory properties, grape seed extracts (GSE) is frequently used as a dietary supplement and is generally considered safe. Analysis of grape cultivars’ seeds, pulp, and peel revealed that the seeds’ capacity to scavenge DPPH was noticeably greater than that of the peels and pulps. Grape seed is effective against common metabolic diseases such as diabetes, Alzheimer’s disease, cancer, hypertension, and microbial pathogens, as proven by in vitro and in vivo experiments, due to the antioxidant molecules it contains. It is responding to a growing consumer demand to replace other synthetic antioxidants in fortifying and extending the shelf life of many foods, such as cheese, milk, and meat. Grape seeds are a natural antioxidant source of functional foods, food additives and pharmacological compounds with their rich bioactive molecule content.
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Hou, Xiaoru, Randi Neerup e Anne-Belinda Bjerre. "Total phenolic content and antioxidant capacity analysis of seaweed biomass". In Protocols for Macroalgae Research, 237–48. Boca Raton : Taylor & Francis, 2018.: CRC Press, 2018. http://dx.doi.org/10.1201/b21460-15.
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Ferreira, R. M., B. Piñeiro-Lago, J. A. Saraiva, S. M. Cardoso, M. D. Torres e H. Domínguez. "Effects of Autohydrolysis on the Phenolic Extraction and Antioxidant Capacity of Camellia sp. Seed Husk Extracts". In Springer Proceedings in Earth and Environmental Sciences, 135–43. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-48532-9_13.
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Echegaray, Noemí, Roberto Bermúdez, Gema Nieto, Rubén Domínguez, Mirian Pateiro, Nestor Sepúlveda, Marco Antonio Trindade e José Manuel Lorenzo. "Antioxidant Capacity". In Methods to Assess the Quality of Meat Products, 153–68. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2002-1_14.
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Wang, Jin Zhi, Gad G. Yousef, Randy B. Rogers, Elvira Gonzalez de Mejia, Ilya Raskin e Mary Ann Lila. "Maqui Berry (Aristotelia chilensis) Juices Fermented with Yeasts: Effects on Phenolic Composition, Antioxidant Capacity, and iNOS and COX-2 Protein Expression". In ACS Symposium Series, 95–116. Washington, DC: American Chemical Society, 2012. http://dx.doi.org/10.1021/bk-2012-1093.ch006.
Texto completo da fonteTrabalhos de conferências sobre o assunto "Phenolics and antioxidant capacity"
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Nethmini, W. D. D., S. Wijesekara e D. C. Abeysinghe. "Phytochemicals, Functional and Physiochemical Properties of Selected Unexploited Fruits in Sri Lanka". In 4th International Conference on Agriculture, Food Security and Safety. iConferences (Pvt) Ltd, 2024. http://dx.doi.org/10.32789/agrofood.2023.1004.
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Abstract: As a tropical country with high biodiversity, Sri Lanka has a diversified variety of fruits, however most of them remain unexploited. Unfortunately, most Sri Lankans are not aware of those neglected fruit crops and their nutritional value and health benefits. Therefore, this study was carried out to determine the total antioxidant capacity, bioactive compounds and physiochemical properties of nine selected underutilized fruit species in Sri Lanka. Extracts of selected nine unexploited fruits namely, Syzygium cumini (Java plum), Ardisia elliptica (Shoebutton fruit), Eugenia uniflora (Surinam cherry), Antidesma alexiteria (Ceylon bignay), Dovyalis hebecarpa (Ceylon gooseberry), Malpighia emarginata (Barbados cherry), Morus alba (Mulberry), Flacourtia indica (Governor’s plum) and Antidesma bunius (Bignay) were assessed for their total phenolic content (TPC), total flavonoid content (TFC) and total antioxidant capacity (TAC) as well as physiochemical properties. TPC, TFC and TAC were determined by Folin-ciocalteu method, a colourimetric method and ferric reducing antioxidant power (FRAP) assay respectively. The fresh weight (FW), moisture content and total soluble solid (TSS) were also determined. Statistical Analysis was done by analysis of variance (ANOVA) followed by Tukey Multiple Range Test using SAS. The highest fresh weight was observed in Eugenia uniflora (7.31 ± 0.60 g) whereas, the highest moisture content was recorded in Morus alba (88.81 ± 0.48 %). Flacourtica indica had the highest TSS value (19.95 ± 0.71%). Malpighia emarginata had significantly the highest TAC (2623 ± 43.37 mg TE/100 g FW) and TPC (1624.01 ± 71.45 mg GAE/100 g FW) whereas, significantly high TFCs were observed in Flacourtica indica (1374.03 ± 222.61 mg RE/100 g FW) and Syzygium cumini (1305.97 ± 202.17 mg RE/100 g FW). This study concluded that Malpighia emarginata, Syzygium cumini and Flacourtica indica had potent sources of bioactive compounds and antioxidants. Keywords: Antioxidant capacity, Flavonoids, Phenolics, Unexploited fruits
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"Determination of Antioxidant Property, Total Phenolics Content, and α-Glucosidase Inhibitory Activity of Different Solvent Extracts of Defatted and Non-Defatted Peanut Skins". In 4th International Conference on Biological & Health Sciences (CIC-BIOHS’2022). Cihan University, 2022. http://dx.doi.org/10.24086/biohs2022/paper.781.
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Peanut skins are by-product with little economic value. The effect of different solvents, on the total phenolic content (TPC), antioxidant property and in vitro antidiabetic activity of defatted and non-defatted peanut skins was determined. TPC was estimated using Folin-Ciocalteau reagent. Antioxidant property was evaluated using ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1- picrylhydrazyl (DPPH) radical scavenging capacity methods, α-glucosidase inhibition was evaluated using 4- nitrophenyl α-D-glucopyranoside (pNPG) method. Peanut skin of the defatted extracted with ethanol had the much of the content of total phenolics (391.76 mg/g GAE). Highest DPPH scavenging property was found in the methanolic extract of defatted peanut skins with IC50 value of 15.00 ± 1.00 μg/mL, while highest FRAP value was found in the aqueous extract of non-defatted extracts. Aqueous extracts demonstrated stronger inhibitory property against α-glucosidase and had IC50 of 16.33 ± 1.15 and 16.33 ± 8.50 μg/mL for defatted and non-defatted extracts, respectively. The finding of the present shows that peanut skins are important by-product for utilization as natural antioxidant and α-glucosidase inhibitors.
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Liu, Xia, Xihong Li e Guiming Lei. "Storage Effects on Total Phenolics, Antioxidant Capacity in Indica-Japonica Genotype Rice Grain". In 2010 4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2010. http://dx.doi.org/10.1109/icbbe.2010.5516717.
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Xiang, Jinle, Xiangfeng Guo, Jinling Fan, Wenxue Zhu e Zhixi Li. "Changes in vitamin C, total phenolics and antioxidant capacity during liquid fermentation of Hovenia dulcis peduncle". In 2013 International Conference on Advanced Mechatronic Systems (ICAMechS). IEEE, 2013. http://dx.doi.org/10.1109/icamechs.2013.6681759.
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Bordean, Despina-Maria, Aurica Breica Borozan, Gabriel Bujanca, Camelia Cioban e Delia Gabriela Dumbrava. "EFFECTS OF BOILING AND ROASTING ON CRUDE PROTEINS, TOTAL ANTIOXIDANT CAPACITY AND TOTAL POLYPHENOLS CONTENT OF POTATO TUBERS". In GEOLINKS International Conference. SAIMA Consult Ltd, 2020. http://dx.doi.org/10.32008/geolinks2020/b1/v2/08.
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Compared with other sources, potato can bring multiple nutritional benefits because it’s naturally low energy food (0.7 kcal), having high water, fiber and starch content. Even if the consummation of potatoes is in decline, it is still considered a source of valuable nutrition. Depending on the method of preparation, potatoes contain significant level of proteins and antioxidants and can offer considerable protection against cardiovascular diseases and cancer. Natural antioxidants are present under different forms in all plants, being the base source of these compounds for humans. The objective of this study was to determine the moisture content, crude protein, total antioxidant capacity and phenolic content of three assortments of potatoes (Solanum tuberosum) available on the Romanian local market (Timis County). The study was carried out on raw, unpeeled, boiled and roasted potatoes. The moisture content was determinate thermogravimetrically using Sartorius thermo balance, crude protein quantified by using a rapid colorimetric method, total antioxidant capacity determinate using CUPRAC method and total polyphenols content using Folin-Ciocalteu assay. The experimental results show that blue roasted potatoes present the highest content of crude protein, total antioxidant capacity and total polyphenols content and the lowest water content. The obtained data are used to create a graphical fingerprint of raw and processed potatoes in order to identify the best options to mix different potatoes assortments and to create innovative nutritious food products
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Rodríguez-Ramírez, Juan, Irene Chaparro-Hernández, Lilia L. Méndez-Lagunas e Luis Gerardo Barriada-Bernal. "Effect of spray drying conditions on antioxidants activity, flavonoids and total phenolic compounds of stevia rebaudiana". In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7518.
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In this work the spray drying of the fresh stevia leaves aqueous extract without encapsulating agents was carried out. The effect of the inlet air temperature (160-200 ºC) and the feed flow rate (2-3 kg/h) on the total phenolic content, the total flavonoid content and the antioxidant capacity were evaluated using Folin-Ciocalteau, aluminum chloride and DPPH methods respectively. The inlet air temperature had a significant effect on all parameters evaluated that showed a decrease when increasing the inlet air temperature, the feed flow rate had a significant effect on total flavonoids content and the antioxidant capacity, by increasing the feed flow rate the inhibition of the DPPH radical decreased and the total flavonoid content increased. The treatment at 160 ºC and 3 kg/h retained highest total flavonoid content and the antioxidant capacity. Keywords: Phenolic compounds, stevia, spray drying, antioxidant capacity
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Marquardt, P., R. Seide e K. Fester. "Antioxidant capacity and phenolic profiling of Combretum collinum from Benin". In Phytotherapie 2017 „Von der Innovation zur Evidenz“. Georg Thieme Verlag KG, 2017. http://dx.doi.org/10.1055/s-0037-1607169.
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Bandara, P. V. P., R. G. S. Wijesekara e D. C. Abeysinghe. "Functional Properties of Fruits of Selected Five Solanum Species in Sri Lanka". In 4th International Conference on Agriculture, Food Security and Safety. iConferences (Pvt) Ltd, 2024. http://dx.doi.org/10.32789/agrofood.2023.1003.
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Abstract: Solanaceae is an economically and medicinally important family consisting of many species. The fruits of Solanum spp. have a significantly high number of secondary metabolites. Therefore, used in the treatment of numerous ailments and it has a lot of attention as a functional food. The present study aims to determine the total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC) of fruits of five selected Solanum spp. namely; Solanum melongena (brinjal), Solanum torvum (thibbatu), Solanum violaceum (thiththa thibbatu), Solanum insanum (prickly calyx; local elabatu) and Solanum insanum (non-prickly calyx; thai elabatu) in Sri Lanka. Homogenous, representative fresh samples in the harvesting stage were collected from home gardens situated in North Western and Southern Provinces in Sri Lanka. TPC, TFC and TAC were determined using the Folin-Ciocalteu method, colorimetric method and ferric-reducing antioxidant power (FRAP) assay respectively. Data were analyzed using analysis of variance (ANOVA) followed by the Turkey Multiple Range Test using SAS. Solanum torvum was reported the significantly higher TPC (13.17 ± 0.23 mg GAE /g DW), TFC (51.96 ± 1.34 mg RE /g DW) and TAC (20.05 ± 1.83 mg TE / g DW). Other selected species were recorded TPC, TFC and TAC as Solanum melongena with seeds (12.17 ± 0.47 mg GAE /g DW, 35.74 ± 0.95 mg RE /g DW, 10.78 ± 1.14 mg TE / g DW), Solanum violaceum with seeds (5.27 ± 0.34 mg GAE /g DW, 8.63 ± 1.07 mg RE /g DW, 6.03 ± 0.63 mg TE / g DW), the flesh of Solanum insanum (prickly calyx) (5.07 ± 0.30 mg GAE /g DW, 10.63 ± 2.00 mg RE /g DW, 5.24 ± 0.33 mg TE / g DW), Solanum insanum (prickly calyx) with seeds (8.68 ± 0.30 mg GAE /g DW, 17.74 ± 1.84 mg RE /g DW, 9.69 ± 0.81 mg TE / g DW), the flesh of Solanum insanum (non-prickly calyx) (6.32 ± 0.63 mg GAE /g DW, 14.18 ± 1.59 mg RE /g DW, 5.86 ± 0.37 mg TE / g DW ) and Solanum insanum (non-prickly calyx) with seeds (11.08 ± 0.93 mg GAE /g DW, 32.96 ± 2.00 mg RE /g DW, 11.10 ± 3.34 mg TE / g DW) respectively. Moreover, this study showed positive correlations of TAC with TPC (R² = 0.7699) and TFC (R² = 0.8935). The results of the present study concluded that fruits of all selected Solanum species exhibited a marked amount of bioactive compounds and antioxidant capacity. Keywords: Antioxidant capacity, Flavonoids, Phenolics, Solanaceae, Solanum spp.
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Handaragamage, P., e D. C. Abeysinghe. "Proximate Composition, Bioactive Compounds and Total Antioxidant Capacity of Immature Leaves of Selected Fruit and Vegetable Crops". In 4th International Conference on Agriculture, Food Security and Safety. iConferences (Pvt) Ltd, 2024. http://dx.doi.org/10.32789/agrofood.2023.1001.
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Abstract: The present study was undertaken to quantify the total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), proximate composition and chlorophyll content of immature leaves of seven selected crops namely Manihot esculenta (cassava), Ipomoea batatas (sweet potato), Cucurbita maxima (pumpkin), Psophocarpus tetragonolobus (winged bean), Lagenaria siceraria (bottle gourd), Spondias dulcis (ambarella) and Passiflora edulis (passion fruit). TPC, TFC and TAC were determined using folin-ciocalteu method, colorimetric method and ferric iron reducing antioxidant power (FRAP) respectively. The moisture, ash and protein were analyzed using the methods reported by the Association of Official Analytical Communities (AOAC). The highest TPC (19.04 ± 0.76 mg GAE /g DW) and TAC (115.94 ± 6.27 mg TE / g DW) were recorded in Manihot esculenta leaves. Significantly, the highest TFC (134.02 ± 3.25 mg RE /g DW) and ash content (10.81 ± 0.21 %) were recorded in Ipomoea batatas leaves. The leaves of Psophocarpus tetragonolobus had the highest protein content (36.71 ± 0.10 %) and total chlorophyll content (2.60 ± 0.01 mg / g FW). According to the results, it can be concluded that all tested immature leaves contained marked amounts of bioactive compounds and total antioxidant capacity. Keywords: Antioxidant capacity, Immature leaves, Phenolic, Proximate composition
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Djelic, Gorica, Milica Pavlović, Snežana Branković, Duško Brković, Zoran Simić e Vesna Veličković. "CONTRIBUTION TO THE KNOWLEDGE OF THE ANTIOXIDANT POWER, PHENOLIC AND MINERAL COMPOSITION OF SANGUISORBA MINOR SCOP". In 1st International Symposium on Biotechnology. University of Kragujevac, Faculty of Agronomy, 2023. http://dx.doi.org/10.46793/sbt28.305dj.
Texto completo da fonteResumo:
In this study, extracts of the aerial partsof Sanguisorba minorScop. wereanalysed for antioxidant activity, quantification of the total phenolic and flavonoid and bioaccumulation potential of heavy metals.The total phenols amounts was the highest at acetone´sextracts of root (117.27 mg GAE /g dry weight), stem and leaf (133.61 mg GAE /g dry weight ) and flower (116.77 mg GAE /g dry weight) and total flavonoids acetone´sextractsof flower (50.69 mg RU/g). The highest DPPH-scavenging capacity had flower methanol extract 7.08 (IC50 µg/ml). The plant accumulates large amounts of Zn, Ni and Cu in the root, stem and leaf and flower. Otherwise Mn, Cr and Pb are represented in whole plant.
Relatórios de organizações sobre o assunto "Phenolics and antioxidant capacity"
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Ozkan, Gursel. Phenolic Compounds, Organic Acids, Vitamin C and Antioxidant Capacity in Prunus spinosa L. Fruits. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, fevereiro de 2019. http://dx.doi.org/10.7546/crabs.2019.02.17.
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Ananieva, Kalina, Emilia Gesheva, Kiril Mishev e Marina Stanilova. Antioxidant Capacity of Two Endemic Verbascum Species. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, junho de 2020. http://dx.doi.org/10.7546/crabs.2020.06.08.
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Kim, Yuan, Edward M. Steadham, Steven M. Lonergan e Elisabeth J. Huff-Lonergan. Antioxidant Capacity of Calcium Lactate on m-Calpain Activity In Vitro. Ames (Iowa): Iowa State University, janeiro de 2009. http://dx.doi.org/10.31274/ans_air-180814-1237.
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Kanner, Joseph, Edwin Frankel, Stella Harel e Bruce German. Grapes, Wines and By-products as Potential Sources of Antioxidants. United States Department of Agriculture, janeiro de 1995. http://dx.doi.org/10.32747/1995.7568767.bard.
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Several grape varieties and red wines were found to contain large concentration of phenolic compounds which work as antioxidant in-vitro and in-vivo. Wastes from wine production contain antioxidants in large amounts, between 2-6% on dry material basis. Red wines but also white wines were found to prevent lipid peroxidation of turkey muscle tissues stored at 5oC. The antioxidant reaction of flavonoids found in red wines against lipid peroxidation were found to depend on the structure of the molecule. Red wine flavonoids containing an orthodihydroxy structure around the B ring were found highly active against LDL and membrane lipid peroxidation. The antioxidant activity of red wine polyphenols were also found to be dependent on the catalyzer used. In the presence of H2O2-activated myoglobin, the inhibition efficiency was malvidin 3-glucoside>catechin>malvidin>resveratol. However, in the presence of an iron redox cycle catalyzer, the order of effectiveness was resveratol>malvidin 3-glucoside = malvidin>catechin. Differences in protein binding were found to affect antioxidant activity in inhibiting LDL oxidation. A model protein such as BSA, was investigated on the antioxidant activity of phenolic compounds, grape extracts, and red wines in a lecithin-liposome model system. Ferulic acid followed by malvidin and rutin were the most efficient in inhibiting both lipid and protein oxidation. Catechin, a flavonal found in red-wines in relatively high concentration was found to inhibit myoglobin catalyzed linoleate membrane lipid peroxidation at a relatively very low concentration. This effect was studied by the determination of the by-products generated from linoleate during oxidation. The study showed that hydroperoxides are catalytically broken down, not to an alcohol but most probably to a non-radical adduct. The ability of wine-phenolics to reduce iron and from complexes with metals were also demonstrated. Low concentration of wine phenolics were found to inhibit lipoxygenase type II activity. An attempt to understand the bioavailability in humans of antocyanins from red wine showed that two antocyanins from red wine were found unchanged in human urine. Other antocyanins seems to undergo molecular modification. In hypercholesterolemic hamsters, aortic lipid deposition was significantly less in animals fed diets supplemented with either catechin or vitamin E. The rate of LDL accumulation in the carotid arteries was also significantly lower in the catechin and vitamin E animal groups. These results suggested a novel mechanism by which wine phenolics are associated with decreased risk of coronary heart diseases. This study proves in part our hypothesis that the "French Paradox" could be explained by the action of the antioxidant effects of phenolic compounds found at high concentration in red wines. The results of this study argue that it is in the interest of public health to increase the consumption of dietary plant falvonoids. Our results and these from others, show that the consumption of red wine or plant derived polyphenolics can change the antioxidant tone of animal and human plasma and its isolated components towards oxidative reactions. However, we need more research to better understand bioavailability and the mechanism of how polyphenolics affect health and disease.
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Geneva, Maria, Kostadin Kostadinov, Stoyan Filipov, Elisaveta Kirova e Ira Stancheva. Analysis of the Antioxidant Capacity of Lettuce Growth at Different Fertilizer Regimes. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, janeiro de 2021. http://dx.doi.org/10.7546/crabs.2021.01.18.
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Pogge, Danielle, e Stephanie L. Hansen. Effect of Vitamin C on Performance and Antioxidant Capacity of Cattle Fed Varying Concentrations of Dietary Sulfur. Ames (Iowa): Iowa State University, janeiro de 2012. http://dx.doi.org/10.31274/ans_air-180814-158.
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López-Valverde, Nansi, Antonio López-Valverde, Juan Manuel Aragoneses, Bruno Macedo de Sousa e José Antonio Blanco Rueda. Systematic review and meta-analysis of the antioxidant capacity of lycopene in the treatment of periodontal disease. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, setembro de 2023. http://dx.doi.org/10.37766/inplasy2023.9.0106.
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Clara Cooper-Mullin, Clara Cooper-Mullin. Should I stay or should I go? Connecting bird behavior during migration to fat stores and antioxidant capacity. Experiment, maio de 2016. http://dx.doi.org/10.18258/7159.
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Nuamah, Emmanuel, Junior Isaac Celestin Poaty Ditengou, Fabrice Hirwa, Inhyeok Cheon, Byungho Chae e Nag-Jin Choi. Dietary Supplementation of Tannins: Effect on Growth Performance, Serum Antioxidant Capacity, and Immunoglobins of Weaned Piglets – A Systematic Review and Meta-Analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, janeiro de 2024. http://dx.doi.org/10.37766/inplasy2024.1.0093.
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Patil, Bhimanagouda S., Ron Porat, G. K. Jayaprakasha e K. N. C. Murthy. Optimization of Postharvest Storage Conditions to Maintain Fruit Quality and Health Maintaining Properties of Grapefruit. United States Department of Agriculture, janeiro de 2010. http://dx.doi.org/10.32747/2010.7613879.bard.
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Antioxidant activity of fruits is gaining wide interest among consumers due to its importance in counteracting oxidative stress, free radicals and preventing DNA damage. Oxygen radical absorbance capacity (ORAC) assay is one of the commonly used assays to measure the antioxidant activity, which is based on hydrogen atom transfer mechanism. Furocoumarins present in grapefruit are reported to have antiproliferative activity, induce GST activity, inhibit biofilm formation and increase bioavailability of drugs. In the present project ORAC values were measured of Star Ruby grapefruit undergone ethylene degreening treatment, cold storage and temperature conditioning treatment, and modified atmosphere packaging which were stored at different temperatures for prolonged period. In addition, furocoumarins were quantified in Star Ruby grapefruits from cold storage and conditioning experiment conducted in Israel. Conditioning treatment is practiced prior cold storage to reduce chilling injury in grapefruits during cold storage for prolonged period. Levels of 6,7-dihyrdoxy bergamottin decreased during storage period in all three treatments.