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Antioxidant activity and phenolic content in organic and conventional vegetables

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Abstract

Considering that consumers are becoming more conscious of their health and more concerned with environmental conditions, there has been an increasing demand for organic foods. The aim of this study was to compare the antioxidant activity and determine the total phenolic content of organic and conventional cultivations of lettuce, arugula, and chicory grown in the same vegetable garden. The antioxidant activity of the methanol extracts of these leaf vegetables wasdetermined using DPPH free radical scavenging assay. The total phenolic content in the extracts was determined spectrometrically according to the Folin-Ciocalteu method and calculated as equivalent of gallic acid. The antioxidant activity against the DPPH free radical was: organic arugula> organic chicory > organic lettuce > conventional arugula > conventional chicory > conventional lettuce. The total phenolic content was higher in the organic vegetables. The results of this study suggest that the organic vegetable can be a good dietary source of natural antioxidant and phenolic compounds; therefore, their consumption must be encouraged.

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... The author mention that the levels of TPC were lower in the petiole of the "Taioba", corroborating with the results of this work. Arbos et al. [41] studied TPC in organic and conventional vegetables and the results were presented in gallic acid equivalent: organic arugula (126.84 ± 4.46 mg GAE/100 g), conventional arugula (90.78 ± 2.23 mg GAE/100 g), organic lettuce (108.72 ± 2.34 mg GAE/100 g), conventional lettuce (91.22 ± 0.91 mg GAE/100 g), organic chicory (92.15 ± 1.09 mg GAE/100 g) and conventional chicory (81.04 ± 3.64 mg GAE/100 g). These data were similar to those found in that study for "Taioba", considering, therefore, this UEP as an alternative to compose the diet. ...
... ± 303.05 mg TEAC/100 g) from the root showed no significant difference (p > 0.05) by the assay DPPH [35]. Arbos et al. [41] determined the antioxidant activity of vegetables by the DPPH method in organic lettuce extract and found 23.1 ± 0.20% inhibition of DPPH (IC 50 = 0.64 mg/mL −1 ). The antioxidant activity of the samples, in general, was directly related to the levels of TPC, mainly for the blade of the "Taioba" (Tables 1 and 2). ...
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Conventional and unconventional food plants, in addition to macronutrients, are also rich in bioactive compounds, which have the antioxidant capacity and, therefore, are associated with the prevention of various diseases. There are several factors that can interfere with the concentration of these substances, such as: parts of the plant, extraction solvents, temperature, etc. The study was undertaken to extract and to characterize quantitatively the content of total phenolic compounds (TPC) in “Taioba” or Cocoyam (Xanthosoma sagittifolium) from Brazil, before and after heat treatments in different parts of the plant. TPC were performed by the Folin-Ciocalteu method and the antioxidant activity by DPPH, ABTS and FRAP methods. Principal component analysis (PCA) was used to explore the data generated. The variables (extraction solvent, parts of “Taioba” and heat treatment) influenced the TPC concentrations and antioxidant activity. The contents (mg/100 g) of TPC were higher in the nature leaf blade (75.44 ± 1.69) and the integral taioba in all treatments ranging from 44.86 ± 0.44 to 50.46 ± 0.93, in the methanolic extract when compared to the aqueous extract. PCA analysis elucidated the differences in the phenolic profile between the different parts of the “Taioba”, extraction solvent and heat treatment used. The graphs of the scores showed a clear separation of the groups according to the extraction solvents and parts of the “Taioba”, while the loading graph showed the separation of the sample groups according to the variables associated with the different heat treatments. The proposed methods were efficient for the determination of TPC in “Taioba”. Therefore, it is suggested to extend the studies to other conventional and unconventional food plants. Graphical abstract
... Similarly as for the above mentioned micronutrients and bioactive compounds, a large number of studies are available comparing levels of total phenolics as well as of individual phenolic compounds for a large number of crops. Examples of crops evaluated as to various phenolic compounds (or total phenolics) in organic and conventional farming systems are; wheat, maize, oats, potatoes, marionberries, strawberries, blueberries, black currant, peach, pear, apple, kiwi, tomatoes, leaf lettuce, collards, pac choi [92,101,[103][104][105][106][107][108][109][110][111][112][113][114][115][116][117][118][119]. Compared with the micronutrients and bioactive compounds discussed above, phenolic compounds seem to be more influenced by the farming system used. ...
... Also for phenolics, there are studies with no significant difference in amounts or composition between crops grown conventionally vs. organically. However, a number of studies report higher values of various phenolic compounds in organic farming compared to conventional farming systems [101,104,105,107,[110][111][112][113][114][116][117][118]. Most of the mentioned studies are comparative, with cultivations either on the same farm or on fields nearby each other. ...
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An increasing interest in organic agriculture for food production is seen throughout the world and one key reason for this interest is the assumption that organic food consumption is beneficial to public health. The present paper focuses on the background of organic agriculture, important public health related compounds from crop food and variations in the amount of health related compounds in crops. In addition, influence of organic farming on health related compounds, on pesticide residues and heavy metals in crops, and relations between organic food and health biomarkers as well as in vitro studies are also the focus of the present paper. Nutritionally beneficial compounds of highest relevance for public health were micronutrients, especially Fe and Zn, and bioactive compounds such as carotenoids (including pro-vitamin A compounds), tocopherols (including vitamin E) and phenolic compounds. Extremely large variations in the contents of these compounds were seen, depending on genotype, climate, environment, farming conditions, harvest time, and part of the crop. Highest amounts seen were related to the choice of genotype and were also increased by genetic modification of the crop. Organic cultivation did not influence the content of most of the nutritional beneficial compounds, except the phenolic compounds that were increased with the amounts of pathogens. However, higher amounts of pesticide residues and in many cases also of heavy metals were seen in the conventionally produced crops compared to the organic ones. Animal studies as well as in vitro studies showed a clear indication of a beneficial effect of organic food/extracts as compared to conventional ones. Thus, consumption of organic food seems to be positive from a public health point of view, although the reasons are unclear, and synergistic effects between various constituents within the food are likely.
... µg GAE/mg of extract) and the lowest for AEMG (27.46 µg GAE/mg). The quantification of phenolic compounds in conventional vegetables by Arbos et al. [71]-lettuce (91.22 mg GAE/g) and arugula (90.78 mg GAE/g)-shows that PP and WP are better sources of these compounds. ...
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Unconventional food plants (UFPs), many of them popularly known as "weeds", are edible species with nutritional and socioeconomic potential that need to be rescued from intensive farming. The aims of this study were: to accomplish an ethnobotanical survey of UFPs consumed on Mem de Sá Island, Sergipe, Brazil and then to characterize the three most commonly used UFPs. The physicochemical parameters and bioactive compounds were assessed, and the in vitro antioxidant activity of the aqueous extracts of the plants was evaluated using DPPH radical assay, ABTS radical cation, and the β-carotene/linoleic acid cooxidation method. The cytotoxicity of the compounds was also analyzed using MTT assay in L929 fibroblasts. The survey identified 31 species of UFPs distributed in 22 families, and revealed that knowledge about the plants was concentrated in older individuals. The three most commonly used were Talinum paniculatum (Jacq.) Gaertn. (29.03%), Ipomoea batatas (L.) Lam. (purple and white) leaf (25.81%) and Amaranthus deflexus L. (16.13%). Ipomoea batatas (L.) Lam. had the highest total carbohydrate content, the purple variety the highest protein and total carotenoids content, and the white variety the highest copper (Cu), while its aqueous extract had the highest phenolic compounds and total flavonoids; Talinum paniculatum (Jacq.) Gaertn. had the highest iron (Fe) content, and, with Amaranthus deflexus L., the highest calcium (Ca); and Amaranthus deflexus L. had the highest vitamin C. The extracts of the analyzed plants showed antioxidant potential. Therefore, these UFPs are alternative nutritional sources for food diversification in modern society. Graphic Abstract
... In addition to the firmness and color characteristics that considerably affect the postharvest quality of lettuce, the literature reports that storage affects the content of several compounds with antioxidant activity (Arbos et al., 2010). In the present study, a reduction in the content of total flavonoids was observed in the WR treatment, after 3 days of storage, which was restored after 7 days of storage (Fig. 1D). ...
Article
Lettuce (Lactuca sativa L.) is the most widespread leafy vegetable in the world, grown in several countries. However, commercially available cultivars have a low content of functional compounds, compared to several other vegetables. In addition, the postharvest period is characterized as a stressful stage, affecting the quality of this vegetable. One strategy that has been shown to be effective in increasing the content of functional compounds in plants is the application of abiotic elicitors, such as drought stress at moderate levels. In addition, there is evidence that plants submitted to these elicitors have greater tolerance to subsequent stresses, such as those arising from the postharvest storage. This study evaluated the effect of the pre-harvest application of moderate levels of drought stress on the pre and postharvest quality of lettuce. For this, lettuce plants were grown with the volume of water needed to saturate 100 % of the soil (C, control), 90 % of the soil (DS 90 %), 80 % of the soil (DS 80 %), or they were subjected to a short-term acute stress by water restriction (WR) for 4 days before harvest. After harvesting, half of plants were stored at 6−8 °C and 80 % humidity for postharvest analysis. The application of moderate drought stress resulted in plants with higher biomass in treatments DS 90 % and WR and did not affect the color or firmness of the plants. The DS 80 % treatment stood out in terms of quality parameters, as it resulted in plants with a higher content of carotenoids, chlorophylls, caffeic acid, monocaffeoyl tartaric acid, malercyl quercetin glucoside, quercetin-3-O-glucuronide, and greater total antioxidant activity at harvest. Plants submitted to moderate drought stress did not show changes in firmness during storage; but showed an increase in the content of flavonoids in WR, and in some phenolic compounds that have been negatively affected by storage. The results indicate that the application of moderate drought stress, especially at the 80 % level, represents an interesting strategy to improve the quality of this vegetable at harvest and after storage.
... sagitifolium L.) presents significant levels of carbohydrates, proteins, iron, minerals and vitamins A and C (Lu et al. 2005, Rodríguez et al. 2006, Brasil 2010, Ndabikunze et al. 2011). However, it is known that the levels of these compounds vary widely according to environmental, genetic and management factors (Melo et al. 2006, Costa et al. 2008, Arbos et al. 2010. ...
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The objective of this study was to characterize the nutritional compounds of interest present in vegetables known as non-conventional, in Brazil. The following evaluations were carried out: antioxidant activity, phenolic compounds, vitamin C, calories, carbohydrates, humidity, lipids, proteins, fiber, acidity and quantification of minerals (P, K, Ca, Mg, S, Cu, Fe, Mn, Zn and B). The species studied were Amaranthus hybridus L., Amaranthus viridis L., Basella alba L., Eryngium campestre L., Hibiscus sabdariffa L., Lactuca canadensis L., Rumex acetosa L., Stachys byzantina K. Koch, Tropaeolum majus L. and Xanthosoma sagittifolium L. Representative samples of plant structures of interest were harvested from each species suitable for human consumption such as leaves, flowers and flower buds. The results were submitted to multivariate analysis - principal components analysis (PCA). All the species present nutritional compounds of interest in different levels among the evaluated structures.
... Considering consumers' increased concern in getting a healthier lifestyle, foods with antioxidant properties have been widely studied, since they demonstrate an important role in combating oxidative stress [6]. Oxidative stress occurs in the body when there is an imbalance between oxidant molecules, including the Reactive Oxygen Species (ROS) and antioxidants, thus generating cell damage [7]. ...
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Chocolate is a product consumed worldwide and it stands out for presenting an important amount of phenolic compounds. In this study, the total phenolic content and antioxidant activity in the cerebral cortex, hippocampus, and cerebellum of male Wistar rats when consuming different types of chocolate, including milk, semisweet, dark, and soy, was evaluated. The total polyphenols concentration and antioxidant activity in vitro by the method of DPPH radical-scavenging test were evaluated in chocolate samples. Lipid peroxidation (TBARS), protein oxidation (carbonyl), sulfhydryl groups, and activity of SOD enzyme in cerebral cortex, hippocampus, and cerebellum of rats treated or not with hydrogen peroxide and/or chocolate were also evaluated. The dark chocolate demonstrated higher phenolic content and antioxidant activity, followed by semisweet, soy, and milk chocolates. The addition of chocolate in the diet of the rats reduced lipid peroxidation and protein oxidation caused by hydrogen peroxide. In the sulfhydryl assay, we observed that the levels of nonenzymatic defenses only increased with the chocolate treatments The SOD enzyme activity was modulated in the tissues treated with the chocolates. We observed in the samples of chocolate a significant polyphenol content and an important antioxidant activity; however, additional studies with different chocolates and other tissues are necessary to further such findings.
... Most studies report similar tendencies. For example, Arbos et al. (2010) compared the AC and TPC contents between lettuce, rocket and chicory, in organic and conventional cultivation, and observed that the organic system contributed, simultaneously, to the highest TPC content and a more effective AC for all the evaluated species. In addition, mango fruits from conventional systems showed lower contents of phenolic compounds, flavonoids, antioxidant capacity, lower concentration of soluble solids, total and reducing sugars and fixed mineral residue in comparison to the fruits from organic and biodynamic cultivation systems (Maciel et al., 2011). ...
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Melon farming is characterized as an important family agriculture activity and the organic production of fruits and vegetables has shown a large growth in terms of areas in Brazil and around the world. This work aimed to study the postharvest quality of melon cultivated in an organic system. The organic treatments constituted of base fertilizer with cattle manure vermicompost (recommended dose, ½ dose and double dose) plus the use of biofertilizer (sprayed or sprayed + irrigated), and an additional treatment with chemical fertilization. The postharvest quality was evaluated through physico-chemical and phytochemical attributes. The organic management with half the recommended dose of vermicompost plus the sprayed biofertilizer and the chemical fertilization management produced fruits with higher levels of sugar, total carotenoids, ascorbic acid and folates, obtaining more balanced fruits, with a better phytochemical quality. The antioxidant capacity was defined mainly by the presence of the phenolic compounds, which were influenced by the type and the dose of the evaluated fertilizers, with superiority in the organic treatments with double the dose of cattle manure vermicompost. © 2015, Departamento de Engenharia Agricola - UFCG/Cnpq. All rights reserved.
... Among analyzed vegetables, antioxidant capacity effectiveness was obtained, in decreasing order: broccolis (69.35% ± 5.29%), kale (63.20% ± 3.84%), cabbage (35.71% ± 3.40%) and carrot (20.39% ± 1.13%). Arbos et al. [18] evaluated antioxidant activity via DPPH method of vegetables arising from organic and conventional cultivation. All analyzed vegetables have demonstrated antioxidant property with variation of intensity, depending on studied sort, extract concentration and cultivation type; it is necessary to stand out that higher activity was found in organic vegetables with consumed DPPH % of 77.3 for rocket, 77.2 for endive and 72.3 for lettuce. ...
... Several studies have compared the nutritional quality of organically and conventionally produced foods in terms of micronutrients (Carbonaro et al., 2002;Lester et al., 2007;Pe´rez-Lo´pez et al., 2007;Arbos et al., 2010;Raigo´n et al., 2010, Soltoft et al., 2010and You et al., 2011. Comparative studies between micronutrients content in organic and conventional tomatoes had been discussed by various authors. ...
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The reducing activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, z.rad;OH radical scavenging potential, in vitro inhibition of lipid peroxidation and modulation of mutagenicity induced by ter-butyl hydroperoxide (TBH) in Escherichia coli were sequentially screened in 45 species of plants used with medicinal purposes in Cuba, in a search for antioxidant agents which protect DNA against oxidative stress.Five species, e.g. Tamarindus indica L., Lippia alba L., Pimenta dioica (L.) Merr, Rheedia aristata Griseb. and Curcuma longa L. displayed IC(50)<30 micro g/ml in the DPPH radical reduction assay and IC(50)<32 micro g/ml in lipid peroxidation inhibition testing. Pimenta dioica and Curcuma longa L. showed also a 20% inhibition of the in vitro induced z.rad;OH attack to deoxyglucose. Further antimutagenesis assay in Escherichia coli IC 188 evidenced that only Pimenta dioica prevents DNA damage by TBH to the test bacteria. A role of antioxidant enzymes is presumed in this case, as judged by a different response in the isogenic Escherichia coli IC 203 deficient in catalase and alkyl hydroperoxide reductase and the discrete inhibition of oxidative mutagenesis also observed when pre-treatment of the extract was assayed. Eugenol, the main constituent of the essential oil of Pimenta dioica, also inhibited oxidative mutagenesis by TBH in Escherichia coli, at concentrations ranging from 150 to 400 micro g/plate.
Article
Numerous diseases are induced by free radicals via lipid peroxidation, protein peroxidation and DNA damage. It has been known that a variety of plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum cuspidatum Sieb. et Zucc has antioxidant activity is unknown. In this study, dried roots of Polygonum cuspidatum were extracted by ethanol and the extract was lyophilized. Free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays were employed to study antioxidant activities. The results indicate that the IC50 value of Polygonum cuspidatum extract is 110 mu g/ml in free radical scavenging assays, 3.2 mu g/ml in superoxide radical scavenging assays, and 8 mu g/ml in lipid peroxidation assays, respectively. Furthermore, Polygonum cuspidatum extract has DNA protective effect in hydroxyl radical-induced DNA strand scission assays. The total phenolics and flavonoid content of extract is 641.1 +/- 42.6 mg/g and 62.3 +/- 6.0 mg/g. The results indicate that Polygonum cuspidatum extract clearly has antioxidant effects.
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The flowers, stems, and leaves of broccoli (Brassica oleracea L var italica Plenca) cultivated in Taiwan were freeze-dried and extracted with methanol, water, or acetone. The antioxidant properties, including reducing power, ferrous ion chelating ability, and α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity, were tested in this study. The above antioxidant properties of broccoli extracts along with alpha-tocopherol and butylated hydroxyanisole (BHA) were compared. Results showed that the methanol and water extracts exhibited a higher reducing power in all three parts; while the acetone extract was the least. The stem extracts showed the highest reducing power, which was 1.3 times those alpha-tocopherol and BHA extracts, followed by the leaf extracts, which exhibited similar reducing power to alpha-tocopherol and BHA. The lowest reducing power was observed on flower extracts, which was only three fourth of the reducing power as compared to alpha-tocopherol and BHA. The methanol and water extracts of broccoli also exhibited high chelating ability; while the acetone extracts showed the lowest. The broccoli stem exhibited the highest chelating ability among three parts of broccoli. The acetone extracts from stems hardly showed any chelating ability as compared to alpha-tocopherol and BHA. The methanol extracts of broccoli showed the highest DPPH radical scavenging activity (>90%) among three different solvent extracts. Its DPPH radical scavenging activity was close to BHA and alpha-tocopherol. The water extracts showed only 43% DPPH radical scavenging activity; while the acetone extracts barely showed any DPPH radical scavenging activity.
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Foram analisadas amostras de batata oriundas dos sistemas de cultivo convencional e orgânico da Região Metropolitana de Curitiba (Paraná – Brasil) em relação à sua composição nutricional e contaminantes. As batatas cultivadas pelo sistema orgânico apresentaram 19,57% a mais de matéria seca e 138,94% a mais de açúcares, comparativamente às convencionais (p
Article
Respectivamente, técnico, assistente técnico, gerente e estagiária da Gerência Setorial de Estudos da Agroindústria do BNDES. Os autores agradecem os comentários e sugestões da Drª Maria Fernanda A. C. da Fonseca (Pesagro-RJ), de Jorge Vailati (IBD), da Drª Maria Cristina Prata Neves, da equipe da Embrapa-Agrobiologia e da Drª Corinne R. B. Gonzáles (Deral/Seab-PR), bem como as informações prestadas por Sítio do Moinho (RJ), Horta e Arte (SP), Agrinatura (RJ), Planeta Orgânico (RJ), Emater (PR, SC e RS), certificadoras de produtos orgânicos e instituições relacionadas nos Anexos. $*5,&8/785$25*Ç1,&$ Em virtude da inexistência de informações sis-tematizadas sobre o setor, grande parte do trabalho resulta de pesquisas e entrevistas feitas no período 2000/01 junto a instituições certificadoras, produtores, processa-dores primários e secundários, distribuidores, consumi-dores, instituições de pesquisa, consultorias, cooperati-vas de produtores e órgãos de extensão rural, além de consultas a portais específicos sobre o assunto no Brasil, na Comunidade Européia e nos países do Nafta. Apresenta-se a agricultura orgânica como uma retomada do uso de antigas práticas agrícolas, porém adaptando-as às mais modernas tecnologias de produ-ção agropecuária com o objetivo de aumentar a produti-vidade e causar o mínimo de interferência nos ecossiste-mas, além de ser uma das alternativas para viabilizar a pequena propriedade.
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Some of the most exciting research in the last decade has been the discovery of a group of nutrients which have protective effects against cell oxidation. These naturally occurring compounds impart bright colour to fruits and vegetables and act as antioxidants in the body by scavenging harmful free radicals, which are implicated in most degenerative diseases. Epidemiological studies have established a positive correlation between the intake of fruits and vegetables and prevention of diseases like atherosclerosis, cancer, diabetes, arthritis and also ageing. So pronounced has been their effect on ageing that they have been called 'fountains of youth'. Fruits and vegetables have thus had conferred on them the status of 'functional foods', capable of promoting good health and preventing or alleviating diseases. Phenolic flavonoids, lycopene, carotenoids and glucosinolates are among the most thoroughly studied antioxidants. The present review highlights the potential of fruits and vegetables rich in antioxidants, their health benefits and the effect of processing on the bioavailability of these nutrients. The paper also reviews some of the important methods used to determine the antioxidant activity.
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Several Korean medicinal plants were selected to evaluate for free radical scavenging capacities and antioxidant activities using commonly accepted assays. They were extracted with dichloromethane, methanol or ethanol, respectively and selected for the best antioxidant results. Flavonoids, such as catechin, morin, naringenin, quercetin and rutin, were included and used as standards in this study. Each sample under assay condition showed a dose-dependent free radical scavenging effect of DPPH (1,1-diphenyl-2-picryl hydrazyl radical) and a dose-dependent inhibitory effect of xanthine oxidase and lipid peroxidation. Among plant extracts, the root bark of Morusalba and the leaf of Saururuschinensis showed stronger SC50 or ID50 values than other plant extracts. They also showed a protective effect on DNA damage caused by hydroxyl radicals generated from UV-induced photolysis of hydrogen peroxide. A rapid evaluation for antioxidants using TLC screening and DPPH staining methods demonstrated each plant extract having various free radical scavenging capacity. Stained silica layer revealed a purple background with yellow spots at the location of drops, which showed radical scavenging capacity. The intensity of the yellow color depends upon the amount and nature of radical scavenger present in the samples. This antioxidant potential corresponded with the results of DPPH spectrophotometric assay.
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The crude tea polyphenols, polysaccharides and proteins of regular green tea and Se-enriched green tea were investigated in vitro for antioxidant activities by auto-oxidation test (AAPH) and α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging method. Results showed that crude tea polyphenols of Se-enriched green tea provided the highest antioxidant activity by DPPH assay and the antioxidant activity was decreased in the order: crude tea polyphenols > crude tea proteins > tea polysaccharides. The crude protein of Se-enriched green tea was found to exhibit the highest antioxidant activity by AAPH method and the antioxidant activity was decreased in the order: crude tea proteins > tea polyphenols > tea polysaccharides. Tea polyphenols and tea polysaccharides of Se-enriched green tea presented significantly higher antioxidant activities than that of regular green tea. No significant difference of antioxidant activities was found between crude tea proteins of Se-enriched green tea and regular green tea. The combinations of Se with tea polyphenols and tea polysaccharides were responsible for the higher antioxidant activities of Se-enriched green tea than regular green tea.
Article
The essential oils, isolated by hydrodistillation, from the aerial parts of Thymus caespititius, Thymus camphoratus and Thymus mastichina, collected during the vegetative phase, were analysed by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC–MS). The antioxidant property of these oils was tested, with and without peroxidation inducer, by the egg yolk-based thiobarbituric acid-reactive substances assay, in the concentrations of 62.5, 125, 250 and 500 mg l−1. α-Terpineol (32%) dominated Th. caespititius essential oil and 1,8-cineole (58%) that of Th. mastichina. Linalool (17%), linalyl acetate (15%) and 1,8-cineole (11%) were the main components of Th. camphoratus oil. The oils demonstrated antioxidant capacity in the absence of radical inducer 2,2′-azobis-(2-amidinopropane) dihydrochloride (ABAP), mainly that of Th. caespititius at 250 and 500 mg l−1, comparable in some cases to that of α-tocopherol and butylated hydroxytoluene (BHT). The presence of ABAP diminished the antioxidant ability of all essential oils tested, Th. caespititius oil still showing the highest antioxidant capacity at 500 mg l−1. At 250 and 500 mg l−1, for BHA, and 500 mg l−1, for α-tocopherol, the antioxidant capacity significantly increased in the presence of ABAP.
Article
Maca (Lepidium meyenii) is a plant from the Andes of Peru. Maca is used as a food for its nutritional value and ethnomedicinal properties linked to fertility and vitality. The purpose of this study was to evaluate the antioxidant activity of Maca. For all experiments an aqueous extract of Maca was used. The antioxidant activity of Maca was assessed by the inhibition of peroxynitrite, 1,1-diphenyl-2-picrylhydrazyl (DPPH), peroxyls and deoxyribose degradation. The cytoprotection capacity of Maca was assessed using macrophages (RAW 264.7) treated with peroxynitrite or hydrogen peroxide (H2O2). Catechins were quantified by reversed-phase HPLC. Addition of Maca extract (0.3–1 mg/ml) to peroxynitrite (300 μM) decreased peroxynitrite concentration by 15 and 41%, respectively (P<0.01). The IC50 for scavenging DPPH and peroxyls was 0.61 and 0.43 mg/ml, respectively. Deoxyribose protection by Maca (1–3 mg/ml) against hydroxyl radicals was in the order of 57 and 74%. Maca (1 mg/ml) protected RAW 264.7 cells against peroxynitrite-induced apoptosis (P<0.01), and increased ATP production in cells treated with H2O2 (1 mM). The concentration of catechins in Maca was lower than in green tea (2.5 mg/g vs 145 mg/g). Collectively, our results indicate that Maca has the capacity to scavenge free radicals and protect cells against oxidative stress.
Article
The total antioxidant activity of 12 fruits and 5 commercial fruit juices was measured in this study using automated oxygen radical absorbance capacity (ORAC) assay. On the basis of the wet weight of the fruits (edible portion), strawberry had the highest ORAC activity (micromoles of Trolox equivalents per gram) followed by plum, orange, red grape, kiwi fruit, pink grapefruit, white grape, banana, apple, tomato, pear, and honeydew melon. On the basis of the dry weight of the fruits, strawberry again had the highest ORAC activity followed by plum, orange, pink grapefruit, tomato, kiwi fruit, red grape, white grape, apple, honeydew melon, pear, and banana. Most of the antioxidant capacity of these fruits was from the juice fractions. The contribution of the fruit pulp fraction (extracted with acetone) to the total ORAC activity of a fruit was usually less than 10%. Among the commercial fruit juices, grape juice had the highest ORAC activity followed by grapefruit juice, tomato juice, orange juice, and apple juice.
Article
Previously, some fruits were shown to contain high antioxidant activities. In this paper, we report the antioxidant activities of 22 common vegetables, one green tea, and one black tea measured using the automated oxygen radical absorbance capacity assay with three different reactive species: a peroxyl radical generator, a hydroxyl radical generator, and Cu2+, a transition metal. Based on the fresh weight of the vegetable, garlic had the highest antioxidant activity (micromol of Trolox equiv/g) against peroxyl radicals (19.4) followed by kale (17.7), spinach (12.6), Brussels sprouts, alfalfa sprouts, broccoli flowers, beets, red bell pepper, onion, corn, eggplant (9.8-3.9), cauliflower, potato, sweet potato, cabbage, leaf lettuce, string bean, carrot, yellow squash, iceberg lettuce, celery, and cucumber (3.8-0.5); kale had the highest antioxidant activity against hydroxyl radicals followed by Brussels sprouts, alfalfa sprouts, beets, spinach, broccoli flowers, and the others. The green and black teas had much higher antioxidant activities against peroxyl radicals than all these vegetables. However, the tea also showed a prooxidant activity in the presence of Cu2+, which was not found with any of the vegetables studied.
Article
Evening primrose meal (EPM: 1% and 2%, w/w) reduced (p </= 0.05) the formation of 2-thiobarbituric acid-reactive substances (TBARS), hexanal, and total volatiles in cooked comminuted pork by 43.6-72.6%. Phenolic compounds in the EPM were extracted under optimum conditions (with 56% acetone at 71 degrees C for 47 min) predicted by a multivariate analysis. The resulting evening primrose crude extract (EPCE) inhibited the bleaching of beta-carotene in a model system. After 2 h of assay, the system containing 200 ppm EPCE [as (+)catechin equivalents] retained 86% of the initial beta-carotene whereas the control retained only 11%. Inhibition of the formation of TBARS, hexanal, and total volatiles in the cooked comminuted pork containing 200 ppm EPCE [as (+)catechin equivalents] ranged from 67. 3% to 97.5%. The EPCE inhibited the formation of conjugated dienes, hexanal, and total volatiles in stripped-bulk corn oil (18.5-63.6% inhibition) and stripped-corn oil-in-water emulsion systems (31.7-65. 6% inhibition). Hydrogen peroxide (H(2)O(2)), hydroxyl radical ((*)OH), and superoxide radical (O(2)(*)(-)) scavenging properties of the EPCE were comparable to those observed for authentic (+)catechin. At 200 ppm of the EPCE [as (+)catechin equivalents], a 100% quenching of (*)OH and O(2)(*)(-) was evident. The EPCE scavenged 44-91% of H(2)O(2) in the assay medium after 10 min as compared to 7% reduction in the control.
Article
The antioxidative activity of a total of 92 phenolic extracts from edible and nonedible plant materials (berries, fruits, vegetables, herbs, cereals, tree materials, plant sprouts, and seeds) was examined by autoxidation of methyl linoleate. The content of total phenolics in the extracts was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Among edible plant materials, remarkable high antioxidant activity and high total phenolic content (GAE > 20 mg/g) were found in berries, especially aronia and crowberry. Apple extracts (two varieties) showed also strong antioxidant activity even though the total phenolic contents were low (GAE < 12.1 mg/g). Among nonedible plant materials, high activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet. In addition, potato peel and beetroot peel extracts showed strong antioxidant effects. To utilize these significant sources of natural antioxidants, further characterization of the phenolic composition is needed.
Article
Brazilian plant extracts belonging to 16 species of 5 different families (71 extracts) were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free-radical. The ability to scavenge DPPH radical was measured in these experiments by the discoloration of the solution. Ginkgo biloba and rutin, commonly used as antioxidants for medical purposes, were used as standards. Based on our results, we can say that as a general rule the ethanol extracts of plants belonging to the Verbenaceae family showed lower EC(50) values than the other plant extracts. Among the partitions, the more polar ones (ethyl acetate and n-butanol) are those that generally have higher antioxidant activity (AA).
Article
To survey existing literature comparing nutrient content of organic and conventional crops using statistical methods to identify significant differences and trends in the data. Published comparative measurements of organic and conventional nutrient content were entered into a database for calculation. For each organic-to-conventional comparison, a percent difference was calculated: (organic - conventional)/conventional x 100. For nutrients where there was adequate data, the Wilcoxon signed-rank test was used to identify significant differences in nutrient content as represented by the percent difference. Mean percent difference values were also calculated for each significant nutrient by study and by vegetable for the most frequently studied vegetables. The nutrient content of the daily vegetable intake was calculated for both an organic and conventional diet. Organic crops contained significantly more vitamin C, iron, magnesium, and phosphorus and significantly less nitrates than conventional crops. There were nonsignificant trends showing less protein but of a better quality and a higher content of nutritionally significant minerals with lower amounts of some heavy metals in organic crops compared to conventional ones. There appear to be genuine differences in the nutrient content of organic and conventional crops.
Article
Three methods widely employed in the evaluation of antioxidant activity, namely 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS-GC) and beta-carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS-GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS-GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity.
Article
A total of 27 extracts from non-cultivated and weedy vegetables traditionally consumed by ethnic Albanians (Arbëreshë) in the Vulture area (southern Italy) were tested for their free radical scavenging activity (FRSA) in the DPPH (1,1-diphenyl-2-picrylhydrazil radical) screening assay, for their in vitro non-enzymatic inhibition of bovine brain lipid peroxidation and for their inhibition of xanthine oxidase (XO). In both antioxidant assays strong activity was shown for Leopoldia comosa (bulbs, syn.: Muscari comosum) and Centaurea calcitrapa (young whorls). In the lipid peroxidation assay, extracts from leaves of Origanum heracleoticum, Urtica dioica and Tordylium apulum showed a remarkable inhibitory activity (> 50%), too. In the case of Leopoldia comosa and Origanum heracleoticum this activity was comparable to quercetin (at a concentration of 50 microM) and Rhodiola rosea extract. Extracts from non-cultivated Cichorium intybus, Chondrilla juncea and Stellaria media showed strong in vitro inhibition of xanthine oxidase, with an activity higher than that of a reference extract from Ledum groenlandicum. These findings suggest that weedy vegetables may be useful antioxidants of interest in the prevention of ageing related diseases, CNS disorders and as potential sources of phytomedicines against hyperuricaemia and gout.
Article
Apparently, one of the primary reasons for purchasing organic food is the perception that it is more nutritious than conventional food. Given the increasing interest towards organic food products, it is imperative to review the existing literature concerning the nutritional value of the produce, and to determine to what extent are consumer expectations met. There are only few well-controlled studies that are capable of making a valid comparison and, therefore, compilation of the results is difficult and generalisation of the conclusions should be made with caution. In spite of these limitations, however, some differences can be identified. Although there is little evidence that organic and conventional foods differ in respect to the concentrations of the various micronutrients (vitamins, minerals and trace elements), there seems to be a slight trend towards higher ascorbic acid content in organically grown leafy vegetables and potatoes. There is also a trend towards lower protein concentration but of higher quality in some organic vegetables and cereal crops. With respect to the rest of the nutrients and the other food groups, existing evidence is inadequate to allow for valid conclusions. Finally, animal feeding experiments indicate that animal health and reproductive performance are slightly improved when they are organically fed. A similar finding has not yet been identified in humans. Several important directions can be highlighted for future research; it seems, however, that despite any differences, a well-balanced diet can equally improve health regardless of its organic or conventional origin.
Article
This study aimed at evaluating the antioxidative activity of nine different families of greens. Raphanus raphanistrum (wild radish), Anchusa azurea (bugloss), Daucus carota (wild carrot), Sonchus oleraceus (sowthistle), Papaver rhoeas (corn poppy), Malva sylvestris (blue mallow), Foeniculum vulgare (fennel), Cichorium intybus (chicory) and Salicornia europaea (jointed glasswort) are native to the Mediterranean and are commonly consumed as a salad or an ingredient in some recipes. The antioxidative activities, including the radical scavenging effects, inhibition of hydrogen peroxide (H(2)O(2)), and Fe(2+)-chelating activity, were studied. All samples showed antioxidant activity as a radical scavenger in the experiment using the DPPH* radical. The ratio between the slopes of the kinetic model was used to compare antioxidant efficiency of different greens. Greens also possessed antioxidative activity toward H(2)O(2). Especially, greens exhibited a marked scavenging effect on H(2)O(2) at 0.2 g/ml concentration. The Fe(2+) ion-chelating activities of the samples except jointed glasswort were greater than 70%. The antioxidant activity of samples with different methods based on the inhibition of different reactions could not be compared. The current dietary guidelines include recommendations for an increase in the consumption of plant foods. Greens should provide an optimal supply of antioxidant substances in the diet.
Article
1,1-Dipehnyl-2-picrylhydrazyl (DPPH) radical scavenging activities were found in the extract of dried leaves of oregano (Origanum vulgare). The water-soluble active ingredients were isolated, and their structures were determined to be 4'-O-beta-D-glucopyranosyl-3',4'-dihydroxybenzyl protocatechuate and 4'-O-beta-D-glucopyranosyl-3',4'-dihydroxybenzyl 4-O-methylprotocatechuate by (1)H-, (13)C-NMR, DEPT, HMQC, and HMBC spectral analyses, and by NOE experiments. The DPPH radical scavenging activities of these compounds were compared with those of rutin, quercetin and rosmarinic acid at a concentration of 2 x 10(-5) M. The scavenging activity of 4'-O-beta-D-glucopyranosyl-3',4'-dihydroxybenzyl protocatechuate was almost the same as that of quercetin and rosmarinic acid, but that of 4'-O-beta-D-glucopyranosyl-3',4'-dihydroxybennzyl 4-O-methylprotocatechuate was less than that of quercetin, rosmarinic acid and 4'-O-beta-D-glucopyranosyl-3',4'-dihydroxybenzyl protocatechuate. The amount of 4'-O-beta-D-glucopyranosyl-3',4'-dihydroxybenzyl protocatechuate was estimated to be 3.8 mg/1 g of dried leaves by an HPLC analysis.
Article
Cancer prevention and treatment using traditional Chinese medicines have attracted increasing interest. This study characterizes antioxidant activity and phenolic compounds of traditional Chinese medicinal plants associated with anticancer, comprising 112 species from 50 plant families. The improved ABTS(*+) method was used to systematically assess the total antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC) of the medicinal extracts. The TEAC values and total phenolic content for methanolic extracts of herbs ranged from 46.7 to 17,323 micromol Trolox equivalent/100 g dry weight (DW), and from 0.22 to 50.3 g of gallic acid equivalent/100 g DW, respectively. A positive, significant linear relationship between antioxidant activity and total phenolic content (all R(2) values>/=0.95) showed that phenolic compounds were the dominant antioxidant components in the tested medicinal herbs. Major types of phenolic compounds from most of the tested herbs were preliminarily identified and analyzed, and mainly included phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes, and curcuminoids. These medicinal herbs exhibited far stronger antioxidant activity and contained significantly higher levels of phenolics than common vegetables and fruits. Traditional Chinese medicinal plants associated with anticancer might be potential sources of potent natural antioxidants and beneficial chemopreventive agents.
Desafios tecnológicos, organizacionais e financeiros da agricultura orgânica no Brasil. Revista de la Facultad de Economia
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LLORACH, R. et al. Valorization of cauliflower (Brassica oleracea L. var. botrytis) by-products as a source of antioxidant phenolics. Journal Agricultural Food Chemistry, v. 51, n. 8, p. 2181-2187, 2003. MACHADO, F.; CORAZZA, R. Desafios tecnológicos, organizacionais e financeiros da agricultura orgânica no Brasil. Revista de la Facultad de Economia, v. 26, n. 4, p. 21-40, 2004.
Introdução à agricultura orgânica. Campinas: Grafimagem
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PENTEADO, S. R. Introdução à agricultura orgânica. Campinas: Grafimagem, 2000.
Manejo ecológico de pragas e doenças. São Paulo: Nobel
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Cadeia produtiva de produtos orgânicos. Brasília: MAPA/SPA
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BUAINAIN, A. M.; BATALHA, M. O. (Coord.). Cadeia produtiva de produtos orgânicos. Brasília: MAPA/SPA, 2007. 108 p. (Série Agronegócios, v. 5).
Territorialização da agricultura orgânica no Paraná: preservando o meio ambiente e produzindo alimentos sadios
  • M C Campos
CAMPOS, M. C. Territorialização da agricultura orgânica no Paraná: preservando o meio ambiente e produzindo alimentos sadios. Disponível em: <http://www.igeo.uerj.br/VICBG-2004/Eixo1/ e1%20279.htm>. Acesso em: 18 abril 2005.
Comparação entre a qualidade do alimento orgânico e a do convencional
  • M R Darolt
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DAROLT, M. R. Comparação entre a qualidade do alimento orgânico e a do convencional. In: STRINGHETA, P. C.; MUNIZ, J. N. Alimentos orgânicos: produção, tecnologia e certificação. Viçosa: Editora UFV, p. 289-312, 2003a.
A qualidade dos alimentos orgânicos
  • M R Darolt
DAROLT, M. R. A qualidade dos alimentos orgânicos. 2003b. Disponível em: <http://www.planetaorgânico.com.br/daroltqualid. htm>. Acesso em: 19 setembro 2003.
O financiamento do banco do Brasil à agricultura orgânica e preservação ambiental do estado do Paraná
  • G A Staub
STAUB, G. A. O financiamento do banco do Brasil à agricultura orgânica e preservação ambiental do estado do Paraná. 2003. 139 f. Dissertação -(Mestrado) -Universidade Federal de Santa Catarina, Florianópolis, 2003.
Phenol antioxidant quantity and quality in foods: vegetables
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VISON, J. A. et al. Phenol antioxidant quantity and quality in foods: vegetables. Journal Agricultural Food Chemistry, v. 46, n. 9, p. 3630-3634, 1998.
Nutritional quality of organic food: shades of grey or shades of green?
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WILLIAMS, C. M. Nutritional quality of organic food: shades of grey or shades of green? Proceedings of the Nutrition Society, v. 61, n. 1, p. 19-24, 2002.