Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Plant Foods Hum Nutr ; 77(3): 340-344, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35902483

RESUMO

Phenolic compounds in camu-camu (Myrciaria dubia) have received interest due to their health-promoting effects. However, these compounds have been poorly investigated in the different parts of the camu-camu fruit (pulp, peel, and seeds). This study aimed to optimize the solvent composition for extraction of phenolic compounds from pulp, peels, and seeds of camu-camu through a simplex-centroid mixture design. Then, the profile of phenolic compounds in samples of camu-camu pulp, peels, and seeds from different regions in Brazil and South America was determined by UPLC-ESI-MS/MS. Aqueous ethanol (80%, v/v) yielded the highest extraction for the pulp and peel, while aqueous methanol (50%, v/v) was selected for the seed. Camu-camu parts had p-coumaric acid, catechin, epicatechin, luteolin, rutin, and quercetin, with catechin as the major compound in the pulp, peels, and seeds of all the evaluated samples. The peel showed lower concentrations of these compounds compared with the pulp and the seed; the content of phenolic compounds also differed according to the geographic region. These results broaden the knowledge on phytochemical extraction and composition of camu-camu pulp, peel, and seed and may guide future applications of their extracts in the food industry.


Assuntos
Catequina , Myrtaceae , Brasil , Catequina/análise , Frutas/química , Myrtaceae/química , Fenóis/análise , Extratos Vegetais/química , Espectrometria de Massas em Tandem
2.
Food Chem ; 364: 130350, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34153595

RESUMO

This study investigated the vitamin C content, total phenolic compounds (TPC), and the potential bioactivities (antioxidant, antiproliferative, antibacterial activities, and inhibition capacity against N-nitrosation) of seven neglected and underutilized species (NUS): culantro (Eryngium foetidum), false roselle (Hibiscus acetosella), roselle (Hibiscus sabdariffa), tree basil (Ocimum gratissimum), Barbados Gooseberry (Pereskia aculeata), purslane (Portulaca oleracea), and tannia (Xanthosoma sagittifolium). Phenolic-rich extracts were obtained by a sequential optimization strategy (Plackett-Burman and Central Composite Design). O. gratissimum presented the highest TPC and X. sagittifolium the greater total vitamin C content. Overall, the plant extracts presented promising bioactive capacities, as scavenging capacity against HOCl, H2O2 and ROO• induced oxidation. P. oleracea demonstrated the highest cytostatic effect against ovarian and kidney tumor cells. O. gratissimum effectively inhibited S. Choleraesuis growth. Maximum inhibition on n-nitrosation was showed by O. gratissimum and E. foetidum. These results highlight the studied NUS as sources of potential health-promoting compounds.


Assuntos
Hibiscus , Peróxido de Hidrogênio , Brasil , Extratos Vegetais/farmacologia , Folhas de Planta
3.
J Food Sci ; 86(5): 1599-1619, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33822383

RESUMO

Ilex paraguariensis is a perennial plant used in the production of mate tea, "chimarrão" and "tererê," cosmetics, and other food products. Its leaves are harvested every 12 or 18 months. Approximately 2 to 5 tons of residue are generated per hectare during the harvest. The bioactive composition of this residue has not been characterized to date. Therefore, this paper presents for the first time, the simultaneous characterization of the bioactive compounds of the leaves, thin branches, and thick branches (residue) from I. paraguariensis grown under two cultivation systems: "full sun" and "shaded." The identification and quantification of the compounds was performed using high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS). Consequently, 35 compounds were identified. The average dry weight of phenolic compounds in the residue was 4.1 g/100 g, whereas that in the bark of the residue was 12.9 g/100 g, which was similar to the content found in leaves. The same compounds were identified in the two cultivation systems but with a difference in their contents. While the "full sun" cultivation had a higher content of phenolic acids, the "shaded" cultivation had a higher content of flavonoids and saponins. It was found that the I. paraguariensis residue, particularly the bark, is rich in bioactive compounds, such as quinic, 3-caffeoylquinic, 5-cafefoylquinic, 3,5-dicaffeoylquinic, and 4,5-dicaffeoylquinic acids as well as rutin, and their contents vary according to the cultivation system. Therefore, this residue is an underutilized natural resource with a potential for industrial applications. PRACTICAL APPLICATION: Yerba mate producers will be able to choose the best cultivation system ("full sun" or "shaded") to increase the content of bioactive compounds. New products may be developed with yerba mate residue due to its high concentration of compounds that are beneficial to the human health. New destinations may be applied to yerba mate residue from the harvest pruning, adding commercial value to this unexplored natural resource.


Assuntos
Ilex paraguariensis/química , Compostos Fitoquímicos/análise , Casca de Planta/química , Extratos Vegetais/química , Folhas de Planta/química , Cromatografia Líquida de Alta Pressão , Humanos , Espectrometria de Massas por Ionização por Electrospray/métodos
4.
Anal Bioanal Chem ; 413(11): 2903-2912, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33709193

RESUMO

Phthalic acid esters (PAEs) and adipates are plasticizers with high applicability in several products and building materials (e.g. cosmetics, packing) very persistent in the environment, features which render them ubiquitous pollutants. These substances can contaminate food through the environment (water, air, and soil) and/or migration from packaging materials, which creates a health concern due to their toxicity. This paper describes an eco-friendly dispersive liquid-liquid microextraction (DLLME) procedure to extract five phthalates and bis(2-ethylhexyl) adipate (DEHA) from bottled herbal-based beverages followed by GC-MS/MS quantification. The method showed low limits of detection (5.0-13 µg L-1) and quantification (20-35 µg L-1), good inter- and intraday precision (RSD < 19%), and recoveries ranging from 82 to 111%. It was applied to 16 real samples, of which 13 showed the presence of at least one of the analytes under study. Additionally, an exposure assessment was performed, and resulted in a hazard quotient less than 1 (HQ < 1) for all analytes. Therefore, PAEs and DEHA found in samples do not pose a health issue.


Assuntos
Adipatos/análise , Bebidas Gaseificadas/análise , Ácidos Ftálicos/análise , Poluentes Ambientais/análise , Ésteres , Embalagem de Alimentos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Limite de Detecção , Microextração em Fase Líquida/métodos , Ácidos Ftálicos/química , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
5.
Biol Trace Elem Res ; 197(2): 676-682, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31907800

RESUMO

The concentrations of 3,4-dihydroxybenzoic acid, caffeic acid, catechin, chlorogenic acid, epicatechin, gallic acid, p-coumaric acid, quercetin, rutin, ferulic acid, and the major metals in graviola (Annona muricata), atemoya (A. squamosa x A. cherimola), fruta do conde (A. squamosa), biribá (Rollinia mucosa), and the North American pawpaw (Asimina triloba) were determined by UPLC-ESI (-)-MS/MS. It enabled the identification and quantification of phenolic compounds. Catechin was only found in atemoya, at a concentration of 38.6 µg/g-dw. Only 3,4-dihydroxybenzoic acid was found in the fruit pulps of all five fruits analyzed. Atemoya stands out for not only having catechin but also for having much more epicatechin (239 µg/g-dw) than the other fruits. At the same time, graviola had more p-coumaric acid (62.6 µg/g-dw), and the North American pawpaw had more chlorogenic acid (48.1 µg/g-dw) than the other fruits. Metals were determined by ICP equipped with axially viewed plasma. All five fruit pulps had relatively high levels of potassium, with concentrations ranging from 7640 to 15,000 µg/g-dw, with pawpaw being the lowest and atemoya being the highest. The concentrations of other metals ranged from Ca 547 to 1110, Na 14.3 to 123, P 1210 to 1690, Mg 472 to 980, Mn 1.86 to 5.27, and Zn 5.55 to 7.32 µg/g-dw. All five fruits in the Annonaceae family that were analyzed in this study have several phenolic compounds in them and were good sources of potassium, calcium, phosphorus, and magnesium.


Assuntos
Annonaceae , Frutas , Antioxidantes , Frutas/química , Fenóis/análise , Extratos Vegetais , Quercetina , Espectrometria de Massas em Tandem
6.
Plant Foods Hum Nutr ; 75(1): 70-75, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31848853

RESUMO

Tamarind fruits are consumed worldwide and their seeds have an underexploited potential. We assessed the effect of the addition of a freeze-dried aqueous of extract tamarind seed (FAE) at three concentration levels (0.3, 1.15 and 2%) on the antioxidant capacity (DPPH, ABTS, FRAP and ORAC) and concentrations of total phenolic compounds in tamarind pulp. Conditions used to prepare the aqueous extracts were established using multivariate optimization. Moreover, nectars prepared from pulps combined with FAE were subjected to sensory tests. Tamarind fruits from three geographic regions in Brazil (Minas Gerais, São Paulo and Bahia) that were harvested in 2013 and 2014 were used in the study. Generally, the freeze-dried aqueous extracts increased the concentrations of antioxidants in the pulp. The results revealed a positive correlation between the FAE concentration in the pulp and the antioxidant capacity of all samples, particularly samples from Bahia and Minas Gerais, which presented an increase of up to 1,942% in the ABTS method when 2% FAE was incorporated into the pulp, from approximately 40.1 to 209.1 mMTrolox/gdw and 13.4 to 143.4 mMTrolox/gdw, respectively. Sensory tests indicated the satisfactory acceptance and non-distinction between nectar samples to which FAE was or was not added when the FAE concentration was less than 2.3gFAE/L, regardless of the geographic origin of the samples.


Assuntos
Tamarindus , Antioxidantes , Brasil , Frutas , Extratos Vegetais , Néctar de Plantas
7.
J Food Sci ; 84(3): 406-411, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30758058

RESUMO

Palm oil is widely used in the food industry, and its quality is associated with the free fatty acids (FFA) content. Determination of FFA in oil is time-consuming, requires chemicals and generates residues. There is a trend of applying process analytical technologies (PAT) for fast and nondestructive determination of oil parameters. Portable near-infrared (NIR) spectrometers are cheaper than bench top equipment, and have been used for several tasks in the food processing industry, as it provides fast and reliable data for inline measurements. This study investigated the use of NIR spectra using a portable equipment, combined with both unsupervised and supervised multivariate analyses for identification of palm oil samples with different levels of FFA. Soft independent modeling of class analogy , k-Nearest Neighbors, and linear discriminant analysis models were able to correctly identify 100% of the studied samples with selected wavelengths from NIR spectra. Calibration models were performed for acidity prediction, achieving R2 = 0.97, with root mean square error of prediction = 4.37 for partial least squares model using most relevant wavelengths. These results demonstrate the feasibility of applying a low-cost portable NIR spectrophotometer to predict quality parameters of palm oil. PRACTICAL APPLICATION: This work presents results that show the feasibility of using a low-cost portable near-infrared spectrophotometer for the classification of raw palm oil samples according to free fatty acids contents. Regression models are presented as a fast and nondestructive alternative to classify samples for acidity, which is an important quality parameter and that directly affects the market value of crude palm oil.


Assuntos
Ácidos/química , Óleo de Palmeira/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Calibragem , Análise por Conglomerados , Análise Discriminante , Concentração de Íons de Hidrogênio
8.
Plant Foods Hum Nutr ; 74(1): 135-140, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30644023

RESUMO

Jabuticaba has a high concentration of phenolic compounds, which have a significant antioxidant capacity. Methodologies have been developed to evaluate the ability of plant extracts to fight free radicals such as H2O2, O2•-, HOCl, ONOO- and ROO•. Thus, the capacity of deactivation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in peel and seed extracts of five varieties of jabuticaba was evaluated. Sabará peel (SFP) deactivated HOCl with IC50 9.24 µg. mL-1; Paulista seed (PF) deactivated O2•- with IC50 16.15 µg. mL-1; Coroada seed (CFP) deactivated ONOO- with IC50 3.84 µg. mL-1; the peel of CFP deactivated ONOO- with IC50 5.88 µg. mL-1; the peel of SFP deactivated the ROO• at 918.16 µmol TE. g-1; and Sabará seed deactivated H2O2 with 49.11% inhibition at a concentration of 125 µg. mL-1 of extract. These results demonstrate the high antioxidant potential of this fruit, indicating that it could be extremely beneficial to human health.


Assuntos
Antioxidantes/farmacologia , Myrtaceae/química , Extratos Vegetais/farmacologia , Espécies Reativas de Nitrogênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidores , Frutas/química , Humanos , Extratos Vegetais/química , Sementes/química
9.
Food Res Int ; 115: 160-166, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599928

RESUMO

Camu-camu, a typical Amazonian fruit, is known for the high vitamin C content of the peel and pulp. As vitamin C is widely used in the food, pharmaceutical, and cosmetics industries, it is of interest to study new sources, extraction techniques, and analytical methods for the identification and quantification of this compound. Here, evaluation was made of extraction and quantification methods, as well as the differences in vitamin C content according to the origin and part of the camu-camu fruit. The extraction techniques studied were pressurized liquid extraction (PLE), acid extraction, and maceration. The analytical methods evaluated were titrimetry and chromatography. Camu-camu samples were obtained from different regions, and the peel and pulp were studied separately. Acid extraction using sulfuric acid as solvent provided the highest vitamin C yields, while PLE, as a completely clean technique, proved to be a promising alternative for the recovery of ascorbic acid (L-AA). The application of an ultra-high performance liquid chromatography methodology (UHPLC-DAD) enabled the fast identification and quantification of L-AA and dehydroascorbic acid (DHAA), with high resolution, sensitivity, and specificity. The results obtained using the chromatographic and titration methods were not significantly different (p < 0.05), indicating that titrimetry is useful for routine analyses. L-AA and DHAA were found in the peel, but only L-AA was found in the pulp. The variation of vitamin C content among the lots could be explained by the edaphoclimatic conditions. The combination of a clean extraction technique and a fast analytical method is a promising approach for the determination of vitamin C in food products.


Assuntos
Ácido Ascórbico/análise , Frutas/química , Myrtaceae/química , Extratos Vegetais/química , Brasil , Cromatografia Líquida de Alta Pressão/métodos , Ácido Desidroascórbico/análise , Preparações Farmacêuticas/análise , Sensibilidade e Especificidade , Solventes
10.
Food Res Int ; 102: 348-354, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29195958

RESUMO

This study determined the content of chlorogenic acids (CA) and rutin during successive aqueous extraction of yerba mate for tererê and chimarrão from four yerba mate types (smooth, native, traditional and coarse ground). Aqueous extracts were prepared aiming to simulate homemade procedure by partially (chimarrão) or completely (tererê) immersing the herb into hot (chimarrão) or cold (tererê) water (30 times consecutively). The content of CA and rutin in the aqueous extracts was compared to those in methanolic extracts (exhaustive extraction). Tererê aqueous extracts gave higher amounts of all phenolic compounds (2.5 to 6 times higher than chimarrão). Among chimarrão, course-ground aqueous extracts had on average 15% more PC (phenolic compounds). By comparing the content in aqueous and methanolic extracts, after 30 successive extractions, on average 14% of the total amount of CA in yerba mate leaves and 9% of rutin were transferred to the chimarrão extracts, whereas tererê achieved between 40% and 100% of transference. Thus, this study shows that CA and rutin are continuously extracted during the preparation of aqueous extracts of chimarrão and tererê, favoring a high intake of these antioxidant species by consumers.


Assuntos
Bebidas/análise , Ácido Clorogênico/análise , Flavonoides/análise , Ilex paraguariensis/química , Extratos Vegetais/análise , Folhas de Planta/química , Ácido Clorogênico/química , Flavonoides/química , Extratos Vegetais/química
11.
Food Res Int ; 99(Pt 1): 522-530, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28784513

RESUMO

This study analysed 100 plants employed in Brazil as ingredients to infusions for their caffeic acid, 3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), 3,4-dicaffeoylquinic acid (3,4-DQA), 3,5-dicaffeoylquinic acid (3,5-DQA), and 4,5-dicaffeoylquinic acid (4,5-DQA) contents. The samples were collected from public markets and analysed using ultra-high performance liquid chromatography (UPLC). The highest concentrations of chlorogenic acids were found in yerba mate (Ilex paraguariensis), 9,2g·100g-1, white tea (Camellia sinensis), winter's bark (Drimys winteri), green tea (Camellia sinensis), elderflower (Sambucus nigra), and Boehmeria caudata (known as assa-peixe in Brazil), 1,1g·100g-1. The present work showcased the investigation of chlorogenic acids in a wide range of plants not yet studied in this regard and also resulted in a comparative table which explores the content of six isomers in the samples.


Assuntos
Ácido Clorogênico/isolamento & purificação , Plantas/química , Boehmeria/química , Brasil , Camellia sinensis/química , Cromatografia Líquida de Alta Pressão , Drimys/química , Humanos , Ilex paraguariensis/química , Isomerismo , Plantas/classificação , Sambucus nigra/química
12.
Plant Foods Hum Nutr ; 72(2): 219-223, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28466135

RESUMO

The beverage obtained from the yerba mate tea, besides being the most consumed in Brazil, has high concentrations of chlorogenic acids. In this study, a central composite design was employed to establish the best infusion time, temperature and water volume to maximize the extraction of chlorogenic acids 5-caffeoylquinic (5CQ), 3.4-dicaffeoylquinic (3.4 DQ), 3.5-dicaffeoylquinic (3.5 DQ) and 4.5-dicaffeoylquinic (4.5 DQ), from the leaves and stems of yerba mate tea (beverage ready for consumption). Analyses were performed by high-performance liquid chromatography and the optimum conditions were obtained through the use of the desirability function of Derringer and Suich. The maximum chlorogenic acids content in the beverage was obtained when the infusion was prepared with 2 g of mate tea, in 300 mL of water at 95 °C, under infusion for 16 min. The optimal conditions were applied for the preparation of beverages from 15 commercial samples of yerba mate tea, and it was observed that the sum of the concentration of the four compounds showed variation of up to 79 times between the average of the samples, which can be attributed to climatic conditions of cultivation of the plant and/or of processing.


Assuntos
Ácido Clorogênico/isolamento & purificação , Ilex paraguariensis/química , Ácido Quínico/análogos & derivados , Brasil , Ácido Clorogênico/análise , Cromatografia Líquida de Alta Pressão , Metanol , Folhas de Planta/química , Caules de Planta/química , Ácido Quínico/análise , Ácido Quínico/isolamento & purificação , Chás de Ervas
13.
Food Chem ; 190: 1159-1167, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26213090

RESUMO

This work used a central composite design to optimise a reverse phase high performance liquid chromatographic method for the simultaneous separation of gallic, syringic, 5-caffeoylquinic, caffeic, p-coumaric, ferulic, 3,4-dicaffeoylquinic, 3,5-dicaffeoylquinic, 4,5-dicaffeoylquinc acids, rutin in aqueous extracts of yerba mate (Ilex paraguariensis). The effect of the linear gradient time, the initial and the final methanol concentration in the mobile phase on the peak resolution and peak symmetry was evaluated. The 26 responses obtained were simultaneously optimised using the desirability method of Derringer and Suich. According to results, the increasing in the resolution and peak symmetry was achieved by using lesser levels of methanol in both initial and final gradient elution (-1.68, -1), as well as higher gradient times (+1, +1.68). The optimal condition (13.9-40% of methanol in 39.4 min) were successfully applied for analysis of chimarrão, tererê and mate tea aqueous extracts, which showed as excellent sources of chlorogenic acids.


Assuntos
Bebidas/análise , Cromatografia Líquida de Alta Pressão/métodos , Ilex paraguariensis/química , Fenóis/análise , Extratos Vegetais/química
14.
J Food Sci ; 80(10): C2127-33, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26305279

RESUMO

UNLABELLED: Dovyalis hebecarpa, which is also known as the Ceylon gooseberry, is an attractive exotic purple berry that is produced in the southwest of Brazil with high yields. Current literature lacks information about the nutritional composition and antioxidant capacity of this fruit. As such, this work aimed to evaluate and compare the proximate composition, phytochemical content, and antioxidant capacity of D. hebecarpa over two seasons through the application of a range of different methods, including FRAP, ABTS, and ORAC assays. The proximate composition and biometric parameters were monitored for quality purposes. The results significantly changed between seasons in accordance with variations in rain incidence and average temperatures. The Ceylon gooseberry contained a similar or higher content of anthocyanins (ACY) than other berries commonly consumed in human diet. These ACY were identified at higher levels in the fruit's skin (284 to 351 mg of cyanidin-3-glucoside equivalents/100 g of fresh weight [FW]) than in its pulp (49 to 69 mg/100 g of FW). The use of an ORAC assay identified higher antioxidant activity (145 µmol of Trolox equivalents [TE]/g in the skins and 179 µmol of TE/g in the pulp on a FW basis) than all other methods used to determine antioxidant activity. Thus, D. hebecarpa is a rich source of ACY that demonstrates high antioxidant activity against the peroxyl radicals formed in ORAC assay conditions. PRACTICAL APPLICATION: Ceylon gooseberry fruit is a source of phytochemicals that could be used in the human diet providing defense against free radicals damage. Moreover, the skins of the fruit, which are not typically consumed, contained higher levels of polyphenols than the pulp. This indicates that the skins of the Ceylon gooseberry may represent a promising source of natural pigments and antioxidants for industrial applications.


Assuntos
Antocianinas/farmacologia , Antioxidantes/farmacologia , Frutas/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Salicaceae/química , Antocianinas/análise , Antioxidantes/análise , Brasil , Dieta , Radicais Livres/metabolismo , Glucosídeos/análise , Humanos , Extratos Vegetais/química , Polifenóis/análise , Ribes/química , Sri Lanka
15.
Food Chem ; 170: 366-77, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25306359

RESUMO

In recent years, agronomical researchers began to cultivate several olive varieties in different regions of Brazil to produce virgin olive oil (VOO). Because there has been no reported data regarding the phenolic profile of the first Brazilian VOO, the aim of this work was to determine phenolic contents of these samples using rapid-resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry. 25 VOO samples from Arbequina, Koroneiki, Arbosana, Grappolo, Manzanilla, Coratina, Frantoio and MGS Mariense varieties from three different Brazilian states and two crops were analysed. It was possible to quantify 19 phenolic compounds belonging to different classes. The results indicated that Brazilian VOOs have high total phenolic content because the values were comparable with those from high-quality VOOs produced in other countries. VOOs from Coratina, Arbosana and Grappolo presented the highest total phenolic content. These data will be useful in the development and improvement of Brazilian VOO.


Assuntos
Cromatografia Líquida/métodos , Olea/química , Azeite de Oliva/química , Fenóis/análise , Óleos de Plantas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Brasil
16.
Food Chem ; 164: 81-8, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24996309

RESUMO

Hydrophilic and lipophilic extracts of ten cultivars of Highbush and Rabbiteye Brazilian blueberries (Vaccinium corymbosum L. and Vacciniumashei Reade, respectively) that are used for commercial production were analysed for antioxidant activity by the FRAP, ORAC, ABTS and ß-carotene-linoleate methods. Results were correlated to the amounts of carotenoids, total phenolics and anthocyanins. Brazilian blueberries had relatively high concentration of total phenolics (1,622-3,457 mg gallic acid equivalents per 100 g DW) and total anthocyanins (140-318 mg cyanidin-3-glucoside equivalents per 100 g DW), as well as being a good source of carotenoids. There was a higher positive correlation between the amounts of these compounds and the antioxidant activity of hydrophilic compared to lipophilic extracts. There were also significant differences in the level of bioactive compounds and antioxidant activities between different cultivars, production location and year of cultivation.


Assuntos
Antioxidantes/análise , Mirtilos Azuis (Planta)/química , Frutas/química , Extratos Vegetais/química , Antocianinas/análise , Brasil , Carotenoides/análise , Interações Hidrofóbicas e Hidrofílicas , Lipídeos , Oxirredução , Fenóis/análise , Especificidade da Espécie
17.
Food Chem ; 164: 347-54, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24996344

RESUMO

Originally from Asia, Dovyalis hebecarpa is a dark purple/red exotic berry now also produced in Brazil. However, no reports were found in the literature about phenolic extraction or characterisation of this berry. In this study we evaluate the extraction optimisation of anthocyanins and total phenolics in D. hebecarpa berries aiming at the development of a simple and mild analytical technique. Multivariate analysis was used to optimise the extraction variables (ethanol:water:acetone solvent proportions, times, and acid concentrations) at different levels. Acetone/water (20/80 v/v) gave the highest anthocyanin extraction yield, but pure water and different proportions of acetone/water or acetone/ethanol/water (with >50% of water) were also effective. Neither acid concentration nor time had a significant effect on extraction efficiency allowing to fix the recommended parameters at the lowest values tested (0.35% formic acid v/v, and 17.6 min). Under optimised conditions, extraction efficiencies were increased by 31.5% and 11% for anthocyanin and total phenolics, respectively as compared to traditional methods that use more solvent and time. Thus, the optimised methodology increased yields being less hazardous and time consuming than traditional methods. Finally, freeze-dried D. hebecarpa showed high content of target phytochemicals (319 mg/100g and 1,421 mg/100g of total anthocyanin and total phenolic content, respectively).


Assuntos
Frutas/química , Extração Líquido-Líquido/métodos , Extratos Vegetais/química , Polifenóis/isolamento & purificação , Ribes/química , Acetona/análise , Antocianinas/química , Brasil , Etanol/análise , Frutas/crescimento & desenvolvimento , Fenóis/análise , Ribes/crescimento & desenvolvimento , Solventes/química , Sri Lanka , Água/análise
18.
Food Chem ; 146: 558-68, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24176381

RESUMO

In Brazil, the consumption of extra-virgin olive oil (EVOO) is increasing annually, but there are no experimental studies concerning the phenolic compound contents of commercial EVOO. The aim of this work was to optimise the separation of 17 phenolic compounds already detected in EVOO. A Doehlert matrix experimental design was used, evaluating the effects of pH and electrolyte concentration. Resolution, runtime and migration time relative standard deviation values were evaluated. Derringer's desirability function was used to simultaneously optimise all 37 responses. The 17 peaks were separated in 19min using a fused-silica capillary (50µm internal diameter, 72cm of effective length) with an extended light path and 101.3mmolL(-1) of boric acid electrolyte (pH 9.15, 30kV). The method was validated and applied to 15 EVOO samples found in Brazilian supermarkets.


Assuntos
Eletroforese Capilar/métodos , Fenóis/química , Óleos de Plantas/química , Brasil , Eletroforese Capilar/instrumentação , Concentração de Íons de Hidrogênio , Azeite de Oliva , Fenóis/isolamento & purificação
19.
Nutrition ; 29(6): 865-71, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23422542

RESUMO

OBJECTIVE: Phytosterols have been used alone, or combined with lipid-altering drugs, to reduce cholesterol levels and the burden of cardiovascular disease. Considerable variation in the composition of phytosterols exists and its consumption, in a regular diet, by the Brazilian population is still unknown. Thus, the aim of the present study was to determine the phytosterols content of the most consumed plant foods and to estimate the phytosterols intake by this population. METHODS: Intake of plant foods of a representative population of the city of São Paulo (n = 1609), randomly selected on the basis of the Brazilian Institute for Geography and Statistics census data (2010), was obtained by a food frequency questionnaire (FFQ). Foods were chosen on the basis of the Consume Expenditure Survey (2002-2003) and from answers to the FFQ. Phytosterols composition of most consumed greens, legumes, cereals, and seeds, fruits, and vegetable oils was determined by gas chromatography (flame ionization detection). Daily phytosterols intake was estimated in terms of mg per 100 g (mg/100 g(-1)) of edible portion. Underreporters and overreporters were excluded. RESULTS: Mean (SE) daily phytosterols intake in the diet of the study population was 100.6 (1.2) mg, with ß-sitosterol as the largest sterol component (65.4%), followed by campesterol (23.2%), and stigmasterol (10%). No significant changes in daily phytosterols intake were observed after exclusion of underreporters and overreporters. Considerable variation was observed in phytosterols content among the most consumed plant foods. CONCLUSIONS: Analysis of phytosterols composition in most consumed plant foods has shown that phytosterols content varied among food groups. Dietary intake of phytosterols in a large population of the city of São Paulo is in the same range of some countries.


Assuntos
Colesterol/análogos & derivados , Comportamento Alimentar , Fitosteróis/administração & dosagem , Sitosteroides/administração & dosagem , Estigmasterol/administração & dosagem , Adulto , Idoso , Brasil , Colesterol/administração & dosagem , Colesterol/análise , Colesterol/sangue , Cromatografia Gasosa , Estudos Transversais , Grão Comestível/química , Fabaceae/química , Feminino , Frutas/química , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Fitosteróis/análise , Óleos de Plantas/química , Plantas Comestíveis/química , Sementes/química , Sitosteroides/análise , Estigmasterol/análise , Inquéritos e Questionários , Verduras/química , Adulto Jovem
20.
J Chromatogr A ; 1218(21): 3345-50, 2011 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-21227437

RESUMO

A method involving headspace-solid phase micro-extraction (HS-SPME), gas chromatography with flame ionization detection (GC-FID) and gas chromatography with mass spectrometry (GC-MS) was developed and optimized to investigate the volatile composition of Capsicum chili peppers. Five SPME fibers were tested for extraction: carboxen/polydimethylsiloxane (CAR/PDMS-75µm), polydimethylsiloxane (PDMS-100µm), divinylbenzene/polydimethylsiloxane (DVB/PDMS-65µm), carbowax/divinylbenzene (CW/DVB-70µm), and divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS-50/30µm), the last of which was shown to be the most efficient fiber to trap the volatile compounds. Optimization of the extraction conditions was carried out using multivariate strategies such as factorial design and response surface methodology. Eighty three compounds were identified by GC-MS when using the optimized extraction conditions, the majority of which were esters.


Assuntos
Capsicum/química , Extratos Vegetais/isolamento & purificação , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/isolamento & purificação , Análise de Variância , Ionização de Chama , Temperatura Alta , Análise dos Mínimos Quadrados , Extratos Vegetais/análise , Compostos Orgânicos Voláteis/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA