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1.
Food Res Int ; 157: 111469, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761700

RESUMO

This study aimed to investigate the impact of different microalgal matrices on the bioaccessibility and uptake by Caco-2 cells of carotenoids and chlorophylls. In this way, the microalgal ingredients/products (whole dry biomass [WDB], whole ultrasonicated paste [WUP], and liposoluble pigment emulsion [LPE]) obtained from Chlorella vulgaris and Arthrospira platensis were submitted to in vitro simulated digestion. Apical uptake of pigments in micelles generated during the simulated digestion by Caco-2 human intestinal cells was determined. The influence of simulated digestion on carotenoid and chlorophyll stability and bioaccessibility was assessed by HPLC-PDA-MS/MS and the carotenoids and chlorophylls' bioaccessibility and cellular uptake were shown to be boosted according to the matrix (LPE > WUP > WDB). Our findings showed that Chlorella vulgaris and Arthrospira platensis could be considered in formulations when carotenoids and chlorophylls are the target molecules in the ingredients/products.


Assuntos
Chlorella vulgaris , Microalgas , Células CACO-2 , Carotenoides , Clorofila , Digestão , Humanos , Spirulina , Espectrometria de Massas em Tandem
2.
Food Chem X ; 13: 100245, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35499011

RESUMO

Sustainable extraction processes based on alternative solvents to recover bioactive compounds of different raw materials have been highlighted as excellent alternatives to supply the needs of society towards a bioeconomy strategy. Little is known about the safety and biological effect of compounds extracted by these processes. In this work, carotenoids from Bactris gasipaes wastes obtained by an IL-based process were investigated in terms of safety, anti-inflammatory and, antioxidant activity in a high-fat-diet animal model on the kidney. Wistar rats were supplemented or not by carotenoids extracted with IL or VOS. The animals supplemented with carotenoids had lower weight than control and high-fat diets. In the animals supplemented with carotenoids, the group IL improved anti-inflammatory and antioxidant activity compared with carotenoids obtained by VOS. Also, the group HFD-VOS showed moderate-severe injuries on the kidney. Then, ILs could represent a novel tool for natural pigments safely applied to food industry.

3.
Food Res Int ; 148: 110596, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507741

RESUMO

The composition of microalgae can contribute to nutritious and functional diets. Among the functional compounds, carotenoids are in focus since positive effects on human health have been established, which are in turn related to their bioaccessibility. In addition to essential nutrients, our hypothesis was that microalgae biomasses could be used as sources of bioaccessible carotenoids. Thus, this study determined for the first time the bioaccessibility of carotenoids from biomass of Scenedesmus bijuga and Chlorella sorokiniana and their possible relationship with the lipid composition of the matrix. The samples were submitted to in vitro digestion protocol, and carotenoids were determined by HPLC-PDA-MS/MS. Individual bioaccessibility of carotenoids was ≥ 3.25%. In general, compounds in their cis conformation were more bioaccessible than trans; and total carotenes more than total xanthophylls. Twelve compounds were bioaccessible from the biomass of S. bijuga, and eight in C. sorokiniana. In S. bijuga, the bioaccessibility of total carotenoids was 7.30%, and the major bioaccessible carotenoids were 9-cis-ß-carotene (43.78%), 9-cis-zeaxanthin (42.30%) followed by 9-cis-lutein (26.73%); while in C. sorokiniana, the total bioaccessibility was 8.03%, and 9-cis-ß-carotene (26.18%), all-trans-ß-carotene (13.56%), followed by 13-cis-lutein (10.71%) were the major compounds. Overall, the total content of lipids does not influence the bioaccessibility of total carotenoids. Still, the lipid composition, including structural characteristics such as degree of saturation and chain length of the fatty acid, impacts the promotion of individual bioaccessibility of carotenes and xanthophylls of microalgae. Finally, the results of this study can assist the development of microalgae-based functional food ingredients and products.


Assuntos
Chlorella , Microalgas , Carotenoides , Ácidos Graxos , Humanos , Espectrometria de Massas em Tandem
4.
Food Funct ; 12(18): 8478-8491, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34297028

RESUMO

Ionic liquids (ILs) have been proposed as more efficient and sustainable solvents to replace volatile organic solvents (VOSs). However, the drawbacks associated with their use are still limiting the regular application of bioactive compounds obtained from the processes they mediate as food ingredients. It is true that the number of ILs approved by the Food and Drug Administration for food applications is still low and mainly focused on the ones from the quaternary ammonium family. However, this trend is changing, judging from the evidence that industries are surpassing overgeneralization about ILs (on price and toxicity) and starting to consider the potential and performance of ILs as solvents. Despite the examples of industries applying ILs in their processes, the use of bioactive compounds obtained from IL-based processes as ingredients in food formulations is still a big challenge. The positive influence of carotenoids on diseases associated or originating from the inflammatory scenario including, among others, obesity, is not new. Moreover, it is also well known that the poorest population worldwide does not have the recommended intake of carotenoids, especially those pro-vitaminic A. In an attempt to help answer this issue, dietary supplements containing adequate doses of natural carotenoids are expected to be the solution, or at least, part of the solution for a healthier life, but also, to reduce hunger. Thus, complete studies evaluating the toxicological potential and the real viability of adding these bioactive compounds in food formulations proving (or not!) their safety to consumers and handlers are highly demanded. This work proposes to investigate the potential of carotenoids extracted from Bactris gasipaes feedstocks mediated by an ethanolic solution of an imidazolium-based IL. Thus, male Wistar rats were randomized in six different groups, supplemented or not by carotenoids extracted by IL or VOS, and fed by control- and/or high-fat-diets (HFD). The adipose tissue-liver axis was studied as a model to investigate the influence of the carotenoids on the levels of inflammation and oxidative stress markers. The main results showed that animals supplemented with carotenoids extracted with IL displayed improvements in serum parameters, besides lower metabolic efficiency, and antioxidant response on the liver, even when fed with HFD. However, animals supplemented with carotenoids extracted by VOS showed higher levels of pro-inflammatory markers and huge oxidative stress on the liver.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Carotenoides/farmacologia , Inflamação/tratamento farmacológico , Líquidos Iônicos/química , Fígado/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Carotenoides/química , Metabolismo Energético/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar
5.
Front Microbiol ; 12: 659911, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34168628

RESUMO

Propolis is a resinous material rich in flavonoids and involved in several biological activities such as antimicrobial, fungicide, and antiparasitic functions. Conventionally, ethanolic solutions are used to obtain propolis phytochemicals, which restrict their use in some cultures. Given this, we developed an alcohol-free high-performance extractive approach to recover antibacterial and antioxidants phytochemicals from red propolis. Thus, aqueous-solutions of ionic liquids (IL) and eutectic solvents were used and then tested for their total flavonoids, antioxidant, and antimicrobial activities. The surface-responsive technique was applied regarding some variables, namely, the time of extraction, the number of extractions, and cavitation power (W), to optimize the process (in terms of higher yields of flavonoids and better antioxidant activity). After that, four extractions with the same biomass (repetitions) using 1-hexyl-3-methylimidazolium chloride [C6mim]Cl, under the operational conditions fixed at 3.3 min and 300 W, were able to recover 394.39 ± 36.30 mg RuE. g-1 of total flavonoids, with total antioxidant capacity evaluated up to 7595.77 ± 5.48 µmol TE. g-1 dried biomass, besides inhibiting the growth of Staphylococcus aureus and Salmonella enteritidis bacteria (inhibition halo of 23.0 ± 1.0 and 15.7 ± 2.1, respectively). Aiming at the development of new technologies, the antimicrobial effect also presented by [C6mim]Cl may be appealing, and future studies are required to understand possible synergistic actions with propolis phytochemicals. Thereby, we successfully applied a completely alcohol-free method to obtain antimicrobials phytochemicals and highly antioxidants from red propolis, representing an optimized process to replace the conventional extracts produced until now.

6.
Molecules ; 26(5)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668167

RESUMO

Jussara pulp (Euterpe edulis Mart.) is rich in bioactive compounds known to be protective mediators against several diseases. In this context, nevertheless, anthocyanins, the most abundant natural pigment in jussara, are sensitive to temperature, pH, oxygen, and light conditions, leading to instability during food storage or digestion, and, thus jeopardizing the antioxidant proprieties retained by these flavonoids and limiting industrial application of the pulp. The production of nanostructures, from synthetic and natural polymers, containing natural matrices rich in bioactive compounds, has been widely studied, providing satisfactory results in the conservation and maintenance of the stability of these compounds. The current work aimed to compare uniaxial and coaxial electrospinning operation modes to produce core-shell jussara pulp nanofibers (NFs). Additionally, the parameters employed in the electrospinning processes were optimize using response surface methodology in an attempt to solve stability issues for the bioactive compounds. The best experimental conditions provided NFs with diameters ranging between 110.0 ± 47 and 121.1 ± 54 nm. Moreover, the coaxial setup improved jussara pulp NF formation, while further allowing greater integrity of NFs structures.


Assuntos
Antioxidantes/química , Materiais Biocompatíveis/química , Euterpe/química , Nanofibras/química , Brasil , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Propriedades de Superfície
7.
Food Res Int ; 140: 110031, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33648259

RESUMO

The bioaccessibility and subsequent uptake by Caco-2 human intestinal cells of chlorophyll pigments from Scenedesmus obliquus were determined for the first time. In order to evaluate the impact of different types of the matrix on bioaccessibility of chlorophyll from microalgae, three different products were evaluated: isolated chlorophyll extract (ICE); wet ultrasonicated biomass (WUB); and whole dried biomass (WDB). The samples were submitted to in vitro digestion model according to the INFOGEST protocol, and Caco-2 cells determined the intestinal uptake. Chlorophyll pigments were determined by HPLC-PDA-MS/MS. A total of ten chlorophyll pigments (8,318.48 µg g-1) were separated in S. obliquus biomass, with chlorophyll a (3,507.76 µg g-1) and pheophytin a' (1,598.09 µg g-1) the major ones. After in vitro digestion, all tested products showed bioaccessible chlorophylls. However, the total bioaccessibility results were as follows: ICE (33.45%), WUB (2.65%), WDB (0.33%). Five compounds were bioaccessible in ICE, three in WUB, and one in WDB. The hydroxypheophytin a showed the highest bioaccessibility (212%) in ICE, while pheophytin a' in WUB (11%) and WDB (2%). As a result, bioavailability estimates of ICE using the Caco-2 cell showed hydroxypheophytin a (102.53%), followed by pheophytin a' (64.69%) as the chlorophyll pigments most abundant in intestinal cells. In summary, from a nutritional perspective, these three types of the matrix (WDB, WUB, and ICE) influence the promotion of chlorophyll bioaccessibility. In this way, the data suggest that chlorophylls bioaccessibility from ICE is greater than that in WDB and WUB. Therefore, ICE should be considered a product that provides bioavailable chlorophyll and could be the best choice, such as ingredients in the development of functional foods chlorophyll-based.


Assuntos
Clorofila , Microalgas , Células CACO-2 , Clorofila A , Humanos , Absorção Intestinal , Espectrometria de Massas em Tandem
8.
Food Chem ; 339: 127818, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32854038

RESUMO

Native extracts from orange peels were obtained by a conventional method using acetone and, an alternative method using ionic liquid (1-butyl-3-methylimidazolium chloride ([C4mim]Cl)). The bioaccessibilities and cellular uptakes of carotenoids, esters and chlorophylls were evaluated, since the influence of esterification on bioaccessibility and bioavailability is not well established. For this, the extracts were emulsified, submitted to in vitro simulated digestion model according to the INFOGEST protocol, followed by uptake by Caco-2 cells. Compounds were separated, identified and quantified by HPLC-PDA-MS/MS. After digestion, 22.0% and 26.2% of the total carotenoids and 45.9% and 68.7% of the chlorophylls were bioaccessible from the acetone and [C4mim]Cl extracts, respectively. The bioaccessibilities of xanthophylls and carotenes were significantly higher than those of the mono- and diesters. The uptake by Caco-2 cells varied from 130.2 to 131.9 ng/mg cell protein for total carotenoids and from 243.8 to 234.2 ng/mg cell protein for chlorophylls in the acetone and [C4mim]Cl extracts, respectively. In general, xanthophylls and esters were better absorbed than carotenes.


Assuntos
Carotenoides/farmacocinética , Fracionamento Químico/métodos , Clorofila/farmacocinética , Citrus sinensis/química , Disponibilidade Biológica , Células CACO-2 , Carotenoides/análise , Carotenoides/isolamento & purificação , Clorofila/análise , Clorofila/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Digestão , Ésteres/farmacocinética , Frutas/química , Humanos , Líquidos Iônicos/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacocinética , Espectrometria de Massas em Tandem , Xantofilas/análise , Xantofilas/isolamento & purificação , Xantofilas/farmacocinética
9.
Nutr Rev ; 79(1): 76-87, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33301001

RESUMO

Vitamin A (VA) and its pro-vitamin carotenoids are naturally occurring lipophilic compounds involved in several cellular processes and metabolic pathways. Despite their broad spectrum of activities in the general population, dietary deficiencies of these compounds can potentially affect pregnancy outcomes. Since maternal nutritional status and diet composition during pregnancy and lactation can have long-lasting effects in offspring until adulthood, this study presents an overview of VA and the role of pro-VA carotenoids during pregnancy and lactation - the nutrition, metabolism, and biological effects in the offspring. The review aimed to discuss the pro-VA carotenoids and VA-associated pathways and summarize the results with reference to gestational disorders, and VA and pro-VA carotenoids as preventive agents. Also, considering that obesity, overweight, and metabolic diseases are major public health concerns worldwide, fetal and neonatal development is discussed, highlighting the physiological role of these molecules in obesity prevention. This review comprehensively summarizes the current data and shows the potential impact of these compounds on nutritional status in pregnancy and lactation.


Assuntos
Carotenoides/metabolismo , Fenômenos Fisiológicos da Nutrição do Lactente , Fenômenos Fisiológicos da Nutrição Materna , Redes e Vias Metabólicas , Vitamina A/metabolismo , Animais , Aleitamento Materno , Carotenoides/farmacologia , Dieta , Feminino , Feto/metabolismo , Humanos , Lactente , Recém-Nascido , Lactação , Estado Nutricional , Obesidade/etiologia , Obesidade/metabolismo , Gravidez , Vitamina A/farmacologia , Vitamina A/fisiologia , Deficiência de Vitamina A
10.
Compr Rev Food Sci Food Saf ; 20(1): 787-818, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33325108

RESUMO

This review will discuss, under the Circular Economy and Biorefinery concepts, the performance of the alternative solvents in the downstream process to recover natural pigments in a more sustainable way. Conventionally, pigments marketed on an industrial scale are produced through chemical synthesis by using petroleum derivatives as the main raw material. Also, the current production chain of the synthetic dyes is linear, with no solvent recycling and waste generation. Thus, the most promising processes of extraction and purification of natural pigments and strategies on the polishing of the solvents are here reviewed. In this review, the use of alternative solvents, namely, ionic liquids, eutectic solvents, aqueous solutions of surfactants, and edible oils, for recovering natural pigments was reviewed. Works discussing higher extraction yields and selectivity, while maintaining the stability of the target pigments, were reported. Also, a panorama between Sustainability and Circular Economy prospection was discussed for better comprehension of the main advances in the field. Behind the analysis of the works published so far on the theme, the most important lacunas to overcome in the next years on the field were pointed out and discussed. Also, the future trends and new perspectives to achieve the economic viability and sustainability of the processes using alternative solvents will be scrutinized.


Assuntos
Líquidos Iônicos , Fenômenos Químicos , Corantes , Alimentos , Solventes
11.
Antioxidants (Basel) ; 8(12)2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31816926

RESUMO

Orange peel is a by-product produced in large amounts that acts as a source of natural pigments such as carotenoids. Xanthophylls, the main carotenoid class found in citrus fruit, can be present in its free form or esterified with fatty acids, forming esters. This esterification modifies the compound's chemical properties, affecting their bioavailability in the human body, and making it important to characterize the native carotenoid composition of food matrices. We aimed to evaluate the non-saponified carotenoid extracts of orange peel (cv. Pera) obtained using alternative green approaches: extraction with ionic liquid (IL), analyzed by high performance liquid chromatography coupled to a diode array detector with atmospheric pressure chemical ionization and mass spectrometry HPLC-DAD-APCI-MS, and supercritical fluid extraction (SFE), followed by supercritical fluid chromatography with atmospheric pressure chemical ionization and triple quadrupole mass spectrometry detection (SFC-APCI/QqQ/MS) in an online system. Both alternative green methods were successfully applied, allowing the total identification of five free carotenoids, one apocarotenoid, seven monoesters, and 11 diesters in the extract obtained with IL and analyzed by HPLC-DAD-APCI-MS, and nine free carotenoids, six carotenoids esters, 19 apocarotenoids, and eight apo-esters with the SFE-SFC-APCI/QqQ/MS approach, including several free apocarotenoids and apocarotenoid esters identified for the first time in oranges, and particularly in the Pera variety, which could be used as a fruit authenticity parameter.

12.
Food Res Int ; 126: 108653, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31732025

RESUMO

The aim of this study was to develop a new method for carotenoid extraction from orange peel, using ionic liquid (IL) to replace conventional organic solvents, assisted by ultrasound. Four different IL were tested: 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), and 1-hexyl-3-methylimidazolium chloride ([HMIM][Cl]). Response surface methodology was applied in order to optimize the carotenoid extraction conditions, and Amberlite XAD-7HP resin was used to separate the carotenoids from the IL, allowing their recovery. Determination of carotenoids was carried out by high-performance liquid chromatography coupled to photodiode array and mass spectrometry detectors (HPLC-DAD-MSn). Thermal stability at different temperatures (60 °C and 90 °C) and peroxyl radical scavenging activity of the carotenoid extracts obtained with acetone and IL were evaluated. [BMIM][Cl] was the most effective IL, leading to a total carotenoid content of 32.08 ±â€¯2.05 µg/g, while 7.88 ±â€¯0.59 µg/g of dry matter was obtained by acetone extraction. IL and carotenoid recoveries using XAD-7HP resin were in the range of 59.5-63.8% and 52.2-58.7%, respectively. A carotenoid extract was successfully obtained with IL, finally isolated just by using ethanol, besides being more stable and presenting higher antioxidant activity than that obtained with acetone.


Assuntos
Carotenoides/isolamento & purificação , Citrus sinensis/química , Frutas/química , Líquidos Iônicos , Acetona , Antioxidantes/química , Carotenoides/química , Estabilidade de Medicamentos , Sequestradores de Radicais Livres/química , Temperatura Alta , Imidazóis , Reprodutibilidade dos Testes , Ondas Ultrassônicas
13.
Phytother Res ; 28(1): 28-32, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23436457

RESUMO

Various species of the genus Passiflora have been extensively used in traditional medicine as sedatives, anxiolytics, diuretics and analgesics. In the present study, after the identification and quantification of phytochemical compounds from yellow passion fruit pulp by liquid chromatography-photodiode array-mass spectrometry (HPLC-PDA-MS/MS), its antihypertensive effect was investigated on spontaneously hypertensive rats. Additionally, the renal function, evaluated by kidney/body weight, serum creatinine, proteinuria, urinary flow, reduced glutathione (GSH) levels and thiobarbituric acid-reactive substances (TBARS) and mutagenicity in bone marrow cells were assessed to evaluate the safety of passion fruit consumption. Yellow passion fruit pulp (5, 6 or 8 g/kg b.w.) was administered by gavage once a day for 5 consecutive days. HLPC-PDA-MS/MS analysis revealed that yellow passion fruit pulp contains phenolic compounds, ascorbic acid, carotenoids and flavonoids. The highest dose of passion fruit pulp significantly reduced the systolic blood pressure, increased the GSH levels and decreased TBARS. There were no changes in renal function parameters or the frequency of micronuclei in bone marrow cells. In conclusion, the antihypertensive effect of yellow passion fruit pulp, at least in part, might be due to the enhancement of the antioxidant status. The exact mechanisms responsible by this effect need further investigation.


Assuntos
Anti-Hipertensivos/farmacologia , Frutas/química , Hipertensão/tratamento farmacológico , Passiflora/química , Animais , Anti-Hipertensivos/química , Antioxidantes/metabolismo , Ácido Ascórbico/química , Pressão Sanguínea/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Carotenoides/química , Cromatografia Líquida de Alta Pressão , Creatinina/sangue , Flavonoides/química , Glutationa/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Estresse Oxidativo , Fenóis/química , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Espectrometria de Massas em Tandem , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
14.
J Biol Chem ; 284(15): 9974-85, 2009 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-19203994

RESUMO

Carotenoids are widespread lipophilic pigments synthesized by all photosynthetic organisms and some nonphotosynthetic fungi and bacteria. All carotenoids are derived from the C40 isoprenoid precursor geranylgeranyl pyrophosphate, and their chemical and physical properties are associated with light absorption, free radical scavenging, and antioxidant activity. Carotenoids are generally synthesized in well defined subcellular organelles, the plastids, which are also present in the phylum Apicomplexa, which comprises a number of important human parasites, such as Plasmodium and Toxoplasma. Recently, it was demonstrated that Toxoplasma gondii synthesizes abscisic acid. We therefore asked if Plasmodium falciparum is also capable of synthesizing carotenoids. Herein, biochemical findings demonstrated the presence of carotenoid biosynthesis in the intraerythrocytic stages of the apicomplexan parasite P. falciparum. Using metabolic labeling with radioisotopes, in vitro inhibition tests with norflurazon, a specific inhibitor of plant carotenoid biosynthesis, the results showed that intraerythrocytic stages of P. falciparum synthesize carotenoid compounds. A plasmodial enzyme that presented phytoene synthase activity was also identified and characterized. These findings not only contribute to the current understanding of P. falciparum evolution but shed light on a pathway that could serve as a chemotherapeutic target.


Assuntos
Carotenoides/metabolismo , Eritrócitos/parasitologia , Plasmodium falciparum/metabolismo , Animais , Clonagem Molecular , Herbicidas/farmacologia , Humanos , Cinética , Malária/terapia , Espectrometria de Massas/métodos , Modelos Químicos , Piridazinas/farmacologia , Terpenos/química , Toxoplasma/metabolismo
15.
Free Radic Res ; 42(10): 885-91, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18985487

RESUMO

The quenching of singlet molecular oxygen ((1)O(2)) by the flavylium cation form of six widespread anthocyanin derivatives: cyanidin 3-glucoside (CG), cyanidin 3-rutinoside (CR), cyanidin 3-galactoside (CGL), malvidin (M), malvidin 3-glucoside (MG) and malvidin 3,5-diglucoside (MDG) was studied in 1% HCl methanol solution by time-resolved phosphorescence detection (TRPD) of (1)O(2) and photostationary actinometry using perinaphthenone and methylene blue as sensitizers, respectively. The average value of the total (k(0)) and chemical (k(c)) quenching rate constants were approximately 4 x 10(8) M(-1) s(-1) and 3 x 10(6) M(-1) s(-1), respectively, indicating the good performance of the studied anthocyanins as catalytic quenchers of (1)O(2). The quenching efficiency was larger for malvidin than for cyanidin derivatives, probably by the extra electron-donating methoxy group in ring B of the malvidin derivatives; and it was also dependent on the number and type of glycosylated substitution. As observed for other phenolic-like derivatives, the quenching of (1)O(2) by anthocyanins was mediated by a charge-transfer mechanism, which was modulated by the total number of -OR substituents that increases the electron-donating ability of these compounds.


Assuntos
Antocianinas/química , Antioxidantes/química , Oxigênio Singlete/química , Cátions , Medições Luminescentes , Modelos Químicos , Estrutura Molecular , Oxirredução , Fotodegradação , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade , Fatores de Tempo
16.
J Agric Food Chem ; 55(13): 5062-72, 2007 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-17530774

RESUMO

The major and minor carotenoids from six fruits, buriti (Mauritia vinifera), mamey (Mammea americana), marimari (Geoffrola striata), peach palm (Bactrys gasipaes), physalis (Physalis angulata), and tucuma (Astrocaryum aculeatum), all native to the Amazonia region, were determined by high-performance liquid chromatography-photodiode array detector-mass spectrometry detector (HPLC-PDA-MS/MS), fulfilling the recommended criteria for identification. A total of 60 different carotenoids were separated on a C30 column, all-trans-beta-carotene being the major carotenoid found in all fruits. The presence of apo-10'-beta-carotenol, found in mamey, was not previously reported in foods. In addition, this is the first time that the identification of beta-zeacarotene in natural sources is supported by MS data. The total carotenoid content ranged from 38 microg/g in marimari to 514 microg/g in buriti. All fruits analyzed can be considered good sources of provitamin A, especially buriti, with 7280 RE/100 g.


Assuntos
Carotenoides/análise , Cromatografia Líquida de Alta Pressão , Frutas/química , Espectrometria de Massas
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