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1.
J Agric Food Chem ; 67(41): 11408-11419, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31556290

RESUMO

In this study, the effects of 2-O-ß-d-glucopyranosyl-l-ascorbic acid (AA-2ßG), a natural ascorbic acid derivative from the fruits of Lycium barbarum, on treating the dextran sulfate sodium (DSS)-induced colitis in mice were investigated. The results revealed that AA-2ßG had palliating effects on DSS-induced inflammatory bowel disease (IBD) in terms of slowing down the trends of body weight and solid fecal mass loss, reducing colitis disease activity index, improving serum physiological and biochemical indicators, increasing colon length, blocking proinflammatory cytokines, and increasing tight junction proteins. Additionally, AA-2ßG treatment could promote the production of short-chain fatty acids and modulate the composition of the gut microbiota. The key bacteria related to IBD were found to be Porphyromonadaceae, Prevotellaceae, Rikenellaceae, Parasutterella, Parabacteroides, and Clostridium. The results indicated that AA-2ßG might treat IBD through the regulation of gut microbiota, suggesting that AA-2ßG has the potential to be used as a dietary supplement in the treatment of IBD.


Assuntos
Ácido Ascórbico/administração & dosagem , Colite/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Lycium/química , Extratos Vegetais/administração & dosagem , Animais , Ácido Ascórbico/química , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Colite/genética , Colite/imunologia , Colite/microbiologia , Citocinas/genética , Citocinas/imunologia , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Frutas/química , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação
2.
Food Chem ; 300: 125231, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374430

RESUMO

This research was to compare mortadella elaborated with synthetic antioxidant and microcrystals of curcumin in relation to its physicochemical and sensorial characteristics for a period of 90 days. It was detect no differences between the three evaluated treatments in relation to the pH, color, and texture profile features. The mortadella with curcumin microcrystals showed significantly lower TBARS values at the end of the storage when compared to the other treatments. In the sensory analysis, the addition of curcumin decreased the acceptance of color's sample and the purchase intention, but no significant difference was observed among the other attributes. The color of the sample containing curcumin also became worse than its day-of-production standard during storage. The results obtained suggest the potential of curcumin in replacing synthetic antioxidants in cooked meat sausage, since it practically does not modify its physicochemical characteristics, besides preventing the oxidation of the food.


Assuntos
Antioxidantes/química , Curcumina/química , Produtos da Carne , Ácido Ascórbico/química , Cor , Comportamento do Consumidor , Culinária , Armazenamento de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Produtos da Carne/análise
3.
Food Chem ; 300: 125221, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351256

RESUMO

In this study, water-soluble curdlan products (Cur and Cur-D) were prepared by an alkali-neutralization treatment process, after which ferulic acid (FA)-grafted Cur conjugates (Cur-g-FA and Cur-D-g-FA) were fabricated in the presence and absence of salt by adopting an approach involving free-radicals generated by the ascorbic acid/hydrogen peroxide redox pair under an inert atmosphere. Results showed that FA was successfully grafted onto the C-6 and C-4 positions of the Cur chains through covalent linkages and that the presence of salt exerted minor influences on the grafting ratios and structural characterizations of the products. Cur-g-FA and Cur-D-g-FA showed decreased crystallinity, thermal stability, and rheological properties, as well as a distinct surface morphology, when compared with those of native Cur. However, Cur-g-FA and Cur-D-g-FA also exhibited remarkably enhanced free-radical scavenging ability and antioxidant capacity in vitro. These results indicate that FA-grafted Cur conjugates have great potential application in the field of functional foods.


Assuntos
Antioxidantes/química , Ácidos Cumáricos/química , beta-Glucanas/química , Antioxidantes/farmacologia , Ácido Ascórbico/química , Radicais Livres/química , Peróxido de Hidrogênio/química , Oxirredução , Reologia , Solubilidade , Propriedades de Superfície , Água/química
4.
Plant Mol Biol ; 101(3): 269-296, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31338671

RESUMO

KEY MESSAGE: The first transcriptome coupled to metabolite analyses reveals major trends during acerola fruit ripening and shed lights on ascorbate, ethylene signalling, cellular respiration, sugar accumulation, and softening key regulatory genes. Acerola is a fast growing and ripening fruit that exhibits high amounts of ascorbate. During ripening, the fruit experience high respiratory rates leading to ascorbate depletion and a quickly fragile and perishable state. Despite its growing economic importance, understanding of its developmental metabolism remains obscure due to the absence of genomic and transcriptomic data. We performed an acerola transcriptome sequencing that generated over 600 million reads, 40,830 contigs, and provided the annotation of 25,298 unique transcripts. Overall, this study revealed the main metabolic changes that occur in the acerola ripening. This transcriptional profile linked to metabolite measurements, allowed us to focus on ascorbate, ethylene, respiration, sugar, and firmness, the major metabolism indicators for acerola quality. Our results suggest a cooperative role of several genes involved in AsA biosynthesis (PMM, GMP1 and 3, GME1 and 2, GGP1 and 2), translocation (NAT3, 4, 6 and 6-like) and recycling (MDHAR2 and DHAR1) pathways for AsA accumulation in unripe fruits. Moreover, the association of metabolites with transcript profiles provided a comprehensive understanding of ethylene signalling, respiration, sugar accumulation and softening of acerola, shedding light on promising key regulatory genes. Overall, this study provides a foundation for further examination of the functional significance of these genes to improve fruit quality traits.


Assuntos
Ácido Ascórbico/química , Etilenos/química , Frutas/fisiologia , Malpighiaceae/genética , Malpighiaceae/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Transdução de Sinais
5.
Food Chem ; 300: 125195, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31326676

RESUMO

Presence of pungent gingerols in ginger oleoresin makes it an ideal natural flavoring candidate for the food industry. The study reports its incorporation for synergistic enhancement of flavor and nutraceutical portfolio of candied mango. The process is systematically optimized at bench-scale for gingerols infusion and subsequent candying treatment in a range of hypo and hypertonic osmotic solutions for critical transport properties. After that, optimization of the drying process and the scale-up study was conducted with a 200 folds increase in the batch size. Collated effects of multistep optimization resulted in 85.6, 76.8, 60.2% retention in ß-carotene, total phenolics, Vitamin C, respectively, along with minor color difference and significant improvement in sensory scores over fresh mango. Mass transfer and quality parameters were comparable in both scales, implying excellent repeatability and scalability of the process. Compared with a similar commercial product, substantial improvement in quality characteristics along with 376.7% reduction in overall processing time was achieved.


Assuntos
Doces , Catecóis/química , Álcoois Graxos/química , Aromatizantes/química , Indústria de Processamento de Alimentos/métodos , Mangifera/química , Ácido Ascórbico/análise , Ácido Ascórbico/química , Cor , Dessecação/métodos , Suplementos Nutricionais/análise , Qualidade dos Alimentos , Frutas/química , Gengibre/química , Humanos , Fenóis/análise , Fenóis/química , Paladar , beta Caroteno/análise , beta Caroteno/química
6.
Food Chem ; 298: 125080, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260985

RESUMO

Propolis extract was investigated as potential substitute for sorbate in orangeade. Extract was prepared by using aqueous solution of hydroxypropyl-beta-cyclodextrins. Propolis extract was incorporated in non-carbonated orange soft drinks and its antioxidant activity, microbiological stability and color changes were estimated and compared to those of orangeade containing potassium sorbate. l-Ascorbic acid (AsA) degradation at concentrations 0.13 and 1.3% w/w was investigated in the presence of propolis during storage using High Performance Liquid Chromatography-Ion Exclusion Column (HPLC-IEC). The results indicate that the rate of degradation decreased with an increase in ascorbic acid concentration, while addition of propolis affected the degradation rate of samples containing a high AsA concentration. The antifungal effect of propolis extract, potassium sorbate and their combination was assayed. Results showed the inhibition of Aspergillus spp. and B. bruxellensis inhibited in low combined concentrations antimicrobials, while Aspergillus spp. and T. macrosporus were inhibited at 450 mg/g propolis extract.


Assuntos
Bebidas , Conservação de Alimentos/métodos , Conservantes de Alimentos/química , Própole/química , Anti-Infecciosos , Antifúngicos/farmacologia , Antioxidantes/química , Ácido Ascórbico/análise , Ácido Ascórbico/química , Aspergillus/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão/métodos , Cor , Microbiologia de Alimentos , Extratos Vegetais/química , Própole/farmacologia , Ácido Sórbico/farmacologia
7.
Food Chem ; 297: 124941, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253326

RESUMO

The effect of a hydroxyl radical generating system (HRGS), which contained FeCl3, sodium ascorbate, and different concentrations of H2O2, on the physiochemical properties of myofibrillar protein (MP) from squid mantles, has been investigated. The effect of different exposure times to HRGS was also considered. Compared to non-oxidized MP, a significant (p < 0.05) increase in carbonyl content (more than 50% of its original content) and protein solubility, as well as in surface hydrophobicity, was observed in the oxidative MP. With different treatment times, a sharp decrease (p < 0.05) in sulfhydryl content was detected. In addition, hydroxyl radical treatment significantly reduced the MP gel's texture properties, whiteness and water holding capacity, especially at higher concentrations of H2O2. This observation could be attributed to extensive disorderly and less compact structure of MP gels. The results demonstrate the negative effect of HRGS on the structural and functional properties of MP from squid mantles.


Assuntos
Decapodiformes/metabolismo , Proteínas de Frutos do Mar/química , Animais , Ácido Ascórbico/química , Géis/química , Interações Hidrofóbicas e Hidrofílicas , Radical Hidroxila/química , Oxirredução , Reologia , Proteínas de Frutos do Mar/metabolismo , Solubilidade , Compostos de Sulfidrila/análise , Água/química
8.
J Food Sci ; 84(7): 1820-1828, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31206662

RESUMO

The aim of this study was to analyze the impact of traditional and combined pretreatment on dehydration kinetics and quality of dried swamp cranberries. Fruits were blanched, cut, or treated by combined technique consisting of blanching and application of pulsed electric field. Afterwards, fruits were subjected for osmotic dehydration (OD; 72 hr) in 61.5% sucrose solution or in ternary solution consisting of 30% sucrose with 0.1% addition of steviol glycosides to ensure similar sweetness of both mixtures. In the case of samples treated by combined method, OD was enhanced during first 30 min by sonication. Partially dehydrated cranberries were air dried at 70 °C. The quality of dehydrated fruits was assessed by the means of phenolics content, anthocyanin content, flavonoid content, vitamin C content, water activity, and color. Blanching decreased drying time by 48% to 50% in comparison to cutting. Utilization of combined method reduced drying time of cranberries up to 55% in comparison to cut samples. Water activity of all samples was below 0.6. Blanched samples or blanched and then treated with pulsed electric field and ultrasound contained more anthocyanins and flavonoids and less sucrose than cut samples. PRACTICAL APPLICATION: According to current trends in food and beverage industry, consumers seek for products which does not contain excessive amounts of sugars, salt, or fats. Dried cranberry fruits are rich in bioactive compounds and need to be osmotically dehydrated in sugar solutions to make the taste of the final product acceptable. Osmotic dehydration is also carried out to decrease time of drying, which is one of the most energy intensive processes. Therefore, there is a need to develop a technology with potential to maintain the bioactive compounds, reduce sugar content in comparison to traditionally process fruits, and enhance the kinetics of drying.


Assuntos
Dessecação/métodos , Conservação de Alimentos/métodos , Vaccinium macrocarpon/química , Animais , Antocianinas/sangue , Ácido Ascórbico/química , Cor , Flavonoides/química , Conservação de Alimentos/instrumentação , Frutas/química , Cinética , Osmose , Fenóis/química , Controle de Qualidade , Paladar
9.
Food Chem ; 296: 56-62, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31202306

RESUMO

Autophagy, a mechanism of recycling intracellular constituents, favors plant growth, especially under nutrient starvation. However, autophagy's role in regulating postharvest fruit senescence is unclear. Here, effects of the autophagy inhibitor hydroxychloroquine (HCQ) and activator LiCl on postharvest jujube fruit senescence were investigated. HCQ significantly reduced weight loss and decay incidence, and enhanced firmness compared with those of the control. LiCl had the opposite effects. Protein oxidation and H2O2 increased significantly in LiCl-treated compared with HCQ-treated fruit. The contents of vitamin C, total thiol, and phenolics, and total antioxidant capacity and DPPH-radical scavenging capacity, followed the order: HCQ > control > LiCl. The HCQ-mediated reduction in fruit respiration was significantly enhanced by ATP and partly reversed by 2,4-dinitrophenol, a mitochondrial uncoupler. Thus, jujube fruit senescence may be regulated by autophagy and the antioxidant capacity. A mechanism of autophagy-mediated postharvest fruit senescence involving mitochondrial biogenesis and respiration was proposed.


Assuntos
Autofagia/efeitos dos fármacos , Hidroxicloroquina/farmacologia , Nutrientes/metabolismo , Ziziphus/metabolismo , Antioxidantes/química , Ácido Ascórbico/química , Frutas/efeitos dos fármacos , Frutas/metabolismo , Peróxido de Hidrogênio/análise , Hidroxicloroquina/química , Cloreto de Lítio/farmacologia , Nutrientes/química , Fenóis/química , Temperatura Ambiente , Ziziphus/efeitos dos fármacos
10.
Food Chem ; 295: 432-440, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174779

RESUMO

This study examined the effects of vacuum, ethanol pretreatment, and infrared-hot air drying methods on the characteristics and quality of scallion slices. The pretreatment of scallion includes four conditions: 1) Control: soaking in distilled water under normal pressure, 2) Ethanol: soaking in 75% ethanol under normal pressure, 3) Water + VC: soaking in distilled water under a vacuum of 0.6 bar, 4) Ethanol + VC: soaking in 75% ethanol under a vacuum of 0.6 bar. The pretreatment times were 5, 10, 20 and 30 min. The drying process was done in an infrared hot air drying oven at 60 °C. The ethanol pretreated samples exhibited better rehydration, odor, vitamin C retention, bactericidal effect and significantly reduced drying time. Water + VC samples showed better scallion morphology and color. Ethanol + VC samples showed the combined advantages of ethanol and Water + VC pretreatments. Therefore, Ethanol + VC pretreatment can significantly improve the drying rate and quality of scallion.


Assuntos
Allium/química , Manipulação de Alimentos/métodos , Ácido Ascórbico/química , Cor , Dessecação/métodos , Etanol/química , Qualidade dos Alimentos , Temperatura Alta , Raios Infravermelhos , Pressão , Vácuo , Água/química
11.
Food Chem ; 297: 124864, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253321

RESUMO

This work studied the effect of multi-wavelength UV processing on the ascorbic acid content of aqueous solutions, at different pH values (3, 4, and 5). The source of radiation was a mid-pressure mercury lamp (460 W), emitting between 250 and 740 nm. The samples were treated for 60 min, at 25 °C and 45 °C, with the lamp on and with the lamp off. A radiation balance was performed to estimate the total radiation power absorbed by the whole solution. Ascorbic acid content was reduced, either in irradiated or non-irradiated solutions, due to aerobic oxidation. But, in most cases, irradiation did not accelerate degradation. This can be explained by the fact that ascorbic acid barley absorbs ultraviolet in the interval of wavelengths emitted by the lamp (only 31% of the incident radiation P(0) could be absorbed by the solutions). Therefore, mid-pressure mercury lamps are helpful to avoid Vitamin C photo-degradation.


Assuntos
Ácido Ascórbico/química , Raios Ultravioleta , Água/química , Concentração de Íons de Hidrogênio , Oxirredução , Fotólise/efeitos da radiação
12.
Inorg Chem ; 58(14): 9326-9340, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31247820

RESUMO

The synthesis of a novel class of cyclometalated gold(III) complexes supported by benzoylpyridine, benzylpyridine, and (1R,2R)-(+)-1,2-diaminocyclohexane (DACH) ligands, along with their crystal structures, is reported. These compounds provide a new scaffold to investigate biological properties of gold(III) complexes. The six complexes were prepared and characterized, following reactions of (C,N) cyclometalated gold(III) scaffolds, [Au(C^N)Cl2] with DACH, which yielded a new series of cyclometaled gold(III), 3-5, of the type [Au(C^NH)(DACH)2]+ and the nitrogen-substituted cyclometalated Au(III), 6-8, of the type [Au(C^N)(DACH)]2+. Antiproliferative activity of these complexes in a panel of cancer cells showed promising results with IC50 in the micromolar range and selectivity over normal epithelial cells, MRC5. Whereas 8 shows minimal interaction with superhelical DNA except at high gold concentrations of 500 µM, complex 5 does not show interaction even at 1000 µM. The complexes display significant uptake in OVCAR8 cancer cells within 200-1200 pmol/million cells with the exception of complex 4. Differential cellular uptake was observed for the complexes; for example, while 3 and 8 display significant uptake, 4 showed minimal uptake. The compounds proved to be stable under physiological conditions and were minimally affected by either glutathione or sodium ascorbate. Cell cycle studies reveal a G1 arrest induced by representative complexes. The results reveal that enhanced Au(III) stabilization promoted by combined cyclometalated and DACH ligands may offer ligand tuning insights for novel anticancer drug design.


Assuntos
Cicloexilaminas/química , Cicloexilaminas/farmacologia , Compostos de Ouro/química , Compostos de Ouro/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Ácido Ascórbico/química , Linhagem Celular Tumoral , Simulação por Computador , Cristalografia por Raios X , Glutationa/química , Humanos , Ligantes , Modelos Químicos , Modelos Moleculares , Estrutura Molecular
13.
Chemosphere ; 229: 200-205, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31078034

RESUMO

In the present study, ascorbic acid (AA) induced persulfate activation was investigated for the further exploration of organic pollutants oxidation by persulfate. We interestingly found that AA showed a significant catalytic activity to persulfate. Under neutral pH and room temperature condition, about 71.3% of pentachlorophenol (PCP, 10 mg L-1) was decomposed in 180 min with 40 mmol L-1 persulfate and 1.0 mmol L-1 AA, while only 15.4% and 3.2% of PCP was removed by alone persulfate and AA respectively. The result of EPR spectra identified sulfate radical (SO4•-) and hydroxyl radical (OH) were generated during the reaction between persulfate and AA. Quenching experiments confirmed that both SO4- and OH contributed to the decomposition of PCP. With the addition of AA augmented from 0 to 1 mmol L-1, the PCP degradation ratio continuously increased. However, excess AA could consume the generated reactive oxygen species (ROSs) that led to the inhibition of PCP degradation. Meanwhile, the PCP degradation by persulfate-AA was strongly pH dependent. The PCP degradation rate was declined as the initial pH increased from 3.5 to 10.5. At pH above 12.5, the base activation began to predominate over AA activation of persulfate. Furthermore, it was observed that the AA inducing persulfate activation was related to the extent of AA ionization, while C6H8O6 promoted the highest persulfate activation for the PCP degradation, and C6H6O62- induced the lowest persulfate activation. This study indicates the high potential of AA induced persulfate activation for treatment of organochlorine contaminated water.


Assuntos
Ácido Ascórbico/química , Pentaclorofenol/química , Sulfatos/química , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Radical Hidroxila/química , Oxirredução
14.
Carbohydr Polym ; 216: 217-223, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047060

RESUMO

This study determines storage stability and release of encapsulated ascorbyl palmitate in normal and high amylose maize starch by pasting and spray drying. The amount of ascorbyl palmitate released was analysed in the stored samples (dark cupboard, and under UV light at a temperature of 40 °C for 12 weeks) and their antioxidant activity determined. Storage of encapsulated ascorbyl palmitate at 40 °C under both dark and UV light conditions did not affect the amount release and the ability to scavenge the free radical (ABTS+). However, the antioxidant activity of free ascorbyl palmitate exponentially decreased at 40 °C under UV light condition. The analysed residues after α-amylase digestion of encapsulated ascorbyl palmitate showed some endothermic peaks, suggesting that amylose-lipids complexes formed were resistant to α-amylase digestion. Encapsulation of ascorbyl palmitate in maize starch may improve its storage stability under light (UV) conditions.


Assuntos
Amilose/química , Ácido Ascórbico/análogos & derivados , Portadores de Fármacos/química , Depuradores de Radicais Livres/química , Zea mays/química , Ácido Ascórbico/química , Ácido Ascórbico/efeitos da radiação , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Depuradores de Radicais Livres/efeitos da radiação , Hidrólise , Temperatura Ambiente , Raios Ultravioleta , alfa-Amilases/química
15.
Talanta ; 201: 295-300, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122426

RESUMO

A novel single-walled carbon nanotubes array-modified glassy carbon electrode (SWCNTs array-GCE) has been fabricated through a simple electrochemical technique. Benefitting from their vertically aligned configuration on the electrode surface, the modified single-walled carbon nanotubes can be used more efficiently in comparison with other modified method. The as-fabricated SWCNTs array-GCE can separate the anodic oxidation potential of dopamine (DA), uric acid (UA) and ascorbic acid (AA) with well-defined peak separation in the presence of each other, and thus employs as a new electrochemical sensor for selective determination of DA and UA. It can make a further improvement of the electrocatalytic ability of the electrode to perform an acetone pretreatment to SWCNTs array-GCE before electrochemical detection, which has been confirmed by atomic force microscope and electrochemical impedance spectroscopic measurements. Especially, unlike other carbon nanotubes-based electrode at which only two redox pairs are observed for dopamine oxidations, a third two-electron oxidation of 5,6-dihydroxyindole to indole-5,6-quinone can be clearly observed at acetone-pretreated SWCNTs array-GCE, showing the excellent electrocatalytic performance of as-fabricated electrode toward dopamine. The practicability of SWCNTs array-GCE was evaluated for the selective detection of DA and UA in real sample solutions of human serum and urine. It revealed acceptable recovery results in the range of 94-104%, indicating that it might be a promising platform for further biosensor development.


Assuntos
Dopamina/sangue , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono/química , Ácido Úrico/urina , Ácido Ascórbico/análise , Ácido Ascórbico/química , Dopamina/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Humanos , Indóis/química , Limite de Detecção , Oxirredução , Ácido Úrico/química
16.
Talanta ; 201: 388-396, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122439

RESUMO

Ascorbic acid (AA) is an essential vitamin and plays an irreplaceable role in humans' daily life. Therefore, it is of profound significance to develop effective strategies for AA sensing. Herein, a novel bi-functional sensing strategy was developed by using carbon dots (CDs) and MnO2 nanosheet as the fluorometric/magnetic signal source. When AA was absence, the fluorescence of CDs was quenched by MnO2 nanosheet due to the inner filter effect. Neither the fluorescence nor magnetic signal of the nanoprobe can be detected. In the presence of AA, a redox reaction occurred between MnO2 nanosheet and AA resulting in the generation of magnetic resonance imaging (MRI) response Mn2+ and decomposing of MnO2 nanosheet structure, thus leading to the recovery of CDs fluorescence. The detection limit of the AA was determined to be 2.89 µM with a linear range of 0-80 µM in fluorescence mode, and detection limit of 0.776 µM with a linear range of 0-80 µM in MRI mode when used transverse relaxation rate as signal. Furthermore, the developed fluorometric/magnetic bi-functional nanoprobe showed good biocompatibility, high response rate, high selectivity towards AA and could be used to analyses AA in real samples. Moreover, in vivo imaging of AA in mice was achieved in magnetic mode. The fluorometric/magnetic bi-function sensor for AA detection was introduced, which provided a novel strategy for sensor design based on CDs.


Assuntos
Ácido Ascórbico/análise , Corantes Fluorescentes/química , Imagem por Ressonância Magnética/métodos , Compostos de Manganês/química , Óxidos/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Animais , Ácido Ascórbico/química , Ácido Ascórbico/metabolismo , Fluorescência , Corantes Fluorescentes/toxicidade , Limite de Detecção , Fenômenos Magnéticos , Masculino , Camundongos Endogâmicos BALB C , Oxirredução , Óxidos/toxicidade , Pontos Quânticos/toxicidade
17.
Int J Biol Macromol ; 132: 1262-1273, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30980874

RESUMO

Cosmetics, personal care and biomedical products obtained by bio-based polymers and natural bioactive compounds are a new growing market. The ecological awareness is changing consumers' demands, causing consumers to look for more sustainable options, with a reduced environmental impact. The innovation of this work was to develop a natural polymer matrix (chitosan) entrapping antioxidant actives compounds such as annatto (Bixa Orellana L.) and vitamin C with potential application as sustainable anti-aging skin mask treatment. Films of chitosan (Ch) and reacetylated chitosan (RCh), exhibiting different degrees of acetylation (DA = 13.3 and 33.9%, respectively), were produced. The formulations of active films of chitosan (BCh) and reacetylated chitosan (BRCh) were 1% (w/w) of chitosan, 1% (w/w) of annatto powder, 5% (w/w) of vitamin C and 1% (w/w) of glycerol (as plasticizer). Reacetylated chitosan films (DA = 33.9%) presented higher water affinity than chitosan films (DA = 13.3%). The elongation of RCh and BRCh increased and the resistance decreased, as compared to Ch and BCh. The antioxidants compounds (annatto and vitamin C) of BRCh films released faster than BCh films. Thus, the BRCh films showed potential application as an anti-aging skin mask.


Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/química , Antioxidantes/farmacologia , Quitosana/química , Cosméticos/química , Portadores de Fármacos/química , Pele/efeitos dos fármacos , Ácido Ascórbico/química , Ácido Ascórbico/farmacologia , Bixaceae/química , Carotenoides/química , Carotenoides/farmacologia , Linhagem Celular , Quitosana/metabolismo , Cor , Portadores de Fármacos/metabolismo , Humanos , Fenômenos Mecânicos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Solubilidade , Vapor
18.
Molecules ; 24(8)2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31027237

RESUMO

A new method using ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) methodology was developed for the determination of ascorbic acid (AA) and dehydroascorbic acid (DHAA) contents in liquid and solid vegetable samples. The advantages of this method are speed, high sensitivity and practical application. In accordance with these advantages, the present method allows the simultaneous determination of AA and DHAA without previous reduction/derivatization of DHAA and without the use of internal standards in the samples. This is of high interest in routine analysis, providing a simpler sample preparation, as well as enhanced accuracy and robustness. Its validation included selectivity, sensitivity and linearity, precision and accuracy, matrix effect, and recovery. The results showed high selectivity and sensitivity, with calibration curves ranging from 10 to 500 ng mL-1 and from 50 to 500 ng mL-1 for AA and DHAA, respectively. Appropriate dilutions for each sample are necessary to avoid the matrix effect with accepted recoveries.


Assuntos
Ácido Ascórbico/química , Cromatografia Líquida de Alta Pressão/métodos , Ácido Desidroascórbico/química , Espectrometria de Massas em Tandem/métodos
19.
J Agric Food Chem ; 67(19): 5647-5660, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31026157

RESUMO

Anthocyanins are natural dyes widely used in the food industry, but their chemical stability in beverages can be affected by the presence of additives. In the present paper, the interaction between anthocyanins and ascorbic acid (AA) is more particularly investigated. Ascorbic acid is an ubiquitous component in food products. In this study, the thermal stability at 43 °C and the photolysis stability in air and in an inert atmosphere (N2) of anthocyanins extracted from black carrot (BC), grape juice (GJ), and purple sweet potato (SP) were studied in the presence and absence of ascorbic acid (in citrate buffer at pH 3). Discriminating the main environmental factors (i.e., heat and light) affecting anthocyanin stability is a key point for better understanding the degradation pathways. The stability of the anthocyanins was followed by UV-vis spectrometry. Moreover, to understand the degradation mechanisms in both the presence and absence of ascorbic acid, various techniques such as fluorescence quenching, cyclic voltammetry, and electron-spin-resonance (ESR) spectroscopy were also used to furnish a full coherent picture of the chemical mechanisms associated with the anthocyanin degradation. In addition, molecular orbitals and bond-dissociation energies (BDE) were calculated to extend the investigation. Moreover, the effects of some supplementary stabilizers (chlorogenic acid, sinapic acid, tannic acid, fumaric acid, ß-carotene, isoquercitrin, myricitrin, green coffee bean extract, and rosemary extract) and sugars (sucrose, fructose, and glucose) on anthocyanins stability in the presence of ascorbic acid were examined.


Assuntos
Antocianinas/química , Ácido Ascórbico/química , Daucus carota/química , Sucos de Frutas e Vegetais/análise , Ipomoea batatas/química , Extratos Vegetais/química , Vitis/química , Cor , Daucus carota/efeitos da radiação , Sucos de Frutas e Vegetais/efeitos da radiação , Temperatura Alta , Ipomoea batatas/efeitos da radiação , Luz , Processos Fotoquímicos , Fotoquímica
20.
Acta Sci Pol Technol Aliment ; 18(1): 5-12, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30927747

RESUMO

The cornelian cherry Cornus mas L. belongs to the Cornaceae family (Cornaceae). It can be found naturally in the central and south-eastern regions of Europe. Its fruits are characterized by oval or oval-oblong shape, with colours ranging from light yellow to dark cherry. The taste of fruits is usually considered to be tart- sweet, sour and in some cases sweet-pineapple. All cultivars of the cornelian cherry have a high biological value, which is mainly connected with their antioxidant activity, as well as with their phenolic compound and ascorbic acid content. The main pro-health properties of the cornelian cherry are related to the large amount of anthocyanins. The basic raw material is fruits; however, leaves, flowers and seeds are also used as a source of active ingredients. The chemical composition of cornelian cherry fruits is diversified and depends to a large extent on the cultivar, as well as on cultivation, and the environmental and climatic conditions.


Assuntos
Antocianinas/química , Ácido Ascórbico/química , Cornus/química , Frutas/química , Antioxidantes/química , Valor Nutritivo , Polifenóis/química
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