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1.
Crit Care ; 23(1): 350, 2019 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-31706360

RESUMO

BACKGROUND: For patients who survive a critical illness and have their oral endotracheal tube removed, dysphagia is highly prevalent, and without intervention, it may persist far beyond hospital discharge. This pre- and post-intervention study with historical controls tested the effects of a swallowing and oral care (SOC) intervention on patients' time to resume oral intake and salivary flow following endotracheal extubation. METHODS: The sample comprised intensive care unit patients (≥ 50 years) successfully extubated after ≥ 48 h endotracheal intubation. Participants who received usual care (controls, n = 117) were recruited before 2015, and those who received usual care plus the intervention (n = 54) were enrolled after 2015. After extubation, all participants were assessed by a blinded nurse for daily intake status (21 days) and whole-mouth unstimulated salivary flow (2, 7, 14 days). The intervention group received the nurse-administered SOC intervention, comprising toothbrushing/salivary gland massage, oral motor exercise, and safe-swallowing education daily for 14 days or until hospital discharge. RESULTS: The intervention group received 8.3 ± 4.2 days of SOC intervention, taking 15.4 min daily with no reported adverse event (coughing, wet voice, or decreased oxygen saturation) during and immediately after intervention. Participants who received the intervention were significantly more likely than controls to resume total oral intake after extubation (aHR 1.77, 95% CI 1.08-2.91). Stratified by age group, older participants (≥ 65 years) in the SOC group were 2.47-fold more likely than their younger counterparts to resume total oral intake (aHR 2.47, 95% CI 1.31-4.67). The SOC group also had significantly higher salivary flows 14 days following extubation (ß = 0.67, 95% CI 0.29-1.06). CONCLUSIONS: The nurse-administered SOC is safe and effective, with greater odds of patients' resuming total oral intake and increased salivary flows 14 days following endotracheal extubation. Age matters with SOC; it more effectively helped participants ≥ 65 years old resume total oral intake postextubation. TRIAL REGISTRATION: NCT02334774, registered on January 08, 2015.

2.
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
3.
Food Sci Nutr ; 7(8): 2537-2545, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31428341

RESUMO

The effects of pulsed vacuum osmotic dehydration (PVOD) and ultrasound osmotic dehydration (USOD) on drying characteristics and quality attributes of ginger were investigated. PVOD was subjected to pulsed vacuum at 13 kPa for 30 min, and USOD was subjected to ultrasound with the frequency of 40 kHz for 30 min. After PVOD and USOD treatments, the samples were then dried at intermittent microwave & air-drying oven with an output of 700 W and temperature of 60°C to the final moisture content of 0.12 g water/g d.w. The results showed PVOD and USOD treatments could improve the total phenolic contents by -1.8% to 16.4%, total flavonoid content by 7.7%-18.7%, DPPH radical scavenging by 9.5%-12.2%, and ABTS+ antioxidant activity by 17.8%-27.4%, although they prolonged the later stages drying of ginger. Besides, the PVOD- and USOD-pretreated dried samples had less brownings than the untreated-dried samples which could be attributed to the inactivation of polyphenol oxidase (PPO) and peroxidase (POD). The PPO activity was significantly reduced in the PVOD and USOD ginger, whereas POD activity was decreased in USOD ginger but increased in PVOD ginger. Moreover, PVOD pretreatment also led to a better preservation of volatile profiles and cell structure than USOD treatment. Therefore, both PVOD and USOD are effective pretreatments for drying of ginger.

4.
Food Chem ; 301: 125282, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31387036

RESUMO

The main contributors to the cooked off-flavor in heat-sterilized lychee juice (HLJ) were studied by means of molecular sensory science. The HLJ which elicited cooked cabbage/potato and onion/garlic off-flavor was compared with fresh lychee juice (FLJ) having desired sensory attributes via chemical analysis and sensory evaluation. Aroma extract dilution analysis, quantitative analysis and calculation of odor activity values (OAVs) were conducted on both FLJ and HLJ. The results showed that compared with FLJ, 15 compounds had increased OAVs in HLJ, among which, dimethyl sulfide (DMS), methional, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and 2,4-dithiapentane presented cooked cabbage/potato, garlic/onion and sulfurous impression. The omission experiment proved that DMS, methional, DMTS, DMDS, 3-methylbutanal and 2,4-dithiapentane had significantly negative effects on the overall aroma of HLJ. Further studies on HLJs from other varieties of lychee confirmed that DMS, methional, DMTS, DMDS and 3-methylbutanal were responsible for the cooked off-flavor of HLJ in general.


Assuntos
Aromatizantes/química , Sucos de Frutas e Vegetais/análise , Temperatura Alta , Litchi/química , Culinária , Aromatizantes/análise , Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise , Esterilização , Paladar
5.
Foods ; 8(8)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374950

RESUMO

The aim of this study was to evaluate the effect of high hydrostatic pressure (HHP) and co-fermentation by Lactobacillus rhamnosus and Gluconacetobacter xylinus on the quality of yacon-litchi-longan (YLL) juice. The carbohydrates, organic acids, free amino acids (FAAs), and volatile compounds in YLL juice were analyzed. Thermal processing (TP) increased the content of total carbohydrates, organic acids and FAAs, and destroyed the aroma components, whereas HHP treatment had a negligible effect. Carbohydrate content was lower, and content of lactic acid, acetic acid, and exopolysaccharide (EPS) were higher in co-fermented juice than in unfermented juice. Furthermore, the content of bitter FAAs in fermented TP and HHP-treated YLL juices decreased by 88.7% and 86.9%, respectively. Co-fermentation also increased ketones and the sum of individual volatile constituents, and improved the overall flavor of juice. Taken together, HHP treatment prior to co-fermentation can be used to improve the quality of YLL juice, especially the flavor thereof.

6.
J Food Biochem ; 43(8): e12934, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31368574

RESUMO

This study investigated the effect of natamycin (NA) treatment on the quality of mulberry fruit throughout the storage at 8°C and 90% relative humidity. The results of this study showed that NA treatment reduced the decay rate of mulberry fruit, inhibited respiration, decreased malondialdehyde (MDA) content, decreased phenylalanine ammonia-lyase (PAL) and polyphenoloxidase (PPO) activity, and maintained sucrose levels, total soluble solids (TSS), and total acids (TA) contents in the fruits throughout storage. NA treatment maintained the surface color and firmness of fruits throughout storage and suppressed the production of fructose, glucose, total phenolics, and the contents of anthocyanin. NA treatment maintained the quality of mulberry fruit throughout storage by enhancing the enzymatic activity of the reactive oxygen species (ROS) scavengers: catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) and inhibiting the production of hydrogen peroxide (H2 O2 ). Treatment of mulberries with increasing concentrations of NA could significantly inhibit the growth of fungal pathogens in mulberry fruits and improve their quality. PRACTICAL APPLICATIONS: The results from our previous study showed that NA was a safe preservative which could effectively inhibit the growth of molds and yeasts in mulberry fruits and improve their quality throughout the postharvest storage. Compared with other treatments for mulberry fruit, NA treatment has the advantages of low cost, simple operation, good application, and extension. The results in this study further prove that application of NA treatment has potential in the food industry to maintain the postharvest quality and extend the shelf life of mulberry fruits throughout storage.

7.
Food Sci Biotechnol ; 28(4): 945-953, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31275694

RESUMO

Sedimentation is a major issue in juice production. This paper aims to study the mechanisms of precipitate formation during the storage of cloudy litchi juice. The sediment concentration, relative turbidity, and ζ potential were analyzed. The supernatant and sediment were separated to determine the contents of proteins and phenolics. The results showed that the amount of sediment increased during the storage. In addition, the total protein and total phenolic content in the supernatant decreased, whereas the glutelin and total phenolic contents in the sediment increased significantly (p < 0.05). Moreover, our results showed that the amounts of procyanidin B2 and quercetin-3-O-rutinose-7-O-rhamnoside in the supernatant decreased noticeably. However, these two substances could not be detected in the sediment. In summary, the formation of sediment from litchi juice is mainly caused by the slow denaturation of proteins and the oxidation of procyanidin B2 and quercetin-3-O-rutinose-7-O-rhamnoside.

8.
J Food Sci Technol ; 56(2): 783-791, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30906036

RESUMO

Blueberry belongs to the genus vaccinium, which is rich in a variety of biologically active components beneficial to the human body. Drying of blueberry is a slow and energy-intensive process because of its waxy skin, which has low permeability to moisture. Therefore, chemical pretreatment of ethyl oleate (AEEO) was adopted to accelerate moisture diffusivity. The results showed that the drying rate of blueberries was increased significantly by AEEO treatment, and the drying time can be shortened by 17.17-40.70%. After AEEO dipping, the effective diffusion coefficient increased from 5.461 × 10-9 to 1.067 × 10-8 m2/s at 60 °C. Six semi-theoretical thin-layer models were used to estimate the curves of air-drying of blueberry, and Wang-Singh model was found to perform better than other models. Besides, the rehydration and retention of nutritional contents were also improved by AEEO dipping. The total phenolics, total flavonoids, total anthocyanin content, and ABTS*+ scavenging activity of blueberry were increased by 37.74%, 21.01%, 47.83%, and 30.75%, respectively. The result of SEM observation and cell-membrane permeability indicated that AEEO could break down the wax layer of blueberry, change the crystal structure of wax layer, and increase cell permeability, which resulted in shorter drying time and higher quality of blueberry.

9.
Food Funct ; 10(2): 635-645, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30648709

RESUMO

The design of zein-based nanoparticles to encapsulate bioactive molecules has gained great attention in recent years. However, the use of ethanol to dissolve zein presents flammability concerns and the scale-up production of zein-based nanoparticles is also a concern. In our study, propolis loaded zein/caseinate/alginate nanoparticles were fabricated using a facile one-step procedure: a well-blended solution was prepared containing deprotonated propolis, soluble zein, dissociated sodium caseinate micelles (NaCas) and alginate at alkaline pH, and then this alkaline solution was added to 0.1 M citrate buffer (pH 3.8) to fabricate composite nanoparticles without using organic solvents and sophisticated equipment. During acidification, the alginate molecules adsorbed on the zein/NaCas surfaces by electrostatic complexation, which improved the stability towards aggregation of zein/NaCas nanoparticles under gastrointestinal (GI) or acidic pH. The nanoparticles prepared under the optimized method (method 3 sample) were of spherical morphology with a particle size around 208 nm and a negative zeta potential around -27 mV. The encapsulation efficiency (EE) and loading capacity (LC) of propolis reached 86.5% and 59.6 µg mg-1 by zein/NaCas/alginate nanoparticles, respectively. These nanoparticles were shown to be stable towards aggregation over a wide range of pH values (2-8) and salt concentrations (0-300 mM NaCl). Compared to free propolis, the bioaccessibility of propolis encapsulated with nanoparticles was increased to 80%. Our results showed a promising clean and scalability strategy to encapsulate hydrophobic nutraceuticals for applications in foods, supplements, and pharmaceuticals.


Assuntos
Alginatos/química , Caseínas/química , Nanopartículas/química , Própole/química , Zeína/química , Tecnologia de Alimentos , Microscopia Eletrônica de Transmissão
10.
Food Funct ; 10(2): 903-911, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30694283

RESUMO

Pericarpium Citri Reticulatae (PCR, Citrus reticulata 'Chachi', Guangchenpi in Chinese) is one of the most famous Chinese citrus herbal medicines. The in vivo anti-asthmatic activity of 'Chachi' PCR was investigated using a histamine-induced experimental asthma model in Guinea pigs. Two alkaloid-type compounds, synephrine and stachydrine, were analyzed and identified in the 'Chachi' PCR alkaloid fraction. The alkaloid fraction and synephrine protected Guinea pigs against histamine-induced experimental asthma in a dose-dependent manner. The respective application of high, middle, and low doses of the 'Chachi' PCR alkaloid fraction significantly increased specific airway resistance by 284%, 328%, and 355%, and decreased dynamic compliance by 57%, 67%, and 75%. A similar change was observed for synephrine. The expression of eosinophils in bronchoalveolar lavage fluid (BALF) and serum IgE, IL-4, and IL-5 levels in histamine-induced experimental asthmatic Guinea pigs were significantly downregulated by the 'Chachi' PCR alkaloid fraction and synephrine compared to the control group, whereas stachydrine did not impart a statistically significant effect on the expression of tested inflammatory cells (leucocytes, eosinophils, neutrophils, and lymphocytes), immunoglobulin (IgE), or cytokines (IL-4 and IL-5). Pathological changes in lung tissues in each treatment group included the infiltration of inflammatory cells around the bronchia.


Assuntos
Alcaloides/uso terapêutico , Asma/induzido quimicamente , Asma/tratamento farmacológico , Broncodilatadores/uso terapêutico , Extratos Vegetais/uso terapêutico , Albuterol/uso terapêutico , Alcaloides/química , Animais , Antiasmáticos , Broncodilatadores/administração & dosagem , Citrus , Feminino , Cobaias , Extratos Vegetais/química , Distribuição Aleatória
11.
Anal Chim Acta ; 1042: 29-36, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30428985

RESUMO

The sensing performance of a Langmuir-Blodgett monolayer was significantly improved by controlling the film organization at the air-water interface. Cellulose acetate (CA) and 4-tert-butylcalix [6]arene (calix) were co-spread and formed a Langmuir film, which was efficiently transferred onto a preoxidized gold electrode, Auox. The modified gold electrode was applied as a fast, highly sensitive electrochemical sensing platform for the quantitative determination of a model molecule, dopamine (DA). The modified gold electrode, CA-calix/Auox, demonstrated better recognition and sensing ability towards dopamine as compared with electrodes modified by a single component. Under the optimized conditions, the reduction peak currents at the CA-calix/Auox increased linearly within the concentration range of dopamine from 5 to 100 and 100-7500 nM, and exhibited a very low limit of detection (LOD) of 2.54 nM (S/N = 3). These results suggest a simple, superior and efficient approach for the controllable rearrangement of Langmuir-Blodgett monolayers on a molecular level. The electroanalytical performance was optimized from the perspective of the electrode-electrolyte interface.

12.
Mikrochim Acta ; 185(3): 198, 2018 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-29594751

RESUMO

Gold nanoclusters (AuNCs) protected with a bovine serum albumin (BSA) coating are known to emit red fluorescence (peaking at 650 nm) on photoexcitation with ultraviolet light (365 nm). On addition of Cu(II) ions, fluorescence is quenched because Cu(II) complexes certain amino acid units in the BSA chain. Fluorescence is, however, restored if pyrophosphate (PPi) is added because it will chelate Cu(II) and remove it from the BSA coating on the AuNCs. Because PPi is involved in the function of telomerase, the BSA@AuNCs loaded with Cu(II) can act as a fluorescent probe for determination of the activity of telomerase. A fluorescent assay was worked out for telomerase that is highly sensitive and has a wide linear range (10 nU to 10 fM per mL). The fluorescent probe was applied to the determination of telomerase activity in cervix carcinoma cells via imaging. It is shown that tumor cells can be well distinguished from normal cells by monitoring the differences in intracellular telomerase activity. Graphical abstract Gold nanoclusters (AuNCs) protected by bovine serum albumin (BSA) and displaying red photoluminescence were prepared as fluorescent probe for the determination of telomerase activity and used for imaging of cervix carcinoma (HeLa) cells.


Assuntos
Ensaios Enzimáticos/métodos , Corantes Fluorescentes/química , Ouro/química , Nanopartículas Metálicas/química , Soroalbumina Bovina/química , Telomerase/metabolismo , Animais , Bovinos , Cobre/química , Células HeLa , Humanos , Limite de Detecção , Microscopia de Fluorescência , Espectrometria de Fluorescência
13.
Food Chem ; 255: 23-30, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29571471

RESUMO

Since polyphenols are known to exhibit antioxidative properties, we prepared and characterized persimmon vinegar polyphenols (PVP) in this study. Furthermore, we investigated the protective effect of PVP on hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells and its underlying mechanisms. Our results showed that flavon-3-ols were the predominant polyphenols in PVP. Pre-treatment with PVP significantly decreased (p < 0.05) H2O2-induced cell damage in a dose-dependent manner, accompanied by decrease in lactate dehydrogenase (LDH) leakage, aminotransferase activities, and ROS accumulation. Moreover, PVP upregulated the expression of antioxidative enzymes, such as heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1), and increased the levels of glutathione. Western blotting results showed that PVP induced the nuclear translocation of nuclear factor (erythroid-derived-2)-related factor 2 (Nrf2). Taken together, our results indicated that PVP effectively protected HepG2 cells against oxidative stress via activation of the Nrf2 antioxidative pathway.


Assuntos
Ácido Acético/química , Diospyros , Peróxido de Hidrogênio/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/farmacologia , Antioxidantes/farmacologia , Frutas/química , Glutationa/análise , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Células Hep G2 , Humanos , Substâncias Protetoras/farmacologia , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
14.
ACS Appl Mater Interfaces ; 10(10): 8947-8954, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29457719

RESUMO

Drug delivery which can offer efficient and localized drug transportation together with imaging capabilities is highly demanded in the development of cancer theranostic approaches. Herein, we report the construction of bovine serum albumin (BSA) gold nanoclusters (BSA@AuNCs) for cell fluoresce imaging and target drug delivery. BSA@AuNCs were modified with cyclic arginine-glycine-aspartate with the product RGD-BSA@AuNCs to enhance cell internalization of the nanoclusters. Furthermore, doxorubicin hydrochloride or doxorubicin (DOX), a widely used chemotherapy drug, was also used to modify RGD-BSA@AuNCs. The final design of the DOX/RGD-BSA@AuNC system was constructed through the disulfide bond. The physical microstructure and biological characterization of the BSA@AuNCs were realized through high-resolution transmission electron microscopy and confocal laser fluorescence microscopy. As the disulfide bonds were cleaved by glutathione in cancer cells, DOX-SH molecules were released from the nanosystem to inhibit the growth of cancer cells. The as-prepared DOX/RGD-BSA@AuNC system can be used not only to deliver drug but also to achieve the antitumor effect by in vivo imaging, demonstrating its promising applications in cancer treatment.


Assuntos
Nanoestruturas , Animais , Doxorrubicina , Sistemas de Liberação de Medicamentos , Ouro , Soroalbumina Bovina
15.
J Zhejiang Univ Sci B ; 18(10): 854-866, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28990376

RESUMO

The stability of clarified juice is of great importance in the beverage industry and to consumers. Phenolic compounds are considered to be one of the main factors responsible for sediment formation. The aim of this study is to investigate the changes in the phenolic content in clarified mulberry juice during storage. Hence, separation, identification, quantification, and analysis of the changes in the contents of phenolic compounds, both free and bound forms, in the supernatant and sediments of mulberry juice, were carried out using high performance liquid chromatographic system, equipped with a photo-diode array detector (HPLC-PDA) and HPLC coupled with quadrupole-time of flight mass spectrometric (HPLC-QTOF-MS/MS) techniques. There was an increase in the amount of sediment formed over the period of study. Total phenolic content of supernatant, as well as free phenolic content in the extracts of the precipitate decreased, whereas the bound phenolic content in the sediment increased. Quantitative estimation of individual phenolic compounds indicated high degradation of free anthocyanins in the supernatant and sediment from 938.60 to 2.30 mg/L and 235.60 to 1.74 mg/g, respectively. A decrease in flavonoids in the supernatant was also observed, whereas the contents of bound forms of gallic acid, protocatechuic acid, caffeic acid, and rutin in the sediment increased. Anthocyanins were the most abundant form of phenolics in the sediment, and accounted for 67.2% of total phenolics after 8 weeks of storage. These results revealed that phenolic compounds, particularly anthocyanins, were involved in the formation of sediments in mulberry juice during storage.


Assuntos
Armazenamento de Alimentos , Sucos de Frutas e Vegetais/análise , Morus/química , Fenóis/química , Antocianinas/análise , Antioxidantes/farmacologia , Precipitação Química , Flavonoides/análise , Fenóis/análise
16.
Talanta ; 169: 8-12, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28411826

RESUMO

Based on the protective performance of polydopamine nanospheres (PDANSs) for DNA against nuclease digestion and the specific recognition characteristic of aptamer, we have developed an enzymatic recycling signal amplification method for highly sensitive and selective detection of adenosine triphosphate (ATP). Fluorescence measurements were carried out to verify the DNA polymerase and exonuclease III (Exo III) assisted target recycling process and fluorescence signal amplification. In the absence of the ATP, initially, the signal DNA-PDANSs complex was in the "off" state due to the efficient fluorescence quenching of 6-carboxyfluorescein (FAM) adjacent to the surface of PDANSs. Due to the binding of the aptamer by ATP, it trigger DNA polymerase and Exo III assisted target recycling process by the product of release, the complex would change into the "on" state as a result of the dissociation of the FAM from the surface of PDANSs, thus providing greatly enhanced fluorescence emission intensity. The method allows quantitative detection of ATP in the range of 20-600nM with a detection limit of 8.32nM. This biosensor requires no complex operations, and is a new high efficiency method for ATP detection.


Assuntos
Trifosfato de Adenosina/análise , Técnicas Biossensoriais/métodos , DNA Polimerase Dirigida por DNA/metabolismo , Exodesoxirribonucleases/metabolismo , Fluorescência , Indóis/química , Nanosferas/química , Polímeros/química , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , DNA/química , DNA/metabolismo , Fluoresceínas/química , Fluoresceínas/metabolismo , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Humanos , Indóis/metabolismo , Limite de Detecção , Nanosferas/metabolismo , Polímeros/metabolismo , Reciclagem
17.
Food Chem ; 230: 649-656, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28407962

RESUMO

A simple and accurate method using high performance liquid chromatography (HPLC) with dual wavelength detection was developed to simultaneously determine the contents of one flavanone glycoside (hesperidin) and five polymethoxylated flavones (PMFs: sinensetin, 4',5,7,8-tetramethoxyflavone, nobiletin, tangeretin and 5-O-desmethyl nobiletin) in Pericarpium Citri Reticulatae (Citrus reticulata 'Chachi') ('Chachi' PCR). By modifying the mobile phase compositions and detection wavelengths, an optimal HPLC condition was obtained, under which the calibration curves of all six compounds exhibited good linearity (R2>0.99). For all the tested compounds, the relative standard deviation (RSD) was less than 4%, and the accuracy ranged from 97.58 to 103.2%. The developed method was successfully applied to monitor the changes in the contents of six flavonoids in 'Chachi' PCR during storage at 25°C, over a three year period. Color parameters and antioxidant capacity were also determined to evaluate the sample quality. The contents of hesperidin decreased while all the polymethoxylated flavones and antioxidant activities increased throughout the storage period, demonstrating that polymethoxylated flavones could be used as indices for the quality change of Chachi' PCR during storage. The results from this study suggest that the longer storage periods increased the quality of PCR.


Assuntos
Citrus/química , Flavonoides/química , Armazenamento de Alimentos/métodos , Antioxidantes , Flavonoides/análise
18.
Mikrochim Acta ; 185(1): 39, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-29594453

RESUMO

Porous graphitic carbon nitride (g-C3N4) was prepared by a one-step acid etching and ultrasonication process. It is found that the strong blue fluorescence of g-C3N4 (with excitation/emission maxima at 320/400 nm) is fairly selectively quenched by uric acid (UA). The morphology and chemical structure of the nanoporous g-C3N4 were characterized by XRD, TEM and FTIR. Quenching studies and Stern-Volmer plots reveal two UA concentration ranges of different quenching efficiency. The first extends from 50 to 500 nM, the other from 0.5 to 10 µM. The limit of detection is 8.4 nM. The two quenching processes are attributed to both dynamic and static quenching. The porous g-C3N4 probes were applied to the determination of UA in (spiked) human serum and human plasma, and the results were as good as those obtained with UA standard solutions. These data illustrate that g-C3N4 can be used to selectively and sensitively quantify trace levels of UA even in a complex environment. Graphical abstract Porous graphite nitride carbon (g-C3N4) is shown to be a viable fluorescent probe for uric acid (UA) via both dynamic and static quenching. The electron transfer of carbon nitride is represented by the arrows; hν is the incident light; PL is the fluorescence emission.

19.
Food Sci Biotechnol ; 26(3): 563-571, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30263580

RESUMO

The changes in antioxidant capacity and phenolics of persimmon during alcoholic fermentation, acetification, and short aging were investigated. An increase in the antioxidant activity was observed when persimmon was transformed from puree to vinegar. The total content of phenolics remained stable, in contrast to the concentration of condensed tannin, which significantly (p < 0.05) increased during alcoholic and acetic fermentations, although followed by a decrease after aging. The phenolic compounds were characterized and quantitated. Gallic acid was the main phenolic compound, and its content increased by 14.4% during alcoholic fermentation and reduced by 53.5% during acetic fermentation. Additionally, the flavan-3-ol compounds increased during alcoholic fermentation and acetification. Vanillyl alcohol, (-)-epigallocatechin, and p-coumaric acid were not observed in persimmon puree but detected in persimmon wine and vinegar. These results indicate that alcoholic and acetic fermentation can improve the antioxidant capacity of persimmon fruit.

20.
J Food Sci ; 81(3): M702-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26764561

RESUMO

In this study, the effect of high pressure homogenization (HPH) and dimethyl dicarbonate (DMDC) on microbial and nutrient qualities of mulberry juice was evaluated. Results showed that repeated HPH passes at 200 MPa or adding DMDC at 250 mg/L significantly inactivated the indigenous microorganisms in mulberry juice (P < 0.05), whereas some surviving microorganisms recovered to grow during storage of 4 °C. The combined treatment with 3 passes of HPH and 250 mg/L of DMDC (HPH-DMDC) decreased the population of surviving indigenous microorganisms to the level attained by heat treatment at 95 °C for 1 min (HT) with no significant increase (P > 0.05) in the population of microorganisms during subsequent storage at 4 °C. Moreover, no significant changes (P > 0.05) in the physical attributes, including pH, TSS ((o) Brix), L*, a*, and b* values were observed in the samples treated by the HPH-DMDC or by HT. Compared with HT, HPH-DMDC treatment resulted in a higher degree of retention in total phenolics, and α-glucosidase inhibitory activity, although the treatment led to higher losses in cyanidin 3-glucoside, cyanidin 3-rutinoside, and antioxidant capacity. Overall, HPH-DMDC treatment can be a useful alternative to conventional thermal pasteurization of mulberry juice, considering its ability to inactive, and inhibit indigenous microorganisms.


Assuntos
Dietil Pirocarbonato/análogos & derivados , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais , Frutas , Morus/química , Pressão , Antocianinas/análise , Antocianinas/farmacologia , Antioxidantes/análise , Antioxidantes/farmacologia , Cor , Dieta , Manipulação de Alimentos/métodos , Frutas/química , Frutas/microbiologia , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Glucosídeos/análise , Glucosídeos/farmacologia , Humanos , Pasteurização , Fenóis/análise , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , alfa-Glucosidases/metabolismo
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