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1.
Food Chem ; 317: 126430, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092612

RESUMO

Electrochemical Synchronous detection of cadmium (Cd(II)) and lead (Pb(II)) was obtained by acid treated multiwalled carbon nanotube (A-MWCNT) functionalized with hyaluronic acid (Hyalu) and this mixture was separately further modified with l-cysteine (l-Cys) and l-serine (l-Ser). Under the optimized circumstance best voltammetric responses were produced by A-MWCNT/Hyalu/l-Cys and A-MWCNT/Hyalu/l-Ser modified electrodes. The peak current was linearly dependent on the Cd(II) and Pb(II) concentrations in the range from 0.4 to 4 µg L-1. The sensitivities were calculated as 0.7 µA/nM (Cd(II)) and 3.5 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.6 µA/nM (Cd(II)) and 2.6 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. From the calibration plot LODs were calculated to be 0.032 µg L-1 (Cd(II)) and 0.015 µg L-1 (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.057 µg L-1 (Cd(II)) and 0.034 µg L-1 (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. Moreover, the proposed electrodes were subjected to the real sample application in honey, cocos nucifera and egg white.


Assuntos
Cádmio/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Chumbo/análise , Nanocompostos/química , Cádmio/química , Calibragem , Cocos/química , Cisteína/química , Clara de Ovo/análise , Eletrodos , Análise de Alimentos/instrumentação , Mel/análise , Ácido Hialurônico/química , Chumbo/química , Limite de Detecção , Nanotubos de Carbono/química , Sensibilidade e Especificidade , Serina/química
2.
Food Microbiol ; 87: 103388, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948629

RESUMO

The growing demand for minimally processed foods with clean labels has stimulated research into mild processing methods and natural antimicrobials to replace intensive heating and conventional preservatives, respectively. However, we have previously demonstrated that repetitive exposure of some bacteria to mild heat or subinhibitory concentrations of essential oil constituents (EOCs) may induce the emergence of mutants with increased resistance to these treatments. Since the combination of mild heat with some EOCs has a synergistic effect on microbial inactivation, we evaluated the potential of such combinations against our resistant E. coli mutants. While citral, carvacrol and t-cinnamaldehyde synergistically increased heat inactivation (53.0 °C, 10 min) of the wild-type MG1655 suspended in buffer, only the combination with carvacrol (200 µl/l) was able to mitigate the increased resistance of all the mutants. Moreover, the combination of heat and carvacrol acted synergistically inactivating heat-resistant variants of E. coli O157:H7 (ATCC 43888). This combined treatment could synergistically achieve more than 5 log10 reductions of the most resistant mutants in coconut water, although the temperature had to be raised to 57.0 °C. Therefore, the combination of mild heat with carvacrol appears to hold promise for mild processing, and it is expected to counteract the development of heat resistance.


Assuntos
Antibacterianos/farmacologia , Cocos/química , Escherichia coli O157/efeitos dos fármacos , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Óleos Vegetais/farmacologia , Acroleína/análogos & derivados , Acroleína/farmacologia , Monoterpenos Acíclicos/farmacologia , Cimenos/farmacologia , Farmacorresistência Bacteriana , Escherichia coli O157/crescimento & desenvolvimento , Temperatura Alta
3.
Biomed Res Int ; 2019: 8428304, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886260

RESUMO

Ayurvedic and traditional medical practitioners of Sri Lanka use the decoction of the immature inflorescence of Cocos nucifera L. (IC) variety aurantiaca for the treatment of menorrhagia. The progestogenic effect of the ethyl acetate soluble proanthocyanidins (EASPA) of the IC in female rats at a dose of 3.5 mg/kg body weight has been reported. Acute and subacute toxicity studies of EASPA of the IC carried out using female Wistar rats according to Organization for Economic Co-operation and Development (OECD) guidelines 423 and 407, respectively, are reported herein. In the acute toxicity study, a single dose of EASPA (2000 mg/kg body weight) was orally administered to rats, which were monitored for 14 days. In the subacute toxicity study, rats were orally administered with EASPA daily for 28 days at doses of 1.75, 3.5, 7, and 14 mg/kg body weight. No rat in either the acute or subacute toxicity study exhibited mortality or clinical signs of toxicity. Further, these rats did not show any significant change in their mean body weight, food, and water intake, haematological and biochemical parameters as well as in the results of their histopathological examinations compared to those of control group rats. According to results of the acute toxicity, the LD50 of EASPA is estimated to be greater than 2000 mg/kg body weight. Considering the results of the subacute toxicity study, the oral administration of EASPA daily for 28 days was well tolerated up to the dose, 14 mg/kg by rats. These results will be useful in the development of a novel therapeutic agent from EASPA of the IC for the treatment of menorrhagia, which incapacitates a considerable proportion of women worldwide.


Assuntos
Acetatos/química , Cocos/química , Inflorescência/química , Proantocianidinas/toxicidade , Testes de Toxicidade Aguda , Animais , Peso Corporal/efeitos dos fármacos , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Tamanho do Órgão/efeitos dos fármacos , Proantocianidinas/isolamento & purificação , Ratos Wistar
4.
Carbohydr Polym ; 223: 115062, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31426967

RESUMO

Nata de coco was chemically modified to afford the bacterial cellulose hydrogels carrying terminal alkynes. The resultant hydrogels were then converted into hydrogels carrying lactosides or those carrying α-2,3-sialyllactosides by the Cu+-catalyzed alkyne-azide cyclization. The stable homo association of the hydrogels carrying lactosides was observed in an aqueous solution containing Ca2+, thereby demonstrating the Ca2+-mediated lactoside-lactoside interactions. Ca2+ also stabilized the hetero associations among the hydrogels carrying lactosides and those carrying α-2,3-sialyllactosides, thereby also demonstrating the Ca2+-induced interactions between the lactosides and the α-2,3-sialyllactosides. The sizes of these hydrogels were of the order of ca. 5 mm, and their associations could thus be readily monitored with the naked eye.


Assuntos
Celulose/química , Hidrogéis/química , Oligossacarídeos/química , Polissacarídeos Bacterianos/química , Alquinos/química , Azidas/química , Cálcio/química , Cocos/química , Cocos/microbiologia , Hidrogéis/síntese química , Magnésio/química , Lectinas de Plantas/química , Ricinus/química , Sódio/química
5.
Environ Sci Pollut Res Int ; 26(27): 28022-28030, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31352599

RESUMO

Biosorption potential of oxidised coconut coir (OCC) for removal of Cd(II) was evaluated by multi-column arrangement by connecting three columns in series. Effect of flow rate at 5, 10 and 15 mL/min was studied at 30 mg/L initial Cd(II) concentration. The dynamic capacity of the system was found to be 321, 206 and 83 mg/L for 5, 10 and 15 mL/min flow rates, respectively, by applying the bed depth service time model. Biosorbent usage rates for single-column and multi-column systems were compared. Better utilisation of biosorbent was observed when the columns are connected in series at similar operating parameters. A simple acid-base regeneration procedure was found to be effective in desorbing/regenerating the cadmium bound biosorbent. Adsorption efficiency was found to decrease from 76.3% for the first cycle to 72.2% and 70.6% in the second and third cycles, respectively. Regeneration efficiencies were more than 94% up to 3 cycles. The study highlights the effectiveness of the multi-column system in biosorption against the conventional single-column system.


Assuntos
Cádmio/química , Poluentes Químicos da Água/química , Adsorção , Cádmio/análise , Cocos/química , Concentração de Íons de Hidrogênio , Íons , Cinética , Lignina/análogos & derivados , Modelos Químicos , Oxirredução , Poluentes Químicos da Água/análise
6.
PLoS One ; 14(4): e0214193, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30939131

RESUMO

Cocos nucifera (C. nucifera) (the coconut palm tree) has been traditionally used to fight a number of human diseases, but only a few studies have tested its components against parasites such as those that cause malaria. In this study, C. nucifera samples were collected from a private natural reserve in Punta Patiño, Darien, Panama. The husk, leaves, pulp, and milk of C. nucifera were extracted and evaluated against the parasites that cause Chagas' disease or American trypanosomiasis (Trypanosoma cruzi), leishmaniasis (Leishmania donovani) and malaria (Plasmodium falciparum), as well as against a line of breast cancer cells. While there was no activity in the rest of the tests, five and fifteen-minute aqueous decoctions of leaves showed antiplasmodial activity at 10% v/v concentration. Removal of some HPLC fractions resulted in loss of activity, pointing to the presence of synergy between the components of the decoction. Chemical molecules were separated and identified using an ultra-performance liquid chromatography (UPLC) approach coupled to tandem mass spectrometry (LC-MS/MS) using atmospheric pressure chemical ionization quadrupole-time of flight mass spectrometry (APCI-Q-TOF-MS) and molecular networking analysis, revealing the presence of compounds including polyphenol, flavone, sterol, fatty acid and chlorophyll families, among others.


Assuntos
Antiparasitários/farmacologia , Cocos/química , Leishmaniose/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antiparasitários/química , Arecaceae/química , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Humanos , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/patogenicidade , Leishmaniose/parasitologia , Malária Falciparum/parasitologia , Panamá , Folhas de Planta/química , Espectrometria de Massas em Tandem , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/patogenicidade
7.
Bioresour Technol ; 284: 214-221, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30939383

RESUMO

The effect of surfactant on the hydrothermal carbonization performance and pseudo-lignin formation were investigated. Especially, the fuel properties and combustion characteristics of hydrochar and solid product were determined. Furthermore, the mechanism of surfactant acted in hydrothermal carbonization was also identified in this article. The results showed that surfactant improved the content of solid products, lignin, heavy bio-oil (HBO), H2 and CO. Moreover, sodium dodecylbenzenesulfonate promoted the increase of the surface area of hydrochar from 4.93 to 41.43 m2/g. The mechanism showed surfactant formed water/oil film around the hydrochar to prevent HBO from leaving the pore or surface of hydrochar and promoted the condensation and polymerization of 5-hydroxymethylfurfura (5-HMF) with hydroxymethylfurfura (HMF) to form pseudo-lignin. The HBO and pseudo-lignin were beneficial for improving integrated combustion characteristic index (SN) during combustion. The article provides a new method to promote hydrothermal carbonization (HTC) for obtaining high value hydrochar as fuels.


Assuntos
Carbono/química , Cocos/química , Tensoativos/química , Lignina/química
8.
Molecules ; 24(7)2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30987245

RESUMO

Macrohyporia cocos is a medicinal and edible fungi, which is consumed widely. The epidermis and inner part of its sclerotium are used separately. M. cocos quality is influenced by geographical origins, so an effective and accurate geographical authentication method is required. Liquid chromatograms at 242 nm and 210 nm (LC242 and LC210) and Fourier transform infrared (FTIR) spectra of two parts were applied to authenticate the geographical origin of cultivated M. cocos combined with low and mid-level data fusion strategies, and partial least squares discriminant analysis. Data pretreatment involved correlation optimized warping and second derivative. The results showed that the potential of the chromatographic fingerprint was greater than that of five triterpene acids contents. LC242-FTIR low-level fusion took full advantage of information synergy and showed good performance. Further, the predictive ability of the FTIR low-level fusion model of two parts was satisfactory. The performance of the low-level fusion strategy preceded those of the single technique and mid-level fusion strategy. The inner parts were more suitable for origin identification than the epidermis. This study proved the feasibility of the data fusion of chromatograms and spectra, and the data fusion of different parts for the accurate authentication of geographical origin. This method is meaningful for the quality control of food and the protection of geographical indication products.


Assuntos
Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cocos/química , Cocos/classificação , Espectroscopia de Infravermelho com Transformada de Fourier , Interpretação Estatística de Dados , Geografia , Triterpenos/análise , Triterpenos/química
9.
Water Sci Technol ; 79(5): 866-876, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31025965

RESUMO

The adsorption mechanism of dichlorvos onto coconut fibre biochar (CFB) was investigated by the batch adsorption technique. Coconut fibre waste material was synthesised at 600 °C for 4 h under oxygen-limited conditions. The biochar was modified by HCl acid to enhance the specific surface area and porosity. The characteristics of the biochar were analysed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface area, and Fourier transform-infrared (FT-IR). The results showed that the BET specific surface area of biochar was 402.4 m2/g. Experimental data presented a good fit to Langmuir isotherm and the pseudo-second-order model. Langmuir isotherm illustrated that monolayer adsorption of dichlorvos occurred on the surface of CFB, with a maximum adsorption capacity of 90.9 mg/g. The diffusion model confirmed that the liquid film diffusion was the rate-limiting step, and the major diffusion mechanism of dichlorvos onto biochar. The BET result after dichlorvos adsorption demonstrated that pore-filling occurred and occupied 58.27%. The pore-filling and chemical interactions, performed important roles in the adsorption of dichlorvos onto CFB. Chemical adsorption is comprised of two interactions, which are hydrophobic and H-bonding, but the prime is H-bonding. CFB is a very potential material for the removal of dichlorvos and environmental pollutants.


Assuntos
Cocos/química , Diclorvós/química , Poluentes Químicos da Água/química , Adsorção , Carvão Vegetal/química , Ligação de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Int J Cosmet Sci ; 41(2): 194-199, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30854660

RESUMO

OBJECTIVE: Although the olfactory receptor OR2AT4 was described as involved in epidermal renewal, there is no data about a cosmetic active ingredient activating this receptor. The aim of this research work was thus to identify a natural molecule binding to this receptor in order to stimulate keratinocyte migration. METHODS: For this purpose, natural molecules were extracted from Cocos nucifera flour. Then, efficacy of this natural extract was evaluated on keratinocyte migration in vitro. Molecules of the Cocos nucifera flour extract were then identified by UPLC-MS/MS. Molecular docking was finally conducted to investigate the potential interaction between identified molecules and the olfactory receptor OR2AT4. RESULTS: The Cocos nucifera flour extract significantly increased keratinocyte migration and results demonstrated that this effect was mediated by the olfactory receptor OR2AT4. Metabolomic analysis revealed two molecules, nonioside D and butyl 4-O-alpha-D-glucopyranosyl-beta-D-glucopyranoside, as significantly present in the Cocos nucifera flour extract compared to both Cocos nucifera oil and water. Finally, molecular docking revealed that butyl 4-O-alpha-D-glucopyranosyl-beta-D-glucopyranoside could interact with the extracellular domain 2 of the OR2AT4. CONCLUSION: This study highlighted for the first time a natural molecule, extracted from Cocos nucifera flour, able to interact with the olfactory receptor OR2AT4 and promote the keratinocyte migration and thus the epithelialization.


Assuntos
Cosméticos/metabolismo , Receptores Odorantes/metabolismo , Cromatografia Líquida , Cocos/química , Farinha , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Relação Estrutura-Atividade , Espectrometria de Massas em Tandem
11.
Ultrason Sonochem ; 55: 135-148, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30853534

RESUMO

In this paper, a coconut milk composite system (glycerin monostearate as an emulsifier) with different maize additives (e.g., maize kernels and starch with different amylose contents) was treated with high-intensity ultrasound irradiation (HIUS, frequency 20 kHz). The stability and structural features of the added coconut milk emulsion were studied. Comparing the mechanical emulsifications, coconut milk with maize kernels was similar to coconut milk with high-amylose maize starch. However, coconut milk with a high proportion of amylopectin had the best stability. After ultrasonic treatment, the particle sizes were found to be smaller than those in the nonultrasound-treated coconut milk, and the particles demonstrated a monomodal size distribution. The electronegativity of the compound system was significantly improved. The electronegativity of the maize kernel and high-amylose maize starch-coconut milk systems was significantly decreased, and this change was beneficial to the stability of the systems. However, ultrasonic treatment did not change the fluid type of the coconut milk compound system (which showed pseudoplastic fluid characteristics). The proportion of amylose in maize had an important influence on the stability of the compound system. The apparent viscosity and crystallization order of the high-amylose maize starch-coconut milk system were high. However, the waxy maize starch system showed high complex viscosity and tended to be liquid with ultrasonic treatment. Ultrasound treatment reduced the particle size of coconut milk and homogenized the distribution of the system. Additionally, the amylase of the system contained amylose encapsulated in the interfacial layer after ultrasound treatment. The tiny gel beads formed by waxy maize starch had a good fusion effect on coconut milk fat/protein droplets. The results indicated that the stability of coconut-grain milk composite systems can be enhanced with the use of maize additives and ultrasound irradiation through space effects, electrostatic effects and continuous phase viscosity.


Assuntos
Amilose/química , Cocos/química , Sonicação , Zea mays/química , Cor , Tamanho da Partícula , Reologia , Tensão Superficial , Viscosidade
12.
Int J Biol Macromol ; 130: 419-428, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30822472

RESUMO

The objective of this research was to study the physical properties, water sorption, thermal and structure of films made from citrus pectin (CP), babassu coconut mesocarp (BCM) and glycerol (G). Seventeen formulations were prepared according to a central compound rotational design combining different proportions of the materials and evaluating the films produced according to their moisture contents, solubility, thicknesses and water vapor permeability. The results showed a direct relationship between the composition of the film and each physical property, providing films with unique mechanical characteristics and barrier properties. In the second phase, the films were reformulated, maintaining the proportions of CP and BCM constant and altering the G content. The results showed films with permeable structures, thus favoring the use of high drying temperatures (up to 70 °C) for the confection of films, without altering their physical and structural properties.


Assuntos
Fenômenos Químicos , Cocos/química , Glicerol/química , Membranas Artificiais , Pectinas/química , Algoritmos , Materiais Biocompatíveis/química , Fenômenos Mecânicos , Modelos Teóricos , Permeabilidade , Solubilidade , Análise Espectral , Vapor
13.
Food Chem ; 284: 259-263, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30744855

RESUMO

In this work, an analytical method for the determination of Cd and Pb in natural coconut water samples, industrialized coconut water samples and coconut milk using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS), after minimum treatment of the sample was developed. The analytical method was applied to 46 samples collected in Salvador, Bahia (Brazil). The ranges of concentrations obtained were: 0.42-18.72 µg L-1 Cd and <0.70-36.32 µg L-1 Pb for natural coconut water samples (n = 14); <0.06-1.49 µg L-1 Cd and 6.57-29.02 µg L-1 Pb for industrialized water coconut samples (n = 16); and <0.10-5.93 ng g-1 Cd and <0.85-22.41 ng g-1 Pb for coconut milk samples (n = 16). For all samples, Cd and Pb concentrations were below the maximum tolerated values recommended by Brazilian Health Surveillance Agency (Agência Nacional de Vigilância Sanitária, ANVISA).


Assuntos
Cádmio/análise , Cocos/química , Sucos de Frutas e Vegetais/análise , Chumbo/análise , Espectrofotometria Atômica/métodos , Brasil , Cocos/metabolismo , Grafite/química , Limite de Detecção , Reprodutibilidade dos Testes , Águas Residuárias/análise
14.
Food Chem ; 284: 303-311, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30744862

RESUMO

This study examined high voltage atmospheric cold plasma (HVACP) technology as a non-thermal intervention for inactivating Salmonella enterica serovar Typhimurium LT2 (ST2) in tender coconut water (TCW). Treatment with HVACP in air at 90 kV for 120 s inactivated 1.30 log10 of ST2. Development of a TCW stimulant suggested an interfering role of magnesium and phosphate salts with HVACP inactivation. Generation of reactive gas species, viz. ozone and hydrogen peroxides were found to be responsible for microbial inactivation. The addition of 400 ppm citric acid to the TCW effectively reduced ST2 by 5 log10 during HVACP treatment. Under these conditions, higher cellular leakage and morphological damage were observed in ST2. Minimal physico-chemical changes in TCW were observed with HVACP treatment, except for an 84.35% ascorbic acid loss (added externally). These results demonstrate a potential pathway for developing highly effective cold plasma treatments to preserve fruit and vegetable juices.


Assuntos
Cocos/química , Sucos de Frutas e Vegetais/análise , Gases em Plasma/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Ácido Ascórbico/farmacologia , Ácido Cítrico/farmacologia , Microbiologia de Alimentos , Viabilidade Microbiana/efeitos dos fármacos , Dióxido de Nitrogênio/química , Dióxido de Nitrogênio/farmacologia , Ozônio/química , Ozônio/farmacologia
15.
Carbohydr Polym ; 210: 127-134, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30732745

RESUMO

Lignocellulosic biomass has been widely studied as a source of cellulose- and related products, attracting the great interest of researchers dealing with renewable energy sources, vegetable waste recycling and biomaterials. In this work, the babassu coconut shells (epicarp and endocarp) were used for the achievement of products such as cellulose, cellulose acetate and cellulose-silica composite, which were chemically and structurally characterized by solid-state 13C nuclear magnetic resonance spectroscopy and scanning electron microscopy, among other techniques. As this precursor also naturally contains a significant amount of silica, a composite containing cellulose fibers mixed with amorphous silica particles (with rosette-like shape) was also produced. Finally, the possibility of synthesis of cellulose acetate was also demonstrated, illustrating the plethora of potential applications of this important lignocellulosic residue for the production of cellulose-based materials of high technological interest.


Assuntos
Celulose/análogos & derivados , Cocos/química , Dióxido de Silício/química , Biomassa , Celulose/química
16.
Analyst ; 144(4): 1401-1408, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30601476

RESUMO

Here, we applied NMR spectroscopy in combination with chemometrics to quantify the adulteration of fresh coconut water, stretched with water-sugar mixtures. Coconut water was extracted from young Costa Rican coconuts and adulterated with concentrations of various sugar solutions. A total of 45 samples were analysed by 1D proton NMR spectroscopy and chemometrics. Results showed highly sensitive quantification, with a limit of detection of adulteration with sugars of 1.3% and a root-mean-squared error of prediction of 0.58%. Interestingly, we identified a regular drift in the chemical shift and a change in the lineshape of malic acid signals concomitant with increasing levels of adulteration. On further investigation, this was found to originate from changes in the concentration of divalent cations, such as magnesium, within the samples. It can be concluded that 1H NMR spectroscopy enables accurate quantification for the degree of adulteration in this product, with the added discovery finding that the shift and lineshape of the malic acid signal can be utilised as a potential diagnostic marker for partial substitution of fresh coconut water with extrinsic components such as sugar mixtures.


Assuntos
Cocos/química , Qualidade dos Alimentos , Fraude/prevenção & controle , Informática , Água/química , Espectroscopia de Ressonância Magnética , Malatos/química
17.
Food Chem ; 276: 129-139, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30409575

RESUMO

This study investigated the structural characteristics of oil bodies from mature coconut (Cocos nucifera L.) fruit. The ultrastructure and the distribution of oil bodies in coconut endosperm were investigated using cryo-scanning electron microscopy. The interfacial characteristics of the oil bodies in suspensions isolated using two different protocols were studied using confocal laser scanning microscopy (CLSM), and the oleosins stabilizing the oil bodies were characterized using sodium dodecyl sulfate polyacrylamide electrophoresis. The oil bodies were found to be preferentially accumulated in endosperm tissues away from the inner endosperm and had a polydisperse size distribution, both intracellularly and in suspensions. The CLSM of oil bodies revealed uniform distribution of proteins and phospholipids at the interface along with glycolipids. Six different proteins were found to be associated with oil bodies some of which were disulfide-linked. This work provides new insights into the structure of coconut oil bodies and mechanisms for their stabilization.


Assuntos
Cocos/ultraestrutura , Endosperma/ultraestrutura , Gotículas Lipídicas/ultraestrutura , Cocos/química , Endosperma/química , Gotículas Lipídicas/química , Microscopia Confocal , Fosfolipídeos/análise , Proteínas de Plantas/análise
18.
Food Chem ; 272: 157-164, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30309526

RESUMO

Here, for the first time, we developed Raman spectroscopy in combination with chemometrics for the quantification of adulteration of fresh coconut water by dilution, and its masking with sugars. Coconut water was extracted from young Costa Rican coconuts and heat treated to emulate pasteurization. Samples were then adulterated by dilution with water and single sugars, mixtures of sugars, and high-fructose corn syrup (HFCS). A total of 155 samples were analysed with Raman spectroscopy at 785 nm excitation and 620 spectra analysed with chemometrics. Results showed successful quantification of dilution and adulteration with single sugars between 1.9 and 2.6%, masking of dilution with mixtures of sugars at 9.8%, and masking of dilution with HFCS at 7.1%. It can be concluded that Raman spectroscopy has significant potential as a rapid accurate analytical method for the detection of adulteration in this product, with the ability to discern small abnormalities in sugar ratios within coconut water.


Assuntos
Cocos/química , Qualidade dos Alimentos , Fraude/prevenção & controle , Informática , Análise Espectral Raman , Açúcares/análise , Água/química , Contaminação de Alimentos/análise , Xarope de Milho Rico em Frutose/análise , Fatores de Tempo
19.
Food Chem ; 272: 372-378, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30309557

RESUMO

Recently body fluids have been found to contain a class of nanoparticles released from cells, referred to as extracellular vesicles; exosomes are a type of small-diameter extracellular vesicle. We selected three types of sample: milk-derived exosomes, adipose-derived stem cell exosomes, and nanoparticles extracted from coconut water, to investigate their morphology, particle size distribution, protein content, and microRNA expression levels. Among the vesicles investigated, coconut nanoparticles had the greatest size distribution, and the protein content of coconut nanoparticles differed from that of mammalian exosomes. Using fluorescence microscopy, we determined that DiI-labeled extracellular vesicles could be absorbed by bacteria. Prominently, milk-derived exosomes could promote the growth of Escherichia coli K-12 MG1655 and Lactobacillus plantarum WCFS1. The studied extracellular vesicles could alter bacterial gene expression. Overall, this study identified differences in exogenous extracellular vesicles from different sources and revealed their supportive effects on microbial growth to make better utilization of microbial resources.


Assuntos
Escherichia coli K12/crescimento & desenvolvimento , Vesículas Extracelulares/metabolismo , Lactobacillus/crescimento & desenvolvimento , Cocos/química , Humanos , Nanopartículas , Tamanho da Partícula
20.
Anal Bioanal Chem ; 411(3): 659-667, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30515537

RESUMO

There are increasing concerns regarding the risks arising from the contamination of manipulators of antineoplastic drugs promoted by occupational exposure or even in the dosage of drugs. The present work proposes the use of an electrochemical sensor based on a biopolymer extracted from the babassu coconut (Orbignya phalerata) for the determination of an antineoplastic 5-fluorouracil (5-FU) drug as an alternative for the monitoring of these drugs. In order to reduce the cost of this sensor, a flexible gold electrode (FEAu) is proposed. The surface modification of FEAu was performed with the deposition of a casting film of the biopolymer extracted from the babassu mesocarp (BM) and modified with phthalic anhydride (BMPA). The electrochemical activity of the modified electrode was characterized by cyclic voltammetry (CV), and its morphology was observed by atomic force microscopy (AFM). The FEAu/BMPA showed a high sensitivity (8.8 µA/µmol/L) and low limit of detection (0.34 µmol/L) for the 5-FU drug in an acid medium. Electrochemical sensors developed from the babassu mesocarp may be a viable alternative for the monitoring of the 5-FU antineoplastic in pharmaceutical formulations, because in addition to being sensitive to this drug, they are constructed of a natural polymer, renewable, and abundant in nature. Graphical abstract ᅟ.


Assuntos
Antimetabólitos Antineoplásicos/análise , Cocos/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Fluoruracila/análise , Ouro/química , Custos e Análise de Custo , Monitoramento de Medicamentos/instrumentação , Eletrodos/economia , Limite de Detecção , Microscopia de Força Atômica , Oxirredução , Anidridos Ftálicos/química , Solubilidade
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