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2.
J Int Soc Sports Nutr ; 17(1): 15, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143716

RESUMO

BACKGROUND: Maximal strength-speed exercise is a powerful stimulus to acutely increase concentrations of circulating steroid hormones and homocysteine [Hcy]. There is some evidence that antioxidant beverages rich in polyphenols can attenuate [Hcy] levels and modulate endocrine responses in favor of an anabolic environment. Polyphenols-rich pomegranate (POM) have been reported to possess one of the highest antioxidant capacities compared to other purported nutraceuticals and other food stuffs. Studies focused on proving the beneficial effect of POM consumption during maximal strength exercises have only measured physical performance, muscle damage, oxidative stress and inflammatory responses, while POM effects on [Hcy] and hormonal adaptations are lacking. The aim of the present study was to investigate the effect of consuming natural polyphenol-rich pomegranate juice (POMj) on the acute and delayed [Hcy] and steroidal hormonal responses to a weightlifting exercises session. METHODS: Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-weightlifting sessions after ingesting either the placebo (PLA) or POMj supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. RESULTS: Compared to baseline values, circulating cortisol [C] decreased (p < 0.01) and testosterone/cortisol [T/C] ratio increased immediately following the training session in both PLA and POMj conditions (p = 0.003 for PLA and p = 0.02 for POM). During the 48 h recovery period, all tested parameters were shown to recover to baseline values in both conditions with significant increases in [C] and decreases in [T/C] (p < 0.01 for PLA and p < 0.05 for POMj) from 3 min to 48 h post-exercises. Compared to PLA, a lower level of plasma testosterone [T] was registered 3 min post exercise using POMj supplementation (p = 0.012) and a significant decrease (p = 0.04, %change = - 14%) in plasma [Hcy] was registered during the 48 h recovery period only using POMj. A moderate correlation was observed between [Hcy] and [T] responses (p = 0.002, r = - 0.50). CONCLUSION: In conclusion, supplementation with POMj has the potential to attenuate the acute plasma [T] response, but did not effect 48 h recovery kinetics of [Hcy] following weightlifting exercise. Further studies investigating androgen levels in both plasma and muscular tissue are needed to resolve the functional consequences of the observed acute POMj effect on plasma [T]. TRIAL REGISTRATION: Clinical Trials.gov, ID: NCT02697903. Registered 03 March 2016.


Assuntos
Sucos de Frutas e Vegetais , Homocisteína/sangue , Hidrocortisona/sangue , Polifenóis/administração & dosagem , Testosterona/sangue , Levantamento de Peso/fisiologia , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Adulto Jovem
3.
J Agric Food Chem ; 68(10): 3286-3296, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32052973

RESUMO

The bacterial disease Huanglongbing (HLB) has been causing large economic losses in the citrus industry worldwide. Aimed at unraveling the mechanisms of scion/rootstock combination on improving HLB-affected orange juice quality, a specific scion/rootstock combination field trial was designed using three sibling rootstocks and two late-maturing sweet orange scion cultivars. Scion/rootstock combination significantly improved the overall consumer liking of orange juice from the HLB-affected trees. Rootstocks showed significant effects on the consumer liking and overall flavor, while scions had significant effects on the freshness and overall orange flavor intensity of the juice. A PLS-DA model combined with KEGG pathway enrichment analysis and some biomarker metabolites further indicated that scions mainly affected metabolism of alanine, aspartate, and glutamate in orange fruits. Meanwhile, rootstocks had an impact on the biosynthetic pathways of secondary metabolites. Sugars and organic acids were not closely correlated with the overall liking and sensory perception of orange juice. Rather, flavonoids, terpenoids, and volatile aromas played important roles in improving consumer overall liking. These results indicated that an optimum tolerant scion/rootstock combination can make a positive contribution toward improved fruit or juice quality from HLB-affected citrus trees.


Assuntos
Citrus sinensis/química , Sucos de Frutas e Vegetais/análise , Melhoramento Vegetal/métodos , Doenças das Plantas/microbiologia , Raízes de Plantas/genética , Citrus sinensis/genética , Citrus sinensis/metabolismo , Frutas/química , Frutas/genética , Frutas/metabolismo , Humanos , Metabolômica , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Rhizobiaceae/fisiologia , Metabolismo Secundário , Paladar
4.
Food Chem ; 313: 126121, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31923870

RESUMO

This study aimed to evaluate the influences of high-intensity ultrasound on the physiochemical properties of kiwifruit juice. Results reported high-intensity ultrasound processing significantly enhanced the color attributes, cloudiness, and sugars of kiwifruit juice. Further, the shear stress, apparent viscosity, storage and loss modulus was increased with the rise of processing time. However, a significant degradation in the nanostructure of water-soluble pectin and suspended particles in ultrasound treated kiwifruit juice was observed. In addition, ultrasound processing resulted in the rupture of cell wall causing the dispersion of the intracellular components into juice while higher damage in the cellular structure was observed by increasing the processing time. These structural changes reveal the physical mechanism of ultrasound in improving the rheological properties, color attributes, cloudiness, and water-soluble pectin of kiwifruit juice. Altogether these findings suggest that high-intensity ultrasound has an enormous potential to improve the physical properties of kiwifruit juice.


Assuntos
Actinidia/metabolismo , Carboidratos/química , Sucos de Frutas e Vegetais/análise , Pectinas/química , Sonicação , Cor , Tamanho da Partícula , Reologia , Resistência ao Cisalhamento , Viscosidade
5.
Food Microbiol ; 87: 103382, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948623

RESUMO

Although due to their acidity some fruit juices are considered safe, several outbreaks have been reported. For processing fruit juices, microwave heating offers advantages such as shorter come-up time, faster and uniform heating, and energy efficiency. Thus, it could be a beneficial alternative to conventional pasteurization. The objective of this study was to study the inactivation kinetics of Escherichia coli O157:H7 and Salmonella Typhimurium under microwave pasteurization at temperatures between 80 and 90 °C, i.e., at conditions that are employed in conventional pasteurization. Inoculated juices were treated at different power levels (600 W, 720 W) and treatment times (5s, 10s, 15s, 20s, 25s). Time-temperature profiles were obtained by fiber-optic sensors in contact with the samples allowing continuous data collection. The log-logistic and Arrhenius equations were used to account for the influence of the temperature history; thus, resulting in two different modeling approaches that were compared in terms of their prediction abilities. Survival kinetics including non-isothermal conditions were described by a non-linear ordinary differential equation that was numerically solved by the Runge-Kutta method (ode45 in MATLAB ®). The lsqcurvefit function (MATLAB®) was employed to estimate the corresponding survival parameters, which were obtained from freshly made apple juice, whereas the prediction ability of these parameters was evaluated on commercial apple juices. Results indicated that inactivation increased with power level, temperature, and treatment time reaching a microbial reduction up to 7 Log10 cycles. The study is relevant to the food industry because it provides a quantitative tool to predict survival characteristics of pathogens at other non-isothermal processing conditions.


Assuntos
Escherichia coli O157/efeitos da radiação , Irradiação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Malus/microbiologia , Salmonella typhimurium/efeitos da radiação , Contagem de Colônia Microbiana , Escherichia coli O157/crescimento & desenvolvimento , Irradiação de Alimentos/instrumentação , Micro-Ondas , Salmonella typhimurium/crescimento & desenvolvimento , Temperatura Ambiente
6.
Food Microbiol ; 87: 103387, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948628

RESUMO

We evaluated the bactericidal efficacy of the simultaneous application of ultraviolet-A (UV-A) irradiation and fumaric acid (FA) against Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in apple juice and as well as investigated the effects of this treatment on product quality. Further, we elucidated the mechanisms underlying their synergistic bactericidal action. Simultaneous UV-A light irradiation and 0.1% FA treatment for 30 min resulted in 6.65-, 6.27-, and 6.49-log CFU/ml reductions in E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, which involved 3.15, 2.21, and 3.43 log CFU reductions, respectively, and these were attributed to the synergistic action of the combined treatments. Mechanistic investigations suggested that the combined UVA-FA treatment resulted in significantly greater bacterial cell membrane damage and intracellular reactive oxygen species (ROS) generation. UVA-FA treatment for 30 min did not cause significant changes to the color, nonenzymatic browning index, pH, and total phenolic content of apple juice. These results suggest that combined UVA-FA treatment can be effectively used to control foodborne pathogens in apple juice without affecting its quality.


Assuntos
Antibacterianos/farmacologia , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Fumaratos/farmacologia , Malus/microbiologia , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/crescimento & desenvolvimento , Escherichia coli O157/metabolismo , Escherichia coli O157/efeitos da radiação , Conservação de Alimentos/instrumentação , Sucos de Frutas e Vegetais/análise , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/metabolismo , Listeria monocytogenes/efeitos da radiação , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/metabolismo , Salmonella typhimurium/efeitos da radiação , Raios Ultravioleta
7.
J Agric Food Chem ; 68(4): 1030-1037, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31903752

RESUMO

The off-flavor produced after thermal stabilization of mandarin (Citrus reticulata, Blanco) juices has limited the production of commercial juices. Methanethiol, a putrid-smelling sulfur volatile, has been identified for the first time in heated mandarin juices. Identification was achieved using a combination of capillary gas chromatography with two dissimilar columns and a dual sulfur-specific pulsed flame photometric detector and selected ion mass spectrometry detection. Static headspace solid-phase microextraction quantitation found that average odor activity values (OAVs) in heated juices were 25.5 for methanethiol compared to 10.8 for dimethyl sulfide. OAVs for methanethiol and dimethyl sulfide in fresh juices were ND (not detected) and 5.5, respectively. Hydrogen sulfide, carbonyl sulfide, carbon disulfide, and dimethyl disulfide were also identified and quantitated. Thermal decomposition studies of nonvolatile sulfur-containing potential precursors indicated that methionine was the major source of methanethiol. Additional heating studies with model juices demonstrated that ascorbic acid greatly accelerated the formation of methanethiol and methional, as well as dimethyl di and tri sulfides.


Assuntos
Citrus/química , Aromatizantes/química , Sucos de Frutas e Vegetais/análise , Compostos de Enxofre/análise , Culinária , Temperatura Alta , Odorantes/análise , Sulfetos/análise , Volatilização
8.
Food Chem ; 312: 126048, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31918363

RESUMO

A quenching based apta-sensing platform was developed for the detection of Patulin. Three different aptamer sequences were studied to screen the aptamer with the maximum affinity towards Patulin. Carboxyfluorescein (CFL) was used as a fluorescent dye while -COOH functionalized multiwall carbon nanotubes (MWCNTs) were applied as novel nanoquenchers. Aptamer tagged at the 3' end with 40 nucleotide bases exhibited the maximum affinity towards Patulin and caused substantial fluorescence recovery. Interestingly, the limit of detection (LOD) and limit of quantification (LOQ) were calculated as 0.13 µg L-1and 0.41 µg L-1 respectively. Commonly occurring mycotoxins in food were also tested to confirm the selectivity of apta-assay. The developed apta-assay was applied to a spiked apple juice sample and toxin recoveries were observed ranging from 96% to 98% (n = 3). These results demonstrated the potential of the developed apta-assay for the selective detection and quantification of Patulin in food samples.


Assuntos
Fluoresceínas/química , Nanotubos de Carbono , Fluorescência , Sucos de Frutas e Vegetais/análise , Limite de Detecção , Malus/química , Patulina/análise
9.
J Sci Food Agric ; 100(4): 1678-1686, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31803940

RESUMO

BACKGROUND: Nitrogen (N) fertilization influences plant growth and yield, and may also affect fruit quality. For two consecutive seasons, we examined the effects of various N fertilization levels - 5 to 200 mg L-1  - on pomegranate fruit, aril and juice quality. Evaluations included fruit and aril weight, size and color, appearance of peel blemishes, internal black rot and nutritional composition of extracted juices. RESULTS: Nitrogen fertilization affected pomegranate fruit, aril and juice quality. The most pronounced effects were observed in trees grown under the lowest N fertilization level, which bore smaller fruit and arils, the latter with lighter color; the fruit suffered from sunburn, and the juice had lower total soluble solid, acidity and anthocyanin contents. The proportion of edible aril weight per total fruit weight gradually increased with an increase in N fertilization concentration. In contrast, N fertilization did not affect peel color, roughness or cracking incidence. Black rot incidence increased with increasing N concentration. CONCLUSIONS: Nitrogen fertilization affected pomegranate fruit, aril and juice quality, and the total number of marketable fruits per tree. The optimal N fertilization levels, which were most beneficial for achieving high-quality marketable fruit, were between 40 and 100 mg L-1 . © 2019 Society of Chemical Industry.


Assuntos
Sucos de Frutas e Vegetais/análise , Nitrogênio/metabolismo , /metabolismo , Fertilizantes/análise , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , /crescimento & desenvolvimento , Controle de Qualidade
10.
Food Chem ; 310: 125741, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31806389

RESUMO

Polyphenol oxidase (PPO), also known as tyrosinase and catechol oxidase, is the enzyme responsible for enzymatic browning in foods. It causes undesirable organoleptic, nutritional and colour changes. Here, we report the preparation of five nanomaterials and a study of their ability to modulate PPO enzyme activity. The materials consist of UVM-7 supports (a mesoporous silica material) modified with diverse functional groups (i.e. amine, carboxylic acid, isocyanate, alkane and pyridine). We also studied the PPO immobilisation capability of the materials. All the materials, except the carboxylic acid functionalised one, offer high PPO loading capabilities and the immobilisation speed increases with functionalisation. Nevertheless, only a minor effect of the inhibition of enzymatic browning was produced. Furthermore, the amine containing material was able to capture not only PPO, but also the oxidation products. Such behaviour was validated with fresh apple juice in which browning was avoided, even 90 min in the presence of oxygen at room temperature.


Assuntos
Catecol Oxidase/química , Catecol Oxidase/metabolismo , Sucos de Frutas e Vegetais , Nanoestruturas/química , Dióxido de Silício/química , Ácidos Carboxílicos/química , Ácido Edético/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Malus/química , Oxirredução , Oxigênio/química , Oxigênio/metabolismo , Piridinas/química , Propriedades de Superfície
11.
J Sci Food Agric ; 100(3): 1080-1091, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31650556

RESUMO

BACKGROUND: The newly developed sugarcorn is conceived for dual-purpose use as a potential biofuel feedstock and a high-energy silage crop. Its agronomic traits are, however, not fully appraised under the umbrella of nitrogen (N) management and with canopy reflectance indicator. A 3-year field study was conducted to examine the responses of silage biomass, stalk sugar concentration, sugar and juice yields to various N applications; and determine the quantitative relationships between canopy reflectance, expressed as the normalized difference vegetation index (NDVI), and stalk sucrose or other sugar measures in a dual-purpose sugarcorn (cv. 'CO384xC103'), in comparison with a commercial leafy silage-specific hybrid (cv. 'Pride A5892G3 EDF'). RESULTS: The moderate N rate, 125 kg ha-1 , produced similar stalk sucrose, silage and grain yields, compared to the high rate (250 kg N ha-1 ), regardless of application methods. The NDVI signatures measured at the V8-V10 stage exhibited significant (P < 0.01) and exponential relationships with stalk sucrose concentrations, sucrose and juice yields at the R3 stage, and with silage yield at approximately 65% whole-plant moisture, the optimum silage-harvest window. CONCLUSION: The results indicate that the moderate N rate, 125 kg ha-1 , which is recommended for conventional grain corn production in the region, was likely close to the economic optimum N rate for leafy silage-specific and sugarcorn. Canopy reflectance, measured at the early growth stages, can be used as a potential indicator of sugar and silage production, and this quantitative relationship necessitates further evaluation with more genotypes and under wide environmental conditions. © 2019 Her Majesty the Queen in Right of Canada Journal of The Science of Food and Agriculture © 2019 Society of Chemical Industry.


Assuntos
Silagem/análise , Açúcares/química , Zea mays/química , Zea mays/crescimento & desenvolvimento , Produção Agrícola , Sucos de Frutas e Vegetais/análise , Nitrogênio/análise , Nitrogênio/metabolismo , Caules de Planta/química , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Açúcares/metabolismo , Zea mays/genética
12.
J Sci Food Agric ; 100(4): 1653-1661, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31802493

RESUMO

BACKGROUND: The consumption of pesticide-contaminated sour cherries as fruit or juice has become a major health concern, and so the search for alternative processing technologies, such as pulsed electric fields (PEF), ozone (O), and ultrasonication (US) has intensified. The objectives of this experimental study of sour cherry juice were fourfold: (1) to quantify the removal efficiency of new processing technologies (PEF, O, US), and their combinations, for the pesticides chlorpyrifos ethyl, τ-fluvalinate, cyprodinil, pyraclostrobin, and malathion; (2) to detect their impact on physical, bioactive, and sensory properties; (3) to determine their microbial inactivation levels for Escherichia coli O157:H7, Bacillus cereus, Pseudomonas syringae subs. Syringae, and Penicillum expansum; and (4) to jointly optimize multiple responses of physical, quality, and sensory properties, pesticides, and microbial inactivation. RESULTS: Except for all the O treatments, the physical, bioactive and sensory properties of sour cherry juice were not adversely affected by the treatments. The joint optimization suggested PEF1 (24.7 kV cm-1 for 327 µs), PEF2 (24.7 kV cm-1 for 655 µs), PEF2 + O + US, US, and PEF2 + O as the five best treatments. PEF2 + O + US best achieved both pesticide removal and microbial inactivation. CONCLUSION: PEF2 + O + US provided promising reductions in pesticide and microbial loads. © 2019 Society of Chemical Industry.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Praguicidas/química , Prunus avium/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Manipulação de Alimentos/instrumentação , Sucos de Frutas e Vegetais/análise , Viabilidade Microbiana , Praguicidas/isolamento & purificação , Prunus avium/química , Controle de Qualidade
13.
J Agric Food Chem ; 68(1): 279-291, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31802659

RESUMO

This study aimed to identify the key aroma-active volatiles in cranberry wines through three vinification methods (White, Red and Thermo) using GC-MS/O to identify the important aroma compounds. A total of 70 compounds were detected, with 67 in wines and 61 in juices. The esters was the most diversified class, while alcohols and acids were the most abundant, especially 3-methylbutanol, methylbutyric acid, and benzoic acid. The volatile profiles of cranberry wines are distinctive from their source juices. Most alcohols, esters, and acids are fermentation-derived, while terpenes, phenols, aldehydes and ketones are varietal. The Red vinification retained the most varietal volatiles from the must, while the White and Thermo vinifications produced more volatiles during fermentation. Thermovinification reduced the yield of benzoic acid and its derivatives after fermentation. Olfactory analysis identified 47 aroma-active compounds, among which 41 were considered as the major aroma contributors (ethyl benzoate had the highest modified detection frequency).


Assuntos
Aromatizantes/química , Sucos de Frutas e Vegetais/análise , Vaccinium macrocarpon/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Fermentação , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise
14.
J Chromatogr A ; 1609: 460454, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31443966

RESUMO

We propose a new capillary electrophoresis (CE)-based open-tubular immobilized enzyme microreactor (OT-IMER) and its application in acetylcholinesterase (AChE) assays. The IMER is fabricated at the capillary inlet (reactor length of ∼1 cm) with the inner surface modified by a micropore-structured layer (thickness of ∼220 nm, pore size of ∼15-20 nm). The use of IMER accomplishes the enzymatic reaction and separation/detection of the products in the same capillary within 3 min. The feasibility of the proposed method is evaluated via online analysis of the activity and inhibition of AChE enzymes. Such method exhibits good reproducibility with relative standard deviation (RSD) of less than 4% for 20 runs, and the enzyme remains over 82% of the initial activity after usage of 7 days. The IMERs are successfully applied to detect the organophosphorus pesticide, paraoxon, in three types of vegetable juice samples with a limit of detection of as low as 61 ng mL-1. Results show that the spiked samples are in the range of 89.6-105.9% with RSD less than 2.7%, thereby indicating its satisfactory level of accurate and reliable analysis of real samples by using the proposed method. Our study indicates that, with combination of advantages of both porous-layer capillary and CE OT-IMER, the proposed method is capable to enhance enzymatic reactions and to achieve rapid analysis with simple instrumentation and operation, thus would pave the way for extensive application of CE-based IMERs in a variety of bioanalysis.


Assuntos
Acetilcolinesterase/análise , Reatores Biológicos , Eletroforese Capilar/métodos , Ensaios Enzimáticos/métodos , Enzimas Imobilizadas/metabolismo , Inibidores da Colinesterase/análise , Sucos de Frutas e Vegetais , Cinética , Paraoxon/análise , Porosidade , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier
15.
J Chromatogr A ; 1609: 460520, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31519407

RESUMO

A sensitive, fast, eco-friendly ultrasound assisted liquid-liquid microextraction (LLME) in combination with hydrophobic deep eutectic solvent (DES) method was developed to preconcentrate and extract sulfonamides in fruit juices, prior to high-performance liquid chromatographic (HPLC) analysis. The DES was synthesized with trioctylmethylammonium chloride (TAC) and 2-octanol at the molar ratio of 1:2. Some parameters which affected the extraction efficiency were investigated and optimized, including the volume of DES, extraction method, extraction time, pH. Under the optimum conditions, good linearity (r = 0.9999) in the range of 0.1-50 µg mL-1 was obtained. The limit of detection (LOD) was 0.02-0.05 µg mL-1. And the accuracy of the developed method was confirmed by analysis of spike method, the recoveries were in the range of 88.09-97.84% at the spike levels of 2-20 µg mL-1 in fruit juices.


Assuntos
Sucos de Frutas e Vegetais/análise , Interações Hidrofóbicas e Hidrofílicas , Microextração em Fase Líquida/métodos , Solventes/química , Sulfonamidas/análise , Ultrassom , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos Testes , Sonicação
16.
Food Chem ; 310: 125812, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31734008

RESUMO

An eco-friendly method was used to synthesize carbon dots (CDs) from Rosemary leaves, as a carbon source. The as-synthesized CDs was applied as a fluorophore in an optical sensor after modification with molecularly imprinted polymers (MIPs) for determination of thiabendazole (TBZ). For this purpose, a silica shell using tetraethoxysilane (TEOS), as a Si source, was stabilized on the surface of CDs via reverse microemulsion technique. Following, MIPs were synthesized in the presence of TBZ as a template, using 3-aminopropyl triethoxysilane and TEOS as a functional monomer and a crosslinker, respectively. After optimization of the experimental parameters, a linear dynamic range of 0.03-1.73 µg/mL TBZ with a detection limit as 8 ng/mL were obtained for the suggested method. Finally, the proposed sensor was successfully applied for the determination of TBZ in apple, orange, and tomato juices. This sensor is a simple, rapid, selective, and non-expensive method for TBZ measurement.


Assuntos
Fluorometria/instrumentação , Sucos de Frutas e Vegetais/análise , Polímeros/síntese química , Pontos Quânticos/química , Tiabendazol/análise , Carbono/química , Corantes Fluorescentes/química , Fluorometria/métodos , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Química Verde , Limite de Detecção , Impressão Molecular/métodos , Silanos/química , Dióxido de Silício/química , Espectrometria de Fluorescência/métodos
17.
J Agric Food Chem ; 68(4): 1038-1050, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31814396

RESUMO

Huanglongbing (HLB) disease has reduced orange yield and flavor quality in Florida. Orange juice (OJ) and peel molasses (PM) compounds are "from the named fruit" (FTNF) and were tested for their effects on HLB-affected OJ taste. These and other "target" compounds, reportedly found in citrus, were spiked into off-flavored, HLB-affected reference juices. The spiked juice was evaluated by a sensory panel in comparison with unspiked juice for "sweetness", "sourness", "bitterness", "astringency", and "aftertaste". Of the target compounds, feruloyl putrescine, taxifolin, and neodiosmin most effectively reduced "bitterness", feruloyl putrescine reduced "astringency" and "aftertaste", while feruloyl putrescine and neodiosmin enhanced perceived "sweetness", perhaps due to reduced bitterness. OJ and PM fractions containing reported bitter limonoids, hydroxycinnamates, hesperidin, and/or polymethoxylated flavones enhanced "sourness', "bitterness", "astringency", and "aftertaste", and/or suppressed perceived "sweetness" (perhaps due to enhanced bitterness). Other fractions, containing feruloyl putrescine and/or vicenin-2 enhanced "sweetness" and reduced "bitterness", "sourness", "astringency", and/or "aftertaste". These potentially FTNF compounds may be useful for management of HLB-affected OJ juice flavor.


Assuntos
Citrus sinensis/química , Aromatizantes/análise , Aditivos Alimentares/análise , Sucos de Frutas e Vegetais/análise , Citrus sinensis/microbiologia , Frutas/química , Frutas/microbiologia , Humanos , Doenças das Plantas/microbiologia , Rhizobiaceae/fisiologia , Paladar
18.
Food Chem ; 312: 125798, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887621

RESUMO

In this work, a green, inexpensive, simple and fast deep eutectic solvent (DES)-based dispersive liquid-liquid microextraction was evaluated, for the first time, for the extraction of phthalates (i.e. benzylbutyl phthalate, diisobutyl phthalate, diisopentyl phthalate, di-n-pentyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate) from different beverages. Separation and determination were achieved by high performance liquid chromatography-diode-array detection while confirmation was carried out by tandem mass spectrometry. The main factors affecting the extraction such as type and volume of DES and emulsifier, pH and ionic strength, were optimised. Choline chloride:phenol-based DES showed the best results. The methodology was validated for tea, apple-based beverage and pineapple juice. Recovery values ranged from 84 to 120% with relative standard deviation values lower than 11%. Limits of detection of the method were in the range 5.1-14.2 µg L-1 for tea, 5.3-17.8 µg L-1 for apple beverages and 5.9-15.6 µg L-1 for pineapple juices.


Assuntos
Sucos de Frutas e Vegetais/análise , Ácidos Ftálicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Cor , Microextração em Fase Líquida/métodos , Solventes/química , Espectrometria de Massas em Tandem/métodos
19.
Food Chem ; 312: 126056, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887620

RESUMO

Cloud and sediment formation is a major problem in juices and drinks. Barberry juice, as a functional and healthy product, is faced with the sedimentation problem, as an emerging issue. The present study was carried out to identify the sediment forming agents in barberry juice concentrate. The sediment was characterized by a range of different analytical techniques including FTIR, UV spectrophotometry, HPLC and LC-MS analysis. The findings of this research revealed that sugar derived organic acids, which were present in high amounts in barberry juice, were mainly responsible for sedimentation of barberry juice concentrate during cold storage. It was reported that such sugar derived acids with active carboxylic groups could cause instability in products rich in these compounds. The isolated sediment could re-crystalize at different juice concentrations with different shapes and sizes as affected by nucleation and crystal growth rates.


Assuntos
Berberis/química , Sucos de Frutas e Vegetais/análise , Precipitação Química , Cromatografia Líquida de Alta Pressão/métodos , Frutas/química , Espectrometria de Massas
20.
Food Chem ; 309: 125761, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31757490

RESUMO

Innovative chemometric approaches by NMR and LC-MS data fusion (multiblock analysis) and decomposition of the GC-MS raw data by PARADISe were applied to evaluate the influence of thermal and non-thermal processing on the composition of cashew apple juices. Comparative investigations by Principal Component Analysis (PCA) highlighted pronounced effect of thermal processing on juice compared to non-thermal processing, as decreases of anacardic acids, sucrose, malic acid, tyrosine, phenylalanine, and important flavor compounds (esters, aldehydes, and ketones). Ultrasound presented relevant influence on increase of anacardic acids concentration. Non-thermal processing carried out at more intense conditions (10 min of ultrasound, 5 min of ozone, and pulsed light at 10 V) showed pronounced effect compared to other non-thermal processing. Although individual PCA enables to detect the influence of different processing technologies, data fusion and PARADISe presented advantages, since a more comprehensive understanding of the relationship among chemical changes from different analytical techniques were established.


Assuntos
Anacardium/química , Sucos de Frutas e Vegetais/análise , Ácidos Anacárdicos/análise , Anacardium/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Espectroscopia de Ressonância Magnética , Malatos/análise , Ozônio/química , Análise de Componente Principal , Sonicação , Espectrometria de Massas em Tandem , Raios Ultravioleta
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