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1.
Talanta ; 236: 122891, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635270

RESUMO

A molecularly imprinted biosensor for lysozyme based on the polymer nanoparticles self-assembled from water-soluble and electroactive poly (γ-glutamic acid) modified with 3-aminothiophene copolymer were prepared. The water-soluble copolymer made imprinting of lysozyme in aqueous solution possible and thus facilitated improvement of the activity of LYS. Subsequent electro-polymerization not only locked the recognition site between copolymer and lysozyme but also created a conductive polymer network, which can enhance the electron transfer rate and increase the conductivity of the film. The prepared molecularly imprinted biosensor exhibited a wide linear range from 1 × 10-10 to 1 × 10-5 mg mL-1, and satisfactory selectivity, stability, repeatability for lysozyme detection.


Assuntos
Técnicas Biossensoriais , Impressão Molecular , Nanopartículas , Muramidase , Polímeros , Água
2.
Food Chem ; 366: 130526, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34274705

RESUMO

An in-house method, employing magnetic stirring-assisted aqueous extraction combined with gas chromatography-flame ionization detector, for determination of ethanol in different foods and beverages was validated according to the ISO/IEC 17025 standard. Validation parameters, including selectivity, method limits of detection (approx. 0.006 mg/g) and quantification (approx. 0.02 mg/g), linearity (R2 of >0.999), trueness (relative biases of <3%), accuracy (recoveries of 96-105%), and precision (relative standard deviations of <5%), were satisfactory. The proposed method was as accurate and precise as and more sensitive than the AOAC method 2016.12, with estimated relative expanded uncertainties of around 8% for all samples. The validated method was successfully applied for determination of ethanol in 108 commercially processed foods and beverages, and it could be used for halal verification. Accordingly, this study provided a reliable method for routine quantitative analysis of ethanol in processed foods and beverages to ensure their halal integrity prior to halal certification.


Assuntos
Bebidas , Etanol , Bebidas/análise , Cromatografia Gasosa , Fenômenos Magnéticos , Água
3.
Food Chem ; 366: 130579, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34284187

RESUMO

This work evaluated the effect of micro- and nano-starch (MS and NS) on the gel properties of fish myofibrillar protein (MP). Both MS and NS could enhance MP gel performance in terms of breaking force, elasticity and water holding capacity (p < 0.05), with more significant effect from NS than MS. The difference between NS and MS in enhancement effect on MP gel is due to nano-size effect and different microstructures of MP/MS and MP/NS gels, with NS rather than MS contributing to the continuity of MP network. Synchrotron FTIR micro-spectroscopic images further verified that NS with large specific surface had good compatibility with MP, while MS was embedded in MP matrix with evident phase separation. Additionally, ß-sheet still dominated the secondary structure of all gels, although adding both MS and NS could change molecular interactions, such as weakening ionic bonds and hydrogen bonds, and strengthening hydrophobic interactions.


Assuntos
Carpas , Amido , Animais , Géis , Interações Hidrofóbicas e Hidrofílicas , Proteínas Musculares , Reologia , Água
4.
Food Chem ; 366: 130634, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34332422

RESUMO

Deep eutectic solvents based on choline chloride, carboxylic acids, urea, and polyols were investigated for separation of 14 metals from plant samples. It was found that carboxylic acid as precursor of DES played key-role for effective metals separation. It was established that the solvent synthesized from choline chloride and malic acid provided highest extraction recovery (from 73 to 88%). Mixing and heating the solvent and sample for 30 min at a temperature of 70 °C provided effective separation of metals from plant sample. The developed procedure is not required a microwave digestion of samples. After separation the solvent phase containing analytes was dissolved in aqueous phase and analyzed. The developed procedure was applied to elemental analysis of plant tobacco and lettuce samples by inductively coupled plasma optical emission spectroscopy. Limits of detection calculated as three times the signal-to-noise ratio were in the range from 0.2 to 17 mg kg-1.


Assuntos
Ácidos Carboxílicos , Metais , Plantas , Solventes , Água
5.
Food Chem ; 367: 130664, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343804

RESUMO

Cyclodextrin-based dispersive liquid-liquid microextraction (CD-DLLME) was developed for the determination of triazole and strobilurin fungicides in water, juice, and vinegar samples using high-performance liquid chromatography-diode-array detection (HPLC-DAD). Undecanol, which is a green solvent, was selected as the extraction solvent. A cyclodextrin aqueous solution was chosen as the dispersion solvent and demulsifier to avoid the use of a toxic dispersion solvent and eliminate the centrifugation step. Dispersion and phase separation were completed within 1 and 60 s, respectively. The linear range of this method was 1 to 100 µg L-1. The limits of detection were 0.3 µg L-1 along with the preconcentration factor of 133 and enrichment factor of 124. The recovery was 83.2% to 103.2%. This pretreatment method was fast, simple, and environmentally friendly and was successfully applied to the analysis of triazole and strobilurin fungicide residues in water, juice, and vinegar samples.


Assuntos
Ciclodextrinas , Fungicidas Industriais , Microextração em Fase Líquida , Poluentes Químicos da Água , Ácido Acético , Cromatografia Líquida de Alta Pressão , Fungicidas Industriais/análise , Solventes , Água , Poluentes Químicos da Água/análise
6.
Food Chem ; 367: 130666, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343805

RESUMO

Considering excess nitrites are detrimental to the human body and environment, designing a rapid, sensitive, and real-time quantitative determination for nitrite is of great significance for environmental preservation and public health. In this paper, Co3O4 nanoflowers coupled with ultrafine MoO3 nanoparticles (MoO3/Co3O4) are obtained via a hybrid electrochemical deposition strategy (HED). The as-designed MoO3/Co3O4/CC integrating electrode exhibits superior electrocatalytic properties towards nitrite oxidation, owing to the synergistic effect between MoO3 and Co3O4 caused by the heterostructure of MoO3/Co3O4. The electrode achieved a low response time of 2 s, an excellent sensitivity of 1704.1 µA mM-1 cm-2, and a low limit of detection of 0.075 µM (S/N = 3). Furthermore, the electrode displays promise for nitrite detection in complex food such as water and sausages samples. Our study will provide a significant strategy for the application of bimetallic heterostructure to explore the design of sensing interfaces.


Assuntos
Nanopartículas , Nitritos , Técnicas Eletroquímicas , Eletrodos , Humanos , Água
7.
Food Chem ; 367: 130639, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34348199

RESUMO

In this work, an ingredient containing non-starch polysaccharides (NSP), obtained from overripe bananas, was characterized using differential scanning calorimetry (DSC) and vapor sorption isotherms. Soluble sugars from overripe bananas were extracted using ethanol, resulting in a solid NSP-rich fraction. The physical properties of this new ingredient and its response to temperature and water interactions are needed for its application as a fiber flour aggregate in food preparations. Results from thermal analyses, including gelatinization, glass transition and fusion, allowed building state diagrams, then compared to vapor sorption isotherms which resulted similar to a Brunauer-Emmet-Teller (BET) type III isotherm at 25 °C, for NSP and standards samples as arabinoxylan and polygalacturonic acid. A good fit was obtained for the glass transition curves using the Kwei model. This approach enabled us to explore the stability of the material, regarding safety limits for microbial deterioration and structural changes due to glass transition.


Assuntos
Musa , Varredura Diferencial de Calorimetria , Farinha/análise , Polissacarídeos , Temperatura , Água
8.
Food Chem ; 367: 130756, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388633

RESUMO

This study was aimed at evaluating the potential of high-intensity ultrasound (HIU, 450 W for 10 min) combined with hydrogen peroxide (H2O2) having various concentrations (0, 50, 100, 200, 400, 800 µmol/g protein) to inhibit the thermal aggregation behavior of myofibrillar proteins (MPs) in water. The results indicated that the addition of H2O2 interfered with the intermolecular sulfhydryl-disulfide interchange and inhibited the disulfide bond cross-linking. The H2O2-mediated conversion of cysteine to thiol derivatives appeared to be the primary mechanism of this effect. The HIU combined with H2O2, especially at the H2O2 concentration of 200 µmol/g, corresponded to a more significant inhibitory effect than that of only H2O2, which attributed to the dissociation of the filamentous myosin structure that led to an enhanced accessibility of the buried sulfhydryl groups. In conclusion, these findings provide direct evidence for the role of HIU combined with H2O2 in improving the thermal stability of MPs.


Assuntos
Peróxido de Hidrogênio , Água , Concentração de Íons de Hidrogênio , Miosinas , Compostos de Sulfidrila
9.
Food Chem ; 368: 130686, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34399176

RESUMO

The functionalities of hydrocolloids and enzymes in texture, retrogradation enthalpy, water mobility and distribution, and anti-staling effects of potato steamed bread stored for 0, 24, and 48 h at 25 °C were investigated. Four kinds of hydrocolloids, including carrageenan, xanthan gum, arabic gum, sodium alginate, and one kind of enzyme (xylanase) showed little effects on the hardness reduction and springiness retention of potato steamed bread during storage, while the presence of α-amylase and lipase could slow down its staling rate. Potato steamed bread with combination of α-amylase (20 mg/kg) and lipase (40 mg/kg) exhibited the lowest hardness, with a significant reduction of 44.20%, besides improving the specific volume, L*, and overall acceptability in sensory evaluation. The addition of α-amylase and lipase could decrease the retrogradation enthalpy and bound water, and increase the mobility of mobile water. These findings shed efficient methods to retard staling of potato steamed bread.


Assuntos
Pão , Solanum tuberosum , Pão/análise , Coloides , Vapor , Água
10.
Food Chem ; 368: 130818, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34403998

RESUMO

High value-added utilization of different aquatic by-products is an increasingly urgent issue in aquatic science and industry. In this work, the effects of extraction methods on the molecular characteristics, structural properties, functional properties, and Pickering emulsion stabilization behaviors of silver carp fin gelatins were comprehensively studied. All the results showed molecular characteristics of silver carp fin gelatin was the key parameter to determine their functional properties such as wide gel strength range, excellent water-holding capacity, and excellent Pickering emulsion stabilization ability. The Pickering emulsion stabilization mechanisms of fin gelatins involved an "extraction method - protein molecular characteristics - fat-binding capacity - droplet structure - water phase properties - Pickering emulsion stability" route. This work could be helpful to understand the basic information on how the molecular characteristics determine the functions of gelatins. It would be also useful for the high value-added utilization of aquatic by-products and gelatins.


Assuntos
Carpas , Gelatina , Animais , Carpas/genética , Emulsões , Água
11.
Food Chem ; 368: 130823, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34404005

RESUMO

The current work focuses on the facile and effective synthesis of a new nanocomposite based on multiwalled carbon nanotubes (MWCNT) decorated with magnetic core-shell Fe3O4@SiO2 and functionalized with 3-mercaptopropyltrimethoxysilane (3-MPTS) used in the vortex-assisted dispersive magnetic solid-phase extraction (VA-DMSPE) of Cd(II) ions in environmental and food samples. The nanocomposite was characterized and the parameters that influenced the VA-DMSPE were optimized through a fractional factorial design 25-1. The proposed method provided a preconcentration factor of 33.14 times, detection and quantification limits of 0.090 µg L-1 and 0.302 µg L-1, respectively, and a linearity range of 0.001-40.0 µg L-1. The developed method was effectively applied to preconcentrate and determine Cd(II) in water, tobacco, green tea leaves, ginkgo biloba, carrots, and rice samples, and its accuracy was evaluated using GF AAS.


Assuntos
Nanotubos de Carbono , Plantas Medicinais , Adsorção , Cádmio , Fenômenos Magnéticos , Dióxido de Silício , Extração em Fase Sólida , Compostos de Sulfidrila , Água
12.
Food Chem ; 368: 130827, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34411855

RESUMO

Curcuminoids are known to exert diverse pharmacological effects and used in some pharmaceutical formulations. This study describes the preparation, characterization, and enhancement in the solubility and anticancer activity of a curcuminoids-rich extract (CRE) using a ternary inclusion complex system. CRE containing 88.9% w/w curcuminoids was prepared using a 'green' microwave extraction coupled with fractionation on a column of hydrophobic adsorbent resin. The ternary complex consisting of CRE, hydroxylpropyl-ß-cyclodextrin and polyvinylpyrrolidone K30 was prepared using the solvent evaporation method and thoroughly characterized using Fourier-transform infrared spectroscopy, powder X-ray diffractograms, differential scanning calorimetry and scanning electron microscopy. The ternary complex of CRE improved the water-solubility of curcuminoids (up to 70.3 µg/mL) as well as the dissolution rate when compared to those of CRE (0 µg/mL). In addition, the ternary complex exhibited significantly stronger anticancer activity against human lung adenocarcinoma (A-549), human cervical adenocarcinoma (HeLa) and human colon adenocarcinoma (HT-29) cell lines than CRE.


Assuntos
Diarileptanoides , Água , Varredura Diferencial de Calorimetria , Humanos , Extratos Vegetais , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
13.
Food Chem ; 368: 130833, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34425342

RESUMO

To investigate the influences of different subcritical water conditions on apple pomace pectic polysaccharides (APP) extraction, 20 samples were successfully prepared and systematically analyzed. At low temperature region (100-120 °C), extraction effect was predominant and extracted APP was high molecular weight, esterification degree and galacturonic acid content as well as light color. At middle temperature region (140 °C), the balance of extraction and degradation effects was reached and led to the highest APP yield (14.89%). At high temperature region (160-180 °C), degradation effect was predominant and led to serious degradation of APP and more extraction of co-extracts, which endowed the APP with low viscosity and good antioxidant activities in vitro. Overall, the relationship between different subcritical water conditions and APP properties are preliminarily illuminated, which not only provides a promising way for directed extraction of specific APP, but also promotes the potential application of subcritical water to commercial pectin.


Assuntos
Malus , Pectinas , Polissacarídeos , Viscosidade , Água
14.
Food Chem ; 368: 130848, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34479088

RESUMO

This study investigated the effects of ultrasonic treatment on the structural characteristics and functional properties of perilla protein isolate (PPI). Besides, the performance of the emulsions stabilized by ultrasonic-treated PPI was analyzed, aiming at exploring the potential mechanism of ultrasonic technology to improve emulsion stability. Results showed that ultrasonic treatment reduced the particle size, induced the exposure of hydrophobic groups and changes in the secondary structure and tertiary conformation of PPI. However, the molecular weight and the crystalline regions were remained unchanged. Apart from this, ultrasonic treatment improved the solubility, water/oil holding capacity, foaming and emulsifying capacity of PPI. Furthermore, the emulsions prepared by ultrasonic-treated PPI possessed the highest stability, which might be due to the smaller droplets size and reduced droplets attraction by higher proportion of interfacial adsorbed protein. This findings will provide a new insight into the application of ultrasonic to improve the stability of PPI-stabilized emulsions.


Assuntos
Perilla , Emulsões , Tamanho da Partícula , Solubilidade , Ultrassom , Água
15.
Food Chem ; 368: 130723, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34500352

RESUMO

The effects of the fat crystal structure on lipid droplets digestion behaviors were investigated using an in vitro digestion model. The crystalline oil-in-water emulsions containing the same solid fat content (SFC) with different fat crystal sizes and polymorphic forms were fabricated by different storage protocols: constant-temperature and inconstant-temperature storage. Oral and gastric processing led to a significant increase (p < 0.05) in the d4,3 values of the two emulsions, and the two emulsions underwent partial coalescence and flocculation/aggregation. The free fatty acid (FFA) release profiles showed that the lipolysis extent decreased due to a larger crystal size. In addition, the two emulsions showed differences in beta polymorphism. This work further demonstrated that the FFA release could be modulated by the physical properties of the fat.


Assuntos
Digestão , Trato Gastrointestinal , Emulsões , Tamanho da Partícula , Água
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120232, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352500

RESUMO

To achieve the ultrastable LMOFs with predominant luminescent sensing performances, the aromatic π-electron mixed ligands strategy was introduced, and the ternary LMOF of {[Zn2(HDDB)(bib)1.5]·3H2O}n (1), was fabricated based on 3,5-di(2',4'-dicarboxylphenyl)benozoic acid (H5DDB) and the N-donor of meta-bis(imidazol-1-yl)benzene (bib) under mixed solvothermal condition. LMOF 1 features the first reported 3D 3,4,4-c {62.83.10}{62.8}2{63.82.10}2 framework with 21.2 % porosity as well as high thermal and chemical stability. Further luminescent sensing showed that LMOF 1 as a bifunctional chemosensor possessing predominant detectability for sensitive detect the hexavalent chromates and nitroimidazoles/nitrofurans antibiotics in water through strong luminescent quenching effects, with excellent reusability as well as trace detection limits. Moreover, luminescent quenching mechanisms were further investigated from electron transfer and energy transfer viewpoints.


Assuntos
Antibacterianos , Zinco , Ânions , Antibacterianos/análise , Cromo , Água
17.
J Environ Manage ; 301: 113943, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731955

RESUMO

To explore the effects of different regulation modes on the soil structure and gas transport characteristics in seasonal permafrost regions, freeze-thaw cycles (FTCs) were used as boundary conditions and three typical soils on the Songnen Plain were used: black soil, baijiang soil and meadow soil. Four treatments were established: biochar addition (B1), straw addition (S1), biochar combined with straw addition (B1S1) and an untreated control (CK). The changes in the proportion of soil water-stable aggregates, total soil porosity (TP), soil water characteristic curves (SWRCs), soil dissolved organic carbon (DOC) and soil air permeability (PL) were analyzed. The results showed that biochar and straw influenced the structure of the three soil types. The proportions of large (2-0.5 mm) and medium (0.5-0.25 mm) aggregates increased significantly. The soil aggregate stability indexes of the treated soils were better than those of the CK, and the three-phase ratios of the treated soils were closer to ideal. The different treatments had particularly obvious effects on the black soil; the generalized soil structure index (GSSI) values reached 95.59, 94.36 and 98.74 in the B1, S1 and B1S1 treatments, respectively. An interaction effect was observed between biochar and straw. B1S1 had a stronger effect than the other treatments, and the soil water holding capacity was significantly improved (FC = 0.317 cm3 cm-3). Under the B1S1 treatment, the DOC contents in black soil, baijiang soil and meadow soil were 160.78 mg/kg, 272.828 mg/kg and 271.912 mg/kg, respectively. Moreover, biochar and straw combined effectively reduced PL fluctuations under FTCs and improved the long-term stability of the soil structure. These results can aid in rational straw and biochar use to achieve comprehensive agricultural waste utilization.


Assuntos
Solo , Água , Carbono , Carvão Vegetal
18.
J Environ Manage ; 301: 113926, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731962

RESUMO

Hybrid flocculant polyacrylamide-ferric chloride (PAM-FeCl3) was developed to improve the dewaterability of sewage sludge and the dewatering performance, properties of treated sludge, composition and morphology distribution of extracellular polymeric substance (EPS) were investigated. The physicochemical properties of the PAM-FeCl3 were characterized, and its effectiveness as a sludge conditioner was evaluated. The results indicated that PAM-FeCl3 conditioning was able to promote sludge dewaterability. Simultaneously, PAM-FeCl3 neutralized the negative charges on the surface of sludge particles and increased the sludge floc size. Besides, PAM-FeCl3 also formed a rough and porous floc structure that reduced sludge compressibility. Meanwhile, the exciting emission matrix analysis suggested that PAM-FeCl3 can effectively disintegrate of EPS fraction in sludge and decompose the aromatic protein-like substances as well as the humic acid-like substances in EPS. Additionally, the larger sludge floc formation, electrostatic interaction and adsorption bridging effect resulted in compression of sludge structure and the decomposition of EPS fractions and improved sludge dewatering performance.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Esgotos , Filtração , Proteínas , Eliminação de Resíduos Líquidos , Água
19.
Food Chem ; 369: 131011, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34507086

RESUMO

Biosurfactants have been put into applications in breadmaking industry, while the effects of mannosylerythritol lipid-A (MEL-A) on gluten network of frozen dough, bread quality and microbial spoilage were firstly investigated in this study. Rheology and differential scanning calorimetry (DSC) analysis showed that MEL-A significantly improved the rheological properties of frozen dough and reduced the content of frozen water. Further experiments showed that MEL-A promoted the formation of aggregates by interacting with gluten protein, and strengthened the gluten network through molecular weight distribution measurement and microstructure observation, effectively avoiding the destruction of ice crystals. A series of bread assessments illustrated MEL-A improved the loaf volume, gas retention ability and textural property. In addition, MEL-A (1.5%) killed 99.97% of the vegetative cells of Bacillus cereus and 75.54% of the spores, and at the same time had a slight inactivation effect on yeast. These results indicate that MEL-A has broad application prospects in the baking industry and the storage stage of flour products.


Assuntos
Pão , Lipídeo A , Farinha , Glutens , Glicolipídeos , Reologia , Esporos , Água
20.
Food Chem ; 369: 130973, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34507087

RESUMO

Polystyrene-polyricinoleic acid copolymer containing silver nano particles (AgPSrici) was synthesized and used in separation of molybdenum from different aqueous and foodstuff samples during a dispersive-µ-solid phase extraction approach. The synthesized nano particles were verified using Fourier transform infraredspectroscopy. An electrothermal atomic absorption spectrometry has been used for measurement of the studied ions. AgPSrici amount pH, sample volume, elution solvent kind, and the time of extraction were the effective parameters that were optimized by one-variable-at-one-time method. Analytical data of the method was calculated and limit of detection, relative standard deviation, limit of quantification were 0.022 µg L-1, 2.9%, 150, and 0.066 µg L-1, respectively. The synthesized adsorption capacity was obtained 170 mg g-1.Accuracy of the method was studied by performing the method on certified reference materials and the presence of different interfering ions was studied. Molybdenum content of different water and foodstuffs was determined by the introduced method.


Assuntos
Microextração em Fase Sólida , Água , Limite de Detecção , Molibdênio , Poliestirenos , Prata , Extração em Fase Sólida , Espectrofotometria Atômica
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