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1.
J Agric Food Chem ; 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33594885

RESUMO

Glycerol-plasticized high-amylose corn starch/konjac glucomannan (HCS/KGM) composite films incorporated with various concentrations of ß-cyclodextrin (ß-CD) were prepared and investigated for structural, mechanical, and physical properties. The results of X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analyses, and scanning electron microscopy indicated that ß-CD excluded from the polymer chains and aggregated to form crystals during film formation, which drove HCS to interact with KGM more compactly. The thickness and transparency of the films increased after ß-CD was incorporated. More associations of HCS/KGM enhanced the mechanical properties and reduced the moisture content of the films. The water vapor permeability of the HCS/KGM composite film was also improved significantly with the incorporation of ß-CD. The enhanced association between biopolymers in the presence of ß-CD will advance the development of a degradable active composite packaging film.

2.
Carbohydr Polym ; 251: 117039, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142597

RESUMO

Recently, starch-based packaging materials have become one of research hot points. In the present study, glycerol-plasticized composite films based on high amylose corn starch (HCS) and konjac glucomannan (KGM) were developed. The influence of KGM on the film-forming properties of HCS and the physicochemical properties of the resulting films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG) analysis and water vapor permeability (WVP). The crystallinity and the proportion of short-range order structure of the films increased first and then declined with the addition of KGM. The micromorphology of the films exhibited the more even texture after KGM was incorporated in. The tensile strength, elongation at break and water resistance of HCS film were also improved significantly. The synergistic effect between HCS and KGM improved the film-forming ability of HCS. The optimal addition amount of KGM was 0.3 %.

3.
Food Chem ; 340: 127893, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889202

RESUMO

In this work, zein/carboxymethyl dextrin nanoparticles were successfully fabricated at different zein to carboxymethyl dextrin (CMD) mass ratios. Zein/CMD nanoparticles with the negative charge and the smallest size (212 nm) were formed when the mass ratio of zein to CMD was 2:1, exhibiting improved encapsulation efficiency of curcumin (85.5%). Electrostatic interactions, hydrogen bonding and hydrophobic interactions were main driven forces for nanoparticles formulation and curcumin encapsulation. Fourier transform infrared spectroscopy determined curcumin might be partially embedded in CMD during encapsulation. The spherical structures of zein/CMD nanoparticles and curcumin-loaded zein/CMD nanoparticles were observed by transmission electron microscopy. The photothermal stability and antioxidant activity of curcumin were significantly enhanced after be loaded in zein/CMD nanoparticles. Furthermore, encapsulation of curcumin in zein/CMD nanoparticles significantly delayed the release of curcumin in simulated gastrointestinal fluids. These results indicated that zein/CMD nanoparticles could be effective encapsulating materials for bioactive compounds in food industry.


Assuntos
Antioxidantes/química , Curcumina/farmacocinética , Dextrinas/química , Nanopartículas/química , Zeína/química , Antioxidantes/farmacologia , Curcumina/administração & dosagem , Curcumina/química , Preparações de Ação Retardada , Estabilidade de Medicamentos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Transmissão , Nanopartículas/administração & dosagem , Tamanho da Partícula , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Difração de Raios X
4.
Food Res Int ; 138(Pt B): 109778, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33288164

RESUMO

High-fat diets (HFDs) can induce health problems including gut microbiota dysbiosis and cardiac dysfunction. In this study, we modulated the gut microbiota in mice to investigate whether Lycium barbarum polysaccharide (LBP), a potential prebiotic fiber, could alleviate HFD-induced myocardial injury. Mice fed a HFD were given LBP (HFPD group) by gavage once/day for 2 months. Left ventricular function and serum trimethylamine N-oxide were significantly improved in HFPD mice compared with HFD mice. HFD increased the abundances of Bifidobacterium, Lactobacillus, and Romboutsia, while LBP increased the abundances of Gordonibacter, Parabacteroides, and Anaerostipes. Fecal metabolic profiling revealed significant increases in metabolites involved in nicotinate, nicotinamide and purine metabolism pathways, as well as indole derivatives of tryptophan metabolites in the HFPD group. LBP reduced intestinal permeability and inflammatory cytokine levels, maintained a healthy intestinal microenvironment, and alleviated myocardial injury. Modulating the gut microbiota is a potential treatment for cardiovascular diseases.

5.
Food Res Int ; 138(Pt A): 109666, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33292956

RESUMO

The physicochemical properties of κ-carrageenan (KC) can be improved by incorporation with small-molecule cosolvents. The texture and rheological properties, micromorphology, and crystallinity of KC incorporating indigestible dextrin (IDD) and beta-limit dextrin (BLD) were investigated. The rheological properties and sol-gel transition temperatures of the gels were slightly improved and the hardness of KC gels was significantly increased after the two dextrins were mixed in. Fourier transform infrared spectroscopy results indicated hydrogen-bonding interactions were strengthened in the presence of the dextrins. Confocal laser scanning microscope images revealed that a more homogenous structure was formed of the KC gel after the addition of dextrins. Moreover, X-ray diffraction patterns indicated the crystallinity of KC gel decreased upon dextrin addition. At the same dextrin content, IDD exerted a greater influence than BLD. IDD contents exceeding 3% (w/w) led to undesirable effects, whereas up to 5% (w/w) of BLD could be added. The two dextrins affected the rearrangement of the KC random coils in the sol state, and facilitated aggregation of the KC chains during cooling to form gel network structures after gelation. Therefore, the appropriate addition of these two dextrins can improve the texture and stability of KC gels and expand their application in functional foods.

6.
Mikrochim Acta ; 187(9): 495, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32793992

RESUMO

An aptasensor is reported for the detection of three different kinds of mycotoxins, i.e., zearalenone (ZEN), ochratoxin A (OTA), and fumonisin B1 (FB1). Based on fluorescence resonance energy transfer effect (FRET) and surface-enhanced Raman scattering (SERS), the levels of ZEN, FB1, and OTA can be simultaneously determined. Under 980-nm and 650-nm laser excitation, the logarithmic values of fluorescence signal intensities at 543 nm and 670 nm are slowly increased as the concentrations of ZEN and OTA vary from 0.1 ng mL-1 and 0.05 ng mL-1 to 100 ng mL-1 and 25 ng mL-1, respectively. For FB1, under 980-nm laser excitation, the logarithmic value of SERS signal intensity at 1567 cm-1 gradually increases with the concentration of FB1 in the range 0.05-200 pg mL-1 (R2 = 0.996). The detection limits of the proposed assay for ZEN, OTA, and FB1 are 0.03 ng mL-1, 0.01 ng mL-1, and 0.02 pg mL-1, respectively. The selectivity experiment results indicate this assay possesses a high selectivity over other commonly encountered mycotoxins. The average recoveries range from 90 to 107%, revealing satisfactory application potential of the proposed assay. The developed aptasensor will bring bright prospects for research in the field of multiplexed mycotoxine detection. Graphical Abstract Schematic representation of an aptamer-based assay for multiple mycotoxins determination.

7.
Carbohydr Polym ; 240: 116331, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32475589

RESUMO

The effect of six anions (Cl-, OH-, NO3-, SO42-, C6H10O62- and PO43-) on a starch (St)-enzyme (thermostable α-amylase, TαA)-calcium (Ca) system was investigated in a low-moisture solid state. Two levels of Ca salts (1 and 10 mmol/100 g St) added to potato starch with and without TαA were analyzed by FT-IR, DSC and SEM. The surface morphologies of the St-Ca complexes were different in the presence of various anions, and the residual Ca salts around the St granules might decrease the enzymatic action. For bioextrusion, TαA (0.5‰ and 1.5‰) were introduced for a relatively low Ca content (1 mmol/100 g). Significant differences in enzyme activity were observed, increasing the activity of TαA by SO42- (146.54 %) > C6H10O62- > Cl- > control > NO3- > OH- ≈ PO43- and C6H10O62- (123.20 %) ≈ Cl- ≈ SO42- > control > PO43 > OH- > NO3- for the low and high enzyme levels, respectively.

8.
Carbohydr Polym ; 242: 116332, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32564855

RESUMO

An enzymatic method was investigated to initiate a strategy of increasing the branch density of pea starch, thus facilitating the formation of a starch-lipid complex after debranching. When the starch was modified by exposure to maltogenic amylase (MAL) and pullulanase (PUL), lower molecular weight values and higher amylose content resulted compared to the untreated sample. High-performance anion-exchange chromatography results suggested that the average chain length decreased and the branch density increased after the starch received MAL treatment. The diffraction intensities and the total melting enthalpies of the dual-enzyme treated complex were greater than those for other samples when the level of MAL between 4-12 U/g. Fourier transform infrared spectroscopy revealed that more ordered structure was formed in MAL (4/8/12)-PUL-starch-lauric acid (Lau) complexes. Digestive performance analysis indicated that the enzyme resistance of the starch-Lau complex was reinforced by applying the MAL-PUL modification to the starch.

9.
Mikrochim Acta ; 187(4): 254, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32239300

RESUMO

An aptamer-based assay for the determination of two different kinds of fusarium mycotoxins, i.e., zearalenone (ZEN) and fumonisin B1 (FB1), is presented. Based on the inner filter effect (IFE) strategy, the contents of ZEN and FB1 can be simultaneously quantified. It is making use of 65-nm gold nanorods (AuNRs), 20-nm upconversion nanoparticles (UCNPs), fluorescence dyes, and DNA sequences. In the absence of ZEN and FB1, the UCNPs and AuNRs associate through DNA sequences. Due to IFE effect, weak fluorescence signals are collected. In the presence of ZEN or FB1, UCNPs and AuNRs become unstable and partially separate from each other. This results in the recovery of fluorescence signals. Under 980-nm laser excitation, the logarithmic values of fluorescence signal intensities at 606 nm and 753 nm gradually increase with the concentration of ZEN and FB1 in the ranges 0.05-100 µg L-1 (the coefficient of determination is 0.997) and 0.01-100 ng L-1 (the coefficient of determination is 0.986), respectively. The limits of detection (LOD) of the fabricated assay for ZEN and FB1 are 0.01 µg L-1 and 0.003 ng L-1, respectively. The proposed method has a high selectivity over other competitive mycotoxins, including aflatoxin B1, ochratoxin A, patulin and ochratoxin B. The applicability of the assay was evaluated in the determination of ZEN and FB1 contents in spiked corn samples. The average recoveries ranged from 89.9 to 106.6%. This result confirms the practicality of this method. Graphical abstract Schematic representation of an aptamer-based fluorometric method for simultaneous determination of two kinds of the fusarium mycotoxins zearalenone and fumonisin B1.

10.
Int J Biol Macromol ; 155: 1-5, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32194113

RESUMO

The modified starch-based hydrogels were prepared by crosslinking modified starch with sodium trimetaphosphate. Modified starch was obtained by esterification of tapioca starch with maleic anhydride. The degree of substitution (DS) increased significantly from 0.078 to 0.258 as the content of maleic anhydride increased from 6.67% to 33.33%. Fourier transform infrared spectroscopy demonstrated that starch was successfully esterified. In addition, the thermal properties of modified starch-based hydrogels were investigated by differential scanning calorimeter and thermogravimetry analysis, which proved that hydrogels had better thermal stability. Esterified starch-based hydrogels showed excellent pH sensitivity by measuring of swelling degree. When DS was 0.250, the adsorption capacity and encapsulation efficiency of starch-based hydrogels were 399.23 µg/g and 80%, respectively, which exhibited satisfactory embedding properties for curcumin. Therefore, esterified tapioca starch-based hydrogels could be as the encapsulating materials to protect bioactive substances, which provided a theoretical basis for their application in food field and pharmaceuticals industry.

11.
Mikrochim Acta ; 187(4): 215, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32162122

RESUMO

An aptamer-based assay is presented for the determination of fumonisin B1 (FB1). It is bimodal in that both surface-enhanced Raman spectroscopy (SERS) and fluorometry are applied for quantitation. It makes use of platinum-coated gold nanorod (AuNR) and DNA sequences. The complementary DNA of aptamer (cDNA) against FB1 is immobilized on the surface of AuNR. The aptamer of FB1 modified with Cy5.5 are complementarily hybridized with cDNA. In the absence of FB1, the aptamer and its cDNA associate. In this situation, strong SERS and weak fluorescence signals are obtained. In the presence of FB1, the aptamer disassociates with its cDNA and binds the target. As the concentration of FB1 increases, the SERS and fluorescence signal intensities of the mixture are gradually decreased and increased, respectively. Under optimized conditions, the SERS signal at 1366 cm-1 decreases linearly in the 10-500 pg mL-1 concentration range with the calibration equation of y = 1997lgx-594 (the coefficient of determination is 0.998). The fluorescence signal at 670 nm increases linearly in the 10-250 pg mL-1 concentration range with the calibration equation of y = 500lgx-383 (the coefficient of determination is 0.991). The assay was applied to the determination of FB1 contents in spiked corn samples. The average recoveries ranged from 92 to 107%, confirming the practicality of this method. The results obtained by this assay are in good agreement with that of LC-MS/MS method. Graphical abstractSchematic illustration of a bimodal aptasensor based on surface enhanced Raman scattering (SERS) and fluorescence change for the detection of fumonisin B1 (FB1).


Assuntos
Aptâmeros de Nucleotídeos/química , Fluorometria , Fumonisinas/análise , Ouro/química , Nanotubos/química , Análise Espectral Raman , Zea mays/química
12.
Food Chem ; 315: 126288, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32032833

RESUMO

ß-Carotene was encapsulated in the Pickering emulsions stabilized by chitosan hydrochloride - carboxymethyl starch (CHC-CMS) nanogels. During ultraviolet radiation and storage, the retention of ß-carotene in Pickering emulsions was higher than that of other formulations, such as Tween 80 stabilized emulsions (TEs) and bulk oil. The Pickering emulsions were found to be stable during thermal treatment. Meanwhile, lipid oxidation was delayed in Pickering emulsions compared to TEs and bulk oil. The vitro digestion results suggested that the free fatty acids (FFA) released were below 30% for all Pickering emulsions, which indicated that a physical barrier was formed by CHC-CMS nanogels to restrain the lipid hydrolysis. The bioaccessibility of ß-carotene in Pickering emulsions was higher than that in bulk oil. This research helped establish a connection between the physicochemical properties of CHC-CMS stabilized Pickering emulsions with their applications in the protection effect and oral delivery of bioactive compounds.


Assuntos
Quitosana/química , beta Caroteno/química , Quitosana/análogos & derivados , Emulsões/química , Ácido Clorídrico/química , Hidrólise , Lipídeos/química , Nanogéis/química , Oxirredução , Tamanho da Partícula , Amido/análogos & derivados , Raios Ultravioleta
13.
Ultrason Sonochem ; 72: 105447, 2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33387758

RESUMO

Ultrasonic treatment can improve the compatibility between a hydrophobic material and a hydrophilic polymer. The light transmittance, crystalline structure, microstructure, surface morphology, moisture barrier, and mechanical properties of a composite film with or without ultrasonication were investigated. Ultrasound increases the film's light transmittance, resulting in a film that has good transparency. Ultrasonication did not change the crystalline structure of the polymer film, but promoted V-type complex formation. The surface of the film became smooth and homogeneous after the film-form suspension underwent ultrasonic treatment. Compared to the control film, after ultrasonication at 70% amplitude with a duration of 30 min, the average roughness and maximum roughness declined from 212 nm to 17.6 nm and from 768.7 nm to 86.5 nm, respectively. The composite film with ultrasonication exhibited better tensile and moisture barrier properties than the nonsonicated film. However, long-term and strong ultrasonication will destroy the polymer structure to some extent.

14.
ACS Appl Mater Interfaces ; 11(46): 43553-43562, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31644868

RESUMO

Biobased materials have the potential to be developed into green multifunctional products to replace their chemosynthetic counterparts, which have environmental and economic concerns. However, designing magnetic and porous biomaterials without pore spaces being occupied by exogenous magnets via traditional encapsulation, load, and/or deposition methods remains challenging. This paper describes a novel, facile, top-down strategy of fabricating zerovalent iron particles (Fe0 Ps) embedded into a three-dimensional (3D) zinc-modified starch (Zn-St) framework using the enzymatic reactive extrusion (eREX) method. Raw St underwent Zn-atom fortification, in situ Fe-atom deposition, and micromixing extrusion to produce (Zn-St)10Fe0n (n = 1, 2, 3, 4) extrudates (Es) in a continuous and large-scale mode. A hierarchical porous structure was formed during eREX processing, with mesopores (∼2-4 nm) and macropores (∼50-300 nm and ∼5-100 µm) generated regularly. The (Zn-St)10Fe0n Es were excellent at dye adsorption and magnetic separation, with high levels of St (>70%) as a biodegradable resource. For instance, (Zn-St)10Fe02 Es (St > 83%) removed 61.03 mg/g of methylene blue (∼19 times higher than that of raw St) at 298 K and pH 4.0 via simultaneous physisorption and degradation and were successfully separated due to their saturation magnetization (Ms) value of 25.41 emu/g. The dye adsorption rate and Ms of the (Zn-St)10Fe0n Es can be increased by manipulating the amount of Fe0 Ps. Thus, the novel 3D (Zn-St)10Fe0n Es are promising biomaterials for water purification applications, as well as other food, biological, and environmental fields.


Assuntos
Corantes/química , Ferro/química , Poluentes Químicos da Água/química , Purificação da Água , Zinco/química
15.
Mikrochim Acta ; 186(8): 555, 2019 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-31327071

RESUMO

A dual-mode aptasensor was employed for ultrasensitive determination of sulfamethazine (SMZ). The assay is based on simultaneous quantification by using fluorometry and chirality. The aptamer against SMZ was immobilized on upconversion nanoparticles (UCNPs) while the complementary DNA of SMZ aptamer was immobilized on Au@Ag@Au core-shell nanoparticles (Au@Ag@AuNPs). Based on complementary base-pairing reactions, the aptamer of SMZ and its complementary DNA sequence (cDNA) were hybridized to form duplex structure. Thus, Au@Ag@AuNPs and UCNPs were in close proximity. Efficient inner filter effect (IFE) from UCNPs (energy donor) to Au@Ag@AuNPs (energy acceptor) occurred under the excitation of 980 nm laser. In the presence of targets (SMZ), as the aptamer of SMZ coupled with SMZ to form stable complex structure. As a result, the hybridization of aptamer and its cDNA deceased and the fluorescence signal recovered. Furthermore, as the degree of the assembly decreased, the circular dichroism (CD) signal also decreased. Fluorescence was measured at excitation/emission wavelengths of 980/655 nm. The linear ranges for detection of SMZ are between 0.10-100 ng·mL-1 and 1.00-100 ng·mL-1 for the fluorescence and circular dichroism modes, respectively. The method was applied to the determination of SMZ in spiked milk with high recoveries. Conceivably, it can be extended to the analysis of numerous other targets for which adequate antibodies or aptamers are available. Graphical abstract Schematic representation of a chirality assay and a fluorometric assay based on inner filter effect (IFE) between upconversion nanoparticles (UCNPs) and Au@Ag@Au core-shell nanoparticles (Au@Ag@AuNPs) for the determination of sulfamethazine (SMZ).

16.
Carbohydr Polym ; 222: 115000, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31320061

RESUMO

The effects of pullulanase debranching on the properties of maize starch (waxy, normal and high amylose)-glycerol monolaurate (GML) complexes were studied. Pullulanase pretreatment produced more starch chains with favourable lengths (DP ≥ 25) to encourage inclusion complex formation. The debranched starch showed higher amylose content (from 11.2 to 58.6%) than the native starch (from 0.68 to 53.4%). The V-type characteristic diffraction peaks (7.5°, 13.1° and 20.2° 2θ) became more obvious after the starch received the debranching treatment. Thermal properties indicated that the melting enthalpy of the debranched starch-GML complexes (from 6.45 to 10.13 J/g) was higher than those of the untreated complexes (from 0 to 8.91 J/g). The swelling power values and degree of hydrolysis of the starches decreased with the increase in amylose content. In vitro digestibility analysis suggested that the hydrolysis of the starch-GML samples was further restricted by applying the debranching treatment to the starch.


Assuntos
Amilose/química , Glicosídeo Hidrolases/química , Lauratos/química , Monoglicerídeos/química , Zea mays/química , Temperatura Alta , Hidrólise , Estrutura Molecular
17.
Food Chem ; 293: 197-203, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151601

RESUMO

The purpose of this research was to prepare nanogels by covalent cross-linking carboxymethyl starch (CMS) and chitosan hydrochloride (CHC) as novel delivery systems for curcumin. The spherical structure of CHC-CMS nanogels was verified by transmission electron microscopy. Fourier transform infrared spectroscopy confirmed that the amide linkage was formed between CHC and CMS. X-ray diffraction data exhibited that the crystalline structure of CHC was destroyed after covalent cross-linking with CMS, which further confirmed that the CHC-CMS nanogels were formed. Furthermore, the nanogels behaved as viscoelastic solids over the entire frequency range. Meanwhile, the nanogels showed excellent pH-sensitivity and high encapsulation efficiency of curcumin (89.49%-94.01%). Compared to free curcumin, curcumin encapsulated in nanogels displayed sustained release profile in simulated gastrointestinal conditions. These results suggested that the nanogels had been successfully fabricated and could be used as ideal carriers for curcumin and other bioactive compounds in functional foods.


Assuntos
Quitosana/química , Curcumina/química , Portadores de Fármacos/química , Polietilenoglicóis/química , Polietilenoimina/química , Amido/análogos & derivados , Curcumina/metabolismo , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Nanogéis , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/química , Difração de Raios X
18.
Int J Biol Macromol ; 134: 1108-1112, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31121224

RESUMO

The combined effects of extrusion (ET) and heat-moisture treatments (EHMT) on the physicochemical properties and in vitro digestibility of corn starch were investigated. Extrusion played a dominant role in reducing relative crystallinity and resistant starch (RS) content, but the swelling power, solubility, rapidly digestible starch (RDS) and slowly digestible starch (SDS) content were increased compared to native starch. EHMT resulted in a decreased swelling power, solubility and a transition in the X-ray diffraction from V- to V+A-type pattern, indicating a structural transformation toward an increased thermodynamic stability. The gelatinization temperatures shifted to higher values while the enthalpy was increased from 1.556 J/g in ET to 3.542 J/g in EHMT. The SDS and RS contents of starch granules were significantly increased, with the latter being increased from 63.03% in ET starch to 71.48% in EHMT starch.


Assuntos
Fenômenos Químicos , Temperatura Alta , Amido/química , Hidrólise , Solubilidade , Análise Espectral , Amido/ultraestrutura , Termodinâmica , Difração de Raios X
19.
Food Chem ; 294: 326-332, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126470

RESUMO

In our study, octenyl succinic anhydride (OSA)-modified dextrin was prepared and characterized as a novel emulsifier to improve the stability of emulsion and curcumin encapsulation. Fourier-transform infrared spectroscopy demonstrated the occurrence of esterification between OSA and dextrin (Mw = 1.041 × 104 g/mol). The absolute value of ζ-potential of OSA-dextrin increased (from 25.37 mV to 34.57 mV) with increasing OSA addition (from 0% to 8%), and then kept constant. Confocal laser scanning microscope results showed that the debranching and esterification of starch improved the oil droplets distribution and reduced the droplet size of emulsions. The emulsifying stability of emulsions coated by dextrin was greatly improved with OSA modification. The particle size of emulsion decreased significantly when the addition of OSA increased during storage. OSA-modified dextrin was in a position to increase encapsulation efficiency of curcumin. This research may increase the utilization of emulsions stabilized by OSA dextrin in food industry.


Assuntos
Curcumina/química , Dextrinas/química , Emulsões/química , Composição de Medicamentos , Emulsificantes/química , Esterificação , Microscopia Confocal , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/química , Anidridos Succínicos/química
20.
Food Chem ; 289: 708-713, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955670

RESUMO

Campylobacter jejuni (C. jejuni) is considered one of the most common cause of human gastroenteritis. Aiming to detect C. jejuni in food products rapidly and sensitively, a dual mode lateral flow assay, based on the peroxidase mimicking and surface enhanced Raman scattering (SERS) enhancement properties of platinum coated gold nanorods (AuNR@Pt), was developed in this study. Under color mode and SERS mode, the proposed assay showed good linear response in the range of 102-106 cfu/mL and 102-5 × 106 cfu/mL with limits of detection of 75 cfu/mL and 50 cfu/mL, respectively (S/N = 3). Furthermore, the reliability of the dual-readout lateral flow assay (LFA) was successfully demonstrated by the application on milk samples, in which the recoveries ranged from 89.33% to 107.62%. Overall, the immunochromatographic assay developed in this work is promising and has good chance to be employed for sensitive detection of C. jejuni in food products.


Assuntos
Campylobacter jejuni/isolamento & purificação , Contaminação de Alimentos/análise , Imunoensaio , Leite/microbiologia , Animais , Microbiologia de Alimentos , Ouro/química , Nanotubos/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise Espectral Raman
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