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1.
Food Chem ; 311: 125878, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31771910

RESUMO

ß-Carotene is a natural nutrient that serves as a natural food colorant. However, the weak physical stability restricts its development in food industrial production. Here, the influences of a variety of external environmental conditions on the stability of ß-carotene enriched zein-carboxymethyl chitosan (CMCS)-tea polyphenols (TP) ternary composite nanoparticles were investigated. Compared with zein unitary and zein-CMCS binary complexes, it was interesting to note that ternary complexes had the best stability against color fading and there was little impact on its nanoparticle size during storage with change in temperature. Besides excellent antioxidant properties, ternary complexes were extremely effective in inhibiting ß-carotene color degradation when exposed to ultraviolet light. Based on our results, the novel zein-CMCS-TP nanoparticles are expected to be an effective delivery system to encapsulate hydrophobic bioactive compounds, which is a promising approach to improve their storage stability against external environmental stresses.

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

RESUMO

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


Assuntos
Alginatos/química , Caseínas/química , Nanopartículas/química , Própole/química , Zeína/química , Tecnologia de Alimentos , Microscopia Eletrônica de Transmissão
3.
Int J Mol Sci ; 20(2)2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30634702

RESUMO

Aquaporins (AQPs) are one diverse family of membrane channel proteins that play crucial regulatory roles in plant stress physiology. However, the heat stress responsiveness of AQP genes in soybean remains poorly understood. In this study, 75 non-redundant AQP encoding genes were identified in soybean. Multiple sequence alignments showed that all GmAQP proteins possessed the conserved regions, which contained 6 trans-membrane domains (TM1 to TM6). Different GmAQP members consisted of distinct Asn-Pro-Ala (NPA) motifs, aromatic/arginine (ar/R) selectivity filters and Froger's positions (FPs). Phylogenetic analyses distinguished five sub-families within these GmAQPs: 24 GmPIPs, 24 GmTIPs, 17 GmNIPs, 8 GmSIPs, and 2 GmXIPs. Promoter cis-acting elements analyses revealed that distinct number and composition of heat stress and hormone responsive elements existed in different promoter regions of GmAQPs. QRT-PCR assays demonstrated that 12 candidate GmAQPs with relatively extensive expression in various tissues or high expression levels in root or leaf exhibited different expression changes under heat stress and hormone cues (abscisic acid (ABA), l-aminocyclopropane-l-carboxylic acid (ACC), salicylic acid (SA) and methyl jasmonate (MeJA)). Furthermore, the promoter activity of one previously functionally unknown AQP gene-GmTIP2;6 was investigated in transgenic Arabidopsis plants. The beta-glucuronidase (GUS) activity driven by the promoter of GmTIP2;6 was strongly induced in the heat- and ACC-treated transgenic plants and tended to be accumulated in the hypocotyls, vascular bundles, and leaf trichomes. These results will contribute to uncovering the potential functions and molecular mechanisms of soybean GmAQPs in mediating heat stress and hormone signal responses.


Assuntos
Aquaporinas/genética , Resposta ao Choque Térmico/genética , Família Multigênica , Reguladores de Crescimento de Planta/metabolismo , Regiões Promotoras Genéticas , Soja/genética , Soja/metabolismo , Aquaporinas/classificação , Mapeamento Cromossômico , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Fenótipo , Transcriptoma
4.
Carbohydr Polym ; 199: 314-319, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143135

RESUMO

The characterization of emulsions covered with cellulose particles prepared under varying hydrolysis durations investigated. The results showed that with the increasing hydrolysis durations, the particle size distribution profiles of emulsion stabilized cellulose particles shifted to a lower particle size. This was primarily because at longer hydrolysis durations, a larger number of particles per interfacial area were expected to be adsorbed at the interface of oil droplets. At hydrolysis durations of 6 and 10 h, the mean particle diameter of emulsion had an increase of 20-30 nm after 7 days and showed good stability with storage time, which can be attributed to a relatively thick interface layer. Emulsions stabilized by cellulose particles prepared at hydrolysis durations of 6 and 10 h showed good stability against changes in pH and NaCl concentration. These results can be useful for designing food and beverage Pickering emulsions with the improved bioavailability of functional nutrients.

5.
Food Chem ; 260: 1-6, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29699649

RESUMO

After formation of the ovalbumin (OVA)-gum arabic (GA) complex coacervates, a more ordered crystal structure was obtained, and the protein denaturation temperature increased from 72 to 96 °C. GA can reduce the pH-induced conformational perturbations of ovalbumin. The presence of GA improved the stability of the α-helix and ß-turn regions against pH, but showed less influence on the random coil and ß-sheet domains. The complex coacervates showed the highest viscosity value at pH 3.7 compared with the other pH values tested (4.0, 3.4, 3.0, 2.7) due to the stronger interactions of OVA and GA. A large thixotropic loop was observed for the coacervate obtained at pH 3.7 compared with that obtained at pH 4.0. Moreover, the salt concentration and OVA:GA ratio influenced the rheological properties by affecting the structure and composition of the complexes. A stronger interaction between OVA and GA led to greater viscoelastic properties.


Assuntos
Goma Arábica/química , Ovalbumina/química , Cristalografia por Raios X , Concentração de Íons de Hidrogênio , Conformação Proteica , Estabilidade Proteica , Reologia , Cloreto de Sódio/química , Análise Espectral Raman , Temperatura Ambiente , Viscosidade
6.
Carbohydr Polym ; 165: 197-204, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28363540

RESUMO

Axiolitic shape nanocellulose particles were prepared using a combined mixed acid hydrolysis and ultrasonic treatment. The crystallinity, morphology and stability properties of cellulose were characterized to investigate the mechanism of nanocellulose formation and stability. It was found the hydrodynamic radius decreased from 205nm to 89nm, and the crystallinity index of the nanocellulose increased from 62.90% to 72.31% with an increase in hydrolysis time from 2 to 10h. Sulfate esters and sulfonate group were present in the nanocellulose, and released more COH groups after hydrolysis. The ζ-potential of cellulose decreased from -11.5 to -43.8mV after 10h of hydrolysis. These results illustrated the amorphous characteristic of cellulose was removed after acid hydrolysis and ultrasonic treatment. The higher ζ-potential and relatively small cellulose particles caused a more stable suspension, suggesting that electrostatic interactions played an important role in maintaining the stability and dispersibility of the nanocellulose particles.

7.
Food Chem ; 215: 256-62, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27542474

RESUMO

The salting-in effect on muscle protein is well-known in food science but hard to explain using conventional theories. Myofibrillar protein extracted from the giant squid (Dosidicus gigas) was selected as a model muscle protein to study this mechanism in KCl solutions. Changes in the secondary structures of myofibrillar protein molecules caused by concentrated salts, particularly in the paramyosin molecule conformation, have been reported. Zeta-potential determinations showed that these secondary structures have modified protein molecule surfaces. The zeta-potential of the myofibrillar protein molecules fell from -7.24±0.82 to -9.99±1.65mV with increasing salt concentration from 0.1 to 0.5M. The corresponding second virial coefficient increased from -85.43±3.8×10(-7) to -3.45±1.3×10(-7) molmLg(-2). The extended law of corresponding states suggests that reduced attractive interactions increase the protein solubility. Solubility measurements in alternating KCl concentrations showed that the conformational change was reversible.


Assuntos
Decapodiformes/metabolismo , Proteínas Musculares/metabolismo , Músculo Esquelético/efeitos dos fármacos , Cloreto de Potássio/farmacologia , Animais , Músculo Esquelético/metabolismo , Estrutura Secundária de Proteína
8.
Food Chem ; 212: 138-45, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27374517

RESUMO

Natural biopolymer stabilized oil-in-water emulsions were formulated using ovalbumin (OVA), gum arabic (GA) solutions and their complexes. The influence of interfacial structure of emulsion (OVA-GA bilayer and OVA/GA complexes emulsions) on the physical properties and antimicrobial activity of thyme oil (TO) emulsion against Escherichia coli (E. coli) was evaluated. The results revealed that the two types of emulsions with different oil phase compositions remained stable during a long storage period. The oil phase composition had an appreciable influence on the mean particle diameter and retention of the TO emulsions. The stable emulsion showed a higher minimum inhibitory concentration (MIC), and the TO emulsions showed an improved long-term antimicrobial activity compared to the pure thyme oil, especially complexes emulsion at pH 4.0. These results provided useful information for developing protection and delivery systems for essential oil using biopolymer.


Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Goma Arábica , Óleos Voláteis , Ovalbumina , Extratos Vegetais/farmacologia , Thymus (Planta) , Acacia , Emulsões/química
9.
J Sci Food Agric ; 96(6): 2047-54, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26108173

RESUMO

BACKGROUND: The aim of this work was to evaluate the effects of egg freshness on baking properties and final qualities in batter systems. Batters were made with eggs of different freshness, and the properties of batter systems were studied through rheological analysis, rapid viscosity analysis (RVA), differential scanning calorimetry (DSC), batter density and expansion rate during the baking and cooling processes. Moreover, the qualities of final baked systems were investigated, including specific volume and texture profile analysis (TPA). RESULTS: The flow behavior of batters showed that the consistency index (K) decreased as the Haugh unit (HU) value decreased, while the flow behavior index (n) increased. Both the storage modulus (G') and loss modulus (G″) determined by mechanical spectra at 20 °C decreased with decreasing HU. RVA and DSC determinations revealed that lower-HU samples had a lower viscosity in the baking process and a shorter time for starch gelatinization and egg protein denaturation. Observation of the batter density revealed an increasing change, which was reflected by a decrease in the specific volume of final models. TPA showed significant differences in hardness and chewiness, but no significant differences in springiness and cohesiveness were found. CONCLUSION: The egg freshness affected the properties of batter systems.


Assuntos
Culinária , Ovos/análise , Farinha/análise , Sacarose/química , Varredura Diferencial de Calorimetria , Temperatura Ambiente , Viscosidade
10.
J Food Sci Technol ; 52(7): 4586-92, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26139929

RESUMO

A novel process for effective separation of phospholipids, triacylglycerol and cholesterol from fresh egg yolk has been developed and validated in this study. Ethanol was the only organic solvent used in the whole procedure. Following initial separation of protein and total lipids by ethanol, most of solidified triacylglycerol was removed from total lipids by low temperature treatment of ethanol extracts within 10 h. Then, ß-cyclodextrin (ß-CD) was used to remove cholesterol from the remaining ethanol extracts and recycling of ß-CD was also studied to obtain cholesterol and reusable ß-CD powder. The highest cholesterol removal rate of nearly 99 % was obtained at ß-CD: cholesterol molar ratio of 5:1, water addition of 15 g/g ß-CD and reacting temperature of 50 °C. Ethanol in residual ethanol extracts was removed for obtaining phospholipids by rotary evaporation. The phospholipids produced in this procedure without cholesterol could be safety used as emulsifiers in food or cosmetic industry.

11.
J Agric Food Chem ; 63(2): 562-8, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25536291

RESUMO

This is the first report concerning the selenium enrichment of Catathelasma ventricosum mycelia. The selenium-containing proteins present in selenium-enriched mycelia (Se-MC) were identified using size-exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS). The selenium-containing amino acids liberated by hydrolysis of these proteins were identified using anion exchange-ICP-MS. Se-MC was found to contain selenoproteins with molecular weights ranging from 1.7 to 60.5 kDa. The main selenium-containing amino acids within them were selenomethionine and selenocysteine. Furthermore, Se-MC possessed excellent antihyperglycemic and antioxidant properties. Se-MC normalized biochemical parameters like insulin level, blood glucose level, body weight, and antioxidant enzyme activity in streptozocin-induced diabetic mice. It also inhibited the α-amylase and α-glucosidase activities present in in vitro gastric and intestinal models. In conclusion, Se-MC has the potential to serve as a dietary supplement of selenium, an antioxidant, or an ingredient for the formulation of nutraceuticals.


Assuntos
Agaricales/química , Antioxidantes/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/química , Compostos de Selênio/química , Animais , Antioxidantes/administração & dosagem , Glicemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Humanos , Hipoglicemiantes/administração & dosagem , Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Micélio/química , Compostos de Selênio/administração & dosagem
12.
Artigo em Inglês | MEDLINE | ID: mdl-24786220

RESUMO

A novel TiO2/diatomite composite (TD) was prepared and then characterized by scanning electron microscope (SEM) and Fourier Transform Infrared (FTIR). The results of SEM showed that after modification, the porous surface of diatomite was covered with TiO2. Both diatomite and TD had clear disc-shaped structures with average grain diameters of around 25 µm. Then TD and pure TiO2 were applied in the purification of phosvitin phosphopeptides (PPPs) from the digest of egg yolk protein, and a comparative study of adsorption properties of PPPs on TD and TiO2 was performed. In the study of adsorption kinetics, the adsorption equilibrium of PPPs on TD and TiO2 fitted well with the Langmuir model, and the time needed to reach adsorption equilibrium were both around 10 min. The maximum dynamic adsorption capacity of TD (8.15 mg/g) was higher than that of TiO2 (4.96 mg/g). The results of repeated use showed that TD and TiO2 were very stable after being subjected to ten repeated adsorption-elution cycles, and TD could easily be separated from aqueous solution by filtration. On the other hand, the present synthetic technology of TD was very simple, cost-effective, organic solvent-free and available for large-scale preparation. Thus, this separation method not only brings great advantages in the purification of PPPs from egg yolk protein but also provides a promising purification material for the enrichment of phosphopeptides in proteomic researches.


Assuntos
Terra de Diatomáceas/química , Fosfopeptídeos/isolamento & purificação , Fosvitina/isolamento & purificação , Titânio/química , Adsorção , Estabilidade de Medicamentos , Gema de Ovo/química , Concentração de Íons de Hidrogênio , Fosfopeptídeos/análise , Fosfopeptídeos/química , Fosvitina/análise , Fosvitina/química
13.
Colloids Surf B Biointerfaces ; 113: 477-82, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24149009

RESUMO

The formation of soluble and insoluble complexes between ovalbumin (OVA) and gum arabic (GA) polysaccharide was investigated under specific conditions (pH 1.0-7.0; temperature 4-55 °C; NaCl concentration 0-60mM; total biopolymer concentration 0.05-3.0 wt%) by turbidimetric analysis. For the 2:1 OVA:GA ratio and in the absence of NaCl, soluble and insoluble complexes were observed at pH 4.61 (pHφ1) and 4.18 (pHφ2), respectively, with optimal biopolymer interactions occurring at pH 3.79 (pHopt). Under the same conditions, OVA alone gave only a weak turbidity intensity (turbidity <0.03), whereas GA had none. As the temperature increased, critical pH values shifted toward lower pH, and the maximum turbidity value occurred at 25 °C. The region between pHφ1 and pHφ2 was narrowed and the electrostatic interactions became weaker with increasing NaCl concentration. The maximum turbidity value increased as the total biopolymer concentration increased until reaching a critical value (2.0%), afterwards becoming a constant value.


Assuntos
Biopolímeros/química , Goma Arábica/química , Ovalbumina/química , Cloreto de Sódio/química , Concentração de Íons de Hidrogênio , Temperatura Ambiente
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