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1.
Food Funct ; 11(1): 1087-1097, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31825447

RESUMO

Native rice starch was modified using different methods which included debranching (DB), octenyl succinylation (OSA), debranching followed by octenyl succinylation (DBOS) and octenyl succinylation followed by debranching (OSDB). The effect of different modifications and the impact of modified starch properties (resistant starch content (RS) and degree of substitution (DS)) on the gastrointestinal fate of emulsified lipids are elucidated using an in vitro digestion model that included the mouth, stomach, and small intestine phases in order to understand their functionality for further applications. The effect of the different modified rice starches on the particle size distribution of the lipid droplets, surface charge (ζ-potential), microstructure, lipid digestion (free fatty acid (FFA) release), and starch hydrolysis was also assessed. The OSA-modified starch and DBOS starch-based emulsions were found stable during the mouth phase and were also found to demonstrate lesser flocculation and coalescence in comparison with the other emulsions due to the presence of more OSA groups that provide greater steric hindrance and better protection from the gastrointestinal conditions. Furthermore, the DBOS starch was found to form emulsions that were more resistant to digestion with a degree of FFA release like dietary fibers and a lower extent of starch digestion that can be attributed to their higher resistant starch content (RS). Thus, the DBOS starch-based emulsions were found to be suitable for further applications such as developing functional foods to control satiety or for designing delivery systems for the sustained release of bioactive compounds.

2.
J Food Sci ; 84(11): 3213-3221, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31589344

RESUMO

Vitamin D3 was encapsulated in 10% wt soybean oil-in-water (O/W) Pickering emulsions stabilized by either nanofibrillated cellulose (NFC) or whey protein isolate (WPI) at 0.3%, 0.5%, and 0.7% w/w. The vitamin D3 -enriched emulsions were tested for their stability against temperature (30 °C to 90 °C), pH (2 to 8), and ionic strength (0 to 500 mM NaCl). The mean particle diameter (d32 ), ζ-potential, and creaming stability of the oil droplets in the emulsions were measured, as well as their vitamin D3 encapsulation efficiency (EE). After preparation, the oil droplet size (d32 ) of the emulsions stabilized by NFC increased with increasing emulsifier concentration, whereas the droplet size of emulsions stabilized by WPI decreased. NFC provided good stability to the emulsions through a combination of steric and electrostatic repulsion. The EE of vitamin D3 increased with increasing emulsifier concentration. Heating or ionic strength did not significantly (P < 0.05) affect the emulsions properties and EE. On the other hand, the NFC-stabilized emulsions were sensitive to highly acidic conditions (pH 2), with an increase in particle size and decrease in EE. The WPI-stabilized emulsions aggregated around the isoelectric point of the adsorbed proteins (pI ≈ 4.8). Increasing NFC or WPI concentration improved the stability and EE of the emulsions against environmental stresses. NFC-stabilized emulsions had good long-term stability. The results show that NFC can be used as an effective emulsifier for creating vitamin-enriched emulsions with good stability. PRACTICAL APPLICATION: This study can be used to develop more effective encapsulation technologies for fat-soluble vitamins in emulsion-based food products. Encapsulation using nanofibrillated cellulose effectively protected the encapsulated vitamins against environmental stresses which occur in industrial food production (such as pH changes, salt addition, and thermal processing). Moreover, nanofibrillated cellulose extracted from mangosteen rind is a nature-derived emulsifier that is environmental friendly.


Assuntos
Celulose/química , Colecalciferol/química , Composição de Medicamentos/métodos , Emulsões/química , Garcinia mangostana/química , Composição de Medicamentos/instrumentação , Estabilidade de Medicamentos , Emulsificantes/química , Concentração Osmolar , Tamanho da Partícula , Cloreto de Sódio/química , Eletricidade Estática , Temperatura Ambiente , Água/química
3.
Asia Pac J Clin Nutr ; 28(3): 467-475, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31464393

RESUMO

BACKGROUND AND OBJECTIVES: Swallowing difficulty and diabetes mellitus are common in the elderly. However, texture-modified foods suitable for blood sugar control are scarce. This study was aimed to identify texture, glycemic indices (GIs) and postprandial responses of original and high-fiber Riceberry rice puddings. METHODS AND STUDY DESIGN: International Dysphagia Diet Standard Initiative (IDDSI)'s methods were used to determine texture. In vitro digestion was performed for estimating glycemic indices. A randomized cross-over controlled trial was conducted in twelve healthy volunteers. Original pudding, high-fiber pudding and white bread containing 40 g carbohydrate each were assigned in random sequence with twelve-day wash-out intervals. Plasma glucose concentrations were measured at 0, 15, 30, 60, 90, 120, 150, and 180 min after food intake. Individual GIs of puddings were calculated. RESULTS: Original and high-fiber puddings were classified as IDDSI level 3 (liquidized) and 4 (pureed), respectively. The in vitro estimated GIs were 51 for original and 48 for high-fiber puddings. Clinical trial showed rapid kinetics (peaked at 30 min) but lower postprandial responses of both puddings, compared to white bread (peaked at 60 min). The adjusted GIs for original and high-fiber puddings were not significantly different (at 41±7.60 and 36±6.40, respectively). CONCLUSIONS: Addition of fiber to the original pudding changed physical properties but not significantly reduced the GI. Original and high-fiber Riceberry rice puddings could be low-GI dysphagia diets, which may be useful for step-wise swallowing practice from IDDSI level 3 to 4 for those who also required blood sugar control.


Assuntos
Transtornos de Deglutição/dietoterapia , Fibras na Dieta/administração & dosagem , Oryza , Adulto , Glicemia/análise , Estudos Cross-Over , Dieta , Feminino , Índice Glicêmico , Humanos , Masculino , Período Pós-Prandial , Adulto Jovem
4.
Analyst ; 139(20): 5075-8, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25134491

RESUMO

Herein, we fabricated amphiphilic gold nanoparticles (GNPs) that can self-assemble at oil-water interfaces. We applied those GNPs for in situ SERS detection of emulsifier molecules within the interfacial region of oil in water (O/W) emulsion systems.


Assuntos
Técnicas de Química Analítica/métodos , Emulsificantes/análise , Ouro/química , Nanopartículas Metálicas/química , Análise Espectral Raman , Lactoglobulinas/química , Óleos/química , Tamanho da Partícula , Análise de Componente Principal , Água/química
5.
J Colloid Interface Sci ; 426: 333-40, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24863801

RESUMO

The impact of biological surfactants (bile salts) on the protein (ß-lactoglobulin) corona surrounding gold nanoparticles (200 nm) was studied using a variety of analytical techniques at pH 7: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); UV-visible (UV) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The bile salts adsorbed to the protein-coated nanoparticle surfaces and altered their interfacial composition, charge, and structure. SERS spectra of protein-coated nanoparticles after bile salt addition contained bands from both protein and bile salts, indicating that the protein was not fully displaced by the bile salts. UV, DLS and TEM techniques also indicated that the protein coating was not fully displaced from the nanoparticle surfaces. The impact of bile salts could be described by an orogenic mechanism: mixed interfaces were formed that consisted of islands of aggregated proteins surrounded by a sea of bile salts. This knowledge is useful for understanding the interactions of bile salts with protein-coated colloidal particles, which may be important for controlling the fate of colloidal delivery systems in the human gastrointestinal tract, or the gastrointestinal fate of ingested inorganic nanoparticles.


Assuntos
Ácidos e Sais Biliares/química , Ouro/química , Lactoglobulinas/química , Nanopartículas Metálicas , Nanopartículas , Proteínas/química , Tensoativos/química , Espectrofotometria Ultravioleta
6.
J Colloid Interface Sci ; 416: 184-9, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24370420

RESUMO

In this work, we investigated the conformational changes of a globular protein (ß-lactoglobulin, ß-lg) coated on the surface of 200 nm gold nanoparticles (GNPs) using a number of analytical techniques: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); localized surface plasmon resonance (LSPR) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The ß-lg (pH 3) concentration had a pronounced effect on the aggregation and surface charge of ß-lg-coated GNPs. The surface charge of GNPs changed from negative to positive as increasing amounts of ß-lg molecule were added, indicating that the globular protein molecules adsorbed to the surfaces of the particles. Extensive particle aggregation occurred when ß-lg did not saturate the GNP surfaces, which was attributed to electrostatic bridging flocculation. Modifications in LSPR and SERS spectra after addition of ß-lg to the GNP suspensions supported the adsorption of ß-lg to the particle surfaces. Moreover, SERS highlighted the importance of a number of specific molecular groups in the binding interaction, and suggested conformational changes of the globular protein after adsorption. This research provides useful information for characterizing and understanding the interactions between globular proteins and colloidal particles.


Assuntos
Ouro/química , Lactoglobulinas/química , Nanopartículas Metálicas/química , Água/química , Adsorção , Animais , Bovinos , Floculação , Concentração de Íons de Hidrogênio , Luz , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Conformação Proteica , Espalhamento de Radiação , Análise Espectral Raman , Ressonância de Plasmônio de Superfície , Temperatura Ambiente
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