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1.
Zhongguo Zhong Yao Za Zhi ; 45(17): 4211-4220, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33164406

RESUMO

To prepare Cangyi nanoemulsion in situ gel and study its nasal mucosa release mechanism in vitro. After proper treatment of different drugs in the compound, the prescription of nanoemulsion was determined by pseudo-ternary phase diagram method. With the ratio of mixed emulsifier to oil phase [(S+COS)/O], the ratio of mixed emulsifier(K_m), the ratio of water phase to mixed emulsifier and oil phase[W/(S+COS+O)] as investigation factors and the normalized value(OD) as evaluation index, the prescription of Cangyi nanoemulsion was optimized by central composite design-response surface method. With the ratio of poloxamer 407(P407) and poloxamer 188(P188) as the investigation factors and the gelation temperature as the evaluation index, the in situ gel prescription of Cangyi nanoemulsion was optimized. The improved Franz diffusion cell was used to explore the nasal mucosa drug-release mechanism of Cangyi nanoemulsion in situ gel with oxymatrine, ferulic acid and salvianolic acid B content as indexes. The optimal prescription of Cangyi nanoemulsion in situ gel was as follows: 6.862% castor oil polyoxyl(EL), 4.262% absolute ethanol, 1.392% ethyl oleate, 7% P407 and 6% P188. The average pH was 5.55 and the average gelation temperature was 32.8 ℃. In vitro release studies showed that oxymatrine, ferulic acid and salvianolic acid B were released simultaneously and the drug release behavior was consistent with that in Higuchi model. The preparation process of Cangyi nanoemulsion in situ gel is stable, with suitable pH value, gelation temperature and viscosity. It has a certain slow-release effect, and can meet the needs of local nasal drug use.


Assuntos
Mucosa Nasal , Poloxâmero , Liberação Controlada de Fármacos , Emulsões/metabolismo , Géis , Mucosa Nasal/metabolismo , Temperatura , Viscosidade
2.
J Food Sci ; 85(9): 2923-2932, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32839962

RESUMO

Benzyl isothiocyanate (BITC) was encapsulated in oil-in-water emulsions stabilized by Pseudosciaena crocea roe protein isolate (PRPI). The stability, lipid digestion, BITC bioavailability, and retention rate of the emulsions were characterized using a simulated gastrointestinal tract model. Tween-corn and PRPI-medium-chain triglycerides (MCT) emulsions were used as controls. The membrane permeability and BITC absorption from these emulsions were investigated by in situ single-pass intestinal perfusion. The results showed that the PRPI-stabilized emulsions were stable under nonacidic environment conditions. Moreover, the PRPI-corn emulsion had more obvious protective effects than PRPI-MCT and Tween-corn emulsions. Atomic force and confocal laser scanning microscopy images showed that the protein hydrolyzed and oil droplets aggregated during simulated gastric phase digestion. Following the exposure of oil droplets in the small intestine phase, the PRPI-corn emulsion had a high rate of free fatty acid release (99.13 ± 2.49%), and the retention rate and bioavailability of BITC from the PRPI-corn emulsion were 75.93 ± 7.17% and 77.32 ± 5.36%, respectively, which were significantly higher than those measured for the other emulsions (P < 0.05). Moreover, the Ka and Peff of the PRPI-corn emulsion reached the maximum value at 45 min and then decreased slowly. These results suggest that the PRPI-corn emulsion delivery system is effective in encapsulating, delivering, and protecting BITC. PRACTICAL APPLICATION: This study provides some useful information for the food industry to develop a Pseudosciaena crocea roe protein isolate (PRPI) emulsion that could be successfully used to construct a BITC delivery system and improve benzyl isothiocyanate (BITC) bioavailability. The protective effect on BITC assessed in vitro simulated gastrointestinal tract and in situ single-pass intestinal perfusion are discussed.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Proteínas de Peixes/química , Mucosa Intestinal/metabolismo , Isotiocianatos/química , Animais , Disponibilidade Biológica , Digestão , Sistemas de Liberação de Medicamentos/instrumentação , Emulsões/química , Emulsões/metabolismo , Proteínas de Peixes/metabolismo , Trato Gastrointestinal/metabolismo , Humanos , Hidrólise , Isotiocianatos/metabolismo , Tamanho da Partícula , Perciformes , Triglicerídeos/química , Triglicerídeos/metabolismo , Zea mays/química
3.
J Sci Food Agric ; 100(6): 2473-2481, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31960429

RESUMO

BACKGROUND: Polysaccharides may enhance/inhibit lipid digestibility of oil-in-water (O/W) emulsions because of their emulsifying and/or stabilizing ability and can also affect the formation, stability, and viscosity of emulsions. Tamarind seed gum (TSG) was used as the sole emulsifier/stabilizer to stabilize an O/W emulsion prepared using high-speed homogenization. We investigated the effects of various TSG concentrations (50-150 g kg-1 ) on the lipid digestibility, rheological properties, and stability of O/W emulsions during in vitro gastrointestinal digestion. RESULTS: A low concentration (50 g kg-1 ) and a high concentration (150 g kg-1 ) of TSG reduced lipid digestibility by about 33% and 45%, respectively, compared to the control sample (without TSG). However, the emulsion containing the intermediate TSG concentration at 100 g kg-1 was the most efficient in the inhibition of lipid digestion, reducing lipid digestibility by about 70% compared to that of the control sample. The stability of emulsion tended to enhance as the concentration of TSG increased. The size of oil droplets before passing through the intestinal phase and the viscosity of the intestinal digested system may be important factors for enhancing/inhibiting lipid digestibility of emulsions. The destabilization of the emulsion during digestion was not clearly detected by rheological analysis because rheological characteristics (e.g. flow behavior index) were mainly driven by TSG. CONCLUSIONS: The addition of TSG in O/W emulsions inhibited lipid digestibility. TSG at a concentration of 100 g kg-1 was the most efficient in the inhibition of lipid digestibility, suggesting that TSG is an attractive alternative ingredient for control of lipid digestibility of emulsion foods. © 2020 Society of Chemical Industry.


Assuntos
Emulsões/química , Metabolismo dos Lipídeos , Gomas Vegetais/química , Tamarindus , Digestão , Emulsificantes , Emulsões/metabolismo , Reologia , Óleo de Soja/química , Água/química
4.
AAPS PharmSciTech ; 21(2): 45, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900652

RESUMO

In order to investigate the possible role of butter oil (BO) and omega-3 fatty acids-rich fish oil (O3FO) in the delivery of donepezil hydrochloride microemulsion (DH-ME) to the brain via intranasal route, the present study was conducted. DH:BO and DH:O3FO binary mixtures (9:1 to 1:9) were prepared by simple physical mixing and subjected to in vitro diffusion study. Ratios of DH:BO and DH:O3FO, which showed the highest diffusion, were selected for further development of microemulsion (ME). Globule sizes of DH-BO-ME and DH-O3FO-ME were found to be 87.66 ± 5.23 nm and 88.59 ± 8.23 nm, respectively. Nasal histopathological study and in vitro cytotoxicity study revealed the safety of the formulation. Higher percentage of nasal diffusion was found with DH-BO-ME (71.22 ± 1.21%) and DH-O3FO-ME (62.16 ± 1.23%) in comparison to DH-ME (59.69 ± 1.74%) and DH solution (55.01 ± 1.19%), which was further supported by in vitro cell permeability study. After intranasal administration, %bioavailability of drug in the rat brain (Sprague-Dawley rats)(on the basis of DH-ME IV) was higher with DH-BO-ME (313.59 ± 12.98%) and DH-O3FO-ME (361.73 ± 15.15%) in comparison to DH-ME (168.62 ± 6.60%) and DH solution (8.960 ± 0.23%). The results of ex vivo diffusion study and in vivo pharmacokinetic study suggested that BO and O3FO helped in enhancing the nasal permeability and the brain uptake of drug when administered intranasally.


Assuntos
Encéfalo/metabolismo , Donepezila/administração & dosagem , Emulsões/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ghee , Administração Intranasal , Animais , Disponibilidade Biológica , Sistemas de Liberação de Medicamentos , Masculino , Ratos , Ratos Sprague-Dawley
5.
Colloids Surf B Biointerfaces ; 188: 110739, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31901623

RESUMO

This study aims to develop in situ microemulsion-gel (ME-Gel) obtained from hydroxypropyl methylcellulose (HPMC) films for transdermal administration of Zidovudine (AZT). Firstly, HPMC films containing propylene glycol (PG) and eucalyptus oil (EO) were obtained and characterized. Later, a pseudo-ternary phase diagram composed of water, EO, tween 80 and PG was obtained and one microemulsion (ME) with a similar proportion of the film components was obtained. ME was transformed in ME-Gel by the incorporation of HPMC. Finally, HPMC films were hydrated with Tween 80 solution to yield in situ ME-Gel and its effect on AZT skin permeation was compared with HPMC film hydrated with water (F5hyd). The results showed that the ME and ME-Gel presented a droplet size of 16.79 and 122.13 µm, respectively, polydispersity index (PDI) < 0.39 and pH between 5.10 and 5.40. The incorporation of HPMC resulted in viscosity about 2 times higher than the use of ME. The presence of AZT did not alter the formulation properties. The in situ ME-Gel promoted a two-fold increase in the permeated amount of AZT compared to F5hyd. The results suggest that it was possible to obtain an ME-Gel in situ from HPMC films and that its effect on transdermal permeation of AZT was significant.


Assuntos
Metilcelulose/química , Pró-Fármacos/química , Zidovudina/química , Administração Cutânea , Animais , Emulsões/administração & dosagem , Emulsões/química , Emulsões/metabolismo , Óleo de Eucalipto/administração & dosagem , Óleo de Eucalipto/química , Óleo de Eucalipto/metabolismo , Géis/administração & dosagem , Géis/química , Géis/metabolismo , Masculino , Metilcelulose/administração & dosagem , Metilcelulose/metabolismo , Tamanho da Partícula , Pró-Fármacos/administração & dosagem , Pró-Fármacos/metabolismo , Propilenoglicol/administração & dosagem , Propilenoglicol/química , Propilenoglicol/metabolismo , Ratos , Ratos Wistar , Pele/química , Pele/metabolismo , Absorção Cutânea , Propriedades de Superfície , Zidovudina/administração & dosagem , Zidovudina/metabolismo
6.
J Sci Food Agric ; 100(1): 129-138, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31452202

RESUMO

BACKGROUND: Capsaicin, as a major pungent ingredient of peppers, has many health benefits. However, the strong irritation effect of capsaicin inhibits its application in the food industry. Emulsions can be an effective approach to alleviate the irritation. RESULTS: In this study, we used tocopheryl polyethylene glycol 1000 succinate (TPGS) as an emulsifier to prepare capsaicin emulsions through high-pressure homogenization. Capsaicin emulsions with a particle size of about 100 nm, -36.4 mV zeta potential, and 91.9% encapsulation efficiency were prepared successfully and showed better environmental stability and higher antioxidant activity. Emulsions reduced the cumulative release of capsaicin and had no toxic effect on buffalo rat liver (BRL-3A) cells. Moreover, the gastrointestinal injury model of rats showed that emulsions reduced the strong irritation of capsaicin. CONCLUSION: This work provides a theoretical basis for the application of irritant ingredients in food industry. © 2019 Society of Chemical Industry.


Assuntos
Capsaicina/química , Capsaicina/metabolismo , Trato Gastrointestinal/metabolismo , Animais , Emulsificantes/química , Emulsões/química , Emulsões/metabolismo , Masculino , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Vitamina E/química
7.
Food Chem ; 306: 125615, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31622833

RESUMO

Phycocyanin (PC), a plant-based protein with interesting biological activity, is rarely directly applied in the food industry because it has structural and functional limitations. This study combined ultra-high-pressure (UHP) treatment with glycation to improve PC functionality and explored resulting structural changes using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, scanning electron microscopy, Fourier-transform infrared spectroscopy, circular dichroism, and UV-visible spectroscopy. The UHP treatment obviously improved the speed and degree of glycation and the composite-modified PC (CM-PC) showed high solubility and good emulsifying and foaming performance. Scanning electron microscopy images showed the CM-PC surface was loose and fluffy. Gel electrophoresis, Fourier-transform infrared spectroscopy, and circular dichroism results demonstrated that the content of α-helix decreased from 78.1% in PC to 26.6% in CM-PC, and hydroxyl groups were introduced. UV-visible spectroscopy showed that the mechanism of composite modification involved stretching of the PC and promotion of binding with sugars.


Assuntos
Ficocianina/química , Spirulina/química , Dicroísmo Circular , Eletroforese em Gel de Poliacrilamida , Emulsões/metabolismo , Glicosilação , Pressão , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Food Chem ; 311: 125946, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31864183

RESUMO

This study describes an experimental design, based on pH-stat, to rapidly screen and assess food formulation effects on the degrees of hydrolysis (DH) of both proteins and lipids throughout in vitro gastro-intestinal digestions. This approach was used to quantitatively compare and hierarchize key structure parameters of protein emulsions. Six matrices (15 wt% whey proteins, 0 or 10 wt% oil), each differing by at least one structure characteristic, were studied. The physical state of the bulk and the oil droplet size were the major structural levers to modulate the hydrolysis of proteins (final DH between 51.7 and 58.3%) and lipids (final DH between 46.9 and 72.7%), with non-trivial interplays between proteolysis and lipolysis. Additionally, pH-stat measurements in presence of a pancreatic lipase inhibitor proved to be an efficient way to widen the scope of the proposed experimental approach to foods that are intrinsically made of both proteins and lipids.


Assuntos
Trato Gastrointestinal/metabolismo , Proteínas do Soro do Leite/química , Proteínas do Soro do Leite/metabolismo , Digestão , Emulsões/química , Emulsões/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Lipólise , Modelos Biológicos , Proteólise
9.
J Nutr ; 150(1): 64-72, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31495898

RESUMO

BACKGROUND: The presence of triacylglycerol (TAG) cystallinity is assumed to influence digestibility and postprandial lipemia (PPL), although studies to date are limited. OBJECTIVE: This study aimed to investigate whether the presence of solid fat compared with undercooled liquid oil, specifically, plays a role in determining PPL by comparing emulsion droplets differing only in terms of physical state. METHODS: Ten percent palm stearin and 0.4% sorbitan monostearate emulsions were tempered to contain identically sized, charged, and shaped (spherical) undercooled liquid (LE) compared with partially crystalline solid (SE; mean ± SEM: 33.2% ± 0.03% solid fat at 37°C) droplets. Fifteen healthy fasting adult men (mean ± SD age: 27.5 ± 5.7 y; BMI: 24.1 ± 2.5 kg/m2) consumed 500 mL of each emulsion on separate occasions and plasma TAG concentrations, particle size of the plasma chylomicron-rich fraction (CMRF), and fatty acid (FA) composition of the CMRF-TAG were serially determined in a 6-h postprandial randomized double-blind crossover acute meal study. Changes from baseline values were analyzed by repeated-measures ANOVA. RESULTS: An earlier (2 compared with 3 h, P < 0.05) significant rise, a 39.9% higher mean postprandial TAG change from baseline (P = 0.08), and higher peak concentration (mean ± SEM: 1.47 ± 0.19 compared with 1.20 ± 0.15 mmol/L, P = 0.04) and iAUC (1.95 ± 0.39 compared with 1.45 ± 0.31 mmol/L × h, P = 0.03) values were observed for LE compared with SE. The compositions of the CMRF-TAG FAs shifted toward those of the ingested palm stearin by 4 h but did not differ between SE and LE (P = 0.90). Nor were there differences in postprandial changes in CMRF particle size (P = 0.79) or nonesterified FAs (P = 0.72) based on lipid physical state. CONCLUSIONS: Despite their identical compositions and colloidal properties, differences in lipid absorption were observed between SE and LE in healthy adult men. This is direct evidence that TAG physical state contributes to PPL, with the presence of solid fat having an attenuating influence.This trial was registered at clinicaltrials.gov as NCT03515590.


Assuntos
Gorduras na Dieta/análise , Emulsões/metabolismo , Refeições , Triglicerídeos/sangue , Adulto , Estudos Cross-Over , Gorduras na Dieta/metabolismo , Método Duplo-Cego , Emulsões/química , Humanos , Masculino , Período Pós-Prandial , Triglicerídeos/química , Adulto Jovem
10.
J Colloid Interface Sci ; 563: 291-307, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31884251

RESUMO

Particle-stabilized Pickering emulsions pose several challenges to scientists researching food delivery systems. This study investigated Pickering emulsions co-stabilized by zein-propylene glycol alginate composite nanoparticles (size: 416.4 ± 8.5 nm) and rhamnolipid, quillaja saponin and tea saponin (0.01-1.00%, w/v). The results showed that different types and concentrations of natural small molecular surfactants (NSMS) had an important influence on the stability, microstructure and rheological properties of the Pickering emulsions. The surfactants were able to not only diffuse into the interfacial gaps but also adsorb onto the surface of particles to modulate the interfacial wettability, which was dependent on their types and concentrations. The negatively charged surfactants endowed the droplets with electrostatic repulsion and steric hinderance to prevent their flocculation and coalescence. In vitro digestion fate demonstrated that the presence of natural surfactants delayed the lipid digestion of the Pickering emulsions in the small intestine, particularly by decreasing the release rate of free fatty acids from 57.37% to 10.76% and 7.84% with the addition of quillaja saponin and tea saponin, respectively. The combination of nanoparticles and individual surfactants at the intermediate concentration (0.50%, w/v) exerted a synergistic effect on stabilizing the Pickering emulsions and inhibited lipolysis in the gastrointestinal tract, exhibiting potential applications as a fat replacer.


Assuntos
Tensoativos/metabolismo , Coloides/química , Coloides/metabolismo , Emulsões/química , Emulsões/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Lipídeos/química , Lipólise , Estrutura Molecular , Tamanho da Partícula , Saponinas/química , Saponinas/metabolismo , Propriedades de Superfície , Tensoativos/química
11.
Food Funct ; 10(12): 8195-8207, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31701112

RESUMO

Altering sn-fatty acid position of glycerol mono-oleate (GMO) from sn-1 to sn-2 decreases fatty acid bioaccessibility by 25.9% providing possible strategies to tailor lipemic responses of food emulsions. Lipid digestion kinetics and fatty acid bioaccessibility of monomodal O/W emulsions stabilized at their minimum surfactant concentration (0.5 < MSC > 0.7 (w/w)) were studied in the TNO Intestinal Model (TIM-1) gastrointestinal (GI) tract. No significant differences were observed between induction times nor rate constants when using 1-GMO and 1-GMS, Span 60, Tween 60 and Tween 80 as surfactants in O/W emulsions, as determined by fitting a three-parameter shifted logistic model to the cumulative bioaccessibility. Comparable trends were observed between area under the curve (AUC) of the absolute bioaccessibility and total overall bioaccessibility.


Assuntos
Lipídeos/química , Tensoativos/química , Água/química , Digestão , Emulsões/química , Emulsões/metabolismo , Trato Gastrointestinal/química , Trato Gastrointestinal/metabolismo , Cinética , Metabolismo dos Lipídeos , Modelos Biológicos , Peso Molecular , Polissorbatos/química , Polissorbatos/metabolismo , Tensoativos/metabolismo , Água/metabolismo
12.
Food Funct ; 10(10): 6604-6614, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31552977

RESUMO

Pterostilbene as a functional food ingredient is limited by low water-solubility and low bioaccessibility. Recently, there has been growing interest to use nanoemulsions to encapsulate hydrophobic compounds. In particular, the lipid type plays a critical role in the efficacy of nanoemulsions. In this study, three different lipids (medium chain triglycerides (MCTs), sunflower oil, and olive oil) were each used as carrier lipids to fabricate nanoemulsions for delivery of pterostilbene. The impact of carrier lipid composition on the physical stability and in vitro digestion of each pterostilbene-loaded nanoemulsion was studied. Its effect on pterostilbene bioaccessibility and Caco-2 cell monolayer permeability of pterostilbene was also investigated. The saturation concentrations of pterostilbene in the three lipids were firstly determined. Nanoemulsions were subjected to in vitro digestion using a model simulating the gastrointestinal tract. Mixed micelles were thus obtained and analyzed for intestinal epithelial permeability using a Caco-2 cell monolayer model. The saturation solubility of pterostilbene in the tested lipids was ranked as follows: MCT > sunflower oil ≈ olive oil. The extent of free fatty acid release during lipid digestion decreased as follows: MCT > sunflower oil > olive oil. Bioaccessibility of pterostilbene followed a similar trend. The highest apparent permeability coefficient of pterostilbene was observed in MCT micelles, followed by sunflower oil or olive oil micelles. Our study indicated that nanoemulsions fabricated with MCTs were more effective for delivering pterostilbene than those produced with long chain triglycerides. Moreover, for long chain triglycerides, the higher unsaturation levels of lipids improved the lipid digestibility and pterostilbene bioaccessibility.


Assuntos
Composição de Medicamentos/métodos , Lipídeos/química , Estilbenos/química , Disponibilidade Biológica , Células CACO-2 , Digestão , Portadores de Fármacos/química , Emulsões/química , Emulsões/metabolismo , Humanos , Permeabilidade , Estilbenos/metabolismo , Triglicerídeos/química
13.
Colloids Surf B Biointerfaces ; 183: 110459, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499452

RESUMO

In present study, lysozyme amyloid fibrils and their complexes with polysaccharides were investigated for stabilizing high internal phase emulsions (HIPEs). Linear polysaccharides, alginate and λ-carrageenan and branching ones, low and high methyl esterified pectins electrostatically bind to amyloid fibrils in nematic phase, forming well dispersed coacervates showing birefringence under polarized light. Comparatively, the polysaccharides associate with the globule protein monomers, leading to the precipitated coacervate. Interaction with the polysaccharides enhances the strength of the amyloid fibrils network. After converting protein monomers to amyloid fibrils, the binding between polysaccharides and the proteins is significantly enhanced with the affinity constant (KD) from sub-nmol to pmol level. For the first time, amyloid fibrils are found to stabilize HIPEs with highly packed polyhedral geometries in microstructure, which is dependent on protein concentration and volume fraction of the internal oil phase. The HIPEs stabilized with the amyloid fibril-polysaccharide complexes are stronger than those stabilized with only amyloid fibrils, which is attributed to the increase in the modulus of the disperse phase. The HIPE systems can encapsulate and stabilize ß-carotene against ultraviolet irradiation, thermal treatment and iron ions in aqueous phase, which is mainly attributed to the protection effects of the interfacial lysozyme amyloid fibril membrane.


Assuntos
Amiloide/química , Emulsões/química , Polissacarídeos/química , beta Caroteno/química , Alginatos/química , Alginatos/metabolismo , Amiloide/metabolismo , Carragenina/química , Carragenina/metabolismo , Emulsões/metabolismo , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Pectinas/química , Pectinas/metabolismo , Polissacarídeos/metabolismo , Ligação Proteica , Eletricidade Estática , Água/química , beta Caroteno/metabolismo
14.
J Agric Food Chem ; 67(34): 9543-9550, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31379164

RESUMO

This study aimed to reveal the mechanisms underlying the interaction between condensed tannins (CTs) and bile salts. The interaction mechanism was analyzed by transmission electron microscopy, exposure to various physicochemical conditions, electrophoresis, fluorescence spectroscopy, isothermal titration calorimetry, and molecular modeling. A new complex was formed from CTs and bile salts. The complex showed a negative enthalpy change and a positive entropy change, demonstrating that the main thermodynamic driving force was both entropy and enthalpy and indicating that binding occurred through hydrogen bonds and hydrophobic interactions. The analysis of the effects of CTs on the stability and digestion properties of bile salt emulsions indicated that CTs were able to inhibit lipid digestion to an extent. Our findings may provide evidence that foods rich in CTs offer health benefits by aggregating with bile salts and reducing the absorption of fat.


Assuntos
Ácidos e Sais Biliares/química , Proantocianidinas/química , Ácidos e Sais Biliares/metabolismo , Calorimetria , Emulsões/química , Emulsões/metabolismo , Entropia , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Proantocianidinas/metabolismo , Termodinâmica
15.
Food Funct ; 10(9): 5302-5311, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31432852

RESUMO

Many of the carotenoids found naturally in fruits and vegetables are beneficial to human health, but they often have low oral bioavailability because of their high hydrophobicity. In this study, the effects of varying the composition of the oil phase of excipient nanoemulsions on carotenoid bioaccessibility from spinach were investigated using a simulated gastrointestinal tract. Nanoemulsions containing different ratios of medium chain triglycerides (MCT) and long chain triglycerides (LCT) were prepared: (i) mixing MCT and LCT oils before homogenization and (ii) mixing MCT droplets with LCT droplets after homogenization. The release of carotenoids from spinach and their solubilization within the mixed micelles formed after lipid digestion depended strongly on the oil phase composition. As expected, carotenoid bioaccessibility was always higher in the presence of excipient nanoemulsions than in their absence. The total free fatty acids released in the small intestine increased as the MCT/LCT ratio increased, which can be attributed to the faster release of shorter chain fatty acids from the oil droplet surfaces during lipid digestion. As the MCT ratio increased, lutein bioaccessibility increased but ß-carotene bioaccessibility decreased. This difference was attributed to the ability of the formed mixed micelles to accommodate the two different kinds of carotenoids in their hydrophobic domains. Interestingly, carotenoid bioaccessibility was significantly lower (P < 0.05) when the oil droplets were mixed after homogenization than when the oils were mixed before homogenization. These results have important implications for the design of excipient foods to improve the bioavailability of hydrophobic nutraceuticals in fruits and vegetables.


Assuntos
Carotenoides/metabolismo , Trato Gastrointestinal/metabolismo , Extratos Vegetais/metabolismo , Spinacia oleracea/metabolismo , Triglicerídeos/metabolismo , Disponibilidade Biológica , Carotenoides/química , Digestão , Emulsões/química , Emulsões/metabolismo , Excipientes/química , Excipientes/metabolismo , Trato Gastrointestinal/química , Humanos , Modelos Biológicos , Extratos Vegetais/química , Spinacia oleracea/química , Triglicerídeos/química
16.
Food Funct ; 10(9): 5498-5509, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31414100

RESUMO

The aim of this study was to restrict the degree of gastric destabilization of Pickering emulsions by using electrostatic deposition of a biopolymeric layer at the proteinaceous particle-laden oil-water interface. Pickering emulsions (20 wt% oil) were prepared using whey protein nanogel particles (WPN, Dh∼ 91.5 nm) (1 wt%) and the emulsions were coated by a layer of anionic polysaccharide, dextran sulphate (DxS) of molecular weight (MW) of 40 or 500 kDa, respectively. The hypothesis was that DxS coating on the protein nanogel particle-laden interface would act as a steric barrier against interfacial proteolysis of WPN by pepsin. During static in vitro gastric digestion, the droplet size, ζ-potential, microstructure (confocal microscopy with fluorescently labelled dextran) and protein hydrolysis were monitored. The ζ-potential measurements confirmed that 0.2 wt% DxS was sufficient to coat the WPN-stabilized emulsion droplets with clear charge reversal from +35.9 mV to -28.8 (40 kDa) and -46.2 mV (500 kDa). Protein hydrolysis results showed a significantly lower level of free amino groups upon addition of 0.2 wt% DxS of either 40 or 500 kDa MW to the WPN (p < 0.05). Emulsions coated with DxS-500 kDa presented stable droplets with lower degree of pepsin hydrolysis of the adsorbed layer as compared to those coated with DxS-40 kDa or uncoated protein nanogel-stabilized interface after 120 min of digestion, highlighting the importance of charge density and molecular weight of the polymer coating. Insights from this study could enable designing gastric-stable emulsions for encapsulation of lipophilic compounds that require delivery to the intestine.


Assuntos
Biopolímeros/química , Emulsões/química , Mucosa Gástrica/metabolismo , Biopolímeros/metabolismo , Digestão , Emulsões/metabolismo , Mucosa Gástrica/química , Humanos , Modelos Biológicos , Peso Molecular , Tamanho da Partícula , Eletricidade Estática
17.
Int J Food Microbiol ; 306: 108261, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31302487

RESUMO

Turbidity in beverages is typically achieved by addition of emulsion based cloud systems. Their intrinsic instability necessitates the widespread use of technological measures and use of food additives to prevent emulsion decay. In this work, we explored the possibility to establish a new generation of natural, stable clouding systems based on bacterial dextrans. Lactobacillus hordei TMW 1.1907 originating from water kefir was used to produce dextrans in sucrose supplemented apple or grape juices. By varying the fermentation conditions, two distinct types of dextran molecules could be produced at yields ranging from 2.5 to 8.5 g/L. The dextran-containing fermentates showed an unchanged turbidity after pasteurization at acidic pH and subsequent storage for three months. No sedimentation of particles occurred upon storage. Neutralization of the acidic fruit juices to pH 7 prior to fermentation significantly increased the dextran yields. The molecular weight, rms radii and turbidity of dextrans produced at 20 °C were higher than those produced at 30 °C. Characterization of the isolated dextrans by asymmetric flow field-flow fractionation coupled to multi-angle laser light scattering revealed a random-coil like structure and rms radii ranging from 66.0 to 87.4 nm. The averaged molar masses of the cloud forming dextrans were in the approximate range of 103.1 to 141.6 MDa. In conclusion, our results demonstrate the possibility to ferment fruit juices for in situ production of dextrans exhibiting novel techno-functional properties beyond gelling and thickening.


Assuntos
Dextranos/metabolismo , Fermentação/fisiologia , Aditivos Alimentares/metabolismo , Sucos de Frutas e Vegetais/análise , Frutas/metabolismo , Ácidos/metabolismo , Emulsões/metabolismo , Kefir/microbiologia , Lactobacillus/metabolismo , Malus/metabolismo , Vitis/metabolismo
18.
Carbohydr Polym ; 221: 10-20, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31227148

RESUMO

ß-carotene has been often used as a hydrophobic nutrient in many functional foods owning to its excellent antioxidant activity. However, the poor orally bioavailability of ß-carotene limits its utilization. To overcome such limitation, a delivery system was designed for the encapsulation of ß-carotene based on oil-in-water emulsion stabilized by oat protein isolate - Pleurotus ostreatus ß-glucan Maillard conjugate. The results showed that such conjugate protected emulsion against environmental stresses by increasing steric and electrostatic repulsion between droplets, mainly manifesting as their smaller particle size and higher surface charge. Additionally, conjugate promoted lipid digestion and formation of mixed micelles, leading to an improved gastrointestinal fate of encapsulated ß-carotene, especially for its in vitro bioavailability. Such effects could enhance the cellular antioxidant activity of encapsulated ß-carotene in Caco-2 cells. Our findings confirmed that Maillard conjugate can structure an emulsion-based delivery system for the encapsulation of hydrophobic ingredients to improve their utilization.


Assuntos
Antioxidantes/farmacologia , Emulsões/química , Trato Gastrointestinal/metabolismo , Glucanos/química , Proteínas de Plantas/química , beta Caroteno/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Avena/química , Células CACO-2 , Óleo de Milho/química , Óleo de Milho/metabolismo , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Emulsões/metabolismo , Glucanos/metabolismo , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Reação de Maillard , Concentração Osmolar , Proteínas de Plantas/metabolismo , Pleurotus/química , beta Caroteno/química , beta Caroteno/metabolismo
19.
Methods Enzymol ; 622: 249-270, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31155055

RESUMO

The ability to rapidly screen interactions between proteins and membrane-like interfaces would aid in establishing the structure-function of protein-lipid interactions, provide a platform for engineering lipid-interacting protein tools, and potentially inform the signaling mechanisms and dynamics of membrane-associated proteins. Here, we describe the preparation and application of water-in-oil (w/o) emulsions with lipid-stabilized droplet interfaces that emulate the plasma membrane inner leaflet with tunable composition. Fluorescently labeled proteins are easily visualized in these synthetic cell-like droplets on an automated inverted fluorescence microscope, thus allowing for both rapid screening of relative binding and spatiotemporally resolved analyses of for example, protein-interface association and dissociation dynamics and competitive interactions, using commonplace instrumentation. We provide protocols for droplet formation, automated imaging assays and analysis, and the production of the positive control protein BcLOV4, a natural photoreceptor with a directly light-regulated interaction with anionic membrane phospholipids that is useful for optogenetic membrane recruitment.


Assuntos
Membrana Celular/metabolismo , Membranas Artificiais , Imagem Óptica/métodos , Fosfolipídeos/metabolismo , Proteínas/metabolismo , Emulsões/metabolismo , Processamento de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência/métodos
20.
Food Funct ; 10(6): 3344-3355, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31095149

RESUMO

The impact of phytic acid on lipid digestion and curcumin bioaccessibility in oil-in-water nanoemulsions was investigated using a simulated gastrointestinal tract (GIT). The size, charge, and structural organization of the colloidal particles in the system were measured as the curcumin-loaded emulsions (7 mg curcumin per g lipid) were passed through simulated mouth (pH 6.8, 2 min), stomach (pH 2.5, 2 hours), and small intestine (pH 7.0, 2 hours) stages. After the small intestine stage, the level of free fatty acids (FFAs) generated and the bioaccessibility of curcumin were measured. The total amount of FFAs released significantly decreased with increasing phytic acid level, from 105.7 ± 5.9% (control) to 78.4 ± 6.4% (0.5% phytic acid). Conversely, curcumin bioaccessibility significantly increased from 39.4 ± 3.5% (control) to 74.7 ± 2.6% (0.5% phytic acid). The inverse relationship between lipolysis and curcumin bioaccessibility was ascribed to the impact of phytic acid on droplet flocculation and the level of free calcium ions present, which affected the production of mixed micelles capable of solubilizing the nutraceutical. The knowledge obtained here might prove beneficial for the employment of phytic acid as a multifunctional ingredient that inhibits lipid digestion while boosting nutraceutical bioavailability.


Assuntos
Curcumina/metabolismo , Trato Gastrointestinal/metabolismo , Gotículas Lipídicas/química , Gotículas Lipídicas/metabolismo , Ácido Fítico/química , Extratos Vegetais/metabolismo , Disponibilidade Biológica , Curcumina/química , Emulsões/química , Emulsões/metabolismo , Excipientes/química , Excipientes/metabolismo , Humanos , Modelos Biológicos , Tamanho da Partícula , Ácido Fítico/metabolismo , Extratos Vegetais/química
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