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1.
Food Chem ; 320: 126650, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32224422

RESUMO

This study aimed to deliver short-chain fatty acids (SCFAs, including propionic and butyric acids) using Pickering emulsions stabilised by hydrophobically modified cellulose nanocrystals (MCNCs). The emulsions (20 wt% oil, 1 wt% MCNCs) were subjected to two in vitro digestion pathways. In the first pathway, the emulsions were used for direct intestinal digestion by bypassing the gastric phase while in the second pathway, the emulsions were subjected to sequential gastrointestinal digestion. Flocculation of emulsion droplets occurred because of charge screening effects by the gastric electrolytes. Such gastric flocculation reduced the droplet surface area, overall lipolysis kinetics and consequently decreased the extent of SCFA release, latter was 40-45% in the gastric-bypassed emulsions and 30-35% in the sequentially-digested emulsions. High proportion of SCFAs remaining after the intestinal digestion (~65%) shows promise in the use of Pickering emulsions for the colon-targeted delivery of SCFAs.

2.
Food Chem ; 318: 126463, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32135421

RESUMO

The stability behaviours of whey-protein-stabilised emulsions under gastric conditions and the effects on the lipolysis of the emulsions were investigated using an in vitro dynamic human gastric simulator and a subsequent small intestinal model. Under gastric conditions, heated whey-protein-stabilised emulsions flocculated to a greater extent and with a larger floc size, whereas unheated emulsions were more prone to coalescence. The greater extent of flocculation delayed the delivery of oil droplets to the small intestine, leading to a lower amount of oil in the emptied gastric digesta from the heated emulsion in the early period of digestion. The differences in oil content, droplet size and interfacial composition led to a greater rate and extent of lipolysis in the subsequent intestinal digestion in the heated emulsion than the unheated emulsion. The results suggest that the lipid digestion of whey-protein-stabilised emulsions in the intestinal stage could be manipulated by thermal treatment.

3.
Clin Nutr ; 39(1): 90-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30824268

RESUMO

Epidemiological and interventional studies have linked saturated fatty acids (SFA) with elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased CVD risk. However, the effects of the SFA chain length on postprandial lipemia in humans are not well elucidated. The aim of this study was to investigate the impact of short, medium and long-chain SFA on postprandial blood lipids in healthy volunteers. Sixteen healthy volunteers consumed test biscuits containing 40 g of either butter (BB), coconut oil (CB) or lard (LB) in a single-blinded, randomized crossover design. Blood samples were collected fasting and 2, 3, 4, and 6 hours postprandially and assessed for blood lipids (total cholesterol, TC; high-density lipoprotein cholesterol, HDL-C; LDL-C and triglyceride, TG). The postprandial TG response following CB was 59.8% lower than following BB (p < 0.01) and 58.8% lower than LB (p < 0.01), although no difference was observed between the BB and the LB responses. The net area under the LDL-C concentration curve was significantly larger after consumption of the CB compared to the BB, despite no significant differences in postprandial net area under the TC and HDL-C concentration curves. Consumption of medium-chain SFA as CB resulted in lower postprandial TG excursions compared to short-chain SFA as BB and long-chain SFA as LB, despite their identical fat and caloric content. These results suggest that SFA differ in their potential to elevate postprandial lipid levels, and that coconut oil, a rich source of medium-chain SFA may not be as hyperlipidemic as animal fats rich in long chain SFA. ANZCTR IDENTIFIER: 12617000903381. CLINICAL TRIAL REGISTRY NUMBER: The study was registered with the Australia New Zealand Trial registry as ACTRN12617000903381.

4.
Dig Dis Sci ; 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745688

RESUMO

BACKGROUND/AIMS: The black population in the USA is a heterogeneous group composed of smaller subgroups from different origins. The definition of black in many colorectal cancer (CRC) risk studies is vague, and differences in CRC risk comparing black subpopulations have not been evaluated. The aim of the study is to compare advanced colorectal neoplasia (ACN) between two subgroups of black populations: African-American (AA) and Afro-Caribbean (AC). A secondary aim was to determine whether there are differences in prevalence of adenomas. METHODS: This was a retrospective study of 3797 AA and AC patients undergoing first time screening colonoscopy in two different institutions in the USA. RESULTS: Overall adenoma prevalence was 29.3% for the entire population with 29.5% in AAs and 29.0% in AC with no statistically significant difference between the study groups (AOR: 1.02; 95% CI 0.88-1.18, P = 0.751). However, ACN was significantly higher in the AA group (11.8%) compared to AC (9.0%) (AOR: 1.30, 95% CI 1.02-1.66, P = 0.034). It was observed that AAs had ACN at a higher BMI than AC. After adjusting for BMI/ethnicity interactions, the difference in ACN between both groups became more significant (AOR: 1.93, 95% CI 1.16-3.23, P = 0.012). CONCLUSIONS: AAs have a higher risk of ACN than AC. Current recommendations to start screening in average-risk AAs at an earlier age may not apply to other black subgroups.

5.
Ann Allergy Asthma Immunol ; 123(5): 476-482.e1, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31382020

RESUMO

BACKGROUND: The evidence on long-term real-life response measures to omalizumab therapy in moderate to severe asthma is limited. A universal assessment tool is needed to adequately evaluate response to omalizumab in these patients. OBJECTIVE: To design a multimodular response assessment tool and use it to measure and define response to omalizumab therapy in real-world settings. METHODS: The Real-life Effectiveness of Omalizumab Therapy (REALITY) study is a retrospective, long-term, real-life clinical study that evaluates response in individuals with allergic asthma who received omalizumab between 2004 and 2011. The Standardized Measure to Assess Response to Therapy (SMART) tool was designed to define response (1 year before to after treatment) by 3 modules: (1) physician's subjective assessment of asthma symptoms and control; (2) objective assessment of 6 parameters: improvement by 50% or more for asthma exacerbation, steroid bursts, emergency department visits, and hospitalizations; increase in forced expiratory volume in 1 second of 200 mL or greater; and improved Asthma Control Test score of 3 or higher; -and (3) true responders (patient meeting both module 1 and 2 criteria). Response was assessed and compared for 3 modules at desired time points. RESULTS: A total of 198 patients (mean age, 31.7 years [range, 3-77 years]; 98 [49%] female; mean omalizumab therapy duration, 2.49 years [range, 3 months to 8 years]; mean omalizumab dosage, 473 mg every 4 weeks; median baseline IgE level, 433 IU/mL) were included in this analysis. Overall visit adherence was 78%, although the adherence rate decreased annually by 20%. Response rates assessed by SMART modules were 61.3%, 60.8%, and 41.8% at 16 weeks, 84.8%, 72.2%, and 64.6% at 1 year, 82.4%, 71.2%, and 63.2% at 2 years, and 95.1%, 87.8%, and 85.4% at 5 years for modules 1, 2, and 3, respectively. There were no significant adverse reactions. CONCLUSION: The REALITY study has demonstrated long-term effectiveness of omalizumab therapy in individuals with allergic asthma in real-life settings. The SMART tool is promising as a potential standard assessment tool to measure and define response to asthma therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01776177.

6.
Langmuir ; 35(37): 12017-12027, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31411485

RESUMO

Droplet-stabilized emulsions (DSEs) were made from oil droplets coated with whey protein microgel (WPM) particles. The WPM particles with z-average hydrodynamic diameters of 270.9 ± 4.7 and 293.8 ± 6.7 nm were obtained by heating whey proteins with 10 mM phosphate buffer, pH 5.9 (-PB) and no buffer (-NPB), respectively. The primary emulsions coated by WPM-NPB and WPM-PB particles had mass fractal dimensions of ∼2.75, as determined by small- and ultra-small-angle neutron scattering (SANS and USANS). The size of the subsequently formed DSEs (D32 ≈ 7-23 µm), which were stabilized by the primary emulsion droplets, made with either WPM-NPB (termed DSE-NPB) or WPM-PB (termed DSE-PB) was dependent on the concentration of the primary emulsion (10-60 wt %) in the aqueous phase. At the DSE-NPB interface, the adsorbed primary emulsion droplets formed a fractal network with a surface fractal dimension of about 3, indicating a rough interfacial layer. Combined SANS and USANS allowed a comprehensive understanding of the multilength scale structures from WPM particles to DSEs.

7.
Food Res Int ; 123: 198-207, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284968

RESUMO

Lactobacillus reuteri LR6 cells were stabilized using a novel combination of wet granulation and fluidized-bed-drying techniques. The stabilized cells were stored at 37 °C and at two water activity (aw) levels (0.11 & 0.30). Superior storage stability was recorded in the lower aw environment, supported by a stronger glassy matrix when skim milk powder was used as the excipient. The initial viable cell populations of the samples stabilized in different matrices ranged from 8.3 to 9.1 log CFU/g. At the end of the storage period, the viable cell populations were reduced to 6.7 to 7.3 log CFU/g at aw 0.11 and to 6.1 to 6.6 CFU/g when the aw was maintained at 0.30. Fourier transform infrared spectroscopic examination of the cell envelopes revealed substantial dissimilarities between samples at the beginning and at the end of the storage period, which indicated alteration in the secondary protein structures of the cell envelope and also correlated well with the loss in cell viability. In milk-powder-based matrices, adjusting the aw to 0.30 resulted in a weaker or no glassy state whereas the same matrices had a high glass transition temperature at aw 0.11. This strong glassy matrix and low aw combination was found to enhance the bacterial stability at the storage temperature of 37 °C. Scanning electron microscopy revealed the formation of corrugated surfaces and blister-type deformations on the cell envelopes during the stabilization process.

8.
J Dairy Sci ; 102(9): 7747-7759, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31326173

RESUMO

We determined seasonal variations in the composition and characteristics of bovine milk, as well as heat-induced changes in the physicochemical properties of the milk, in a typical seasonal-calving New Zealand herd over 2 full milking seasons. Fat, protein, and lactose contents varied consistently during the year in patterns similar to those of the lactation cycle. Seasonality also had significant effects on milk calcium, ionic calcium, fat globule size, buffering capacity, and ethanol stability, but not on casein micelle size. The ratio of casein to total protein did not vary significantly over the season, but late-season milk had the highest content of glycosylated κ-casein (G-κ-CN) and the lowest content of α-lactalbumin in both years. We observed significant between-year effects on protein, total calcium, ionic calcium, pH, and casein:total protein ratio, which might have resulted from different somatic cell counts in the 2 years. Compared with heating at 90°C for 6 min, UHT treatment (140°C for 5 s) induced greater dissociation of κ-casein, a similar extent of whey protein denaturation, a lower extent of whey protein-casein micelle association, and a larger increase in casein micelle size. Indeed, UHT treatment might have triggered significant dissociation of G-κ-CN, resulting in aggregation among the casein micelles and increased apparent mean casein micelle diameter. Seasonality had significant effects on the partitioning of G-κ-CN between the micelle and the serum phase, the extent of whey protein-casein micelle association under both heating conditions, and the casein micelle size of the UHT milk.


Assuntos
Bovinos , Temperatura Alta , Proteínas do Leite/química , Leite/química , Estações do Ano , Proteínas do Soro do Leite/química , Criação de Animais Domésticos , Animais , Caseínas/química , Feminino , Micelas
9.
Food Funct ; 10(8): 4584-4592, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31347643

RESUMO

The natural food-derived compound curcumin (from turmeric root) is known for its anti-inflammatory and anti-oxidant effects. However, due to its poor solubility when consumed in isolation, it is poorly bioavailable. In this crossover study we compared the bioavailability of curcumin from a meal containing either curcumin powder, turmeric powder or grated fresh turmeric root, all containing 400 mg of curcumin, along with mashed potatoes and cream. Healthy male participants consumed the meals following overnight fasting, and postprandial blood samples were taken to measure plasma curcuminoids (curcumin, dimethylcurcumin (DMC) and bisdimethylcurcumin (BDMC)). All plasma curcumin values refer to total curcumin (sum of free and conjugated curcumin). The meals were also analysed using confocal laser scanning microscopy to determine the location of curcuminoids. Both of the turmeric meals produced significantly higher amounts (p < 0.05) of plasma curcuminoids at 1-3 hours after the meal was consumed, as compared to the curcumin powder. Plasma curcumin Cmax was 4.9 ng ml-1 95% CI (confidence interval) [2.2, 7.5] for the fresh turmeric meal, 8.4 ng ml-1 95% CI [4.4, 12.48] for the turmeric powder meal and 0.19 ng ml-1 95% [-0.08, 0.47] for the curcumin powder meal. Plasma DMC and BDMC were significantly higher (p < 0.05) following the turmeric powder meal, compared with the fresh turmeric meal and the curcumin powder meal. Microscopy images showed that the curcuminoid particles were mostly confined within curcuminoid cells in the fresh turmeric meal. They were unconfined but in clusters in the turmeric powder meal, while the curcuminoid particles appeared smaller in the curcumin powder meal. Conclusion: curcumin bioavailability is enhanced when consumed as fresh or powdered turmeric, which could be due to the co-presence of other turmeric compounds and/or a turmeric matrix effect.


Assuntos
Curcuma/metabolismo , Curcumina/metabolismo , Extratos Vegetais/metabolismo , Adolescente , Adulto , Disponibilidade Biológica , Estudos Cross-Over , Curcuma/química , Curcumina/química , Humanos , Masculino , Extratos Vegetais/química , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Pós/química , Pós/metabolismo , Adulto Jovem
10.
J Agric Food Chem ; 67(23): 6614-6624, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31117487

RESUMO

Self-assembled micelles based on octenyl succinic anhydride (OSA)-modified starch were prepared to enhance the solubility of ß-carotene. The critical micelle concentration (CMC) was lower for OSA-modified starch with a lower molecular weight (Mw) or higher degree of substitution (DS). Above the CMC, OSA-modified starch assembled into spherical micelles with an average hydrodynamic diameter of <20 nm, as determined by dynamic light scattering (DLS). All the radii of gyration ( Rg), obtained from Guinier fitting of small-angle X-ray scattering (SAXS) data, were between 3 and 9 nm, and they were positively correlated with the Mw but negatively correlated with both the DS and the starch concentration. ß-Carotene was encapsulated effectively into the starch micelles, and the concentration of ß-carotene in the micelles was positively correlated with the concentration, Mw, and DS of the starch, with a maximum value of 53.14 µg/mL. The incorporation of ß-carotene enlarged the hydrophobic core and induced a significant increase in the Rg of the micelles determined by SAXS, and it may have also promoted the aggregation of the micelles resulting in a marked increase in the Dh determined by DLS.


Assuntos
Amido/análogos & derivados , beta Caroteno/química , Composição de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Micelas , Peso Molecular , Espalhamento a Baixo Ângulo , Solubilidade , Amido/química , Difração de Raios X
11.
J Clin Gastroenterol ; 53(10): 724-730, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31021890

RESUMO

GOALS: We compare bowel cleanliness in patients taking same-day versus split-dose 4-L polyethylene glycol laxative for afternoon colonoscopy. Secondary objectives included patient satisfaction, adverse effects and patient tolerability. BACKGROUND: Afternoon colonoscopies have been associated with inadequate bowel preparation and lower adenoma detection rates. Same-day (morning) or split-dosing of the laxative have improved preparation quality but differences between these options are unclear. MATERIALS AND METHODS: Single-center prospective randomized endoscopist blinded trial. Patients aged 18 years and above prescribed 4-L polyethylene glycol for colonoscopy were randomized into same-day or split-dose preparation. Preparation quality was assessed using the Ottawa Bowel Preparation Scale. Patient satisfaction and side effects was collected using a questionnaire. Intention-to-treat and per-protocol analysis were performed. RESULTS: A total of 300 patients (158 split-dose, 142 same-day) were evaluated. No statistically significant difference was seen on total Ottawa score among the groups (P=0.47) or by individual colonic segments in intent-to-treat and per-protocol analysis. Patients in split-dose group were more likely to complete the entire preparation (P=0.01) but reported more sleep loss (P=0.001). The same-day preparation group reported higher incidence of vomiting (P=0.036). Patients ingesting bowel preparation ≥7 hours before colonoscopy had higher total Ottawa scores (P=0.001). CONCLUSIONS: There were no differences in quality of preparation in patients taking same-day versus split-dose preparation for afternoon colonoscopy. Those receiving same-day preparation were less likely to lose sleep but more likely to have emesis. These differences should be considered when selecting a bowel preparation regimen.

12.
Dig Dis Sci ; 64(10): 2798-2805, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30955174

RESUMO

BACKGROUND: Open access colonoscopy (OAC) has gained widespread acceptance and has the potential to increase colorectal cancer (CRC) screening. However, there is little data evaluating its appropriateness for CRC prevention. AIMS: The aim of this study is to evaluate the appropriateness of OAC in CRC screening and polyp surveillance by comparing to procedures ordered by gastroenterologists (NOAC). As secondary outcomes, we compared the quality of bowel preparation and adenoma detection rate (ADR) between OAC and NOAC. METHODS: It is retrospective single-center study. Inclusion criteria included patients > 50 years of age undergoing a colonoscopy for CRC screening and surveillance. Appropriateness was defined as those colonoscopies performed within 12 months of the recommended 2012 consensus guidelines. Secondary outcomes included the quality of bowel preparation and ADR. RESULTS: 5211 colonoscopies met inclusion criteria, and 64.9% were OAC. Screening OAC was appropriately 91.6% and NOAC 92.9% of the time (p = 0.179). Surveillance NOAC were inappropriate in 26.4% of cases, and surveillance OAC was 32.6% (p = 0.008). Multivariate analysis demonstrated that OAC did not influence ADR (OR for NOAC 0.97; 95% CI 0.86-1.1; p = 0.644) or an adequate bowel preparation (OR for NOAC 1.11; 95% CI 0.91-1.36; p = 0.306). CONCLUSION: OAC performed similarly to NOAC for screening indications, quality of bowel preparation, and ADR. However, more surveillance procedures were inappropriate in the OAC group although both groups had a high number of inappropriate indications. Although OAC can be efficiently performed for screening indications, measures to decrease inappropriate surveillance colonoscopies are needed.

13.
J Colloid Interface Sci ; 546: 312-323, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30927595

RESUMO

An electrostatic nanocomplex between naturally occurring ε-poly-l-lysine (εPL) and ß-cyclodextrin sulphate (sCD) was designed, and its capacity to entrap four model proteins with high or low molecular weight and isoelectric point, i.e., lactoferrin, albumin, actinidin, and lysozyme, was investigated. The optimal formulations gave nanocomplexes with an average diameter around 276 ±â€¯16 nm, a ζ-potential of -39 ±â€¯1.5 mV, and a spherical shape with a core-shell structure. Different strategies were pursued to increase the entrapment efficiency for selected proteins, which led to 40-100% entrapment depending on the protein type. Under simulated gastric conditions with pepsin, the complexes protected lactoferrin and albumin against proteolysis, whereas actinidin and lysozyme were intrinsically stable. In Caco-2 cells, these complexes transiently decreased the trans-epithelial electrical resistance, indicating the potential to enhance the paracellular permeability of bioactive macromolecules. Thus, these εPL-sCD complexes would be a promising system for loading diverse proteins for gastric protection and enhancing intestinal absorption.


Assuntos
Albuminas/metabolismo , Cisteína Endopeptidases/metabolismo , Sistemas de Liberação de Medicamentos , Trato Gastrointestinal/efeitos dos fármacos , Lactoferrina/metabolismo , Muramidase/metabolismo , Polilisina/farmacologia , Substâncias Protetoras/farmacologia , beta-Ciclodextrinas/farmacologia , Albuminas/análise , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cisteína Endopeptidases/análise , Relação Dose-Resposta a Droga , Humanos , Lactoferrina/análise , Estrutura Molecular , Muramidase/análise , Tamanho da Partícula , Polilisina/química , Substâncias Protetoras/química , Relação Estrutura-Atividade , Propriedades de Superfície , beta-Ciclodextrinas/química
14.
Food Chem ; 286: 216-225, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30827598

RESUMO

The digestion behaviours of pasteurized and UHT homogenized milks were investigated in in vivo rat stomach and in an in vitro dynamic human gastric simulator. The formation of coagulum under gastric conditions and the protein digestion profiles were similar in both systems. UHT milk formed curds with fragmented and crumbled structures, compared with the more cohesive curds formed from unheated or pasteurized milk. UHT milk had faster rates of protein hydrolysis and of the release of fat globules during digestion. These results are attributed to the differences in the structures of the curds formed from the samples with different treatments. The fragmented and crumbled structure of the curds obtained from UHT milk was probably the result of ß-lactoglobulin binding with casein micelles during processing, which sterically hindered aggregation of the casein micelles under gastric conditions. This study provides knowledge for understanding the gastric emptying and digestion of processed consumer milk.


Assuntos
Leite/química , Leite/metabolismo , Pasteurização/métodos , Animais , Caseínas/metabolismo , Digestão , Temperatura Alta , Humanos , Masculino , Proteínas do Leite/química , Proteínas do Leite/metabolismo , Ratos Sprague-Dawley , Estômago , Temperatura Ambiente
15.
J Dairy Sci ; 102(3): 2749-2759, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30638994

RESUMO

The fat globules in milk are unique oil droplets that are stabilized by a specific and structurally complex membrane, the milk fat globule membrane (MFGM). In the last decade, excellent progress has been made on studying the structure of the milk fat globules and the MFGM and how common processing treatments affect these structures to deliver dairy products with improved functional properties. Although the digestion of milk fat to deliver energy and lipid-soluble nutrients is essential for survival of the neonate, there is little understanding of the complex processes involved. The structural alterations to fat globules during gastrointestinal processing affect the way in which milk fat is digested, absorbed, and metabolized. The packaging of these globules within the MFGM or in other forms may affect the bioaccessibility of raw or processed milk fat globules; in turn, this may affect access of the gastrointestinal enzymes to the globules and, therefore, may influence the rate and extent of lipid digestion. This review focuses on recent advances in understanding milk fat globules during gastrointestinal digestion, including the effects of processing on their bioavailability and the kinetics of lipid digestion. Possible effects of the dairy matrix on lipid digestion and physiological responses are briefly described.


Assuntos
Digestão , Trato Gastrointestinal/metabolismo , Glicolipídeos/metabolismo , Glicoproteínas/metabolismo , Leite/metabolismo , Animais , Glicolipídeos/química , Glicoproteínas/química , Humanos , Lipídeos/análise , Leite/química , Conformação Molecular
16.
J Agric Food Chem ; 67(9): 2626-2636, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30608676

RESUMO

Droplet-stabilized emulsions use fine protein-coated lipid droplets (the shell) to emulsify larger droplets of a second lipid (the core). This study investigated the oxidation resistance of polyunsaturated fatty acid (PUFA) oil within droplet-stabilized emulsions, using shell lipids with a range of melting points: olive oil (low melting), trimyristin (high-melting), and palmolein oil (intermediate melting point). Oxidation of PUFA oil was accelerated with a fluorescent lamp in the presence of ferrous iron (100 µM) for 9 days, and PUFA oxidation was monitored via conjugated dienes, lipid hydroperoxides, and hexanal levels. Oxidation was slower in droplet-stabilized emulsions than in conventional emulsions or control emulsions of the same composition as droplet-stabilized emulsions but different structure, and trimyristin gave the greatest oxidation resistance. Results suggest the structured interface of droplet-stabilized emulsions limits contact between pro-oxidants and oxidation-sensitive bioactives encapsulated within, and this antioxidative effect is greatly enhanced with solid surface lipids.


Assuntos
Antioxidantes/química , Emulsões/química , Ácidos Graxos Insaturados/química , Lipídeos/química , Água/química , Estabilidade de Medicamentos , Azeite de Oliva/química , Oxirredução , Óleo de Palmeira/química , Tamanho da Partícula , Temperatura de Transição , Triglicerídeos/química
17.
Comput Biol Chem ; 78: 144-152, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30521988

RESUMO

We have reported synthesis of a novel 1,2,3-triazole conjugate of lithocholic acid by 1,3-dipolar cycloaddition reaction. The molecular properties such as geometry, conformations, bond lengths and dihedral angles were investigated theoretically. The bond order analysis was performed using Wiberg bond order (WBO), Fuzzy bond order (FBO) and Laplacian bond order (MBO) method. Electronic properties of molecule such as electrostatic surface potential analysis, frontier molecular orbital analysis, reduced density gradient, total density of states, and global chemical reactivity indices have been investigated. The nonlinear optical properties were also investigated. Total dipole moment, mean polarizability and hyperpolarizability were found to be much higher than standard urea molecule which suggests that it could act as potential NLO material. The molecular docking calculations are also performed to investigate its potential as PTP 1B enzyme inhibitor.


Assuntos
Inibidores Enzimáticos/farmacologia , Ácido Litocólico/farmacologia , Simulação de Acoplamento Molecular , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Triazóis/farmacologia , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Ácido Litocólico/síntese química , Ácido Litocólico/química , Estrutura Molecular , Fenômenos Ópticos , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Relação Estrutura-Atividade , Triazóis/química
18.
Food Funct ; 10(1): 112-124, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30566166

RESUMO

As the food matrix is a determinant of the rate of fat digestion and absorption, it is important for the modulation of postprandial triglyceridaemia. High postprandial triglyceride levels are associated with an increase in inflammation, oxidative stress, an imbalance in the lipoprotein profile and an increase in the risk of developing chronic diseases. This study was designed to assess the in vitro digestion patterns and the postprandial lipaemic responses to test foods with the same nutrient composition but differing in the form and structure. A liquid, a semi-solid and a solid test food with the same nutrient and energy composition were designed. The digestion profiles of the three foods were assessed using a dynamic in vitro model. The foods were also consumed by healthy young adults who donated blood samples after an overnight fast and again 0.5, 1, 2, 3, 4 and 6 h after consuming each of the test foods and who were also assessed for appetite sensations. The solid food showed phase separation during gastric digestion and a lower release of fatty acids during intestinal digestion than the liquid and semi-solid foods. During the postprandial feeding experiments, the solid food caused a lower increase in serum triglycerides than the liquid food and produced higher fullness and satisfaction. In conclusion, the food form and structure modulated fat release, postprandial triglyceridaemia and appetite sensations independent of the nutrient and energy content. Thus, manipulation of the food structure and form may be used in designing strategies for improving metabolic markers and satiety.


Assuntos
Análise de Alimentos , Metabolismo dos Lipídeos , Período Pós-Prandial , Adolescente , Adulto , Apetite , Estudos Cross-Over , Digestão , Feminino , Humanos , Lipídeos/química , Masculino , Triglicerídeos/sangue , Adulto Jovem
19.
Food Chem ; 276: 129-139, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30409575

RESUMO

This study investigated the structural characteristics of oil bodies from mature coconut (Cocos nucifera L.) fruit. The ultrastructure and the distribution of oil bodies in coconut endosperm were investigated using cryo-scanning electron microscopy. The interfacial characteristics of the oil bodies in suspensions isolated using two different protocols were studied using confocal laser scanning microscopy (CLSM), and the oleosins stabilizing the oil bodies were characterized using sodium dodecyl sulfate polyacrylamide electrophoresis. The oil bodies were found to be preferentially accumulated in endosperm tissues away from the inner endosperm and had a polydisperse size distribution, both intracellularly and in suspensions. The CLSM of oil bodies revealed uniform distribution of proteins and phospholipids at the interface along with glycolipids. Six different proteins were found to be associated with oil bodies some of which were disulfide-linked. This work provides new insights into the structure of coconut oil bodies and mechanisms for their stabilization.


Assuntos
Cocos/ultraestrutura , Endosperma/ultraestrutura , Gotículas Lipídicas/ultraestrutura , Cocos/química , Endosperma/química , Gotículas Lipídicas/química , Microscopia Confocal , Fosfolipídeos/análise , Proteínas de Plantas/análise
20.
J Dairy Sci ; 101(8): 6842-6852, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29753488

RESUMO

The coagulation behavior and the kinetics of protein hydrolysis of skim milk powder, milk protein concentrate (MPC), calcium-depleted MPC, sodium caseinate, whey protein isolate (WPI), and heated (90°C, 20 min) WPI under gastric conditions were examined using an advanced dynamic digestion model (i.e., a human gastric simulator). During gastric digestion, these protein ingredients exhibited various pH profiles as a function of the digestion time. Skim milk powder and MPC, which contained casein micelles, formed cohesive, ball-like curds with a dense structure after 10 min of digestion; these curds did not disintegrate over 220 min of digestion. Partly calcium-depleted MPC and sodium caseinate, which lacked an intact casein micellar structure, formed curds at approximately 40 min, and a loose, fragmented curd structure was observed after 220 min of digestion. In contrast, no curds were formed in either WPI or heated WPI after 220 min of digestion. In addition, the hydrolysis rates and the compositions of the digesta released from the human gastric simulator were different for the various protein ingredients, as detected by sodium dodecyl sulfate-PAGE. Skim milk powder and MPC exhibited slower hydrolysis rates than calcium-depleted MPC and sodium caseinate. The most rapid hydrolysis occurred in the WPI (with and without heating). This was attributed to the formation of different structured curds under gastric conditions. The results offer novel insights about the coagulation kinetics of proteins from different milk protein ingredients, highlighting the critical role of the food matrix in affecting the course of protein digestion.


Assuntos
Digestão/fisiologia , Proteínas do Leite/metabolismo , Animais , Caseínas/metabolismo , Mucosa Gástrica , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Leite , Estômago , Proteínas do Soro do Leite/metabolismo
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