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1.
Food Chem ; 305: 125436, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514047

RESUMO

The physicochemical properties of wheat bran have an effect on its technofunctional and nutritional profile. The possibility to induce physicochemical modifications in wheat bran using microfluidisation was investigated. An I-optimal experimental design was used to investigate the effect of microfluidisation processing parameters (pressure, number of passes, bran concentration and initial particle size) on important properties of wheat bran (particle size, microstructure, chemical composition, water retention capacity (WRC), extractability, viscosity and sedimentation). With the parameters used in this study, microfluidisation reduced wheat bran median particle size to 14.8 µm and disintegrated starch granules from the attached endosperm. This coincided with an increased extractability of starch and arabinoxylan. While the initial particle size was of minor importance, a higher pressure, larger number of passes and lower bran concentration during microfluidisation resulted in a smaller particle size, higher WRC and extractability, and an increased viscosity and stability in a 2% wheat bran suspension.

2.
Microbiome ; 7(1): 103, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291994

RESUMO

BACKGROUND: Accumulating evidence is supporting the protective effect of whole grains against several chronic diseases. Simultaneously, our knowledge is increasing on the impact of gut microbiota on our health and on how diet can modify the composition of our bacterial cohabitants. Herein, we studied C57BL/6 J mice fed with diets enriched with rye bran and wheat aleurone, conventional and germ-free C57BL/6NTac mice on a basal diet, and the colonic fermentation of rye bran in an in vitro model of the human gastrointestinal system. We performed 16S rRNA gene sequencing and metabolomics on the study samples to determine the effect of bran-enriched diets on the gut microbial composition and the potential contribution of microbiota to the metabolism of a novel group of betainized compounds. RESULTS: The bran-enriched study diets elevated the levels of betainized compounds in the colon contents of C57BL/6 J mice. The composition of microbiota changed, and the bran-enriched diets induced an increase in the relative abundance of several bacterial taxa, including Akkermansia, Bifidobacterium, Coriobacteriaceae, Lactobacillus, Parasutterella, and Ruminococcus, many of which are associated with improved health status or the metabolism of plant-based molecules. The levels of betainized compounds in the gut tissues of germ-free mice were significantly lower compared to conventional mice. In the in vitro model of the human gut, the production of betainized compounds was observed throughout the incubation, while the levels of glycine betaine decreased. In cereal samples, only low levels or trace amounts of other betaines than glycine betaine were observed. CONCLUSIONS: Our findings provide evidence that the bacterial taxa increased in relative abundance by the bran-based diet are also involved in the metabolism of glycine betaine into other betainized compounds, adding another potential compound group acting as a mediator of the synergistic metabolic effect of diet and colonic microbiota.

3.
Am J Clin Nutr ; 109(6): 1630-1639, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31136658

RESUMO

BACKGROUND: Wholegrain consumption has been associated with beneficial health effects including reduction of diabetes and cancer risk; however, the underlying mechanisms are not fully understood. OBJECTIVE: The aim of this study was to characterize the effects of wholegrain rye intake on circulating metabolites in a human intervention study using untargeted metabolomics. METHODS: The intervention consisted of 2 successive 4-wk periods in a randomized crossover design, where 15 adults consumed wholegrain rye bread (WGR) or white wheat bread enriched with fermented rye bran (WW+RB), following a 4-wk rye-free period with white wheat bread (WW). Fasting plasma samples were collected at the end of each period and analyzed using liquid chromatography-mass spectrometry. Metabolic profiles were compared to identify compounds discriminating WGR from the WW+RB and WW periods. Because peripheral serotonin is produced mainly in the gut, a hypothesis of its altered biosynthesis as a response to increased cereal fiber intake was tested by measuring intestinal serotonin of mice fed for 9 wk on a high-fat diet supplemented with different sources of fiber (rye bran flour, ground wheat aleurone, or powdered cellulose). RESULTS: Five endogenous metabolites and 15 rye phytochemicals associated with WGR intake were identified. Plasma concentrations of serotonin, taurine, and glycerophosphocholine were significantly lower after the WGR than WW period (Q < 0.05). Concentrations of 2 phosphatidylethanolamine plasmalogens, PE(18:2/P-18:0) and PE(18:2/P-16:0), were lower after the WGR period than the WW+RB period (Q < 0.05). The concentration of serotonin was significantly lower in the colonic tissue of mice that consumed rye bran or wheat aleurone compared with cellulose (P < 0.001). CONCLUSIONS: Wholegrain rye intake decreases plasma serotonin in healthy adults when compared with refined wheat. Intake of rye bran and wheat aleurone decreases colonic serotonin in mice. These results suggest that peripheral serotonin could be a potential link between wholegrain consumption and its associated health effects.Data used in the study were derived from a trial registered at www.clinicaltrials.gov as NCT03550365.

4.
Int J Mol Sci ; 20(8)2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-31003566

RESUMO

The development of prebiotic fibers requires fast high-throughput screening of their effects on the gut microbiota. We demonstrated the applicability of a mictotiter plate in the in vitro fermentation models for the screening of potentially-prebiotic dietary fibers. The effects of seven rye bran-, oat- and linseed-derived fiber preparations on the human fecal microbiota composition and short-chain fatty acid production were studied. The model was also used to study whether fibers can alleviate the harmful effects of amoxicillin-clavulanate on the microbiota. The antibiotic induced a shift in the bacterial community in the absence of fibers by decreasing the relative amounts of Bifidobacteriaceae, Bacteroidaceae, Prevotellaceae, Lachnospiraceae and Ruminococcaceae, and increasing proteobacterial Sutterilaceae levels from 1% to 11% of the total microbiota. The fermentation of rye bran, enzymatically treated rye bran, its insoluble fraction, soluble oat fiber and a mixture of rye fiber:soluble oat fiber:linseed resulted in a significant increase in butyrate production and a bifidogenic effect in the absence of the antibiotic. These fibers were also able to counteract the negative effects of the antibiotic and prevent the decrease in the relative amount of bifidobacteria. Insoluble and soluble rye bran fractions and soluble oat fiber were the best for controlling the level of proteobacteria at the level below 2%.


Assuntos
Fibras na Dieta/metabolismo , Ácidos Graxos Voláteis/biossíntese , Microbioma Gastrointestinal/efeitos dos fármacos , Prebióticos/administração & dosagem , Bacteroidetes/efeitos dos fármacos , Bacteroidetes/isolamento & purificação , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/isolamento & purificação , Ácidos Graxos Voláteis/administração & dosagem , Ácidos Graxos Voláteis/química , Fezes/química , Fermentação , Humanos , Proteobactérias/efeitos dos fármacos , Proteobactérias/isolamento & purificação
5.
J Agric Food Chem ; 66(40): 10394-10399, 2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30253094

RESUMO

In legumes such as faba bean, phytic acid can form very stable complexes with proteins, thus hindering their accessibility for gastrointestinal digestion. This study was set up to investigate the influence of enzymatic phytase treatment and lactic acid bacteria fermentation ( Lactobacillus plantarum VTT E-78076) on phytic acid reduction as well as on the protein quality and digestibility of faba bean flour. The soluble protein and release of free amino acids from faba bean flours were followed during a simulated in vitro digestion process. Phytase treatment efficiently reduced the amount of phytic acid in faba bean flour up to 89% degradation. The reduction of phytic acid content caused a shift in the protein solubility curve, showing higher solubility levels at low pH. Further, the enzyme-aided degradation of phytic acid considerably enhanced the digestibility of faba bean proteins (dose-dependent) and the release of free amino nitrogen in the first stage of digestion (gastric phase). The results propose the benefits of phytase treatment in plant-based foods where the phytic acid content may hinder the digestion of protein.


Assuntos
Manipulação de Alimentos/métodos , Lactobacillus plantarum/metabolismo , Ácido Fítico/metabolismo , Proteínas de Plantas/metabolismo , Vicia faba/metabolismo , Vicia faba/microbiologia , Aminoácidos/análise , Aminoácidos/metabolismo , Digestão , Fermentação , Humanos , Ácido Fítico/análise , Proteínas de Plantas/análise , Vicia faba/química
6.
Am J Clin Nutr ; 108(5): 971-979, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30256894

RESUMO

Background: Epidemiologic evidence suggests that diets rich in whole grains are associated with a reduced risk of developing chronic diseases and all-cause mortality. However, the molecular mechanisms behind these beneficial metabolic effects are poorly understood. Objective: Our aim was to investigate novel trimethylated (betainized) compounds from mice and humans, and their association with whole grain-rich diets and insulin resistance and insulin secretion. Design: Fasting plasma samples were obtained in a mouse (C57BL/6J male) feeding trial and a controlled dietary intervention. The mouse trial involved feeding the mice a rye and wheat bran-enriched feed which was compared with a high-fat diet. In the human trial, participants recruited from Kuopio, Finland (n = 69) and Naples, Italy (n = 54) with characteristics of the metabolic syndrome were randomly assigned to either a whole grain-enriched diet or a control diet for 12 wk. Plasma concentrations of betainized compounds were analyzed with the use of liquid chromatography-tandem mass spectrometry. Insulin resistance and insulin secretion were assessed in an oral-glucose-tolerance test and a meal-glucose-tolerance test. Results: The betaines that were increased in mouse plasma after bran-enriched feeding were identified de novo via chemical synthesis and liquid chromatography-tandem mass spectrometry, and confirmed to be associated with an increased intake of whole-grain products in humans. In particular, the concentrations of pipecolic acid betaine were increased at the end of the whole-grain intervention in both the Kuopio cohort (P < 0.001) and the Naples cohort (P < 0.05), and these concentrations inversely correlated with the postprandial glucose concentration. Furthermore, the concentration of valine betaine was substantially increased during the intervention in Naples (P < 0.001) with an inverse correlation with the postprandial insulin concentration. In addition, the concentrations of other betaines, e.g., glycine betaine and proline betaine, correlated with glucose and insulin concentrations at the end of the intervention. Conclusions: Novel betainized compounds in humans are associated with diets rich in whole grains, and they improve insulin resistance and insulin secretion. These results suggest that these novel compounds may contribute to the beneficial effects of whole grain-rich diets. The studies were registered at clinicaltrials.gov as NCT00945854 (Naples) and NCT00573781 (Kuopio).

7.
Carbohydr Polym ; 173: 508-518, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28732894

RESUMO

Water suspensions of cellulose nanofibres with xylan, xyloglucan and pectin were studied for foaming and structural properties as a new means for food structuring. The dispersions were analysed with rheological measurements, microscopy and optical coherence tomography. A combination of xylan with TEMPO-oxidized nanocellulose produced a mixture with well-dispersed air bubbles, while the addition of pectin improved the elastic modulus, hardness and toughness of the structures. A similar structure was observed with native nanocellulose, but the elastic modulus was not as high. Shear flow caused cellulose nanofibres to form plate-like flocs in the suspension that accumulated near bubble interfaces. This tendency could be affected by adding laccase to the dispersion, but the effect was opposite for native and TEMPO-oxidized nanocellulose. Nanocellulose type also influenced the interactions between nanofibers and other polysaccharides. For example, xyloglucan interacted strongly with TEMPO-oxidized nanocellulose (high storage modulus) but not with native nanocellulose.


Assuntos
Parede Celular/química , Celulose/química , Células Vegetais/química , Polissacarídeos/química , Óxidos N-Cíclicos , Glucanos , Nanofibras , Pectinas , Xilanos
8.
Carbohydr Polym ; 154: 305-12, 2016 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-27577922

RESUMO

The objective was to evaluate the potential of birch xylan as a food hydrocolloid and dietary fibre. High-molecular weight xylan was isolated from birch kraft pulp by alkaline extraction, and enzymatically hydrolysed. Fermentability of xylans was evaluated using an in vitro colon model and performance as a hydrocolloid was studied in low-fat acid milk gels (1.5% and 3% w/w). Texture of the gels and water holding capacity of xylans were compared with inulin, fructooligosaccharide and xylooligosaccharide. Xylans showed slower fermentation rate by faecal microbiota than the references. Xylan-enriched acid milk gels (3% w/w) had improved water holding capacity (over 2-fold) and showed lower spontaneous syneresis, firmness and elasticity when compared to control (no hydrocolloids) or to references. In conclusion, birch xylan improved texture of low-fat acid milk gel applications, and the slow in vitro fermentation rate predicts lower incidence of intestinal discomfort in comparison to the commercial references.


Assuntos
Betula/química , Coloides/química , Géis/química , Leite/química , Xilanos/química , Animais , Fibras na Dieta , Fermentação , Humanos , Hidrólise , Madeira/química
9.
Mol Nutr Food Res ; 59(8): 1550-62, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25944556

RESUMO

SCOPE: Bioprocessing of whole grain cereals may affect the bioavailability of phytochemicals associated with grain fiber and ultimately lead to different health outcomes. Here, we studied the impact of long-term feeding with intact and bioprocessed rye bran on the urinary phytochemical profile of mice. METHODS AND RESULTS: Nontargeted hydrophilic interaction chromatography-ESI-qTOF-MS metabolite profiling approach was applied on urine samples collected from three groups of diet-induced obese mice fed for 8 weeks with one of the three diets: high-fat (HF) control diet, HF diet enriched with intact rye bran, or HF diet enriched with bioprocessed rye bran. The most striking finding was the increased urinary excretion of several amino-acid derived betaines after both rye diets. These included proline betaine, alanine betaine, valine betaine, phenylalanine betaine, pipecolic acid betaine, and trigonelline, but not glycine betaine. Furthermore, bioprocessing may have improved the bioavailability of rye-derived phytochemicals, as higher increase in, e.g. ferulic acid and benzoxazinoid metabolites were observed in urine of mice fed with bioprocessed than intact rye bran. CONCLUSION: Urinary excretion of various betaines was greatly increased in mice fed rye brans. Furthermore, bioprocessing of rye bran appears to serve as a beneficial way to improve the bioavailability of various phytochemicals.


Assuntos
Aminoácidos/urina , Betaína/análogos & derivados , Fibras na Dieta/administração & dosagem , Obesidade/urina , Secale/química , Regulação para Cima , Grãos Integrais/química , Alcaloides/análise , Alcaloides/metabolismo , Alcaloides/urina , Aminoácidos/análise , Aminoácidos/química , Aminoácidos/metabolismo , Animais , Betaína/análise , Betaína/metabolismo , Betaína/urina , Biomarcadores/urina , Dieta Hiperlipídica/efeitos adversos , Fibras na Dieta/metabolismo , Fibras na Dieta/microbiologia , Fezes/química , Fermentação , Manipulação de Alimentos , Glicosídeo Hidrolases , Hidrólise , Masculino , Metabolômica/métodos , Camundongos Endogâmicos C57BL , Valor Nutritivo , Obesidade/etiologia , Obesidade/metabolismo , Distribuição Aleatória , Saccharomyces cerevisiae/metabolismo , Secale/microbiologia , Grãos Integrais/metabolismo , Grãos Integrais/microbiologia
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