The potential of sourdough to improve bread quality of barley and oat enriched wheat breads may depend on the characteristics of the added flour (cereal type, variety, extraction rate). We compared ...the effect of different barley flours and oat bran (substitution level 40%), unfermented and as sourdoughs (20% of total flour), on composite wheat dough and bread characteristics by combining empirical rheological analyses (DoughLab, SMS/Kieffer Dough and Gluten Extensibility Rig) with small-scale baking of hearth loaves. Whole grain barley flour sourdough increased resistance to extension (Rmax) of the dough and improved the form ratio of hearth loaves compared to unfermented whole grain barley flour. However, sourdough showed little effect on the breads prepared with sifted barley flour or oat bran. The breads made with oat bran showed highest bread volume, lowest crumb firmness and highest β-glucan calcofluor weight average molecular weight (MW). The heat treatment of oat bran inactivated endogenous enzymes resulting in less β-glucan degradation. High MW β-glucans will increase the viscosity of the doughs water phase, which in turn may stabilise gas cells and may therefore be the reason for the higher bread volume of the oat bran breads observed in our study.
► Sourdough improves the structure (Rmax) of dough containing whole grain barley. ► Sourdough improves the quality of bread containing whole grain barley. ► Sourdough may be useful to improve whole grain bread quality in general. ► β-glucan content and MW is positively correlated with composite wheat bread volume. ► β-glucan has a potential to improve the quality of bread containing barley or oat.
The cereal fibre β-glucan reduces postprandial glycaemia, however, the underlying mechanisms are not fully understood. Thus, the aim of this study was to investigate the acute effect of a ...β-glucan-enriched oat bread on gastric emptying half-time (T
), gastric emptying lag phase (T
), and gastric emptying rate (GER), and the secretion of glucagon-like peptide-1 (GLP-1) as potential means to influence postprandial glycaemia.
A randomised crossover trial was conducted in 22 healthy adults (age 24.6 ± 3.1 years, BMI 23.1 ± 2.7 kg/m
) receiving 25 g available carbohydrates from a β-glucan-enriched oat bread or a control whole-wheat bread at two non-consecutive days. T
, T
, and GER were determined based on ultrasound measures of the cross-sectional gastric antrum area in the fasting state and 15, 30, 45, 60, 90, and 120 min postprandially. Capillary glucose, serum insulin, and plasma GLP-1 concentrations were measured at the same time points.
A biphasic pattern of gastric emptying with a distinct T
before the commencement of emptying was observed in most subjects for both bread types. While no differences in GER were evident (p = 0.562), consumption of the oat bread significantly increased T
by 18 min and T
by 14 min compared with the whole-wheat bread (p = 0.005 and p = 0.010, respectively). In addition, the oat bread significantly reduced iAUC
for glucose and insulin responses compared with the whole-wheat bread (p = 0.001 and p < 0.001, respectively). There were no significant differences in GLP-1 response between the two breads (p = 0.892).
The increased T
and T
could offer a potential mechanism for the observed attenuation of postprandial glycaemia and insulinemia after consumption of the β-glucan-enriched oat bread compared with the whole-wheat bread.
The study is registered at clinicaltrails.gov (NCT04571866).
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•Processing conditions influence the bioactive properties of protein hydrolysates.•FTIR and SEC fingerprints are correlated with bioactivities of protein hydrolysates.•PLSR models ...predicted ACE-1 inhibition and DPPH radical scavenging activity.•FTIR-based models were observed to be more robust than SEC-based models.
Characterization of protein hydrolysates is a vital step in developing peptide-based bioactive ingredients. Multivariate correlation of chemical fingerprints and bioactivity of poultry by-product protein hydrolysates is explored as a potential analytical strategy for characterization and quality control. Chemical fingerprints of sixty hydrolysates were acquired using Fourier-transform infrared spectroscopy (FTIR) and size exclusion chromatography (SEC). Bioactivities (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and angiotensin-1-converting enzyme (ACE-1) inhibition) were measured in vitro. Partial least squares regression models based on FTIR fingerprints or SEC chromatograms showed a better prediction performance for ACE-1 inhibition (coefficients of determination (R2) = 0.91, root mean square error of prediction (RMSECV) = 2.8; R2 = 0.85,RMSECV = 3.5, respectively) than for DPPH radical scavenging (R2 = 0.74, RMSECV = 0.3; R2 = 0.75,RMSECV = 0.3, respectively). Such models are promising tools for rapid prediction of bioactivities and as a quality control technology in production of bioactive peptides.
Cell wall disrupted and dried
(Mg),
(Tc) and
(Cv) microalgae biomasses, with or without ethanol pre-treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread ...protein by 30%. Baking performance, protein quality and basic sensory properties were assessed. Compared to wheat, Mg, Tc and Cv contain higher amounts of essential amino acids and their incorporation markedly improved protein quality in the bread (DIAAS 57-66 vs. 46%). The incorporation of microalgae reduced dough strength and bread volume and increased crumb firmness. This was most pronounced for Cv and Tc but could be improved by ethanol treatment. Mg gave adequate dough strength, bread volume and crumb structure without ethanol treatment. To obtain bread of acceptable smell, appearance, and colour, ethanol treatment was necessary also for Mg as it markedly reduced the unpleasant smell and intense colour of all algae breads. Ethanol treatment reduced the relative content of lysine, but no other essential amino acids. However, it also had a negative impact on
protein digestibility. Our results show that Mg had the largest potential for protein fortification of bread, but further work is needed to optimize pre-processing and assess consumer acceptance.
The effect of oat β-glucan on lipid digestion relies on the delivery form of the polymer.
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•The structure of oat tissue is an important factor for determining its influence on (in ...vitro) lipid digestion.•β-glucan release from oat cell walls during digestion was not complete.•Processing of oats affects the rate and extent of lipolysis.•Viscosity is not the only factor affecting lipolysis.
Oat β-glucan has been shown to play a positive role in influencing lipid and cholesterol metabolism. However, the mechanisms behind these beneficial effects are not fully understood.
The purpose of the current work was to investigate some of the possible mechanisms behind the cholesterol lowering effect of oat β-glucan, and how processing of oat modulates lipolysis. β-Glucan release, and the rate and extent of lipolysis measured in the presence of different sources of oat β-glucan, were investigated during gastrointestinal digestion.
Only a fraction of the original β-glucan content was released during digestion. Oat flakes and flour appeared to have a more significant effect on lipolysis than purified β-glucan.
These findings show that the positive action of β-glucan is likely to involve complex processes and interactions with the food matrix. This work also highlights the importance of considering the structure and physicochemical properties of foods, and not just the nutrient content.
IntroductionIn 2012, the estimated global prevalence of pre-diabetes was 280 million, and the prevalence is expected to rise to 400 million by 2030. Oat-based foods are a good source of beta-glucans, ...which have been shown to lower postprandial blood glucose. Studies to evaluate the effectiveness of the long-term intake of beta-glucan-enriched bread as part of a habitual diet among individuals with pre-diabetes are needed. Therefore, we designed a multicentre intervention study in adults with pre-diabetes to investigate the effects of consumption of an oat-derived beta-glucan-enriched bread as part of a normal diet on glycated haemoglobin (HbA1c) in comparison to consumption of whole-grain wheat bread.Methods and analysisThe CarbHealth trial is a multicentre double-blind randomised controlled 16-week dietary intervention trial in participants 40–70 years of age with a body mass index of ≥27 kg/m2 and HbA1c of 35–50 mmol/mol. The study is conducted at four universities located in Norway, Sweden and Germany and uses intervention breads specifically designed for the trial by Nofima AS. The aim is to recruit 250 participants. The primary outcome is the difference in HbA1c between the intervention and the control groups. The main analysis will include intervention group, study centre and baseline HbA1c as independent variables in an analysis of covariance model.Ethics and disseminationThe study protocol was approved by respective ethical authorities in participating countries. The results of the study will be communicated through publication in international scientific journals and presentations at (inter)national conferences.Trial registration numberNCT04994327.
•TVP produced from faba bean protein concentrate and oat beta-glucan rich fraction.•Feed rate and moisture content during LME had most impact on the TVP properties.•Best LME conditions at 28.5/5/150 ...or 30.8/4/160 for MC (%), FR (Kg/h) and HZ6 (⁰C).•The blending improved the DIAAS score.•The beta glucan content qualifies for EFSA health claim “reduces LDL-cholesterol”.
Texturized vegetable protein (TVP) from a blend of faba bean protein concentrate and an oat beta-glucan rich fraction was produced by low-moisture extrusion to combine nutritional benefits of both ingredients. The effect of extrusion conditions (temperature in zone 6 (HZ6), feed rate (FR) and moisture content (MC)) on physicochemical, nutritional, textural, and sensory attributes was studied. Overall, effect of the FR and MC of the blend showed greater impact on TVP properties rather than the temperature. TVPs produced at 28.5%, 5 Kg/h and 150⁰C and at 30.8%, 4 Kg/h and 160⁰C for MC, FR and HZ6, respectively, presented improved properties to be further formulated into a meat analogue product. The beta-glucan content of TVP (5.6g/100g dm) was high enough to reach >1 g beta-glucan per serving in a final food product (e.g., vegan burger), which qualifies for the health claim “reduces low-density lipoprotein (LDL)-cholesterol” approved by the European Food Safety Authority. The combination of these ingredients resulted simultaneously in an improved composition of essential amino acids and increased the protein quality of the blend as the calculated digestible indispensable amino acid score (DIAAS) improved from 72.2 (beta-glucan rich fraction alone) or 76.1 (faba bean protein concentrate alone) to 90.2 (blend).
Daily use of wholegrain foods is generally recommended due to strong epidemiological evidence of reduced risk of chronic diseases. Cereal grains, especially the bran part, have a high content of ...dietary fiber (DF). Cereal DF is an umbrella concept of heterogeneous polysaccharides of variable chemical composition and molecular weight, which are combined in a complex network in cereal cell walls. Cereal DF and its distinct components influence food digestion throughout the gastrointestinal tract and influence nutrient absorption and other physiological reactions. After repeated consumption of especially whole grain cereal foods, these effects manifest in well-demonstrated health benefits. As cereal DF is always consumed in the form of processed cereal food, it is important to know the effects of processing on DF to understand, safeguard and maximize these health effects. Endogenous and microbial enzymes, heat and mechanical energy during germination, fermentation, baking and extrusion destructurize the food and DF matrix and affect the quantity and properties of grain DF components: arabinoxylans (AX), beta-glucans, fructans and resistant starch (RS). Depolymerization is the most common change, leading to solubilization and loss of viscosity of DF polymers, which influences postprandial responses to food. Extensive hydrolysis may also remove oligosaccharides and change the colonic fermentability of DF. On the other hand, aggregation may also occur, leading to an increased amount of insoluble DF and the formation of RS. To understand the structure–function relationship of DF and to develop foods with targeted physiological benefits, it is important to invest in thorough characterization of DF present in processed cereal foods. Such understanding also demands collaborative work between food and nutritional sciences.
High intake of dietary fiber is claimed to protect against development of colorectal cancer. Barley is a rich source of dietary fiber, and possible immunomodulatory effects of barley polysaccharides ...might explain a potential protective effect. Dietary fiber was isolated by extraction and enzyme treatment. A mixed-linked β-glucan (WSM-TPX, 96.5% β-glucan, Mw 886 kDa), an arabinoxylan (WUM-BS-LA, 96.4% arabinoxylan, Mw 156 kDa), a mixed-linked β-glucan rich fraction containing 10% arabinoxylan (WSM-TP) and an arabinoxylan rich fraction containing 30% mixed-linked β-glucan (WUM-BS) showed no significant effect on IL-8 secretion and proliferation of two intestinal epithelial cell lines, Caco-2 and HT-29, and had no significant effect on the NF-κB activity in the monocytic cell line U937-3κB-LUC. Further enriched arabinoxylan fractions (WUM-BS-LA) from different barley varieties (Tyra, NK96300, SB94897 and CDCGainer) were less active than the mixed-linked β-glucan rich fractions (WSM-TP and WSM-TPX) in the complement-fixing test. The mixed-linked β-glucan rich fraction from NK96300 and CDCGainer showed similar activities as the positive control while mixed-linked β-glucan rich fractions from Tyra and SB94897 were less active. From these results it is concluded that the isolated high molecular weight mixed-linked β-glucans and arabinoxylans from barley show low immunological responses in selected in vitro test systems and thus possible anti-colon cancer effects of barley dietary fiber cannot be explained by our observations.
Intake of soluble fibers including beta-glucan, is known to improve post-prandial glycemic response. The mechanisms have been attributed to the viscous gel forming in the stomach and small intestine, ...giving a longer absorption time. However, recent evidence suggests a link between intake of beta-glucan and improved glycemic regulation at subsequent meals through the gut microbiota. We investigated the short-term effect of granola with different amounts of cereal beta-glucan on glycemic response and gut microbiota. After a two-week run-in period (baseline), fourteen healthy, normal weight adults completed a dose-response dietary crossover study. Different amounts of cereal beta-glucan (low: 0.8 g, medium: 3.2 g and high: 6.6 g) were provided in granola and eaten with 200 ml low-fat milk as an evening meal for three consecutive days. Blood glucose and insulin were measured fasted and after an oral glucose tolerance test (OGTT) the following day, in addition to peptide YY (PYY) and glucagon-like peptide (GLP-2), fasting short chain fatty acids (SCFA) in blood, breath H
, and gut microbiota in feces. Only the intervention with medium amounts of beta-glucan decreased blood glucose and insulin during OGTT compared to baseline. Fasting PYY increased with both medium and high beta-glucan meal compared to the low beta-glucan meal. The microbiota and SCFAs changed after all three interventions compared to baseline, where acetate and butyrate increased, while propionate was unchanged. Highest positive effect size after intake of beta-glucan was found with
, followed by
and
. Furthermore, we found several correlations between different bacterial taxa and markers of glycemic response. In summary, intake of granola containing 3.2 g cereal beta-glucan as an evening meal for three consecutive days reduced the glycemic response after an OGTT 0-180 min and changed gut microbiota composition. Since we cannot rule out that other fiber types have contributed to the effect, more studies are needed to further explore the effect of cereal beta-glucan on glycemic regulation.
www.clinicaltrials.gov, identifier NCT03293693.
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