Glycemic Response to Oat Bran Muffins Treated to Vary Molecular Weight of β‐Glucan

Oat bran muffins, containing 4 or 8 g of β‐glucan per two‐muffin serving, were prepared with or without β‐glucanase treatment to produce a range of β‐glucan molecular weights from 130,000 to just over 2 million. Following an overnight fast, the glycemic responses elicited by the untreated and treated muffins was measured in 10 healthy subjects and compared with a control whole wheat muffin. Taken all together, the 4‐g β‐glucan/serving muffins reduced blood glucose peak rise (PBGR) by 15 ± 6% compared with the control. The 8‐g β‐glucan/serving muffins had a significantly greater effect (44 ± 5% reduction compared with the control, P < 0.05). The efficacy of the muffins decreased as the molecular weight was reduced from a 45 ± 6% reduction in PBGR (P < 0.05) for the untreated muffins (averaged of both serving sizes) to 15 ± 6% (P < 0.05) for muffins with the lowest molecular weight. As the molecular weight was reduced from 2,200,000 to 400,000, the solubility of the β‐glucan increased from a mean of 44 to 57%, but as the molecular weight was further decreased to 120,000, solubility fell to 26%. There was a significant correlation (r² = 0.729, P < 0.001) between the peak blood glucose and the product of the extractable β‐glucan content and the molecular weight of the β‐glucan extracted.     

Prediction of β‐Glucan Concentration Based on Viscosity Evaluations of Raw Oat Flours from High β‐Glucan and Traditional Oat Lines

Rheological properties of raw oat flour slurries were determined in experimental high β‐glucan (≤7.8%) and traditional oat lines (4–5% β‐glucan) grown in two consecutive years. Three different media were used to disperse oat flours: deionized water, silver nitrate solution (to inactivate endogenous enzymes), and alkali solution (to solubilize both water‐soluble and water‐insoluble β‐glucans). Significant correlations (P < 0.05) between viscosity of slurries and β‐glucan concentration obtained in either deionized water (r = 0.833), silver nitrate (r = 0.940), or alkali (r = 0.896) solutions showed that β‐glucans were the main contributor to oat extract viscosity. The highest correlation was obtained in silver nitrate solution, suggesting that inactivating endogenous enzymes is important to obtain high correlations. Predictive models of oat β‐glucan concentration based on the viscosity profile were developed using partial least squares (PLS) regression. Prediction of β‐glucan concentration based on viscosity was most effective in the silver nitrate solution (r = 0.949, correlation coefficient of predicted vs. analyzed β‐glucans) and least effective in the alkali solution (r = 0.870). These findings demonstrate that the β‐glucan in oat could be predicted by measuring the viscosity of raw flours in silver nitrate solution, and this method could be used as a screening tool for selective breeding.     

Pasting and Thermal Properties of Flours from Oat Lines with High and Typical Amounts of β‐Glucan

Experimental oat lines high in β‐glucan (6–7.8%) and traditional lines (3.9–5.7% β‐glucan) were used to evaluate the effect of β‐glucan on pasting (by rapid viscoanalysis) and thermal properties (by differential scanning calorimetry) of oat flours. Significant correlations established between β‐glucan concentration and the pasting parameters after amylolysis demonstrated the role of β‐glucans in oat pasting. The relative decrease of peak viscosity (PV) observed after enzymatic removal of β‐glucans was correlated with β‐glucan concentration (r = 0.880, P < 0.010) and reconfirmed their contribution to pasting. A significant increase of PV with β‐glucan concentration obtained under conditions of either autolysis (deionized water used for dispersion) (r = 0.89, P < 0.010) or inhibition (silver nitrate solution used for dispersion) (r = 0.91, P < 0.001) might be explained by an increase in water retention capacity caused by the β‐glucans. Predictive models of β‐glucan concentration based on the whole pasting profile or selected profile regions were developed using partial least squares (PLS) regression.Prediction of β‐glucan based on the whole profile obtained in the silver nitrate solution was the most effective (r = 0.93, correlation coefficient of predicted vs. analyzed β‐glucans, P < 0.050). No correlations were observed between the thermal properties of oat flours and the β‐glucan concentration.     

Reducing Beta-Glucan Solubility in Oat Bran Muffins by Freeze-Thaw Treatment Attenuates Its Hypoglycemic Effect

The viscosity of soluble fibers such as β-glucan depends on their concentration in solution and molecular weight (MW) distribution. We investigated whether freezing treatment of oat bran muffins affected the physicochemical properties of β-glucan, and its physiological effectiveness in lowering postprandial blood glucose response. A controlled range of β-glucan solubility was achieved by subjecting oat bran muffins containing two levels of β-glucan to repeated freeze-thaw temperature cycling. β-Glucan solubilized by in vitro digestion extraction was measured by flow-injection analysis. MW distributions of β-glucan were analyzed using size-exclusion chromatography. β-Glucan solubility decreased as the number of freeze-thaw cycles increased, while MW distribution of β-glucan decreased slightly. Peak blood glucose rise (PBGR) after fresh muffins (8 and 12 g of β-glucan/serving) was significantly lower than that after muffins (8 and 12 g of β-glucan/serving) treated with four freeze-thaw (FT) cycles (1.84 ± 0.2 vs. 2.31 ± 0.1 mmol/L, P = 0.007). Compared with the control whole wheat muffins, the reduction in incremental area under the glucose response curve (AUC) after fresh muffins (8 and 12 g of β-glucan/serving) was nearly twice that after 4 FT cycles (43.3 ± 4.4% vs. 27.0 ± 5.4%, P = 0.016). A significant inverse linear relationship was found between the log [concentration] of extractable β-glucan and PBGR (r² = 0.85, P = 0.01), and AUC (r² = 0.71, P = 0.03). The results show that reduction of β-glucan solubility in foods attenuates its physiological effectiveness in lowering postprandial glycemia.     

Molecular Weight Distribution of β‐Glucan in Oat‐Based Foods

Oats, different oat fractions as well as experimental and commercial oat‐based foods, were extracted with hot water containing thermostable α‐amylase. Average molecular weight and molecular weight distributions of β‐glucan in extracts were analyzed with a calibrated high‐performance size‐exclusion chromatography system with Calcofluor detection, specific for the β‐glucan. Oats, rolled oats, oat bran, and oat bran concentrates all had high Calcofluor average molecular weights (206 × 10⁴ to 230 × 10⁴ g/mol) and essentially monomodal distributions. Of the oat‐containing experimental foods, extruded flakes, macaroni, and muffins all had high average molecular weights. Pasteurized apple juice, fresh pasta, and teacake, on the other hand, contained degraded β‐glucan. Calcofluor average molecular weights varied from 24 × 10⁴ to 167 × 10⁴ g/mol in different types of oat bran‐based breads baked with almost the same ingredients. Large particle size of the bran and short fermentation time limited the β‐glucan degradation during baking. The polymodal distributions of β‐glucan in these breads indicated that this degradation was enzymatic in nature. Commercial oat foods also showed large variation in Calcofluor average molecular weight (from 19 × 10⁴ g/mol for pancake batter to 201 × 10⁴ g/mol for porridge). Boiling porridge or frying pancakes did not result in any β‐glucan degradation. These large differences in molecular weight distribution for β‐glucan in different oat products are very likely to be of nutritional importance.     

Effect of Health Information on Consumer Acceptability of Bread Fortified with β‐Glucan and Effect of Fortification on Bread Quality

Fortifying bread with β‐glucan reduces bread sensorial properties, though fortification using β‐glucan concentrates of low solubility under the conditions of dough preparation has not been investigated. This study investigated the consumer acceptability and purchase intent of bread fortified with a less soluble β‐glucan concentrate at levels corresponding to 0, 0.75, and 1.5 g β‐glucan/serving bread in relation to the provision of health information, gender, and whole wheat bread consumption. The effect of β‐glucan concentration on the physical properties of the bread produced under pilot plant settings was also investigated. β‐Glucan addition decreased (P < 0.05) loaf volume, increased firmness, and produced a darker, redder bread (P < 0.05), though fortification at 1.5 g β‐glucan/serving bread decreased height as well (P < 0.05). Consumer evaluation (n = 122) revealed that health information increased liking of appearance, flavor, and overall acceptability of the 1.5 g/serving bread to levels similar to or exceeding that of the control. Liking of the 1.5 g β‐glucan/serving bread appearance increased more in women than in men and for consumers who regularly consumed whole wheat bread for perceived health benefits when β‐glucan health information was provided. The provision of β‐glucan health information may be the key to increasing consumer acceptability of bread fortified with β‐glucan.     

Fermentability of Oat and Wheat Fractions Enriched in β‐Glucan Using Human Fecal Inoculation

Fermentation by human fecal bacteria of fractions of wheat bran prepared by preprocessing technology were examined and compared with a β‐glucan‐rich oat bran and a purified β‐glucan (OG). The wheat fractions were essentially a beeswing bran (WBA), mainly insoluble dietary fiber, and an aleurone‐rich fraction (WBB) containing more soluble fiber and some β‐glucan (2.7%). The oat bran (OB) had more endosperm and was very rich in β‐glucan (21.8%). Predigestion of WBB and OB to mimic the upper gastrointestinal (GI) tract gave digested wheat bran fraction B (WBBD) and digested oat bran (OBD), respectively. These predigested fractions were fermented in a batch technique using fresh human feces under anaerobic conditions. Changes in pH, total gas and hydrogen production, short chain fatty acids (SCFA), and both soluble and insoluble β‐glucan and other polysaccharide components, as determined from analysis of monosaccharide residues, were monitored. Fractions showed increasing fermentation in the order WBA < WBBD < OBD < OG. Variations in SCFA production indicated that microbial growth and metabolism were different for each substrate. Polysaccharide present in the supernatant of the digests had disappeared after 4 hr of fermentation. Fermentability of oat and wheat β‐glucan reflected solubility differences, and both sources of β‐glucan were completely fermented in 24 hr. Although the overall patterns of fermentation indicated the relative amounts of soluble and insoluble fiber, the anatomical origin of the tissues played a major role, presumably related to the degree of lignification and other association with noncarbohydrate components.     

Predicted Glycemic Index and Glycemic Index of Rice Varieties Grown in Taiwan

Two cooked brown rice and six white rice varieties were selected for assessing the variations in predicted glycemic index (pGI) determined by using in vitro starch digestion and the glycemic index (GI) determined in vivo. Marked varietal differences in apparent amylose content, dietary fiber content, pGI, and GI were observed. Most of the tested rice samples were classified as medium‐GI foods. The varieties Khazar and Taikeng 9 were categorized as high‐GI foods when bread was used as the reference. But brown and white rice samples of TRGC9152 and Taichung Sen 17 fell into the low‐GI category when glucose was used as the reference. A significant correlation coefficient (r = 0.946) was found between pGI and GI of rice samples by using bread as the reference with a regression equation of GI = 28.778 + 0.717 × pGI (R² = 0.8951, P ≤ 0.001). Overall, the in vitro pGI measurement is a rapid and useful method to predict the GI of cooked rice samples.     

Extraction and Physicochemical Characterization of Rye β‐Glucan and Effects of Barium on Polysaccharide Molecular Weight

Use of saturated Ba(OH)₂ to extract rye β‐glucan led to a depolymerized product. Similar depolymerization of β‐glucan was observed when oat bran was extracted with this reagent. Isolated oat β‐glucan, detarium xyloglucan, guar galactomannan, and wheat and rye arabinoxylan were also depolymerized by treatment with the barium reagent. The degree of depolymerization was related to time of contact with, and concentration of, the barium. Rye β‐glucan of two different molecular weights (MW) were isolated and characterized. The structure of rye β‐glucan, as evaluated from the ratio of (1→3)‐linked cellotriosyl to (1→3)‐linked cellotetraosyl primary structural units, most closely resembles barley β‐glucan. Analytical variability of this ratio is discussed. A freshly prepared solution (2%) of the higher MW sample showed shear thinning behavior typical of cereal β‐glucans. The lower MW sample at 2% was not shear thinning, but on further purification, after storage for seven days, a 6% solution had gelled as shown by the mechanical spectrum.     

In Vitro Binding of Bile Acids by Rice Bran,Oat Bran,Barley and β‐Glucan Enriched Barley

The in vitro bile acid binding by rice bran, oat bran, dehulled barley, and β‐glucan enriched barley was determined using a mixture of bile acids at a duodenal physiological pH of 6.3. Six treatments and two blank incubations were conducted testing substrates on an equal protein basis. The relative in vitro bile acid binding of the cereal brans on an equal total dietary fiber (TDF) and insoluble dietary fiber (IDF) basis considering cholestyramine as 100% bound was rice bran 45 and 49%; oat bran 23 and 30%; dehulled barley 33 and 57%; and β‐glucan enriched barley 20 and 40%, respectively. Bile acid bindings on equal protein basis for the respective cereals were 68, 26, 41, and 49%. Bile acid binding by rice bran may account to a great extent for its cholesterol‐lowering properties, while bile acid binding by oat bran suggests that the primary mechanism of cholesterol lowering by oat bran is not due to the bile acid binding by its soluble fiber. Bile acid binding was not proportional to the soluble fiber content of the cereal brans tested. Except for dehulled barley, bile acid binding for rice bran, oat bran, and β‐glucan enriched barley appear to be related to their IDF content. Highest relative bile acid binding values for rice bran and β‐glucan enriched barley were observed on an equal protein basis, whereas highest values for dehulled barley were based on IDF. Data suggest that of all four cereals tested, bile acid binding may be related to IDF or protein anionic, cationic, physical and chemical structure, composition, metabolites, or their interaction with active binding sites.     

Oat Bran Fermentation by Rye Sourdough

Hydration of oat bran including fermentation by rye sourdough was studied. Three types of oat bran suspensions were prepared (a control, one with whole meal rye flour added, and one with rye starter added). The suspensions were incubated for 1, 2, 3 and 4 hr. β‐Glucan content and solubilities of protein and β‐glucan were analyzed. Viscosity of the supernatants of oat bran suspensions was determined. Neither the rye sourdough nor the rye flour alone had a significant effect on the total β‐glucan content of oat bran suspensions. However, the addition of rye, either as whole meal rye flour or as sourdough starter, markedly increased the solubility of β‐glucan and proteins and simultaneously decreased the viscosity of the water‐soluble fraction of oat bran suspension. This suggests that a hydrolysis of β‐glucan had occurred that could change the rheological properties of oat bran in baking and the physiological potential of oat bran in nutrition.     

Viscosity and Solubility of β‐Glucan Extracted Under In Vitro Conditions from Barley β‐Glucan‐Fortified Bread and Evaluation of Loaf Characteristics

Fortifying bread with β‐glucan has been shown to reduce bread quality and the associated health benefits of barley β‐glucan. Fortification of bread using β‐glucan concentrates that are less soluble during bread preparation steps has not been investigated. The effects of β‐glucan concentration and gluten addition on the physicochemical properties of bread and β‐glucan solubility and viscosity were investigated using a less soluble β‐glucan concentrate, as were the effects of baking temperature and prior β‐glucan solubilization. Fortification of bread with β‐glucan decreased loaf volume and height (P ≤ 0.05) and increased firmness (P ≤ 0.05). Gluten addition to bread at the highest β‐glucan level increased height and volume (P ≤ 0.05) to values exceeding those for the control and decreased firmness (P ≤ 0.05). β‐Glucan addition increased (P ≤ 0.05) extract viscosity, as did gluten addition to the bread with the highest β‐glucan level. Baking at low temperature decreased (P ≤ 0.05) β‐glucan viscosity and solubility, as did solubilizing it prior to dough formulation. Utilization of β‐glucan that is less soluble during bread preparation may hold the key to effectively fortifying bread with β‐glucan without compromising its health benefits, although more research is required.     

Metabolic Responses to Venezuelan Corn Meal and Rice Bran Supplemented Arepas (Breads)

The metabolic responses to South American foods remain to be determined. Using glycemic index (GI) and insulinemic index (II) values as references for therapeutic potential of foods, this study investigated the glucose responses to a typical Venezuelan corn bread (arepa) and to an arepa supplemented with rice bran. Adding rice bran to the bread increased the content of resistant starch and dietary fiber measured as total, soluble, and insoluble dietary fiber. It also increased the protein content of the arepa. Three meals, white wheat bread, 100% corn meal arepa, and an arepa supplemented with 20% rice bran, were administered within a one‐week period. Available starch in the foods was determined to provide 50 g of available carbohydrate per meal. To calculate the indices, bread was used as the reference. The GI and II of the two arepa meals were significantly smaller than the GI and II of white wheat bread, although the differences between the two types of arepas were not significant. It is concluded that Venezuelan arepas (corn meal bread) may have potential health benefits and that the presence of 20% rice bran in the arepa meal did not produce a significant improvement in the glucose response. Due to the presence of antioxidant elements in the supplemented arepa and its higher protein, dietary fiber, and resistant starch content, it may have a potential preventive effect against the development of other pathologies.     

Effect of Processing on Viscosity and Molecular Weight of (1,3)(1,4)‐β‐Glucan in Western Australian Oat Cultivars

Six Australian milling oat cultivars grown over two growing seasons were characterized for differences in (1,3)(1,4)‐β‐glucan (β‐glucan) viscosity, solubility, molecular weight (M_w), and the effect of processing. Oat cultivars grown in 2012 had significantly higher extracted β‐glucan viscosity from oat flour than the same oat cultivar grown in 2011 (P < 0.05, mean 137 and 165 cP, respectively). Noodle β‐glucan mean viscosity for 2012 (147 cP) was significantly higher than for 2011 (128 cP). β‐Glucan from ‘Williams’ and ‘Mitika’ oats had the highest viscosity (P < 0.05) in flour (5.92 and 5.25%, respectively) and noodles (1.64 and 1.47%, respectively) for both years, compared with the other oat cultivars. β‐Glucan (M_w) of Williams for 2012 and ‘Kojonup’ for both years were the least affected by processing, with an average drop of 33% compared with a maximum of 63% for other cultivars. Therefore, Williams showed superior β‐glucan properties to other oat cultivars studied, and can potentially provide improved health benefits. High and low β‐glucan M_w populations were found in the same elution peak after processing. Oat cultivars chosen for processing should be those with β‐glucans that are more resistant to processing, and that maintain their physiochemical properties and, therefore, bioactivity.     

Development of a Germination Process for Producing High β‐Glucan,Whole Grain Food Ingredients from Oat

Germination can be used to improve the texture and flavor of cereals. However, germination generally causes breakdown of β‐glucans, which is undesirable with respect to the functional properties of β‐glucan. Our aim was to assess possibilities of germinating oat without substantial loss of high molecular weight β‐glucan. Two cultivars, hulled Veli and hull‐less (naked) Lisbeth were germinated at 5, 15, and 25°C and dried by lyophilization or oven drying. Elevated germination temperatures led to an increase in Fusarium, aerobic heterotrophic bacteria, Pseudomonas spp., lactic acid bacteria, enterobacteria, and aerobic spore‐forming bacteria. Therefore, the germination temperature should be kept low to avoid excessive growth of microbes. Of the samples germinated at 15°C, only one contained low amounts of the Fusarium toxin deoxynivalenol (52 μg/kg). Germination led to the breakdown of β‐glucans, but the decrease in the molecular weight of β‐glucan was initially very slow. A short germination schedule (72 hr, 15°C) terminated with oven drying was developed to produce germinated oat with retained β‐glucan content. Compared with the native oat, 55–60% of the β‐glucan could be retained.     

Effect of Formulation and Processing Treatments on Viscosity and Solubility of Extractable Barley β‐Glucan in Bread Dough Evaluated Under In Vitro Conditions

β‐Glucan shows great potential for incorporation into bread due to its cholesterol lowering and blood glucose regulating effects, which are related to its viscosity. The effects of β‐glucan concentration, gluten addition, premixing, yeast addition, fermentation time, and inactivation of the flour enzymes on the viscosity of extractable β‐glucan following incorporation into a white bread dough were studied under physiological conditions, as well as, β‐glucan solubility in fermented and unfermented dough. β‐Glucan was extracted using an in vitro protocol designed to approximate human digestion and hot water extraction. The viscosity of extractable β‐glucan was not affected by gluten addition, the presence of yeast, or premixing. Fermentation produced lower (P ≤ 0.05) extract viscosity for the doughs with added β‐glucan, while inactivating the flour enzymes and increasing β‐glucan concentration in the absence of fermentation increased (P ≤ 0.05) viscosity. The physiological solubility of the β‐glucan concentrate (18.1%) and the β‐glucan in the unfermented dough (20.5%) were similar (P > 0.05), while fermentation substantially decreased (P ≤ 0.05) solubility to 8.7%, indicating that the reduction in viscosity due to fermentation may be highly dependent on solubility in addition to β‐glucan degradation. The results emphasize the importance of analyzing β‐glucan fortified foods under physiological conditions to identify the conditions in the dough system that decrease β‐glucan viscosity so that products with maximum functionality can be developed.     

Influence of Oat β‐Glucan Preparations on the Perception of Mouthfeel and on Rheological Properties in Beverage Prototypes

The aim was to study the effect of concentration and molecular weight of four different β‐glucan preparations on the perceived sensory quality of a beverage prototype. The correlations between sensory and instrumental measures were investigated. Two of the preparations were brantype containing high molecular weight β‐glucan, two were more‐processed low molecular weight β‐glucan preparations. Twelve beverage samples containing 0.25–2% β‐glucan and one reference sample thickened with carboxymethyl cellulose (CMC) were profiled by a sensory panel and analyzed by instrumental measurements (viscosity and molecular weight). Sensory profiles of the beverages varied at the same concentration of β‐glucan, depending on β‐glucan preparation. Beverages made with the bran‐type preparations were more viscous and had higher perceived thickness than beverages made with more‐processed, low molecular weight preparations. Moderate correlations were obtained between perceived thickness and sliminess and instrumental viscosity at all shear rates between 26 and 100/sec (r = 0.63–0.78; P ≤ 0.001). Technologically, more‐processed β‐glucan preparations are easier to add into a beverage in amounts sufficient for achieving a physiologically functional amount of β‐glucan in a product.     

Comparison of Different Types of NIR Instruments in Ability to Measure β‐Glucan Content in Naked Barley

Importance of β‐glucan in human nutrition is mirrored in numerous approval applications registering β‐glucan containing products as health beneficial products in accordance with forthcoming EU Health Claims Regulation. In comparison to other cereals, barley contains considerable amounts of β‐glucan. Naked barley is of particular interest because it circumvents the costs and loss of beneficial substances related to dehusking. In this study, the potential of near‐infrared spectroscopy as an accurate, fast and economic method of determination of β‐glucan in naked barley was appraised. Four different near‐infrared instruments were used to analyze 107 barley samples, in both whole grain and milled form. Importantly, both black and purple pericarp samples, which are of additional nutritional interest due to high anthocyanin content, and waxy samples, which show an extraordinary high β‐glucan content could be analyzed within the same calibration set as the normal samples. All tested dispersive near‐infrared reflection instruments showed suitability for supervision of breeding experiments and β‐glucan monitoring in food industries (R² > 0.78). Common, industrially used near‐infrared transmission instruments also provided reasonable results, although only suitable for rough selection according to β‐glucan levels. On the other hand, the Fourier transform near‐infrared reflection instrument was able to perform analytical analyses (R² = 0.96–0.98).     

Microenzymatic Evaluation of Oat (Avena sativa L.) β‐Glucan for High‐Throughput Phenotyping

Oats (Avena sativa L.) have received significant attention for their positive and consistent health benefits when consumed as a whole grain food, attributed in part to mixed‐linkage (1‐3,1‐4)‐β‐d ‐glucan (referred to as β‐glucan). Unfortunately, the standard enzymatic method of measurement for oat β‐glucan is costly and does not provide the high‐throughput capability needed for plant breeding in which thousands of samples are measured over a short period of time. The objective of this research was to test a microenzymatic approach for high‐throughput phenotyping of oat β‐glucan. Fifty North American elite lines were chosen to span the range of possible values encountered in elite oats. Pearson and Spearman correlations (r) ranged from 0.81 to 0.86 between the two methods. Although the microenzymatic method did contain bias compared with the results for the standard streamlined method, this bias did not substantially decrease its ability to determine β‐glucan content. In addition to a substantial decrease in cost, the microenzymatic approach took as little as 6% of the time compared with the streamlined method. Therefore, the microenzymatic method for β‐glucan evaluation is an alternative method that can enhance high‐throughput phenotyping in oat breeding programs.     

Molecular Weight of β‐Glucan Affects Physical Characteristics,In Vitro Bile Acid Binding,and Fermentation of Muffins

Muffins containing different amounts and molecular weights (MW) of β‐glucan were evaluated for the effect of β‐glucan on the physical characteristics of the muffins and on in vitro bile acid binding and fermentation with human fecal flora. Wheat flour muffins were prepared with the addition of β‐glucan extracts with high‐, medium‐, or low‐MW. For oat flour muffins, the native oat flour contained high‐MW β‐glucan; the oat flours were treated to create medium‐ and low‐MW β‐glucan within the prepared muffin treatments. For each 60‐g muffin, the amounts of β‐glucan were 0.52, 0.57, and 0.59 g for high‐, medium‐, and low‐MW β‐glucan wheat flour muffins, and 2.38, 2.18, and 2.23 g for high‐, medium‐, and low‐MW β‐glucan oat flour muffins, respectively. The lower the MW of the β‐glucan in muffins, the lower the height and volume of the muffins. The oat flour muffins were less firm and springy than the wheat flour muffins as measured on a texture analyzer; however, MW had no effect on muffin texture. The oat flour muffins bound more bile acid than did the wheat flour muffins. The muffins with high‐MW β‐glucan bound more bile acid than did those with low‐ and medium‐MW β‐glucan. Muffin treatment affected the formation of gas and total short‐chain fatty acids (SCFA) compared with the blank without substrate during in vitro fermentation. There were no differences in pH changes and total gas production among muffin treatments. The high‐MW β‐glucan wheat flour muffins produced greater amounts of SCFA than did the wheat flour muffin without β‐glucan and the oat flour muffins; however, there were no differences in SCFA production among muffins with different MW. In general, the β‐glucan MW affected the physical qualities of muffins and some potential biological functions in humans.