[Show abstract][Hide abstract] ABSTRACT: Studies have suggested links between colonic fermentation of dietary fibers and improved metabolic health. The objectives of this study were to determine if non-digestible feruloylated oligo- and polysaccharides (FOPS), a maize-derived dietary fiber, could counteract the deleterious effects of high-fat (HF) feeding in mice and explore if metabolic benefits were linked to the gut microbiota. C57BL/6J mice (n = 8/group) were fed a low-fat (LF; 10 kcal% fat), HF (62 kcal% fat), or HF diet supplemented with FOPS (5%, w/w). Pronounced differences in FOPS responsiveness were observed: four mice experienced cecal enlargement and enhanced short chain fatty acid production, indicating increased cecal fermentation (F-FOPS). Only these mice displayed improvements in glucose metabolism compared with HF-fed mice. Blooms in the gut microbial genera Blautia and Akkermansia were observed in three of the F-FOPS mice; these shifts were associated with reductions in body and adipose tissue weights compared with the HF-fed control mice. No improvements in metabolic markers or weights were detected in the four mice whose gut microbiota did not respond to FOPS. These findings demonstrate that FOPS-induced improvements in weight gain and metabolic health in mice depended on the ability of an individual's microbiota to ferment FOPS.
[Show abstract][Hide abstract] ABSTRACT: Although the composition of the gut microbiota is of interest, the functionality, or metabolic activity, of the gut microbiota is of equal importance: the gut microbiota can produce either harmful metabolites associated with human disease or beneficial metabolites that protect against disease. The purposes of this study were to determine the associations between dietary intake variables and fecal short and branched chain fatty acid (S/BCFA) concentrations; to determine the associations between dietary intake variables and inulin degradation, short and branched chain fatty acid (S/BCFA) production, and ammonia production during in vitro fecal fermentation of a highly fermentable substrate (inulin); and finally to compare results from the fermentation of inulin with those obtained in a previous report using a poorly fermentable substrate (whole wheat; Yang and Rose, Nutr. Res., 2014, 34, 749-759). Stool samples from eighteen individuals that had completed one-year dietary records were used in an in vitro fecal fermentation system with long-chain inulin as substrate. Few dietary intake variables were correlated with fecal S/BCFA concentrations; however, intakes of several plant-based foods, especially whole grain, dry beans, and certain vegetables that provided dietary fiber, plant protein, and B vitamins, were associated with acetate, propionate, butyrate, and total SCFA production during inulin fermentation. In contrast, intake of dairy and processed meats that provided cholesterol and little fiber, were associated with ammonia and BCFA production. Comparing results between inulin and whole wheat fermentations, significant correlations were only found for butyrate and BCFA, suggesting that regardless of the type of carbohydrate provided to the microbiota, long-term diet may have a pronounced effect on the propensity of the gut microbiota toward either beneficial metabolism (butyrate production) or detrimental metabolism (BCFA production). These results may help in the development of new dietary strategies to improve gut microbiota functionality to promote human health.
[Show abstract][Hide abstract] ABSTRACT: The objective of this work was to determine the impact of extrusion variables [moisture (17-25%), screw speed (170-250 r.p.m.) and temperature (90-150 °C)] on the physical properties and antioxidant activity of proso millet extrudates. Extrusion variables were adjusted using an inscribed central composite rotatable design. Response variables were bulk density (BD), radial expansion ratio, water absorption index, water solubility index, hardness, colour (L*, a*, b*) and antioxidant activity. Moisture and screw speed were the most influential variables affecting millet extrusion: their linear, quadratic and interaction terms accounted for more than 50% of the variability in all responses except for b*. Expansion was greatest at severe conditions of low moisture and high screw speed. These conditions were also consistent with the highest antioxidant activity. This study demonstrated that high expansion and antioxidant activity can be obtained by extruding proso millet under low moisture and high screw speed conditions.
No preview · Article · Nov 2015 · International Journal of Food Science & Technology
[Show abstract][Hide abstract] ABSTRACT: The dietary fiber in wheat bran, principally non-starch polysaccharides (NSP), is mostly water-unextractable and is poorly utilized by human gut microbiota. The purpose of this study was to determine the change in water-extractability of NSP in wheat bran upon extrusion and then to determine if extrusion impacts the availability of NSP for fermentation by the fecal microbiota during in vitro fecal fermentation. A secondary objective was to incorporate extruded bran into a product formulation to determine if changes in WE-NSP and NSP fermentation were maintained in a finished product. Bran was extruded using combinations of high or low moisture (15% and 30% wb) and high or low screw speed (120 and 250 rpm). All extrusion conditions resulted in increases in WE-NSP and fecal microbiota short chain fatty acid (SCFA) production upon fermentation compared with unextruded bran. Low screw speed and low moisture resulted in the greatest increase in WE-NSP (3-fold) as well as the highest production of SCFA during fermentation (1.4-fold) compared with unextruded bran. Whole wheat breads containing extruded bran did not show increases in either WE-NSP or SCFA production compared with the control. In conclusion, extrusion of wheat bran increased WE-NSP, which enabled greater fermentability by human fecal microbiota. However, once extruded bran was used in a whole wheat bread formulation the changes in fermentation outcomes were no longer evident.
No preview · Article · May 2015 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: Resistant starch (RS) has shown benefits to gastrointestinal health, but it is present in only small amounts in most grain-based foods. The purpose of this study was to increase RS in whole wheat flour to improve its potential health benefits. Zero to 7 cycles of cooking (20 min, boiling water) and freezing (−18 °C, 23 h) of whole wheat flour in water (1:15 %w/v) were performed. Increasing cooking–freezing cycles increased RS from 1.03 to 8.07% during in vitro starch digestion. During in vitro fecal fermentation, increasing cooking–freezing cycles increased short chain fatty acids, mainly propionate. Increases in butyrate were also noted during the first 8 h of fermentation. All flours resulted in significant increases in Bifidobacterium of >0.5 log during fermentation compared to baseline. Thus, even modest increases in the RS content of whole wheat flour modulated the metabolic activity of gut microbiota to increase production of beneficial metabolites.
No preview · Article · Jan 2015 · Journal of Functional Foods
[Show abstract][Hide abstract] ABSTRACT: Whole wheat breads are becoming a dominant presence in the market; however, the sensory qualities that drive consumer liking have not been well described. The purpose of this study was to identify sensory attributes and consumer acceptance of commercial whole wheat breads. Six whole wheat breads were evaluated for 26 attributes by a trained panel (N = 8). Two distinct groups of attributes were noted for the breads: those that were sweet, moist, and sticky versus those with characteristics associated with whole wheat such as wheaty, earthy, and bitter. In the consumer panel (N = 75), three clusters were formed. Cluster 1 (n = 28) had higher mean hedonic scores for all attributes compared with the other clusters (P < 0.01), although these consumers did not distinguish well among samples. Significant differences were found in all attributes in clusters 2 (n = 33) and 3 (n = 14). Cluster 2 preferred samples with sweet flavors and moist, cohesive textures, whereas cluster 3 preferred samples with earthy, roasted, and whole wheat flavors. A portion of consumers appeared to prefer breads not only with sweet and moist characteristics but also with some of the more hearty attributes like roasted and fermented. These data may be useful in developing new whole wheat products.
No preview · Article · Jan 2015 · Cereal Chemistry
[Show abstract][Hide abstract] ABSTRACT: Two sorghum genotypes (red, tannin; white, non-tannin), were evaluated for their potential use in breakfast cereals. Two levels of whole grain sorghum flour (550 g/kg dry mix or 700 g/kg dry mix) were processed per genotype using a pilot-scale, twin screw extruder. A whole grain oat-based cereal was used as a reference. White sorghum cereals (WSC) had significantly (p < 0.05) higher starch, brightness (L*), and yellowness (b*) than red sorghum cereals (RSC). RSC had higher protein and bulk density than the WSC. Cereals made with 700 g sorghum flour/kg were smaller and denser with lower water solubility and absorption indices than those made with 550 g/kg. In vitro protein digestibility of the RSC (43-58%) was significantly reduced compared with the WSC (69-73%) and the reference sample (72%). WSC with 700 g sorghum flour/kg contained significantly more resistant starch than the RSC cereals and the oat reference (208 g/kg starch versus 81-147 g/kg starch, respectively). Overall acceptability and texture of sorghum cereals did not differ significantly from the oat reference, although appearance and aroma liking were significantly reduced. Therefore, non-tannin sorghum has potential to be used in the breakfast cereal industry with minimal impact on nutritional profile and sensory properties.
No preview · Article · Dec 2014 · Lebensmittel-Wissenschaft und-Technologie
[Show abstract][Hide abstract] ABSTRACT: The gut microbiota plays important roles in proper gut function and can contribute to or help prevent disease. Whole grains, including oats, constitute important sources of nutrients for the gut microbiota and contribute to a healthy gut microbiome. In particular, whole grains provide NSP and resistant starch, unsaturated TAG and complex lipids, and phenolics. The composition of these constituents is unique in oats compared with other whole grains. Therefore, oats may contribute distinctive effects on gut health relative to other grains. Studies designed to determine these effects may uncover new human-health benefits of oat consumption.
Preview · Article · Oct 2014 · British Journal Of Nutrition
[Show abstract][Hide abstract] ABSTRACT: Oats are a uniquely nutritious food as they contain an excellent lipid profile and high amounts of soluble fibre. However, an oat kernel is largely non-digestible and thus must be utilised in milled form to reap its nutritional benefits. Milling is made up of numerous steps, the most important being dehulling to expose the digestible groat, heat processing to inactivate enzymes that cause rancidity, and cutting, rolling or grinding to convert the groat into a product that can be used directly in oatmeal or can be used as a food ingredient in products such as bread, ready-to-eat breakfast cereals and snack bars. Oats can also be processed into oat bran and fibre to obtain high-fibre-containing fractions that can be used in a variety of food products.
Preview · Article · Oct 2014 · British Journal Of Nutrition
[Show abstract][Hide abstract] ABSTRACT: Diet influences gut microbiota composition. Therefore, we hypothesized that diet would impact the extent of dietary fiber utilization and the types of metabolic end products produced by the microbiota during in vitro fecal fermentation. By obtaining long-term dietary records from fecal donors, we aimed to determine the correlations between dietary intake variables and dietary fiber degradation and short/branch chain fatty acid (S/BCFA) and ammonia production during in vitro fecal fermentation. Eighteen subjects completed 1-year diet history questionnaires and provided fecal samples that were used for in vitro fermentation of a whole wheat substrate. The percent of dietary fiber fermented was not correlated with nutrient intakes; however, butyrate production was correlated with fecal donor intake of many nutrients of which principal components analysis revealed were mostly contributed by grain-, nut-, and vegetable-based foods. Negative correlations were found for propionate with intake of total carbohydrate, added sugar, and sucrose, and for ammonia and BCFA production with intake of unsaturated fats. Thus, our analysis did not support our first hypothesis: the percent of dietary fiber fermented during in vitro fermentation was not correlated with dietary records. However, production of butyrate, BCFA, ammonia, and to a lesser extent propionate, were correlated with the diet records of fecal donors; thus supporting our second hypothesis. These results suggest that diets high in plant-based foods and are high in unsaturated fats are associated with microbial metabolism that is consistent with host health.
Full-text · Article · Aug 2014 · Nutrition Research
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to determine to role of flake shape on the packing characteristics of popped popcorn. Unilateral, bilateral, and multilateral popcorn flakes, named for the direction of expansion of the popcorn flake, were digitized and packed into a virtual conical frustum-shaped container using a digital packing algorithm to simulate particle packing. Corresponding laboratory experiments were also conducted. Number of flakes required to fill the container agreed between simulated and laboratory experiments (r = 0.996; p < 0.0001) and ranged from about 340 for 50% bilateral +50% multilateral to >600 for 100% unilateral. Statistical modeling revealed 36.9% bilateral +63.1% multilateral would minimize the number of flakes required to fill the container. Packing fraction varied from ρ = 0.14 for 10% unilateral +75% bilateral +15% multilateral to ρ = 0.28 for 100% unilateral shape. These results offer insights into the packing characteristics of irregularly-shaped materials.
[Show abstract][Hide abstract] ABSTRACT: High-pressure hydrothermal treatment of cereal bran results in fragmentation of the cell wall, releasing soluble, non-digestible, feruloylated oligo- and polysaccharides (FOPS), which may be beneficial to gut health. The objectives of this study were to (1) determine treatment temperatures for production of FOPS from maize bran and wheat bran and (2) determine the fermentation properties of partially purified FOPS from maize bran and wheat bran. FOPS were produced by heating bran and water (10%, w/v) in a high-pressure stirred reactor until the slurry reached 160-200 °C (in 10 °C increments). Final temperatures of 190 °C for maize bran and 200 °C for wheat bran resulted in the highest release of FOPS (49 and 50% of starting non-starch polysaccharide, respectively). Partial purification with ion exchange and dialysis resulted in a final product containing 63 and 57% total carbohydrate and 49 and 30% FOPS, respectively (other carbohydrate was starch). Following in vitro digestion (to remove starch), in vitro fermentation revealed that wheat FOPS were more bifidogenic than maize FOPS. However, maize FOPS led to continual production of short-chain fatty acid (SCFA), resulting in the highest SCFA and butyrate production at the end of the fermentation. In addition, maize FOPS showed significantly higher antioxidant activity than wheat FOPS. This study identified a process to produce FOPS from maize bran and wheat bran and showed that, considering the overall beneficial effects, FOPS from maize bran may exhibit enhanced benefits on gut health compared to those of wheat bran.
Preview · Article · Dec 2013 · Journal of Agricultural and Food Chemistry
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to produce wholegrain wheat flour on a laboratory-scale with particle size distributions similar to commercially-milled samples without re-milling the bran. The moisture contents of four hard winter wheat cultivars were adjusted to 7.29–7.98% (by drying), 9.00–10.6% (“as is”), and 15.6% (by tempering) prior to milling into wholegrain flour. The moisture treatments appeared to affect the partitioning of wholegrain flour particles into each of three categories: fine (<600 μm), medium (600–849 μm) and coarse (≥850 μm). When the distributions of particles were grouped into these categories, wholegrain flours made from dried and “as is” wheat fell within the values for commercial wholegrain flours, while that from tempered wheat contained more coarse particles than even the coarsest commercial wholegrain flour. Loaf volumes and crumb firmness were not significantly different between bread made from wholegrain flour that had been produced from dried or “as is” wheat, but loaf volume was significantly lower and bread crumb firmness was significantly higher when wholegrain flour from tempered wheat was used. These results show that wheat may be milled without tempering to produce wholegrain flour with particle size similar to some commercially-milled flours without needing to re-grind the bran.
Full-text · Article · Nov 2013 · Journal of Cereal Science
[Show abstract][Hide abstract] ABSTRACT: The freezing rate used in industrial applications may vary for a number of reasons, such as changes in food mass, food composition, and freezing equipment operation. In this study, we evaluated the influence of freezing rates on the microstructure, stability and physicochemical properties of model emulsion-based sauces. Slow freezing (−0.015 °C/min) resulted in a larger mean particle size than fast freezing (−0.11 °C/min), which was attributed to increased fat droplet flocculation and coalescence. The influence of various additives (salt, sugar, gums) on the properties of the sauces was also investigated. The addition of 200 mmol/L NaCl promoted droplet flocculation and phase separation whereas 150 mmol/L sucrose inhibited droplet flocculation and phase separation, and inhibited ice crystal growth. The addition of 0.2% xanthan gum promoted flocculation, but inhibited phase separation and ice crystal growth. Our results are interpreted in terms of the influence of the additives on the phase behavior of water, and the colloidal interactions between the fat droplets. This study provides valuable information about the major factors, i.e., salt and sugar, and influence on the stability of emulsion-based products to freeze–thaw abuses, which has important implications for the development of high quality frozen meals.
No preview · Article · Nov 2013 · Journal of Food Engineering
[Show abstract][Hide abstract] ABSTRACT: Abstract Gut bacteria may influence obesity through the metabolites produced by dietary fiber fermentation (mainly, short-chain fatty acids [SCFA]). Five cereal grain samples (wheat, rye, maize [corn], rice, and oats) were subjected to in vitro digestion and fermentation using fecal samples from 10 obese and nine normal weight people. No significant differences in total SCFA production between the normal weight and obese groups were observed [279 (12) vs. 280 (12), mean (standard error), respectively; P=.935]. However, the obese microbiota resulted in elevated propionate production compared with that of normal weight [24.8(2.2) vs. 17.8(1.9), respectively; P=.008]. Rye appeared to be particularly beneficial among grain samples due to the lowest propionate production and highest butyrate production during fermentation. These data suggest that the dietary fibers from cereal grains affect bacterial metabolism differently in obese and normal weight classes and that certain grains may be particularly beneficial for promoting gut health in obese states.
No preview · Article · Sep 2013 · Journal of medicinal food
[Show abstract][Hide abstract] ABSTRACT: Lipolytic activity in whole wheat flour (WWF) is largely responsible for the loss in baking quality during storage. Metal ions affect the activity of seed lipases; however, no previous studies have applied this information to WWF in a way that reduces lipase activity, is practical for commercial manufacture, and uses common food ingredients. NaCl, KCl, Ca-propionate, or FeNa-ethylenediaminetetraacetic acid (FeNa-EDTA) were applied to hard red winter (HRW) and hard white spring (HWS) wheats during conditioning as aqueous solutions at concentrations that would be acceptable in baked goods. Salts affected lipase activity to different degrees depending on the type of wheat used. Inhibition was greater in HRW compared with HWS WWF, probably due to higher lipase activity in HRW wheat. In HRW WWF, 1% NaCl (flour weight) reduced hydrolytic and oxidative rancidity and resulted in higher loaf volume and lower firmness than untreated WWF after 24weeks of storage.
[Show abstract][Hide abstract] ABSTRACT: The effects of six dietary fibers [pectin, guar gum, inulin, arabinoxylan, β-glucan, and resistant starch] on the human fecal microbiota during in vitro fermentation were determined. Bifidobacterium increased almost 25% on pectin compared with the control; a significant increase in Bifidobacterium adolescentis type-2 was observed on resistant starch. Bacteroides exhibited a positive correlation with propionate/short chain fatty acid (SCFA) production (r=0.59, p<0.01), while Ruminococcaceae and Faecalibacterium displayed positive correlations with butyrate/SCFA production (r=0.39, 0.54, p<0.01). A negative correlation was detected between inulin utilization and Subdoligranulum (r=-0.73, p≤0.01), while strong positive relationships were found between β-glucan utilization and Firmicutes (r=0.73, p≤0.01) and resistant starch utilization and Blautia wexlerae (r=0.82, p<0.01). Dietary fibers have specific and unique impacts on intestinal microbiota composition and metabolism. These findings provide a rationale for the development of functional ingredients targeted towards a targeted modulation of the gut microbiota.
[Show abstract][Hide abstract] ABSTRACT: Many carbohydrate polymers that have been used as carriers for colon-targeted drugs have shown benefits against colonic diseases. The objectives of this project were to (1) synthesize a derivative of 5-aminosalicylic acid (5-ASA), a drug used to treat inflammatory bowel disease, containing inulin, a carbohydrate polymer that has shown benefits against inflammatory bowel disease; (2) quantify the release of 5-ASA from the conjugate during in vitro digestion and fermentation; and (3) determine the in vitro fermentation properties of the conjugated inulin. Inulin was esterified with 5-formyl-aminosalicylic acid (5-fASA), a derivative of 5-ASA, with a degree of substitution of 0.185±0.014. During in vitro digestion and fermentation, 56.2±6.5% of 5-fASA was released in 24 h. Gut bacteria did not deformylate 5-fASA to 5-ASA as anticipated. Though conjugation of inulin with 5-fASA reduced bifidogenicity at 24 h compared with native inulin (8.26±0.03 log cfu/g versus 8.59±0.09 log cfu/g, respectively, p<0.01), conjugated 5-fASA-inulin showed protracted fermentation with higher short chain fatty acid (SCFA) and equivalent butyrate concentration at 24 h (9.02±0.68 μmol SCFA/mg carbohydrate versus 7.54±0.53 μmol SCFA/mg carbohydrate, p<0.01; 2.16±0.22 μmol butyrate/mg carbohydrate versus 2.34±0.17 μmol butyrate/mg carbohydrate, respectively, p=0.09). These data suggest that conjugation of inulin with 5-fASA may support SCFA and especially butyrate-producing bacteria through inulin fermentation in the distal colon, an important site of inflammation, together with delivery of 5-fASA. However, gut bacteria were unable to hydrolyze the formyl group from 5-fASA; thus alternative strategies to conjugate 5-ASA to inulin or remove the formyl group from 5-fASA are needed.
[Show abstract][Hide abstract] ABSTRACT: Frybreads were prepared using wheat flour and wheat-sorghum composite flours (refined and whole grain; white, tannin-free and red, tannin-containing) at 0, 25, 50, and 75% sorghum flour. Hardness, volume, specific volume, color, and oil uptake were determined. Frybreads made with refined white, tannin-free sorghum were also evaluated in a sensory panel. Substitution of sorghum flour for wheat flour reduced the volume and increased the darkness of the fried dough pieces compared with wheat flour controls. Oil absorption was unaffected when using white, tannin-free sorghum. When using red, tannin-containing sorghum, oil absorption increased for refined flour and decreased for whole grain flour, suggesting that a component only present in the whole grain tannin-containing Sorghum-perhaps tannins themselves-may decrease oil uptake. Panelists rated frybreads containing up to 50% white, tannin-free sorghum flour as not significantly different from control frybreads made with refined wheat flour.
No preview · Article · Jun 2013 · Food Science and Technology International
[Show abstract][Hide abstract] ABSTRACT: The objective of this research was to determine the conversion efficiency of proso millet to ethanol compared to corn in a bench-scale dry-grind procedure. Seven proso millet cultivars and six advanced breeding lines containing waxy starch were fermented with Saccharomyces cerevisiae and ethanol production was compared with normal corn and “highly fermentable” corn. The highly fermentable corn exhibited the highest fermentation efficiency (97.0 ± 1.4%). Among proso millet lines, those with the highest fermentation efficiencies were: Huntsman (85.9 ± 0.6%), 172-2-9 (90.8 ± 0.2%), 172-2-13 (85.1 ± 2.5%), and 182-4-24 (84.7 ± 2.1). Waxy proso millet lines resulted in higher fermentation efficiencies than the non-waxy proso millet varieties containing normal starch (82.4 ± 5.5% vs. 75.5 ± 7.4%, respectively, p = 0.01). Proso millet distiller's dried grains with solubles (DDGS) contained more protein (26.6–33.4%) than the DDGS from corn (17.2–23.4%). These data indicate that proso millet exhibits promise as a feedstock for ethanol production, especially if breeding programs focus on selecting “highly fermentable” lines for advancement.
No preview · Article · May 2013 · Industrial Crops and Products