Oat Β-glucan Research Articles

ULTRASOUND-ASSISTED AND ENZYMATIC-BASED METHOD FOR ISOLATION OF β-GLUCANS FROM OAT BRAN

β-Glucans are a group of non-starchy polysaccharides, or (1,3),(1,4)-β-D-glucans, that can be found in the cell walls of several species of bacteria, algae, lichens, fungi, and cereal grains. These carbohydrates are extensively used in food industry, cosmetics, pharmaceuticals and healthcare, therefore optimization of the extraction and isolation of β-glucans from grain sources has an especial importance in various fields of biotechnology, drug design, food science and technology. The aim of the study was to develop an optimized technological scheme for isolation of β-glucans from oat bran based on ultrasonic and enzymatic processing of raw material. Materials and methods. β-Glucans were isolated from grinded oat cereals during multi-stage process, which includes extraction of grain fats, hydrobarothermic processing, ultrasonification, enzymatic hydrolysis of concomitant starch and proteins, precipitation of β-glucan fraction by ethanol, centrifugation, and dry-freezing. Yield of β-glucans from raw material and its concentration in the final product were determined after hydrolysis by sulfuric acid or enzymatic cleavage by endo-1,3(4)-β-glucanase. Results. As shown by acidic hydrolysis of the final product, the yield of β-glucans was 10.8 ± 0.23% and concentration was 79.6 ± 3.89%, while enzymatic hydrolysis gave 8.7 ± 0.82% and 65.1 ± 4.72%, respectively. Thus, the use of hydrobarothermic and ultrasound pre-treatment of raw material in combination with proteolytic digestion of ballast lipids and proteins allowed producing oat β-glucans in amounts comparable with those in case of acid- or alkali-based procedures. Conclusions. The described technological scheme of β-glucan isolation from oat bran based on sequential hydrobarothermic processing, ultrasonification, and enzymatic removing starch and proteins can be widely used for routine β-glucan production for various purposes in food technology, pharmacological industry, and medicine.

Influence of partial substitution of wheat flour with sprouted oat flours on physicochemical and textural characteristics of wheat bread

There is an issue to be solved in wheat bread processing that the substitution of oat flour enhanced the nutritional value, but deteriorated the texture of wheat bread. To improve the textural attributes of the bread, the inclusion of sprouted oat flour for up to 120 h was investigated in this study. Results indicated that oat β-glucan (OBG) of the bread decreased from 7.86 to 1.88 g/100 g, while total phenols and γ-aminobutyric increased nearly threefold after sprouting for 120 h. The dough stability and rheological properties of wheat with sprouted oat flour were determined to aid the prediction of the textural properties of the final bread products. There was a positive relationship between stability time and viscoelasticity of mixed dough and textural parameters of wheat bread with sprouting oat flour. Compared with wheat bread with unsprouted oat flour, wheat bread with sprouted oat flour was characterized by lower hardness, chewiness, and gumminess, higher cohesiveness, springiness, and resilience. Additionally, the confocal laser scanning microscope illustrated that unsprouted oat flour destroyed the continuity of gluten protein network. Surprisingly, dough with oat flour sprouting for 72 h presented an orderly and dense network structure resulting from the OBG integration. This study suggests that it is promising to develop multigrain bread with more various nutrition and more satisfying textural attributes by an appropriate sprouting process.

Effects of different sources of β-glucan on pasting, gelation, and digestive properties of pea starch

The effects of Lentinula edodes β-glucan (LG), yeast β-glucan (YG), and oat β-glucan (OG) on pasting, gelation, and digestive properties of pea starch (PeS) were studied. Because of different molecular weights and spatial conformation, β-glucan interacted differently with PeS. With the increase of molecular weight of OG, YG, and LG, the pasting property and the gelatinization enthalpy (ΔH) of β-glucan-PeS (G-PeS) suspension decreased by rapid viscosity analyzer and differential thermal scanning analysis, respectively, which was consistent with the results of X-ray diffraction; texture parameters of G-PeS gel were increased and the scanning electron microscope furtherly showed that the structure of 0.5% G-PeS gel was more stable. The rheological parameters (energy storage modulus (G′) and loss modulus (G″) of G-PeS were LG-PeS ≈ YG-PeS > OG-PeS. And the blue shift degree of absorption peak in the Fourier transform infrared spectrum of G-PeS gels (1639.09 cm −1 , 1639.12 cm −1 , and 1637.78 cm −1 ) proved that LG and YG with trihelix structure could form stronger hydrogen bonds with starch granules compared with OG without trihelix structure. In vitro simulated digestion experiments showed that the inhibition degree of β-glucan on the digestion rate of G-PeS was LG > YG > OG. Herein, adding β-glucan to pes starch has a big potential to promote the texture of PeS-based foods and help diabetics control postprandial glucose levels. • β-Glucan of oat (OG), yeast (YG) and Lentinula edodes (LG) enhanced the wrapping effect on pea starch (PeS) as molecular weight increased. • LG and YG with trihelix structure could form stronger hydrogen bonds with PeS compared to OG. • LG had the better inhibition effect on the digestion rate of PeS than YG and OG.

Total fibre vs types and sources of fibre in subjects with and without diabetes: Role of molecular weight and viscosity

Dietary fibre is an important short-fall nutrient with average intakes in North America being only 50–67% of recommended. Food fortification or fibre supplements could help fill the gap, but what sources/types of fibre should be recommended? This paper addresses the role of fibre viscosity on blood-glucose and -lipids in humans. The postprandial glycaemic response (PPGR) of healthy adults after test-meals containing oat β-glucan (OBG) is inversely related to OBG viscosity, which, in turn, is determined by OBG dose and molecular weight (MW). A systematic-review and meta-analysis (SRMA) showed that OBG dose and MW significantly influenced the effect of OBG on PPGR. Indeed, 10–15 times more medium-MW (300–1000 kDa) or low-MW (<300 kDa) OBG was required to reduce PPGR compared to 0.2 g/30 g available-carbohydrate for high-MW OBG (>1000 kDa). Studies also suggest that MW determines the effect of OBG on serum-cholesterol. The effects of fibre in diabetes were assessed by an umbrella review of published SMRA. All fibre types reduced HbA1c by (mean [95% confidence interval]) −0.37 [-0.51, −0.22]% (n = 74), fasting-glucose by −0.70 [-0.95, −0.45] mmol/L (n = 74) and serum-cholesterol by −0.33 [-0.49, −0.16] mmol/L (n = 38), but the effects differed by fibre type and source. Non-viscous fibres elicited statistically but not clinically significant reductions in HbA1c (−0.17 [-0.30, −0.04]%) and fasting-glucose (−0.35 [-0.60, −0.11] mmol/L), whereas viscous fibres elicited statistically and clinically significant reductions in HbA1c (−0.57 [-0.87, −0.27]%), fasting-glucose (−1.00 [-1.42, −0.58] mmol/L) and LDL-cholesterol (−0.34 [-0.62, −0.06] mmol/L). Is it time to reconsider the use of viscous fibre supplements in the treatment of diabetes?

Oat β-glucan supplementation pre- and during pregnancy alleviates fetal intestinal immunity development damaged by gestational diabetes in rats.

Oat β-glucan (OG) has been shown to improve intestinal microecology in gestational diabetes mellitus (GDM), but the effect on fetal intestine health is unknown. Herein, we aimed to investigate the effects of OG supplementation during gestation in GDM dams on fetal intestinal immune development. OG was supplemented one week before mating until the end of the experiment. GDM rats were made with a high-fat diet (HFD) with a minimal streptozotocin (STZ) dose. The fetal intestines were sampled at gestation day (GD) 19.5, and the intestinal morphology, chemical barrier molecules, intraepithelial immune cell makers, and levels of inflammatory cytokines were investigated. The results showed that OG supplementation alleviated the decrease of the depth of fetal intestinal villi and crypts, the number of goblet cells (GCs), protein expression of mucin-1 (Muc1) and Muc2, the mRNA levels of Gpr41, Gpr43, and T cell markers, and increased the number of paneth cells (PCs), the mRNA levels of defensin-6 (defa6), and macrophage (Mø) marker and the expression of cytokines induced by GDM. In addition, OG supplementation alleviated the function of immune cell self-proliferation, chemotaxis and assembly capabilities, protein, fat, folic acid, and zinc absorption damaged by GDM. As indicated by these findings, OG supplementation before and during pregnancy improved the fetal intestinal chemical barriers, immune cells, cytokines, and the metabolism of nutrients to protect the fetal intestinal immunity.

A pilot study of dietary fibres on pathogen growth in an ex vivo colonic model reveals their potential ability to limit vancomycin-resistant Enterococcus expansion.

Aim: Dietary fibre is important for shaping gut microbiota. The aim of this pilot study was to investigate the impact of dietary fibres on pathogen performance in the presence of gut microbiota. Methods: In an ex vivo gut model, pooled faecal samples were spiked with a cocktail of representative gastrointestinal pathogens and fermented with yeast β-glucan for 24 hours, after which 16S rRNA amplicon sequencing and short-chain and branched-chain fatty acid (SCFA and BCFA) analyses were performed. In addition, oat β-glucan, arabinoxylan, yeast β-glucan, and galactooligosaccharides were each tested against individual representative pathogens and pathogen growth was assessed via qPCR. Glucose served as a control carbon source. Results: Based on 16S rRNA amplicon sequencing, yeast β-glucan selected for higher proportions of Bacteroides (P = 0.0005, ~6 fold) and Clostridia (P = 0.005, ~3.6 fold) while species of Escherichia/Shigella (P = 0.021, ~2.8 fold) and Lactobacillus (P = 0.007, ~ 15.7-fold) were higher in glucose. Pathogen relative abundance did not differ between glucose and yeast β-glucan. In the absence of pathogens, higher production of BCFAs (P = 0.002) and SCFAs (P = 0.002) fatty acids was observed for fibre group(s). For individual pathogens, yeast β-glucan increased growth of Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes (P < 0.05), arabinoxylan increased S. typhimurium (P < 0.05). Tested fibres decreased vancomycin-resistant Enterococcus faecium (P < 0.05), with yeast β-glucan causing a 1-log reduction (P < 0.01), while galactooligosaccharides decreased L. monocytogenes (P < 0.05). Conclusion: Tested fibres differentially influenced the growth of pathogens, but yeast β-glucan could represent a dietary strategy to help limit vancomycin-resistant enterococci (VRE) expansion in the gut.

Oil-in Water Vegetable Emulsions with Oat Bran as Meat Raw Material Replacers: Compositional, Technological and Structural Approach.

The unique composition and technological properties of some oat bran components (mainly protein and soluble fiber) and olive oil make them a good choice to form oil-in-water vegetable emulsions. The different concentrations of oat bran were studied to form olive oil-in water (O/W) emulsions to apply as a replacement for fat and meat. As a result, four O/W emulsions (OBE) were formulated with 10% (OBE10), 15% (OBE15), 20% (OEB20), and 30% (OBE30) oat bran concentrations and 40% olive oil, with the corresponding amount of water added for each O/W emulsion. Composition, technological properties (thermal stability, pH, texture), and lipid structural characteristics were evaluated. The results showed that low oat bran content (OEB10)-with a lower concentration of oat protein and β-glucans-resulted in an O/W emulsion with an aggregated droplet structure and lower thermal stability and hardness. These connections between composition, technology, and structural properties of olive O/W emulsions elaborated with oat bran could help in making the optimal choice for their potential application in the production of foods such as healthier meat products.

Modulating gut microbiota and metabolites with dietary fiber oat β-glucan interventions to improve growth performance and intestinal function in weaned rabbits.

The effect of oat β-glucan on intestinal function and growth performance of weaned rabbits were explored by multi-omics integrative analyses in the present study. New Zealand White rabbits fed oat β-glucan [200 mg/kg body weight (BW)] for 4 weeks, and serum markers, colon histological alterations, colonic microbiome, colonic metabolome, and serum metabolome were measured. The results revealed that oat β-glucan increased BW, average daily gain (ADG), average daily food intake (ADFI), and decreased serum tumor necrosis factor-α (TNF-α) interleukin-1β (IL-1β), and lipopolysaccharide (LPS) contents, but did not affect colonic microstructure. Microbiota community analysis showed oat β-glucan modulated gut microbial composition and structure, increased the abundances of beneficial bacteria Lactobacillus, Prevotellaceae_UCG-001, Pediococcus, Bacillus, etc. Oat β-glucan also increased intestinal propionic acid, valeric acid, and butyric acid concentrations, decreased lysine and aromatic amino acid (AAA) derivative contents. Serum metabolite analysis revealed that oat β-glucan altered host carbohydrate, lipid, and amino acid metabolism. These results suggested that oat β-glucan could inhibit systemic inflammation and protect intestinal function by regulating gut microbiota and related metabolites, which further helps to improve growth performance in weaned rabbits.

Simultaneously enhanced stability and biological activities of chlorogenic acid by covalent grafting with soluble oat β-glucan

Chlorogenic acid (CA) has a wide range of biological activities but the chemical structure is extremely unstable. In this study, CA was grafted onto a soluble oat β-glucan (OβGH) to improve the stability. Although the crystallinity and thermal stability of CA-OβGH conjugates reduced, the storage stability of CA significantly improved. The DPPH and ABTS scavenging ability of CA-OβGH IV (graft ratio 285.3 mg CA/g) were higher than 90 %, which is closed to activities of equivalent concentration of Vc (93.42 %) and CA (90.81 %). The antibacterial abilities of CA-OβGH conjugates are improved compared to the equivalent content of CA and potassium sorbate. Particularly, the inhibition rate of CA-OβGH for gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) are significantly higher than that of gram-negative bacteria (Escherichia coli). The results demonstrated that covalent grafted CA with soluble polysaccharide is an effective strategy to enhance its stability and biological activities.

Oat β-glucan ameliorates diabetes in high fat diet and streptozotocin-induced mice by regulating metabolites

Oats are widely distributed worldwide and oat β-glucan has positive effects on human health. Particularly, oat β-glucan is reported to be beneficial in the management of type 2 diabetes. The aim of the present study is to investigate the effects of oat β-glucan and its possible underlying mechanisms on diabetes in type 2 diabetic mice that was induced by streptozotocin/high-fat diet (STZ/HFD). The data indicated that oat β-glucan significantly reduced the fasting blood glucose, improved glucose tolerance, and insulin sensitivity. The results further showed that oat β-glucan remarkably decreased the levels of total cholesterol (TCHO), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and free fatty acids. Moreover, oat β-glucan remarkably increased the hepatic glycogen content, but largely decreased the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in STZ/HFD-induced diabetic mice. Histological analysis showed that oat β-glucan alleviated visceral lesions. Finally, the metabolomic analysis indicated that the metabolic profile was remarkably changed after oat β-glucan intervention in diabetic mice. There were 88 and 106 differential metabolites screened as biomarkers in negative ion mode (NEG) and positive ion mode (POS) after oat β-glucan treatment, respectively. In addition, oat β-glucan significantly affected the serum metabolites of amino acids, organic acids and bile acids. Collectively, the current study elucidates oat β-glucan displays an effective nutritional intervention in diabetes.

Novel thermostable GH5_34 arabinoxylanase with an atypical CBM6 displays activity on oat fiber xylan for prebiotic production.

Carbohydrate active enzymes are valuable tools in cereal processing to valorize underutilized side streams. By solubilizing hemicellulose and modifying the fiber structure, novel food products with increased nutritional value can be created. In this study, a novel GH5_34 subfamily arabinoxylanase from Herbinix hemicellulosilytica, HhXyn5A, was identified, produced and extensively characterized, for the intended exploitation in cereal processing to solubilize potential prebiotic fibers: arabinoxylo-oligosaccharides. The purified two-domain HhXyn5A (catalytic domain and CBM6) demonstrated high storage stability, showed a melting temperature Tm of 61°C and optimum reaction conditions were determined to 55°C and pH6.5 on wheat arabinoxylan. HhXyn5A demonstrated activity on various commercial cereal arabinoxylans and produced prebiotic AXOS, whereas the sole catalytic domain of HhXyn5A did not demonstrate detectable activity. HhXyn5A demonstrated no side activity on oat β-glucan. In contrast to the commercially available homolog CtXyn5A, HhXyn5A gave a more specific HPAEC-PAD oligosaccharide product profile when using wheat arabinoxylan and alkali extracted oat bran fibers as the substrate. Results from multiple sequence alignment of GH5_34 enzymes, homology modeling of HhXyn5A and docking simulations with ligands XXXA3, XXXA3XX and X5 concluded that the active site of HhXyl5A catalytic domain is highly conserved and can accommodate both shorter and longer ligands. However, significant structural dissimilarities between HhXyn5A and CtXyn5A in the binding cleft of CBM6, due to the lack of important ligand-interacting residues, is suggested to cause the observed differences in substrate specificity and product formation.

Fabrication and Characterization of Konjac Glucomannan/Oat β-Glucan Composite Hydrogel: Microstructure, Physicochemical Properties and Gelation Mechanism Studies.

The aim of this study was to evaluate the effect of oat β-glucan on the formation mechanism, microstructure and physicochemical properties of konjac glucomannan (KGM) composite hydrogel. The dynamic rheology results suggested that the addition of oat β-glucan increased the viscoelastic modulus of the composite hydrogel, which was conducive to the formation of a stronger gel network. Gelling force experiments showed that hydrogen bonds and hydrophobic interactions participated in the formation of the gel network. Textural profile analysis results found that the amount of oat β-glucan was positively correlated with the elasticity, cohesiveness and chewiness of the composite hydrogel. The water-holding capacity of the composite hydrogel was enhanced significantly after the addition of oat β-glucan (p < 0.05), which was 18.3 times that of the KGM gel. The thermal stability of KGM gel was enhanced after the addition of oat β-glucan with the increase in Tmax being approximately 30 °C. Consequently, a composite hydrogel based on KGM and oat β-glucan was a strategy to overcome pure KGM gel shortcomings.

Insights into the rheological properties, multi-scale structure and in vitro digestibility changes of starch-β-glucan complex prepared by ball milling

High amylose corn starch (HACS)-oat β-glucan (OBG) complex was prepared by ball milling treatment. The morphology and structure of the samples were characterized, and the digestibility of the samples was studied. SEM analysis showed that the grain structure of oat β-glucan-starch after ball milling showed an irregular aggregate shape. The rheological results indicated that the apparent viscosity of the solution of HACS-OBG complex prepared by ball milling, with the values of both G′ and G″ decreasing on the increase of OBG addition. Multi-scale structure analysis showed that the disorder of the crystal structure and short-range structure of the HACS-OBG complex would lead to the decrease of the double helix structure content. In terms of digestibility, the RDS of the complex decreased from 75.88 % to 66.26 %, which suppressed the digestibility of starch. Molecular docking and quantum chemistry techniques further demonstrated the strong hydrogen bond interaction between HACS and OBG and the inhibition rate of OBG on the enzyme, which was conducive to the slow digestion of HACS-OBG complex. Therefore, ball milling treatment can promote the binding of OBG to starch, which may be an effective method for postprandial blood glucose control.

The Effect of the Addition of Low-Alkaloid Lupine Flour on the Glycemic Index In Vivo and the Physicochemical Properties and Cooking Quality of Durum Wheat Pasta

The aim of this research was to determine the effect of the addition of lupine flour (LF) on the values of the glycemic index (GI) and glycemic load (GL), physicochemical properties, and cooking quality of durum semolina pasta. The pasta was enriched with 0–25% of lupine flour (LF0-LF25). Additionally, 7.5 and 20% of oat β-glucans, 5% of vital gluten, and 20% of millet flour were used in a selected sample. The addition of 7.5% β-glucans and 5% vital gluten to the product resulted in only a slight decrease in the GI of the products. A significant decrease in pasta GI was noted after the addition of 20% of lupine flour. The product enriched with 20% of lupine flour, 20% of β-glucans, and 20% of millet flour had the lowest glycemic index and glycemic load (GI = 33.75%, GL = 7.2%, respectively). At the same time, the lupine-flour-enriched products were characterized by an increased concentration of protein, fat, ash, and dietary fiber. The addition of lupine flour at the level of up to 20% yielded functional products characterized by good cooking quality.

FUNCTIONAL AND TECHNOLOGICAL PROPERTIES OF OAT BETA-GLUCAN IN ACIDOPHILIC-WHEY ICE CREAM

The purpose of the work is to study the functional and technological properties of oat beta-glucan both individually and as part of acidophilic-whey ice cream. The research methods, that were used, are well known and have relevant references in the work. At the first stage of the experiment, the functional and technological properties of oat beta-glucan from two manufacturers were studied: «AMULYN» (China) and «DANSON» (China). According to the results of sensory evaluation, beta-glucan «DANSON» received 8.75 points, and «AMULYN» - 10 points. It was found that the water holding capacity of beta-glucan «AMULYN» is 15.45 % higher than with beta-glucan «DANSON», and fat binding capacity is higher by 8.61 %, which is probably due to the different degree of purification of these additives. Therefore, a more effective beta-glucan «AMULAN» was chosen for further use in acidophilic-whey low-fat ice cream. At the second stage of scientific work the influence of oat beta-glucan «AMULYN» on the quality of acidophilic-whey low-fat ice cream was studied. It was found that beta-glucan in the amount of 0.75 % increases the indicator of overrun more than twice compared to the control sample without beta-glucan. Beta-glucan in a certain amount also significantly improves the organoleptic characteristics of ice cream, increases resistance to melting and ensures uniform distribution of the air phase throughout the volume of the product, as evidenced by microstructural analysis of its samples. A significant effect of beta-glucan on the dynamic viscosity coefficient of ice cream mixes has been established. The detected effect allows to reduce the ripening process of ice cream mixtures with beta-glucan in the amount of 0.75 % by 2 hours, provided that the recommended viscosity of these systems is achieved. Thus, the expediency of using oat beta-glucan as an effective functional and technological ingredient in acidophilic-whey ice cream is scientifically substantiated.

Prebiotics and β-Glucan as gut modifier feed additives in modulation of growth performance, protein utilization status and dry matter and lactose digestibility in weanling pigs

There are growing interests in developing novel gut modifier feed additives and alternative therapeutics to replace antimicrobials to enhance efficiency of nutrient utilization and to address the antimicrobial resistance threat to public health facing the global pork production. Biological mechanisms of supplementing lactose for enhancing weanling pig growth and nitrogen utilization are unclear. Thus, this study was prompted to determine effects of dietary supplementation of 3 prebiotics and oat β-glucan vs. a sub-therapeutic antibiotic on growth performance, whole-body protein utilization status, the apparent total tract dry matter (DM) and lactose digestibility in weanling pigs fed corn and soybean meal (SBM)-based diets. Six experimental diets were formulated with corn (40%), SBM (28%) and supplemented with dried whey powder (20%) and fish meal (9%) with titanium oxide (0.30%) as the digestibility marker. Diet 1 (NC, negative control), as the basal diet, contained no antibiotics and no supplemental prebiotics or β-glucan. Diet 2 (PC, positive control), contained an antibiotic premix (Lincomix-44 at 0.10%) in the basal diet at the expense of cornstarch. Diets 3, 5 and 6 contained 0.75% of the three test prebiotics of retrograded cornstarch (Diet 3), Fibersol-2 (Diet 5, a modified digestion-resistant maltodextrin) and inulin (Diet 6), and the viscous soluble fiber oat β-glucan (Diet 4), respectively, at the expense of cornstarch. A total of 144 Yorkshire pigs, at the age of 21 days (d) and an average body weight (BW) of 5.5 kg, were allocated to 12 floor pens with 3 barrows and 3 gilts per pen, and fed one of the 6 diets for 21 d in 2 study blocks according to a completely randomized block design. Initial and final pig BW, average daily gain (ADG), average daily feed intake (ADFI), representative pig plasma urea concentration as well as the apparent total tract DM and lactose digestibility during d 8-15 were measured. Analyses of variances, Dunnett’s and Tukey’s tests were conducted on the endpoints by using the SAS mixed model. There were no differences (P&amp;gt; 0.05) in ADG, ADFI, feed to gain ratio, plasma urea concentration, the apparent total tract apparent DM and lactose digestibility and the predicted whole-gut lactase digestive capacity among the diets, as examined by the Tukey’s test. There were no differences (P&amp;gt; 0.05) in these endpoints between each of the four treatment diets and the NC or the PC diet as examined by the Dunnett’s test. The total tract lactose digestibility was determined to be at 100%. The predicted whole-gut lactase digestive capacity was about eight times of the daily lactose intake when dietary lactose contents were supplemented at 10 - 12% (as-fed basis). In conclusion, dietary supplementation (at 0.75%) of the prebiotics and the oat β-glucan did not significantly affect the major growth performance endpoints, whole-body protein utilization status as well as the apparent total tract DM and lactose digestibility in the weanling pigs fed the corn and SBM-based diets. The promoting effect for growth and nitrogen utilization associated with dietary supplementation of lactose is due to the fact that lactose is a completely and rapidly digestible sugar rather than acting as an effective prebiotic in weanling pig nutrition.

Effects of the oat β-glucan on the functional and structural properties of defatted walnut meal flour

The effects of oat β-glucan (OβG) with different concentrations (0–2.5%) on the functional and structural properties of walnut meal flour (WMF) were investigated. Fourier transform infrared (FTIR) analysis showed that the β-sheet content in WMF-OβG mixtures increased to 48.13%, while α-helix, random coil and β-turn decreased to 13.79%, 12.08% and 25.28%, respectively. Scanning electron microscopy (SEM) analysis exhibited that the surface structures of WMF and WMF-OβG mixtures were similar. Moreover, WMF-OβG mixtures presented a larger average particle size and a lower zeta-potential. Differential scanning calorimetry (DSC) result confirmed that the transition temperature of WMF-OβG mixtures was significantly higher than WFM, but the enthalpy was lower (p < 0.05). The rheological evaluation revealed that the OβG increased the storage modulus (G′), loss modulus (G′′) and viscosity of WMF. The WMF-OβG mixtures showed the higher foaming capacity, foaming stability and emulsion stability than that of WMF, while the emulsifying activity decreased. These findings suggest that OβG is an appropriate ingredient for modifying WMF functional properties, and can be potentially used in bakery, beverage and meat products.

Effect of oat β-glucan on in vitro digestion characteristics of set- type yogurt

The main objective of the study was to evaluate the effect of added 0.3% (w/w) oat β-glucan (OG) in set-type yogurt on its protein digestion using an in vitro gastrointestinal model. During gastric digestion phase, the amount of soluble proteins and peptides increased to 25% and 40% for control yogurt (yogurt without OG) and 0.3% OG yogurt, respectively. Buccal digestion has little effect on the structure of yogurts, while large spherical vesicles were formed for both control yogurt and 0.3% OG yogurt after gastric digestion. The presence of 0.3% OG promoted the hydrolysis of yogurt in the gastric digestion phase and caused higher antioxidant activity. Compared with that of control yogurt, the inhibition of cholesterol solubility of 0.3% OG yogurt showed no differences after buccal digestion but significantly higher after gastrointestinal digestion (21.3% for gastric and 22.7% for intestinal digestion). Overall, this study enhances the understanding of digestion characteristics of 0.3% OG-fortified set-type yogurt and provides a theoretical basis for the development of this kind of dairy products.

836-P: A Prebiotic Fiber Blend Improved Postprandial Glucose (PPG) and Time in Range (TIR) as Evaluated by Continuous Glucose Monitoring (CGM) in Healthy Subjects with Normal Glucose Tolerance

This open-label, pre-post, pilot study evaluated the impact of a prebiotic fiber blend (including green banana resistant starch &amp; oat beta-glucan) on PPG and TIR measured by CGM (Abbott Freestyle Libre Pro) . Five healthy subjects (3M/2F; 41±7y, fasting glucose 92.2±10.9 mg/dL, BMI 23.9±3.2 kg/m2, mean+/-SD) consumed high glycemic index foods (e.g. cornflakes &amp; rice milk) as the first meal of the day for 6 consecutive days followed by identical meals for 6 consecutive days with 7.5 grams of the prebiotic fiber blend. Addition of the prebiotic blend resulted in a significant 26.4% reduction in the baseline-adjusted 2-hr PP interstitial glucose (IG) area-under-the curve (Fig. 1a; 4125.9 ± 2468.9 vs. 3038.1 ± 1701.8 mg/dL, p=0.043) . Pooled subject 6-day % TIR (IG = 70-140 mg/dL) , % time above range (TAR, IG&amp;gt;140 mg/dL) , and % time below range (TBR, IG&amp;lt;70 mg/dL) showed a significantly higher % TIR (p=0.043) and lower % TBR (p=0.043) with the prebiotic blend (Fig. 1b) . This exploratory pilot study suggests the potential impact of a prebiotic fiber supplement as a complement to other dietary and pharmaceutical interventions for glycemic control. A randomized placebo controlled trial is currently underway to evaluate the impact of a full nutrition meal replacement shake with and without a similar fiber blend in persons with type 2 diabetes. Disclosure C.J.Damman: Advisory Panel; Evolve Biosystems, Employee; Uplifting Results Labs. J.Frias: Advisory Panel; Altimmune, Becton, Dickinson and Company, Eli Lilly and Company, Gilead Sciences, Inc., Intercept Pharmaceuticals, Inc., Merck &amp; Co., Inc., Sanofi, Consultant; 89bio, Inc., Akero Therapeutics, Inc., Altimmune, Becton, Dickinson and Company, Carmot Therapeutics, Inc., Eli Lilly and Company, Novo Nordisk, Pfizer Inc., Sanofi, Research Support; Afimmune Limited, Akero Therapeutics, Inc., AstraZeneca, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb Company, Carmot Therapeutics, Inc., Eli Lilly and Company, Intercept Pharmaceuticals, Inc., Ionis Pharmaceuticals, Janssen Pharmaceuticals, Inc., Madrigal Pharmaceuticals, Inc., Merck &amp; Co., Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk, Pfizer Inc., Poxel SA, Sanofi, Speaker's Bureau; Eli Lilly and Company, Merck &amp; Co., Inc., Novo Nordisk, Sanofi. M.L.Lee: Consultant; UR Labs. L.Rikse: Employee; Uplifting Results Labs. W.Lam: Employee; UR Labs. R.Lai: Employee; UR Labs. M.Washington: Employee; UR Labs (Uplifting Results) .

Effect of Replacing Cellulose With Primarily Insoluble Fiber on the Microbiome and Short Chain Fatty Acids, and Fecal Calprotectin in Mice Fed a High Fat Diet

ObjectivesMost semi-purified rodent diets contain only cellulose as the fiber source, and do not provide diverse fermentable substrates for the gut microbiota. The focus of this work was to determine how replacing cellulose with a mix of cereal fiber, pectin and beta-glucan affected the gut microbiota, short chain fatty acids, and fecal calprotectin in C57BL/6 mice.MethodsUsing a suggested, one day, adequate fiber human diet from the Institute of Medicine (IOM), the relative proportions of cellulose (57%), hemicellulose (20%), lignin (4%), pectin (15%) and beta-glucan (4%) were estimated using a food composition database. A combination of oat hull fiber, pectin and beta-glucan was added to a 45% kcal from fat rodent diet to provide these fiber sources at the typical US nutrient density (9g/1000 kcal), or at the IOM recommended level (14 g/1000 kcal). Mice were fed the experimental diets for 16 weeks. Cecal and fecal samples were collected at the end of the study and the microbiome was determined by 16S rRNA sequencing, short chain fatty acids by GC-FID, and fecal calprotectin by ELISA.ResultsThere were no differences in weight gain, final weight, and lean mass, but for mice fed the low fiber diet there was a trend for lower % fat mass (p = 0.08). There were no differences in either alpha or beta diversity in the cecal or fecal microbiome samples. According to the Linear discriminant analysis Effect Size (LEfSe), at the genus level, the DIO diet was characterized by Lactococcus, the high fiber diet by Allobaculum, and the low fiber diet by Enterococcus. There were no significant differences in cecal SCFAs, but there was a trend for mice fed the high fiber diet to have more acetate (p = 0.053) and less isobutyrate (p = 0.06) and isovalerate (p = 0.07). There were no differences in empty cecum weight nor colon length. However, mice fed the low fiber diet had significantly more fecal calprotectin than mice fed the DIO or high fiber diets (p < 0.01).ConclusionsAdding a blend of purified fibers to the DIO diet resulted in few effects on the microbiome composition or metabolism. However, there was a trend for mice fed the higher fiber to have less body fat. In addition, increasing the fiber intake from typical US levels to those recommended by the IOM was associated with less gut inflammation, as measured by calprotectin.Funding SourcesFunded by the National Institute of Food and Agriculture.