Preparation of a Novel Oat ß-Glucan-Chromium(III) Complex and Its Hypoglycemic Effect and Mechanism.

This study synthesized a novel oat ß-glucan (OBG)-Cr(III) complex (OBG-Cr(III)) and explored its structure, inhibitory effects on α-amylase and α-glucosidase, and hypoglycemic activities and mechanism in vitro using an insulin-resistant HepG2 (IR-HepG2) cell model. The Cr(III) content in the complex was found to be 10.87%. The molecular weight of OBG-Cr(III) was determined to be 7.736 × 104 Da with chromium ions binding to the hydroxyl groups of OBG. This binding resulted in the increased asymmetry and altered spatial conformation of the complex along with significant changes in morphology and crystallinity. Our findings demonstrated that OBG-Cr(III) exhibited inhibitory effects on α-amylase and α-glucosidase. Furthermore, OBG-Cr(III) enhanced the insulin sensitivity of IR-HepG2 cells, promoting glucose uptake and metabolism more efficiently than OBG alone. The underlying mechanism of its hypoglycemic effect involved the modulation of the c-Cbl/PI3K/AKT/GLUT4 signaling pathway, as revealed by Western blot analysis. This research not only broadened the applications of OBG but also positioned OBG-Cr(III) as a promising Cr(III) supplement with enhanced hypoglycemic benefits.

Oat Beta-Glucan as a Metabolic Regulator in Early Stage of Colorectal Cancer-A Model Study on Azoxymethane-Treated Rats.

Factors that reduce the risk of developing colorectal cancer include biologically active substances. In our previous research, we demonstrated the anti-inflammatory, immunomodulatory, and antioxidant effects of oat beta-glucans in gastrointestinal disease models. The aim of this study was to investigate the effect of an 8-week consumption of a diet supplemented with low-molar-mass oat beta-glucan in two doses on the antioxidant potential, inflammatory parameters, and colonic metabolomic profile in azoxymethane(AOM)-induced early-stage colorectal cancer in the large intestine wall of rats. The results showed a statistically significant effect of AOM leading to the development of neoplastic changes in the colon. Consumption of beta-glucans induced changes in colonic antioxidant potential parameters, including an increase in total antioxidant status, a decrease in the superoxide dismutase (SOD) activity, and a reduction in thiobarbituric acid reactive substance (TBARS) concentration. In addition, beta-glucans decreased the levels of pro-inflammatory interleukins (IL-1α, IL-1ß, IL-12) and C-reactive protein (CRP) while increasing the concentration of IL-10. Metabolomic studies confirmed the efficacy of oat beta-glucans in the AOM-induced early-stage colon cancer model by increasing the levels of metabolites involved in metabolic pathways, such as amino acids, purine, biotin, and folate. In conclusion, these results suggest a wide range of mechanisms involved in altering colonic metabolism during the early stage of carcinogenesis and a strong influence of low-molar-mass oat beta-glucan, administered as dietary supplement, in modulating these mechanisms.

Rheological, thermal, and in vitro starch digestibility properties of oat starch-lipid complexes.

The influence of oat lipids on the structural, thermal, rheological, and in vitro digestibility properties of oat starch under heat processing conditions was investigated. X-ray diffraction, fourier infrared spectroscopy, and differential scanning calorimetry revealed the formation of a V-shaped crystal structure between starch and lipid, resulting in enhanced orderliness and enthalpy. Oat lipids decreased the final viscosity and gel strength of oat starch while weakening the trend towards gel network formation. Additionally, oat lipids exhibited enhanced resistance to starch hydrolase, leading to elevated contents of slowly digestible starch and resistant starch. Consequently, this leads to an augmentation in the rate constants for the rapid digestion fraction (k1) and the slow digestion fraction (k2). When the lipid content reached 7.50 %, a significant increase of 42.20 % was observed in the maximum digestibility of slow digestion fraction (C∞2), while a notable decrease of 44.06 % was noted in the maximum digestibility of rapid digestion fraction (C∞1). The correlation analysis revealed that lipid content, final viscosity, and enthalpy exerted significant influences on in vitro starch digestion. These results demonstrate the substantial impact of lipid content on oat starch structure, subsequently affecting its thermal, rheological, and digestive properties.

Consumption of Feed Supplemented with Oat Beta-Glucan as a Chemopreventive Agent against Colon Cancerogenesis in Rats.

Colorectal cancer (CRC) accounts for 30% of all cancer cases worldwide and is the second leading cause of cancer-related deaths. CRC develops over a long period of time, and in the early stages, pathological changes can be mitigated through nutritional interventions using bioactive plant compounds. Our study aims to determine the effect of highly purified oat beta-glucan on an animal CRC model. The study was performed on forty-five male Sprague-Dawley rats with azoxymethane-induced early-stage CRC, which consumed feed containing 1% or 3% low molar mass oat beta-glucan (OBG) for 8 weeks. In the large intestine, morphological changes, CRC signaling pathway genes (RT-PCR), and proteins (Western blot, immunohistochemistry) expression were analyzed. Whole blood hematology and blood redox status were also performed. Results indicated that the histologically confirmed CRC condition led to a downregulation of the WNT/ß-catenin pathway, along with alterations in oncogenic and tumor suppressor gene expression. However, OBG significantly modulated these effects, with the 3% OBG showing a more pronounced impact. Furthermore, CRC rats exhibited elevated levels of oxidative stress and antioxidant enzyme activity in the blood, along with decreased white blood cell and lymphocyte counts. Consumption of OBG at any dose normalized these parameters. The minimal effect of OBG in the physiological intestine and the high activity in the pathological condition suggest that OBG is both safe and effective in early-stage CRC.

Impact of Environmental Conditions on the Concentrations of Trichothecenes, Their Glucosides, and Emerging Fusarium Toxins in Naturally Contaminated, Irradiated, and Fusarium langsethiae Inoculated Oats.

Trichothecenes produced by Fusarium species are commonly detected in oats. However, the ratios of the concentrations of free trichothecenes and their conjugates and how they are impacted by different interacting environmental conditions are not well documented. This study aims to examine the effect of water activity (0.95 and 0.98 aw) and temperature (20 and 25 °C) stress on the production of T-2 and HT-2 toxins, deoxynivalenol and their conjugates, as well as diacetoxyscirpenol (DAS). Multiple mycotoxins were detected using liquid chromatography-tandem mass spectrometry from 64 contaminated oat samples. The highest concentrations of HT-2-glucoside (HT-2-Glc) were observed at 0.98 aw and 20 °C, and were higher than other type A trichothecenes in the natural oats' treatments. However, no statistical differences were found between the mean concentrations of HT-2-Glc and HT-2 toxins in all storage conditions analysed. DAS concentrations were generally low and highest at 0.95 aw and 20 °C, while deoxynivalenol-3-glucoside levels were highest at 0.98 aw and 20 °C in the naturally contaminated oats. Emerging mycotoxins such as beauvericin, moniliformin, and enniatins mostly increased with a rise in water activity and temperature in the naturally contaminated oats treatment. This study reinforces the importance of storage aw and temperature conditions in the high risk of free and modified toxin contamination of small cereal grains.

Beta-Glucan as a Soluble Dietary Fiber Source: Origins, Biosynthesis, Extraction, Purification, Structural Characteristics, Bioavailability, Biofunctional Attributes, Industrial Utilization, and Global Trade.

This paper explores the multifaceted nature of ß-glucan, a notable dietary fiber (DF) with extensive applications. Beginning with an in-depth examination of its intricate polysaccharide structure, the discussion extends to diverse sources like oats, barley, mushrooms, and yeast, emphasizing their unique compositions. The absorption and metabolism of ß-glucan in the human body are scrutinized, emphasizing its potential health benefits. Extraction and purification processes for high-quality ß-glucan in food, pharmaceuticals, and cosmetics are outlined. The paper underscores ß-glucan's biofunctional roles in immune modulation, cholesterol regulation, and gastrointestinal health, supported by clinical studies. The review discusses global trade dynamics by tracing its evolution from a niche ingredient to a global commodity. In summary, it offers a comprehensive scientific perspective on ß-glucan, serving as a valuable resource for researchers, professionals, and industries exploring its potential in the dietary fiber landscape.

Yeast cell wall capsules for delivery of oat biomarker avenanthramide-C.

Avenanthramide-C (AVN-C) is the biomarker for oat with a variety of physiological functions, whereas its application is constrained by low stability and bioavailability. Avenanthramide-C is the biomarker for oat with a variety of physiological functions, whereas its application is constrained by low stability and bioavailability. This study evaluated the potential of yeast cell (YC) and yeast cell wall (YCW) capsules as delivery systems for stabilizing AVN-C. It was observed that these yeast capsules possessed the ellipsoidal morphology and intact structure without visual pores. Additionally, the YCW capsules exhibited higher encapsulation and loading capacity due to the large internal space. The interaction of yeast capsules with AVN-C involved the hydrophobic interactions and hydrogen bonding. Moreover, the loading of AVN-C induced high hydrophobicity inside the yeast capsules, which helped to protect AVN-C against degradation and release AVN-C in a slow and sustained manner in the simulated gastrointestinal tract. The YCW capsules have potential as controlled delivery system for AVN-C, which could be further used as a nutraceutical and added to functional foods.

Augmenting the quality and storage stability of soymilk by incorporation of untreated and ozonated oat 1,4-ß-D-glucan.

The study aimed to improve the quality and storage stability of novel plant-based soymilk with the incorporation of untreated (UtßG) and modified oat derived 1,4-ß-D-glucan (OzßG) at varying concentrations (0, 1, and 2 % labelled as S0, S1 and S2). The treated soymilk was characterized for physical, chemical, nutritional, rheological, particle size, zeta potential, sensory and storage stability characteristics. The results revealed that 1, 4-ß-D-glucan incorporation increased the acidity (0.67 to 0.73 %), viscosity (3.4 to 4.7 Cp) and ash content (0.74 to 0.92 %), however color remains natural. The frequency sweep and shear experiments showed that the 1,4-ß-D-glucan modified the rheological parameters of the soymilk. The sensory analysis (n = 30) indicated that texture, mouthfeel and overall acceptability (8.38). Compared to OzßG-treated soymilk, UtßG soymilk, especially S2, exhibited superior thickening and rheological properties. The storage study indicated minimal phase separation in 1,4-ß-D-glucan-incorporated samples, maintaining stability for 15 days under refrigerated conditions without compromising overall quality. Thus, this study provides valuable insights into the potential application of 1,4-ß-D-glucan for improving the technological quality of soymilk that highlights possible implications for its commercialization potential.

The combined actions of the granule surface barrier and multiscale structural evolution of starch on in vitro digestion of oat flour.

The digestive properties of oat-based food have garnered considerable interest. This study aimed to explore the internal and external factors contributing to different digestion properties of oat flour under actual processing conditions. Analysis of the ordered structure of oat starch revealed that an increase in gelatinization moisture to 60 % led to a decrease in crystallinity, R1047/1022 value, and helical structures content to 0, 0.48 %, and 1.45 %, respectively. Even when the crystal structure was completely destroyed, the short-range structure retained a certain degree of order. Surface structure observations of starch granules and penetration experiments with amylase-sized polysaccharide fluorescence probes indicated that non-starch components and small pores effectively hindered the diffusion of the probes but low-moisture (20 %) gelatinization substantially damaged this barrier. Furthermore, investigations into starch digestibility and starch molecular structure revealed that the ordered structure remaining inside the starch after high gelatinization delayed the digestion rate (0.028 min-1) and did not increase the content of resistant starch (7.10 %). It was concluded that the surface structure and non-starch components of starch granules limited the extent of starch digestion, whereas the spatial barrier of the residual ordered structure affected the starch digestion rate.

Isolation, purification and characterization of ß-glucan from cereals - A review.

ß-glucans are soluble fibers found in cereal compounds, including barley, oats etc., as an active component. They are used as a dietary fiber to treat cholesterol, diabetes and cardiovascular diseases. These polysaccharides are important because they can provide many therapeutic benefits related to their biological activity in human like inhibiting tumour growth, anti-inflammatory action, etc. All these activities were usually attached to their molecular weight, structure and degree of branching. The present manuscript reviews the background of ß-glucan, its characterization techniques, the possible ways to extract ß-glucan and mainly focuses on membrane-based purification techniques. The ß-glucan separation methods using polymeric membranes, their operational characteristics, purification methods which may yield pure or crude ß-glucan and structural analysis methods were also discussed. Future direction in research and development related to ß-glucan recovery from cereal were also offered.

Impact of temperature and humidity conditions as abiotic stressors on the phytochemical fingerprint of oat (Avena sativa L.) sprouts.

This study aimed to evaluate the effect of temperature (20, 25, and 30 °C) and relative humidity (RH, 50, 55, and 60 %) as abiotic stressors during oat (Avena sativa L.) germination using a 2-level factorial design with central point. UPLC-QToF-MSE identified eighty polyphenols, nine avenanthramides, twelve lignans, and five phytosterols Notably, 100 % germination was achieved at 25 °C/60 % RH from day 3, yielding the longest radicle size. The highest content of most phenolic acids, avenanthramides, and lignans occurred at 30 °C/65 % RH, where 100 % germination was attained by day 5, but with a shorter radicle size. The best flavonoid and phytosterol profle was obtained at 20 °C/55 % RH, achieving only a 67 % germination rate. Therefore, while these conditions enhance the bioactive compound profile, the associate decrease in germination metrics suggests potential distress effects. Consideration of both photochemical outcomes and germination yield is crucial for comprehensive assessments in future applications.

In vitro digestibility of starch and protein in cooked wheat and oat whole flours: A comparative study.

Whole grains have garnered significant attention in the food industry due to their retained abundant nutrients when compared to refined grains. However, limited knowledge exists regarding the digestive behavior of starch and protein. This study compared the physicochemical properties and in vitro starch and protein digestibility of cooked whole wheat flour (WF) and naked oat flour (NOF), and evaluated the impact of endogenous components (protein, lipid, ß-glucan, and polyphenol) on the physicochemical properties and digestibility of WF and NOF. The result indicated that the final hydrolysis rate of WF samples (starch: 23.2 %∼46.3 %; protein: 23.1 %∼63.0 %) was lower than that of NOF samples (starch: 32.1 %∼61.0 %; protein: 32.3 %∼63.6 %). The removal of different endogenous components led to improved digestibility of starch and protein in both WF and NOF. This study contributes to the understanding of the starch and protein digestibility of whole grains, consequently facilitating the development of whole grain products.

Disruption of the FMN-A524 interaction cascade and Glu513-induced collapse of the hydrophobic barrier promotes light-induced Jα-helix unfolding in AsLOV2.

The C-terminal Jα-helix of the Avena sativa's Light Oxygen and Voltage (AsLOV2) protein, unfolds on exposure to blue light. This characteristic seeks relevance in applications related to engineering novel biological photoswitches. Using molecular dynamics simulations and the Markov state modeling (MSM) approach we provide the mechanism that explains the stepwise unfolding of the Jα-helix. The unfolding was resolved into seven steps represented by the structurally distinguishable states distributed over the initiation and the post initiation phases. Whereas, the initiation phase occurs due to the collapse of the interaction cascade FMN-Q513-N492-L480-W491-Q479-V520-A524, the onset of the post initiation phase is marked by breaking of the hydrophobic interactions between the Jα-helix and the Iß-strand. This study indicates that the displacement of N492 out of the FMN binding pocket, not necessarily requiring Q513, is essential for the initiation of the Jα-helix unfolding. Rather, the structural reorientation of Q513 activates the protein to cross the hydrophobic barrier and enter the post initiation phase. Similarly, the structural deviations in N482, rather than its integral role in unfolding, could enhance the unfolding rates. Furthermore, the MSM studies on the wild-type and the Q513 mutant, provide the spatiotemporal roadmap that lay out the possible pathways of structural transition between the dark and the light states of the protein. Overall, the study provides insights useful to enhance the performance of AsLOV2-based photoswitches.

Nutritional and Phytochemical Composition and Associated Health Benefits of Oat (Avena sativa) Grains and Oat-Based Fermented Food Products.

Oats (Avena sativa L.) are a popular functional cereal grain due to their numerous health benefits. This review article summarized the information on the chemical composition and phytonutrients of oats grown in different countries. It also reviewed recently developed fermented oat products to highlight their potential for human health. Oats have an interesting nutritional profile that includes high-quality protein, unsaturated fats, soluble fiber, polyphenolic compounds, and micronutrients. Oat grain has a unique protein composition, with globulins serving as the primary storage protein, in contrast to other cereals, where prolamins are the main storage proteins. Oats have the highest fat content of any cereal, with low saturated fatty acids and high essential unsaturated fatty acid content, which can help reduce the risk of cardiovascular diseases. Oats are a good source of soluble dietary fiber, particularly ß-glucan, which has outstanding functional properties and is extremely important in human nutrition. ß-Glucan has been shown to lower blood cholesterol and glucose absorption in the intestine, thereby preventing diseases such as cardiovascular injury, dyslipidemia, hypertension, inflammatory state, and type 2 diabetes. Oats also contain high concentration of antioxidant compounds. Avenanthramides, which are unique to oats, are powerful antioxidants with high antioxidative activity in humans. Recognizing the nutritional benefits of oats, oat-based fermented food products are gaining popularity as functional foods with high probiotic potential.

Effect of extrusion temperature on the structure and emulsifying properties of soy protein isolate-oat ß-glucan conjugates formed during high moisture extrusion.

In this study, extrusion was used to induce Maillard reaction between soy protein isolate (SPI) and oat ß-glucan (OG) and effect of extrusion temperature (70, 90, 110 and 130 °C) on the structure and emulsifying properties of extruded SPI-OG was investigated. SDS-PAGE and fluorescence spectroscopy provided evidence for the formation of SPI-OG conjugates during extrusion. The results showed that 90 °C and 110 °C extruded SPI-OG had the highest level of degree of glycosylation (were 14.34% and 13.70%, respectively, p > 0.05). Structural analysis found that α-helix content of extruded SPI-OG decreased by 8.93-13.14% compared to mixture of SPI and OG. Meanwhile, extruded SPI-OG had lower protein solubility (29.83-34.38%) and surface hydrophobicity (1549-2027), larger average particle size (2363-4807 nm) and higher emulsion stability (74.33-90.15%). Therefore, these findings may provide a theoretical basis for the development of novel food emulsion stabilizers.

A comprehensive review on oat milk: from oat nutrients and phytochemicals to its processing technologies, product features, and potential applications.

Plant-based milk alternatives have become increasingly desirable due to their sustainability and the increased consumer awareness of health. Among many varieties of emerging plant-based milk, the smooth texture and flavor of oat milk make it spread rapidly around the world. Furthermore, as a sustainable source of diet, oats can provide rich nutrients and phytochemicals. Issues on the stability, sensory properties, shelf life, and nutritional quality of oat milk have been highlighted in published studies. In this review, the processing techniques, quality improvement, and product features of oat milk are elaborated, and the potential applications of oat milk are summarized. Besides, the challenges and future perspectives of oat milk production in the future are discussed.

Ultrasonication-assisted enzymatic bioprocessing as a green method for valorizing oat hulls.

Ultrasonication-assisted enzymatic treatments using Viscozyme®, Alcalase®, and feruloyl esterase were applied to recover proteins, avenanthramides, phenolic acids, free sugars, and organic acids from oat hulls (OH). The profiles of the chemical compounds in OH were markedly influenced by the nature of enzymes, ultrasonication frequency, and processing time. A significant increase in the contents of proteins and phenolic acids was observed in the liquid fraction of all enzymatic treatments, which was 2-19 folds higher than those detected in untreated OH. In contrast, avenanthramides were mostly degraded during enzyme hydrolyses. The highest content of proteins (68.9 g/100 g DM) was found in the liquid fraction after the feruloyl esterase treatment assisted with 90 min of ultrasonication at 25 kHz. This fraction also contained 0.07% phenolic acids, 14.1% free sugars, and 1.8% organic acids, which can be potentially used as the ingredient of novel food products.

Effects of Oat ß-Glucan on the Textural and Sensory Properties of Low-Fat Set Type Pea Protein Yogurt.

This study investigated the effect of oat ß-glucan as a fat substitute on the structure formation, texture, and sensory properties of pea protein yogurt. The results showed that the incorporation of 0.5% ß-glucan significantly accelerated the lactic acid bacteria-induced fermentation, with the time for reaching the target pH of 4.6 shortened from 3.5 h to 3 h (p < 0.05); increased the plastic module (G') from 693 Pa to 764 Pa when fermenting 3 h (p < 0.05); and enhanced the water-holding capacity from 77.29% to 82.15% (p < 0.05). The identification of volatile organic compounds (VOCs) in low-fat pea protein yogurt by GC-IMS revealed a significant decrease in aldehydes and a significant increase in alcohols, ketones and acids in the pea yogurt after fermentation (p < 0.05). Among them, the levels of acetic acid, acetone, 2,3-butanedione, 3-hydroxy-2-butanone, and ethyl acetate all significantly increased with the addition of oat ß-glucan (p < 0.05), thereby providing prominent fruity, sweet, and creamy flavors, respectively. Combined with the results of sensory analysis, the quality characteristics of pea protein yogurt with 1% oil by adding 1% oat ß-glucan were comparable to the control sample with 3% oil. Therefore, oat ß-glucan has a good potential for fat replacement in pea protein yogurt.

Effect of soluble oat fiber on intestinal microenvironment and TNBS-induced colitis.

Soluble oat fibers, including ß-glucan, have been shown to alter the gut microbiome composition and ameliorate DSS-induced colitis; however, the beneficial effect of soluble oat fiber on colonic inflammation is not yet fully understood. In this study, we demonstrated that soluble oat fibers ameliorate T cell-dependent colitis through the induction of peripherally induced regulatory T cells (pTregs). Soluble oat fibers elevated colonic butyrate production dose-dependently, which coincided with the overrepresentation of Faecalibaculum rodentium (an analog of butyrate-producing Holdemanella biformis) in the gut microbiome. Soluble oat fibers promoted the growth of F. rodentium and H. biformis even in vitro, and increased the concentration of butyrate in the culture supernatant. These results indicate that soluble oat fibers are an energy source for butyrate-producing bacteria and are a fermentation substrate. Soluble oat fibers increased the percentage of colonic pTregs and ameliorated the weight loss and inflammation in acute 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis; this may in part be mediated by the increase in IL-10-producing T cells. In conclusion, our results suggest that the administration of soluble oat fibers is a promising prebiotic treatment for the prevention of colitis mediated via altered gut microbiota composition and elevated butyrate production.

Application of Cellulase for Contributing Phenolic Release and Conversion in Oats (Avena sativa L.) During Microbial Fermentation.

In this work, Monascus fermentation and cellulase hydrolysis (MCF) of oats (Avena sativa L.) to release and convert phenolic fraction was investigated. Results showed the fungus Monascus grew well with a biomass of 27.03 mg/g glucosamine equivalent in MCF, following the destruction of oat cellular structures. SDS-PAGE revealed lots of enzymes were regulated with the α-amylase and FPase activity achieved 139.25 U/g and 1.84 U/g in MCF, respectively. Compared with unfermented oats, content of the total phenolic fractions was increased by 19.2 times in MCF, suggesting a phenolic release process occurred during fermentation. Moreover, the soluble-free chlorogenic acid upregulated to 510.00 mg/kg whereas the insoluble-bound ferulic acid downregulated to 193.36 mg/kg in MCF, indicating a transformation process of chlorogenic acid from ferulic acid in oats was enhanced. Based on this, a possible pathway of phenolic release and conversion in oats during fermentation with Monascus spp. was revealed. This study was helpful to enrich the theory of microbial metabolism and transformation in grain materials.