Empirical tests developed for an objective evaluation of noodle texture as well as sensory methods provide no information about the rheological parameters responsible for differences in the texture of Asian noodles. Therefore, there is a need for a technique to evaluate the rheological properties of Asian noodles that is fast, easy and inexpensive. Promising results from ultrasonic assessments of the rheological properties of wheat flour doughs and preliminary noodle studies were an encouragement to use ultrasound to address such need in this thesis. Using ultrasound at a relatively high frequency (1.4 MHz), the rheological properties of raw noodles made with three Canadian wheat varieties at various barley β-glucan (BBG) contents, sheeting work input levels and salt to kansui ratios (formulas) were evaluated. Conventional rheological, i.e., stress relaxation (SR) and uniaxial extension (Kieffer), measurements were employed for comparison purposes. The capability of ultrasound for evaluating the effects of BBG addition and sheeting work input on the rheological properties of raw wheat noodles of this study was confirmed. A greater sensitivity of ultrasound to microscopic changes in noodle dough structure, compared to SR and Kieffer tests, was reflected in differences between the results of ultrasound and those of the SR and Kieffer tests with respect to the influences of flour variety and formula on noodle rheology. Investigations of the density of raw noodles showed that air bubbles were present in the noodle dough matrix. A simple, fast and low-cost method, based on the measurement of noodle dough dimensions during the sheeting process, was proposed for a quick evaluation of noodle dough rheology. The results of the proposed method were in agreement with those of conventional rheological measurements on the effects of flour variety and sheeting work input on noodle texture. The time-dependent effect of kansui on noodle dough structure was confirmed by comparing the results of this new method with those of SR and Kieffer tests with respect to the effect of formula on noodle rheology. Further investigations are proposed to establish this method for quick assessment of Asian wheat noodle rheology. / February 2017

β-glucans are unavailable carbohydrates and a dietary fiber that cannot be readily metabolized by our own bodies’ enzymes in the gastrointestinal tract. They are instead metabolized by our microbiota in the large intestine, were they have multiple health benefits. They help with keeping the microbiota in balance and regulating our immune system. They have also been shown to have cholesterol lowering effects. β-glucans are found in cereals like barley, oat, rye, and wheat but they can also come from other sources like bacterial cell walls and fungi. However, depending on their origin, they have different structures and properties. β-glucans from cereals are linear polymers of β-(1→4)-D-glycopyranosyl units separated by single units of β-(1→3)-D-glycopyranosyl in a mixed linkage. The concentration of β-glucan is highly varied between cereal type as well as cultivar of the same cereal. The aim of this study was to investigate if there is a difference in β-glucan content between commercial bread baked using traditional versus modern cereal cultivars. β-glucan was determined using the Megazyme assay kit, a method approved by the American association of cereal chemists (AACC) International. The method uses a highly specific enzymatic breakdown of β-glucan into D-glucose that can then be determined colorimetrically. The results for β-glucan showed high variation between different types of cereals and bread tested, were grains like barley and rye had higher β-glucan content compared to oat and wheat, showing clear health benefits to eating grains like barley and rye, over grains like wheat. The β-glucan content for cereals ranged from 0.30 – 3.66% of dry weight, whereas the different bread had β-glucan ranging from 0.31 – 1.14% of dry weight. There was no significant difference between modern versus traditional cultivars and therefore neither had any greater health benefits from a β-glucan content perspective. The daily consumption of β-glucan needed to show cholesterol lowering effects is 3g, which in this study mean that about 7.5 bread slices (about 300 g) of the highest β-glucan containing bread is needed to be eaten daily to achieve the daily intake goal.

This thesis examined effects of dietary supplementations (0.75%) of the prebiotics of retrograded resistant cornstarch, fibersol-2 and inulin, and oat β-glucan in replacing feed antibiotics on growth performance, plasma urea concentrations, total tract dry matter (DM) and lactose digestibility, fecal scores, proximal jejunal and serum alkaline phosphatase (AP) kinetics and large intestinal fermentation in weanling pigs fed corn and soybean meal-based diets. There were no differences (P > 0.05) in the growth performance, plasma urea concentrations, DM and lactose digestibility and the volatile short-chain fatty acid concentrations in the cecal and fecal samples among the treatment diets. Dietary lactose was completely digested in the weanling pigs. Supplementations of fibersol-2, inulin and β-glucan significantly affected some of the jejunal and serum AP kinetics. In conclusion, lactose was a highly digestible carbohydrate and dietary supplementations of the three prebiotic and β-glucan at 0.75% had little effects on growth performance and plasma urea concentration but might affect gut and the whole body health status via influencing the AP detoxification kinetics in the weanling pigs. / Ontario Pork, Ontario Ministry of Agriculture, Agriculture Adaptation Council

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Agradecemos a compreensão. on 2016-09-05T17:59:45Z (GMT) / Submitted by Mariana Maluli Marinho de Mello null (marimaluli@gmail.com) on 2016-09-06T20:23:53Z No. of bitstreams: 1 Dissertação Mariana Maluli IMPRIMIR.pdf: 1983967 bytes, checksum: 0667ac45479a626e249d2757e1cefb45 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-08T16:41:04Z (GMT) No. of bitstreams: 1 mello_mmm_me_jabo.pdf: 1983967 bytes, checksum: 0667ac45479a626e249d2757e1cefb45 (MD5) / Made available in DSpace on 2016-09-08T16:41:04Z (GMT). No. of bitstreams: 1 mello_mmm_me_jabo.pdf: 1983967 bytes, checksum: 0667ac45479a626e249d2757e1cefb45 (MD5) Previous issue date: 2016-07-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Manejos inerentes da piscicultura intensiva, como o transporte, desencadeiam resposta de estresse nos animais, podendo causar perdas na produtividade. Como alternativa, o β-glucano, um polissacarídeo derivado da parede celular de cereais, bactérias e fungos, vem sendo muito utilizado na aquicultura pelo seu efeito imunoestimulante. Há evidências de que o β-glucano minimiza os efeitos negativos do estresse por atuar no sistema imune, porém é pouco investigado o seu efeito direto sobre a resposta clássica de estresse. Neste contexto, o presente estudo avaliou, em juvenis de pacu, o uso oral de 0.1% de duas gerações de β-glucano, de diferentes graus de pureza e processamentos, na resposta de estresse e no sistema imune inato, após transporte e inoculação com Aeromonas hydrophila. Avaliamos a concentração de cortisol e glicose plasmáticos como indicadores da resposta de estresse, a atividade respiratória de leucócitos, a atividade hemolítica do sistema complemento, a atividade de lisozima e contagem total e diferencial de leucócitos, como indicadores do sistema imune inato, e o hematócrito, número de eritrócitos, concentração de hemoglobina e volume corpuscular médio de eritrócitos como indicadores hematológicos. As duas gerações de β-glucano utilizadas modularam os níveis de cortisol circulantes, mantendo os níveis elevados até 24 horas após o transporte, sem alteração após o desafio bacteriano. O β-glucano aumentou a atividade hemolítica do sistema complemento e de lisozima após o manejo e após a inoculação bacteriana, e manteve a população de leucócitos circulantes após recuperação de leucopenia, evidenciando o efeito imunoestimulante. A análise geral dos resultados deste estudo sugere o fortalecimento da resposta imune de juvenis de pacu alimentados por 15 dias antes de manejo estressante, com ração contendo 0.1% β-glucano derivado da parede celular de levedura (Sacaromyces cerevisiae). / Inherent handling in intensive fish farming, such as transport, trigger stress response in animals, and may cause losses in productivity. As an alternative, the β-glucan, a polysaccharide derived from the cell walls of cereals, bacteria and fungi, has been widely used in aquaculture due their immunostimulatory effect. The β-glucan minimizes the negative effects of stress by acting on the immune system, but it is little investigated its direct effect on the classical stress response. In this context, the present study evaluated in pacu, the oral administration of 0.1% of two generations of β-glucan, with different degrees of purity and processing methods, on the stress and innate immune system responses, after transport and inoculation with Aeromonas hydrophila. We evaluated the plasma concentration of cortisol and glucose, as stress response indicators, the respiratory activity of leukocytes, the hemolytic activity of the complement system, lysozyme activity and total and differential counts of leukocytes as innate immune system indicators, and hematocrit, number of erythrocytes, hemoglobin concentration, and mean corpuscular volume of erythrocytes as hematological indicators. The two generations of β-glucan modulated the circulating levels of cortisol, keeping the high levels 24 hours after transportation, without changes after the bacterial challenge. The β-glucan increased the hemolytic activity of the complement system and lysozyme after handling and after bacterial inoculation, and kept the population of circulating leukocytes after recovery of leukopenia, demonstrating the immunostimulatory effect. The general results of this study suggest the strengthening of the immune response of pacu juveniles fed for 15 with feed containing 0,1% β-glucan derived from yeast cell wall (Sacaromyces cerevisiae) days before stressful handling. / CNPq: 138990/2014-0

The global population is rapidly aging. It is estimated that over the next thirty years, the number of individuals >60 years of age will increase by over a billion, and the number of individuals over age 80 may increase by 300 million. As humans age, our immune system becomes progressively weaker through a process called immune senescence. This age-related decrease in immune function increases susceptibility to infection and chronic diseases. Sepsis is a leading cause of death worldwide. Over the past two decades, there has been an increased incidence of sepsis which is due, in part, to our aging population and immune senescence. The gut microbiome, which plays an essential role in health and disease, is altered in aging and sepsis. Specifically, the commensal microorganisms of the gut microbiota are replaced with potentially pathogenic bacteria. This contributes to immune dysfunction and worsened outcomes in critical illness. The innate immune system can be “trained” to respond more effectively to pathogens. We examined trained immunity as an approach to modulating immunosenescence and microbiome diversity in aging. We investigated the effect of trained immunity on: i) immune cells from healthy aging subjects and sepsis patients and ii) the diversity of the microbiome in aging and sepsis. Our results indicate that trained immunity is effective in combatting age-related immunosenescence. We found that β-glucan induced trained immunity enhances monocyte metabolism, increases functionality as well as alters the transcriptome and epigenome in aging individuals and sepsis patients. We also found that trained immunity induced the expansion of a unique population of myeloid cells in sepsis. These cells are defined as FSChi, CD11b+, GR-1hi and express high levels of immunosuppressive PD-L1. In addition, we found that trained immunity reversed age-related changes to the microbiome and prevented alterations to the microbiome in septic mice. We found that the Firmicutes/Bacteroidetes ratio increased in aging; however, trained immunity reversed this increase and increased Clostridia in aged mice. In sepsis, trained immunity prevented expansion of Proteobacteria observed in control mice. Thus, our results indicate that trained immunity may be effective in modulating immune senescence and the microbiome in aging and sepsis.

Avena sativa L. (2n = 6x = 42, AACCDD genome composition) or common oat is the cereal grain possessing the highest levels of water-soluble seed (1-3,1-4)-β-D-glucan (β-glucan), a hemicellulose important to human health due to its ability to lower serum LDL cholesterol levels. Understanding the mechanisms of β-glucan accumulation in oat endosperm is, consequently, of great interest. We report a genome-wide association study (GWAS) to identify quantitative trait loci (QTLs) controlling β-glucan production in oat, identifying 58 significantly associated markers. Synteny with the barley (Hordeum vulgare L.) genome identified four major regions of interest, the CslF and CslH gene families along with UGPase and AGPase as candidate genes. Subgenome-specific expression of the A, C, and D homoeologs of major β-glucan synthase AsCslF6 revealed that AsCslF6_C is the least expressed in all tissue types and time points, with low-β-glucan varieties recording the highest proportion of AsCslF6_C expression. In order to further investigate the candidate genes identified in our GWAS study and gain a greater understanding of the other cell wall polysaccharides that comprise the total fiber content in oat we sought to characterize five additional genes. Accordingly, we cloned and sequenced the three homoeologs of AsUGP and AsAGPS1. AsAGPS1 is the small subunit 1 gene of the enzyme ADP-glucose pyrophosphorylase (AGPase), which is responsible for catalyzing the first committed step in the starch biosynthesis pathway through the production of ADP-glucose. AsUGP is the gene the codes for UDP-glucose pyrophosphorylase (UGPase) an enzyme responsible for the reversible production of UDP-glucose (UDPG). UDPG is used directly or indirectly as a precursor for the biosynthesis of cell wall polysaccharides. In high β-glucan mutant line ‘OT3044’ we observed increased expression of AsUGP with a corresponding reduction of AsAGPS1 expression. Similarly, we observed an inverse expression pattern in low-fiber mutant line ‘OT3018’, wherein AsUGP expression was decreased in favor of AsAGPS1 expression. Further, we also found evidence that these changes in both AsUGP and AsAGPS1 expression are due primarily to up- or down-regulation in the A-genome homoeoalleles. Additionally, we characterized genes in the CslC family (CslC4, CslC9) and CslA family (CslA7) responsible for xyloglucan and glucomannan synthesis, respectively. High-fiber line ‘HiFi’ showed the least amount of overall expression of these three genes, raising the possibility that the increased β-glucan is due to a reduction in other hemicelluloses. After analyzing homoeolog-specific expression in multiple genes we observed that the A genome consistently had the most highly expressed homoeoallele, hinting at a universal preference for expression of this subgenome. We present hypotheses regarding multiple points in carbohydrate metabolism having the potential to alter β-glucan content in oat.

Dectin-1/CLEC7A is a pattern recognition receptor that recognizes β-1,3 glucans, and its stimulation initiates signaling events characterized by the production of inflammatory cytokines from human dendritic cells (DCs) required for antifungal immunity. β-glucans differ greatly in size, structure, and ability to activate effector immune responses from DC; as such, small particulate β-glucans are thought to be poor activators of innate immunity. We show that β-glucan particle size is a critical factor contributing to the secretion of cytokines from human DC; large β-glucan-stimulated DC generate significantly more IL-1β, IL-6, and IL-23 compared to those stimulated with the smaller β-glucans. In marked contrast, the secretion of TSLP and CCL22 were found to be insensitive to β-glucan particle size. Furthermore, we show that the capacity to induce phagocytosis, and the relative IL-1β production determined by β-glucan size, regulates the composition of the cytokine milieu generated from DC. This suggests that β-glucan particle size is critically important in orchestrating the nature of the immune response to fungi.

Rodents are a natural host for the dimorphic pathogenic fungi Coccidioides immitis and Coccidioides posadasii, and mice are a good model for human infection. Humans and rodents both express Dectin-1 and Toll-like receptor 2 (TLR2) on myeloid cells, and those receptors collaborate to maximize the cytokine/chemokine responses to spherules (the tissue form of the fungi) and to formalin-killed spherules (FKS). We showed that Dectin-1 is necessary for resistance to pulmonary coccidioidomycosis, but the importance of TLR2 in vivo is uncertain. Myeloid differentiation factor 88 (MyD88) is the adapter protein for TLR2 and -4, interleukin-1R1 (IL-1R1), and IL-18R1. MyD88/TRIF -/- and MyD88 -/- mice were equally susceptible to C. immitis infection, in contrast to C57BL/6 (B6) controls. Of the four surface receptors, only IL-1R1 was required for resistance to C. immitis, partially explaining the susceptibility of MyD88 -/- mice. We also found that FKS stimulated production of IL-1Ra by bone marrow-derived dendritic cells (BMDCs), independent of MyD88 and Dectin-1. There also was a very high concentration of IL-1Ra in the lungs of infected B6 mice, supporting the potential importance of this regulatory IL-1 family protein in the largely ineffective response of B6 mice to coccidioidomycosis. These results suggest that IL-1R1 signaling is important for defense against C. immitis infection.

β-Glucans have long been used as an immunostimulant in aquaculture. However, the relationship of its structure to its immunomodulatory properties are poorly understood. In this study, the particle size and chemical structure of β-glucans extracted from wild-type strain of baker's yeast (Saccharomyces cerevisiae) and its null-mutant yeasts Gas1 were characterised. Using Sigma β-glucan as a reference, the immunomodulatory properties of these polysaccharides in the germ-free Artemia franciscana model system in the presence of Vibrio harveyi bacterial challenge were investigated. The survival of the A. franciscana nauplii, upon challenge with V. harveyi, was significantly higher in all three glucan-treated groups compared to the control. The glucan Gas1 with a lower degree of branching and shorter side chain length had the most prominent V. harveyi-protective effects. The particle size did not affect the nauplii survival when challenged with V. harveyi. Results also showed that the salutary effect of the tested glucans was associated with the upregulation of innate immune genes such as lipopolysaccharide and β-1,3-glucan-binding protein (lgbp), high mobility group box protein (hmgb), and prophenoloxidase (proPO). Interestingly, the up-regulation of superoxidase dismutase (sod) and glutathione-s-transferase (gst) was only observed in Gas1 treated group, indicating that Gas1 could function to induce higher reactive oxygen species and stronger immunomodulatory function in A. franciscana, and therefore higher survival rate. The expression of heat shock protein 70 (hsp70), peroxinectin (pxn), and down syndrome cell adhesion molecule (dscam) remain unaltered in response to glucan treatment. Taken together, this study provides insights into the structure-function relationship of β-glucan and the results confirmed that β-glucan can be an effective immunostimulant in aquaculture, especially the Gas1 glucan.

In the last decade, the potential of β-glucan, a fungal cell wall component, to induce epigenetic and functional modification of innate immune cells, signified as trained innate immunity (TII) has been demonstrated in several pre-clinical and clinical studies. Parenteral administration of β-glucan has resulted in centrally induced TII in the bone marrow/circulating monocytes. Such trained innate immune cells play a critical role in protection against secondary infections. However, there are now indications that inducing local long-lasting immunity at mucosal barrier tissues such as the lung is warranted for protective immunity against respiratory pathogens. Currently, it remains unclear whether respiratory mucosal administration of β-glucan will induce long-lasting resident-memory macrophages and TII and if so, what are the underlying mechanisms of development and maintenance of memory macrophages at respiratory mucosa. To address this, and kinetics of immune responses in the lung were studied. Profound changes in airway macrophage (AM) pools were observed starting from 3 days post-exposure, which was associated with monocyte recruitment, and this was followed by a series of phenotypic shifts in AMs. The altered AM phenotype profile persisted for up to 8 weeks post-exposure. Importantly, β-glucan-trained AMs demonstrated heightened MHC II expression, enhanced responses to secondary stimulation and improved capacity to perform bacterial phagocytosis. Furthermore, mice with, β-glucan-trained AMs displayed higher rates of survival and improved bacterial control, in the lung and periphery, following a lethal S. pneumoniae infection. Our findings together indicate that a single intranasal delivery of β-glucan is able to train AMs. Further work into epigenetics, metabolism, and the contribution of AMs in protection is needed. / Thesis / Master of Health Sciences (MSc) / The immune system has been classically divided into two major compartments known as the innate and adaptive immune system. For decades, the predominant consensus amongst the field was that only the adaptive immune system can form memory against any pathogens encountered. It has been well established that plants and invertebrates only possess an innate immune system and still show boosted responses and enhanced protection against previously encountered as well as new pathogens. Recently, such capacity for innate immune memory has also been demonstrated in humans and pre-clinical animal models. Innate immune memory provides non-specific, broad- spectrum protection whereas adaptive memory is specific to a singular pathogen. Inducing broad-spectrum protection can be crucial for the future of human medicine. Activation of both adaptive and innate immune arms could prove to be extremely beneficial in vaccination strategies. Through the use of a pre-clinical model, we have found that administering β-glucan, a component of fungal cell wall, directly into the lung significantly alters the phenotype and functionality of lung immune cells, and also provides enhanced protection against a heterologous infection.