This research was conducted to determine the potential of hulless winter barley (Hordeum vulgare L.) as an improved feed crop in the mid-Atlantic region. Winter barley is an excellent crop in rotation with soybean (Glycine max L.); however, production of winter barley during the past few years has decreased mainly due to low market prices, even though the mid-Atlantic region is a feed grain deficient area. Therefore, value added traits need to be developed in order for barley production to continue in the region. In the first part of this study, the objectives were to: (i) evaluate the agronomic performance and potential of six experimental hulless winter barley lines compared with two commercial hulled cultivars; (ii) determine and compare fiber, b-glucan, protein, and fat concentrations, and true metabolizable energy, corrected for nitrogen (TMEn) among these genotypes; and (iii) evaluate the genetic potential of winter hulless barley accessions from the world collection for use as parents in hulless breeding programs. Six hulless lines all derived from the cross VA75-42-45/SC793556//CI2457 were acquired from Clemson University in South Carolina. The six lines were evaluated for yield, test weight, heading date, plant height, and lodging. These hulless lines along with two hulled cultivars were planted in replicated yield plots in four states with a total of eight locations, and were managed according to standard recommended practices. Grain from each of the hulless lines and hulled checks, along with that of Trical 498 triticale (X Triticosecale) and Jackson wheat (Triticum aestivum L.) were analyzed for fiber, b-glucan, fat, protein, and ash concentration, and TMEn value. Eight hundred and seven winter or facultative habit hulless barley lines were obtained from the USDA-ARS National Small Grains Collection in Aberdeen, ID. These lines were screened for reaction type to races 8 and 30 of barley leaf rust (Puccinia hordei) and to a composite population of powdery mildew (Blumeria graminis f. sp. hordei). These accessions also were planted in observation rows to evaluate heading date, plant height, lodging, and seed threshability. The hulless lines yielded 23% less, but had 13% higher test weights than the hulled check cultivars. There was no difference between hulled and hulless barley in heading date and plant height. Hulless lines had a higher protein and lower fiber concentration than hulled barley. They also had higher b-glucan and fat concentrations than triticale or wheat. TMEn was similar between hulled and hulless barley, triticale, and wheat. Approximately 100 hulless barley lines from the world collection were selected for potential use as parents among 800 accessions tested, based on evaluations of lodging, plant height, threshability, and seed color. In the second part of the study the objectives were to determine the effects of (i) hulled and hulless barley, and (ii) b-glucanase on the performance of broilers fed different diets from 21 to 42 days of age. Diets comprised of 30% hulless or hulled barley, and a standard corn (Zea mays)/soybean meal diet with and without b-glucanase enzyme were evaluated to determine the effects of barley on gut viscosity, carcass weight, gain, percent shell, and feed efficiency in 21 to 42 day old broilers. In the first year, diets comprised of hulless lines SC890573 and SC860972, and the hulled cultivar Callao were compared to a standard check diet. In the second year SC860972 was replaced with SC880248 due to the inability to secure a sufficient amount of seed. Each year one hulled and two hulless barley diets were compared to a standard diet. Each diet was fed with and without enzyme, for a total of eight diets. Broilers 21 days of age were fed the diets until day 42 when they were processed. There was a significant decrease (P<0.05) in gut viscosity of birds fed diets with enzyme compared to birds fed diets without enzyme; however, gut viscosity did not affect weight gain or percent shell. Barley substituted at the 30% level did not have a significant effect on broiler performance, nor did the addition of enzyme. Absence of enzyme effect was attributed to bird age, since older birds are able to hydrolyze b-glucan more effectively than juveniles. The potential of hulless barley as an improved feed source for the poultry and swine industry is great for the mid-Atlantic region. Increases in grain yield are currently being realized through focused breeding efforts, and hulless lines exhibit positive nutritional components that combine favorable attributes of both wheat and hulled barley. Barley substituted at the 30% level in the diets of broilers did not cause any detrimental effects. Addition of hulless barley may potentially lead to a reduction in cost per pound of gain of broilers, and provide an alternative crop for mid-Atlantic region grain producers and feeders. / Ph. D.

No description available.

The goal of this research was the development of a method to extract pure (1,3/1,6)-β-glucans from Saccharomyces cerevisiae. These β-glucans are of pharmaceutical importance because an animal’s immune system can recognize glucan molecules, and these molecules can act as immunomodulators, essentially turning on the immune system. The problem in the past has been that previously published methods produce β-glucans with low side chain lengths and few branching occurrences. This issue was tackled by a multivariable approach that reduced extraction steps, initial sample size, and concentrations of reagents used. This method has been shown to produce greater yields of β-glucans while maintaining high purity. Analyses such as 1H-NMR and GC-MS have been used to confirm the content of the extracted glucans. Ideally, this research will generate interest for further β-glucan studies and ultimately be utilized pharmacologically with immunocompromised individuals.

β-D-Glucan has been proposed to suppress appetite related perceptions thus contribute favourably to the regulation of energy intake and the increasing obesity problem in North America. Due to its low concentrations in grains, the challenge has been to produce β-glucan concentrates that can be incorporated into foods without adversely affecting product attributes. Therefore in the first part of the study, a protocol for the concentration of β-glucan, based on protein-polysaccharide incompatibility, was investigated. The extract obtained was utilized in the second part, where the effect of beverages with increased β-glucan content on perceived satiety and blood glucose, at different fibre concentrations was studied. Twenty nine healthy adults participated in this study. 5 beverage pre-loads, containing between 0-2.5 g of β-glucan in 500 mL of the sample, were ingested 120 min before the given meal. Results showed a trend towards a decrease in appetite scores with increasing β-glucan content of the beverages, as well as differences in the blood glucose readings, though these were not significant, and could not solely be attributed to β-glucan content due to differences in beverage composition.

Health benefits of high molecular weight (MW) β-glucans are well documented. Therefore, understanding and controlling depolymerization of β-glucan in baked products, would increase the effectiveness of β-glucan to confer health benefits. In this study we demonstrated that endogenous β-glucanase in wheat kernels are responsible for the depolymerization of β-glucans. A protocol was developed based on the Megzayme procedure to detect low levels of β-glucanase activity in wheat flour. This was confirmed by using HPLC-Calcofluor detection to monitor molecular weight changes. The distribution of β-glucanase in wheat kernels was also investigated. The effect of genotype, location, planting season and environmental factors on the level of endogenous β-glucanase in selected wheat cultivars was investigated using different wheat varieties planted under different condition and different seasons. Furthermore, kinetics of β-glucan depolymerization by endogenous glucanase in two dough systems with different moisture content was investigated. The results demonstrated that enzymes with β-glucanase activity are concentrated primarily in the outer layer of wheat kernels. Also genotype, environmental conditions and agronomic practice all had significant effects on the β-glucanase activity in wheat flours and poor harvesting conditions can significantly increase β-glucanase activity level in wheat. The kinetics results demonstrated that moisture content, incubation time and levels of endogenous β-glucanase activity of the system had significant impact on the final MW of β-glucan in the dough. Among all factors investigated, moisture content had the greatest impact. This study presents opportunities for industry to fortify baked products with high molecular weight β-glucan. / Ontario Ministry of Agricultural Food and Rural Affairs

The aim of this study was to understand the cellular mechanisms in enterocytes, which may decrease glucose uptake by viscous oat β-glucan. An in-vitro cell model examined the effect of diffusion limitation, fluid shear stimulation, and increased intestinal stretching. Mechanical stimulation of IEC-6 was assessed. A Flexcell Cell Streamer device applied different fluid flow stresses on cells. Flexcell FX-4000 was used for biaxial stretching of the cells. Following the confirmation of appropriate use of the cell model, the results indicated that high viscosity oat β-glucan might provide a physical barrier limiting diffusion of nutrients to the cells apical surfaces. Western blot analysis confirmed weak mechanical stimulation on the cells. Mechanical stimulation did not influence glucose uptake. Strain-induced cells showed lower activities in their glucose uptake. In conclusion, there may be a significant contribution of direct effects of the viscosity of oat β-glucan on cellular mechanisms of uptake in enterocytes.

Barley has been receiving increased attention as a human food due to the health benefits associated with β-glucan fiber and its potential as a low glycemic index (GI) functional food. Research has shown a relationship between the physico-chemical properties of β-glucan and the physiological effects, which may be altered by processing. However, it is not known if the physiological effects of consuming barley are affected by variations in chemical composition among cultivars or by common processing methods such as pearling or milling. The primary objective of this thesis was to characterize the effects of differences in cultivar starch and fibre content, level of pearling and milling on the GI, satiety and the physico-chemical properties of β-glucan. Nine barley cultivars varying in starch-type and β-glucan content were studied in three experiments in separate groups of ten healthy participants. Blood glucose and satiety ratings were measured and the GI was calculated. Total starch, total fibre, β-glucan, molecular weight (MW), solubility and β-glucan viscosity were determined in vitro. Results showed that GI varied by cultivar (CDC-Fibar, 26 ± 3 vs. AC-Parkhill, 35 ± 4, P < 0.05) and pearling (WG, 26 ± 4 vs. WP 35 ± 3, P < 0.05). When two cultivars were milled and processed to wet pasta the GI increased by 184% (P < 0.05). The pearled wet pasta had a significantly lower GI compared to the whole grain (P < 0.05). Boiled barley kernels tended to elicit greater satiety than white bread, but the difference was not significant. In both the boiled barley kernels and the wet pasta, pearling did not affect the MW, viscosity and solubility. MW did not significantly differ between cultivars but solubility and viscosity did (P < 0.05). The wet pasta had significantly lower MW, solubility, viscosity but not β-glucan content than the boiled barley kernels (P < 0.05). In conclusion, pearling did not have an effect but milling and extruding resulted in significant reduction in MW, solubility and viscosity. The GI of barley is influenced significantly by cultivar, pearling and milling. Further studies are required to determine the effect on satiety.

Barley has been receiving increased attention as a human food due to the health benefits associated with β-glucan fiber and its potential as a low glycemic index (GI) functional food. Research has shown a relationship between the physico-chemical properties of β-glucan and the physiological effects, which may be altered by processing. However, it is not known if the physiological effects of consuming barley are affected by variations in chemical composition among cultivars or by common processing methods such as pearling or milling. The primary objective of this thesis was to characterize the effects of differences in cultivar starch and fibre content, level of pearling and milling on the GI, satiety and the physico-chemical properties of β-glucan. Nine barley cultivars varying in starch-type and β-glucan content were studied in three experiments in separate groups of ten healthy participants. Blood glucose and satiety ratings were measured and the GI was calculated. Total starch, total fibre, β-glucan, molecular weight (MW), solubility and β-glucan viscosity were determined in vitro. Results showed that GI varied by cultivar (CDC-Fibar, 26 ± 3 vs. AC-Parkhill, 35 ± 4, P < 0.05) and pearling (WG, 26 ± 4 vs. WP 35 ± 3, P < 0.05). When two cultivars were milled and processed to wet pasta the GI increased by 184% (P < 0.05). The pearled wet pasta had a significantly lower GI compared to the whole grain (P < 0.05). Boiled barley kernels tended to elicit greater satiety than white bread, but the difference was not significant. In both the boiled barley kernels and the wet pasta, pearling did not affect the MW, viscosity and solubility. MW did not significantly differ between cultivars but solubility and viscosity did (P < 0.05). The wet pasta had significantly lower MW, solubility, viscosity but not β-glucan content than the boiled barley kernels (P < 0.05). In conclusion, pearling did not have an effect but milling and extruding resulted in significant reduction in MW, solubility and viscosity. The GI of barley is influenced significantly by cultivar, pearling and milling. Further studies are required to determine the effect on satiety.

The viscous properties of oat beta-glucan in the gut are influenced not only by beta-glucan content, but also solubility and molecular weight. The objective of this study was to determine the effects of oat processing, genotype and growing location on the physicochemical properties of beta-glucan. Five oat genotypes (HiFi, Leggett, CDC Dancer, Marion and CDC Morrison) grown in two locations (Saskatoon and Kernen) were dehulled (untreated) and processed in a pilot facility through kilning (kilned/not flaked) and subsequent steaming and flaking (kilned/flaked). Three oat genotypes (HiFi, Leggett and Furlong) went through a commercial processing including dehulling, kilning and steaming and flaking. Both pilot and commercial scale processing, genotype and growing environment had significant effects on viscosity, molecular weight and solubility of beta-glucan. Results indicate that there is potential for processors to improve the physicochemical/nutritional properties of oat end products through processing of specific oat genotypes from selected growing locations.

Barley grain is an important source of energy and protein for ruminant animals. However, feeding must be carefully managed to avoid maladies caused by the rapid breakdown of barley starch in the rumen. The development of slower degrading barley for ruminants may alleviate health problems associated with barley grain consumption. Selection for hard endosperm may result in slower starch degradation and improved feed quality. The objectives of this study were to: examine the effect of grain hardness, variety and environment on dry matter disappearance rate (DMDR); identify accurate and efficient hardness selection tools; and study environmental effects, inheritance and heritability of hardness.<p>To study grain hardness and genetic and environmental effects on DMDR, two genotypes grown at multiple locations in 2004 were analyzed for Single Kernel Characterization System (SKCS) hardness, by scanning electron microscopy (SEM), and for in situ DMDR. Genotype by environment interaction influenced DMDR, while neither SKCS hardness nor SEM analysis accurately differentiated DMDR between genotypes. <p>Eight genotypes were grown at multiple locations during 2003 and 2004 to study grain hardness measurement methodology, and genetic and environmental effects on hardness. Genotypes were analyzed for SKCS hardness, milling energy, endosperm light reflectance, feed particle size, protein and beta-glucan. Hardness measurements ranked genotypes similarly across environments. Feed particle size was correlated with milling energy but not other hardness measurements. Hardness measurements appeared to be influenced by protein and beta-glucan.<p>To examine the inheritance and heritability of barley grain hardness, 245 double haploid (DH) genotypes and parents, grown in 2003 and 2004, were analyzed for SKCS hardness, milling energy, protein, beta-glucan, with 100 evaluated for light reflectance. The population exhibited normal distributions for SKCS hardness, milling energy, protein and beta-glucan, suggesting quantitative inheritance for these traits with no apparent epistatic gene interaction. Narrow-sense heritability was 0.75 for SKCS hardness and 0.41 for protein. Light reflectance was not normally distributed, suggesting complementary gene interaction. Broad-sense heritability was 0.53.<p>Barley grain hardness is highly heritable and an efficient tool in making selections in a breeding program. However, breeding for high beta-glucan and protein may be better selection criteria for indirect selection of DMDR.