A series of investigations was undertaken regarding the biorefining of biomass for the recovery of multiple high-value products. The overall objective was to develop a simple, selective breakdown approach for flax shive, addressing three specific research areas: material properties; extraction processing; and product purification. This thesis includes five published papers and additional research all related to the topic. Flax shive represents the woody residue left over after removing fibre from flax straw. It is composed of lignified xylem tissue. Flax shive is readily available in large quantities, at low cost, and with relatively consistent particle-size and composition characteristics. Frictional behaviour investigations of bulk flax shive showed differing effects for addition of alcohols versus water. Adding any liquid significantly increased internal friction. The wall friction effects, however, depended on the liquid. Friction was increased significantly by water, but not as much by alcohols. Absorptive behaviour of flax shive, specifically liquid-holding capacity, was assessed using five liquids and compared to three other biomass materials. Flax shive was found to be a comparatively poor absorbent, a desirable behaviour for a feedstock used in aqueous- or alcohol-based processing. The first step extraction employed sodium ethoxide catalyst in anhydrous ethanol. Yield of solvent-soluble organics varied linearly with catalyst concentration. At 1.0 M the yield was 54.5 ± 14.5 mg/g dry basis (db). Analyses using 1H NMR consistently showed extracts to be phenolic in nature, and to contain no carbohydrate constituents. The second step extraction of hemicellulose polysaccharides was done using aqueous 1.0 M sodium hydroxide. The yield of carbohydrate precipitates was consistent, 99.4 ± 5.1 mg/g (db), and was unaffected by pretreatment. Analyses of polysaccharide backbone monomers showed consistently high molar ratios of xylose-to-glucose, i.e., 25.5 ± 3.4, with no mannose present. These results suggested a high concentration of glucuronoxylan polymer, likely greater than 90% by mass, with no glucomannan present. Economic evaluation showed two-stage extraction of high-value products to be a potentially viable business. Such processing also tied directly to government polices aimed at increasing value-add from agricultural materials. Overall, flax shive was found to be a desirable feedstock for recovery of high-value bio-products.

No description available.

The purpose of this study was to determine if the Atkins diet had an effect on resting metabolic rate. In addition, the study will further explore the effects of the Atkins diet on blood lipids (total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides) and glucose as well as body composition. Eighteen healthy women (mean age 42.4 ± 7.4 yrs, mean BMI 33.7± 5.6 kg' m -2) participated in the 6-week diet intervention. Pre- testing and post-testing included collection of: fasting blood lipids, resting metabolic rate and body composition data measured by air displacement plethysmography. Statistical analysis used to compare baseline and post study data included dependant t-tests. A significant decrease from baseline was noted in resting metabolic rate (1518 to 1374 kcals' day -1). Decreases in body mass (91.0 ± 4.0 to 86.6 ± 3.9 kg), fat mass (42.3 ± 3.1 to 38.0 ± 3.1 kg, and BMI (33.7 ± 1.3 to 32.1 ±1.3 kg' m "2) were noted but there was no significant change in fat-free mass (48.6 ± 1.3 to 48.6 ±1.1 kg). The only significant finding from the blood lipid profile was a decrease in triglyceride levels (121 ± 17.9 to 98 ±12.7 mg ' dL-1). In conclusion, this study showed that adherence to the Atkins diet for six weeks did improve body composition; decrease triglycerides and decrease resting metabolic rate. / School of Physical Education, Sport, and Exercise Science

A series of investigations was undertaken regarding the biorefining of biomass for the recovery of multiple high-value products. The overall objective was to develop a simple, selective breakdown approach for flax shive, addressing three specific research areas: material properties; extraction processing; and product purification. This thesis includes five published papers and additional research all related to the topic. Flax shive represents the woody residue left over after removing fibre from flax straw. It is composed of lignified xylem tissue. Flax shive is readily available in large quantities, at low cost, and with relatively consistent particle-size and composition characteristics. Frictional behaviour investigations of bulk flax shive showed differing effects for addition of alcohols versus water. Adding any liquid significantly increased internal friction. The wall friction effects, however, depended on the liquid. Friction was increased significantly by water, but not as much by alcohols. Absorptive behaviour of flax shive, specifically liquid-holding capacity, was assessed using five liquids and compared to three other biomass materials. Flax shive was found to be a comparatively poor absorbent, a desirable behaviour for a feedstock used in aqueous- or alcohol-based processing. The first step extraction employed sodium ethoxide catalyst in anhydrous ethanol. Yield of solvent-soluble organics varied linearly with catalyst concentration. At 1.0 M the yield was 54.5 ± 14.5 mg/g dry basis (db). Analyses using 1H NMR consistently showed extracts to be phenolic in nature, and to contain no carbohydrate constituents. The second step extraction of hemicellulose polysaccharides was done using aqueous 1.0 M sodium hydroxide. The yield of carbohydrate precipitates was consistent, 99.4 ± 5.1 mg/g (db), and was unaffected by pretreatment. Analyses of polysaccharide backbone monomers showed consistently high molar ratios of xylose-to-glucose, i.e., 25.5 ± 3.4, with no mannose present. These results suggested a high concentration of glucuronoxylan polymer, likely greater than 90% by mass, with no glucomannan present. Economic evaluation showed two-stage extraction of high-value products to be a potentially viable business. Such processing also tied directly to government polices aimed at increasing value-add from agricultural materials. Overall, flax shive was found to be a desirable feedstock for recovery of high-value bio-products.

Background: There are a number of biological pathways that affect our ingestive behaviours, including energy homeostasis, food reward, and taste. Given that carbohydrates such as sugars, provide energy and a sweet taste, examining candidate genes in each pathway may help explain differences in carbohydrate consumption behaviours. Objective: To determine whether variations in genes encoding a glucose transporter (GLUT2), a dopamine receptor (DRD2), and sweet taste receptor (TAS1R2) are associated with differences in sugar consumption in two distinct populations. Methods: Population 1 included diabetes-free young adults where dietary intake was assessed using a one month 196-item food frequency questionnaire (FFQ). Population 2 consisted of individuals with type 2 diabetes. Dietary intake was assessed using 3-day food records administered 2 weeks apart; food record 1 (FR1) and 2 (FR2). Subjects were genotyped for the Thr110Ile variation in GLUT2 (n1=587; n2=100), the C957T variation in DRD2 (n1=313; n2=100), and the Ser9Cys and Ile191Val variations in TAS1R2 (n1=1037; n2=100) using real-time PCR. Results: In comparison to individuals homozygous for the GLUT2 Thr allele, consumption of sugars was higher among Ile carriers in population 1 (133 ± 5 vs 118 ± 3 g/d, p=0.006) and population 2 on two separate food records (FR1: 112 ± 9 vs 87 ± 5 g/d, p=0.02; FR2: 105 ± 8 vs 78 ± 4 g/d, p=0.002). For the C957T variation in population 1, we detected a significant DRD2xSex interaction with the consumption of sucrose decreasing with each T allele among men (p=0.03) and a heterosis mode of inheritance among women where heterozygotes consumed the most (p=0.01). For TAS1R2, we detected a significant TAS1R2xBMI interaction and among overweight individuals, carriers of the Val allele consumed less sugars than those with the Ile/Ile genotype (103 ± 6 vs122 ± 6 g/d, p=0.01). In population 2, carriers of the Val allele consumed less sugars than individuals with the Ile/Ile genotype (83 ± 6 vs 99 ± 6 g/d, p=0.04) on FR2. Conclusions: Our findings demonstrate that genetic variation in GLUT2, DRD2 and TAS1R2 affect habitual sugar consumption and suggest that selection of dietary sugars can be influenced by different biological pathways.

xvi, 257 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1975)--The Dept. of Agricultural Biochemistry and Soil Science, University of Adelaide

Typescript (photocopy) / x, 210 leaves, [2] leaves of col. plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1982

xvii, 214 leaves : ill., graphs, tables ; 29 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Physiology, 1980

Thesis (Ph.D.)--University of Wollongong, 2004. / Includes appendices. Typescript. Includes bibliographical references: leaf 154-184.

Thesis (M. Med. Sc.)--University of Hong Kong, 2005.