Dissertations / Theses on the topic 'Food substitutes – Physiological effect'

Our objective was to investigate the mode of interaction between selected food proteins and phenolic compounds. Bovine serum albumin (BSA), bovine beta-lactoglobulin, and soybean glycinin were used with the following phenolic compounds; 3,4,5-trihydroxybenzoic acid (gallic acid), 3,4-dihydroxy cinnamic acid (caffeic acid), p -hydroxycinnamic acid (courmaric acid), and 5,7-dihydroxy 4-methoxy isoflavone (biochanin A). The interaction was investigated using incubation temperatures of 35°, 45° and 55°C at pH 5, 7 and 9. Native and SDS-polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy were used to identify protein-phenol interactions. Certain phenolic compounds combined with BSA and prevented protein aggregation. In general, the thermal stability of the proteins increased as a result of interaction with phenolic compounds; the most pronounced effect was observed with beta-lactoglobulin in the presence of gallic acid at pH 7. The interaction of the phenols with the proteins resulted in changes in protein secondary structure. (Abstract shortened by UMI.)

Selective isolation protocols of selenium (Se) species integrated to Se specific atomic absorption spectroscopy (AAS) detection were developed and optimized for Se speciation in food supplements, including selenized yeasts. By ultrafiltration, 69.18% of Se in the extract was found as a low molecular weight soluble form, the remaining 30.82% was bound to high molecular weight components. After a cation-exchange chromatography of the ultrafiltrate, 3.77% of the Se in the extract was found in the aqueous washings of the column indicating the presence of free inorganic anions of Se; the 65.41% of Se retained on the column corresponded to the free organic Se cations. The limit of detection for the HPLC-THG-AAS system was 1.85 ng of Se. Se was shown to be widely distributed over all the proteins with one sharp peak corresponding to the free forms of Se. Four major peaks were found at MW $>$ 250 000 Da (15.97% of Se recovered), between 102 330 and 117 490 Da (7.06%), between 48 977 and 53 703 Da (12.71%) and close to the dye migration band (17.25%).
Selective isolation and HPLC-AAS protocols were also developed and optimized for the determination of free organic forms e.g. selenomethionine (SeMet), selenocystine (SeCystine) and inorganic forms of selenium in aqueous solutions, and in complex matrices such as nutritional supplements and mixtures of free amino acids. The selenoamino acid in alkaline solution was first derivatized with 1-fluoro-2,4-dinitrobenzene. After removal of excess of reagent by partitioning with diethyl ether, the N-dinitrophenyl (DNP)-derivatized selenoamino acid was acidified and extracted with diethyl ether. Inorganic Se(IV) was extracted from the acidic aqueous phases by complexation with 1,2-phenylenediamine, forming a piazselenol. Se derivatives were determined selectively by HPLC-THG-AAS. A selective chromatographic mechanism based on $ pi$-electron interactions was optimized using a silica stationary phase derivatized with p-nitrophenyl moieties. Co-injections of DNP-SeMet, DNP-SeCystine and piazselenol save retention times of 3.7, 4.0 and 4.9 min, respectively, using a methanolic mobile phase containing 1.5% triethylamine and 0.013M acetic acid. Primary analytical validation parameters including stability, linearity and limits of detection were obtained using purified DNP-SeMet, DNP-SeCystine and piazselenol standards which were characterized by $ sp1$H-, $ sp{13}$C- and $ sp{77}$Se-NMR analysis and/or fast atom bombardment MS techniques. The calibration graphs for sequential dilutions of these Se standards were linear and the limits of detection from the resultant calibration graphs were 17 ng, 0.21 ng and 18.53 ng of Se, respectively. The purified DNP-SeMet and DNP-SeCystine were found to be photosensitive. The recovery of SeMet, SeCystine and inorganic Se from the stock solutions and/or nutritional supplements was virtually quantitative. In the presence of a 500-fold excess of other amino acids, the recovery of SeMet and SeCystine (96.1 $ pm$ 3.9% and 98.08 $ pm$ 4.2%, respec

Melatonin is a hormone secreted by the pineal gland, which is known to modulate biological rhythms in mammals. This study investigated the effect of food access schedule and dietary composition on serum melatonin and pineal NAT activity in adult male Wistar rats. These rats were maintained on a 12:12 h light:dark schedule with lights on at 0800h. The rats were randomly assigned to two dietary groups. A group was simultaneously fed a protein-rich and carbohydrate-rich granulated diet and the other group fed granulated rat chow. Each dietary group was further divided based on dietary feeding schedules. Animals were fed between 0800--1600 h or fed ad libitum. The study revealed that protein intake of rats fed the dietary choice was lower with the restricted access than in the free access. In rats fed dietary choice, the nocturnal melatonin levels and pineal NAT activity were significantly lower under the restricted access feeding when compared to the ad libitum feeding schedule. This was not observed in rats fed single chow diet. In conclusion our data demonstrate that food composition does affect the nocturnal synthesis of melatonin as well as the activity of the enzyme NAT. This could be via dietary intake of tryptophan, which is a precursor melatonin synthesis in the pineal gland.

In this research, beta-lactoglobulin was chemically modified by attaching different levels of stearic acid to the protein. The effect of this modification on hydrophobic!ty, emulsifying and foam properties, digestibility and allergenicity of the protein was investigated. It was found that the effect of fatty acid attachment or lipophilization depended on the amount of fatty acids attached to the protein. Incorporation of the hydrophobic ligands led to increased hydrophobic interactions, resulting in a decreasing solubility with extent of incorporation. Furthermore, the surface hydrophobicity measurements showed that the two fluorescence probes 8-anilinonaphthalene-l-sulfonate (ANS) and cis-parinaric acid (CPA) used for the surface hydrophobicity measurements were not equivalent This may support the. observation by earlier workers that ANS measures aromatic hydrophobicity and CPA aliphatic hydrophobicity. The studies on surface functional properties i.e. emulsifying and foaming properties, indicated that there was some improvement in these functional properties at low and medium levels of incorporation which decreased as the extent of fatty acid attachment further increased. The improvement, of these functional properties could be attributed to improved amphiphilicity of the proteins at these levels of incorporation. This research also showed that both high solubility and high ANS surface hydrophobicity is needed for the best emulsifying properties. In vitro digestibility studies showed a decrease in digestibility of the modified proteins with increased lipophilization. From the passive cutaneous anaphylaxis experiments, it was found that the level of fatty acid attachment to the protein had a significant effect on its ability to elicit IgE antibodies. Increased ability to elicit IgE antibodies was observed at a low level of fatty acid. When a medium level of fatty acid was attached the ability to elicit antibodies was reduced and almost completely destroyed when a higher level of fatty acid was incorporated. The above observations could be explained by the fact that the low level incorporation of fatty acid led to changes in the protein structure which exposed more allergenic sites. The almost complete destruction of the allergenicity could be attributed to denaturation of the protein which reduced or destroyed available allergenic sites. The antigenicity or binding of the modified proteins to the IgG antibodies raised against the native protein was studied by both direct and competitive enzyme linked immunosorbent assay. It was found that at low and medium levels of incorporation, the proteins demonstrated increased binding ability compared to the native protein. This was attributed to the increased exposure of antigenic sites on the protein with fatty acid incorporation. However, the protein with high level of incorporated fatty acid showed decreased binding ability.
Land and Food Systems, Faculty of
Graduate

The purpose of this study was to examine the relationship between comfort food preferences of college faculty when under normal (non-stressful) and stressful conditions. Thirty-four percent (n=63) of the participants were males and 66 percent (n=121) were females. Sixty-seven percent (n=123) experienced a change in appetite when stressed, with 69 percent (n=85) experiencing an increase and 31 percent (n=38) experiencing a decrease in appetite. Participants chose a significantly wider variety of foods when under stressful conditions for both sweet (p=<.001) and salty/crunchy food categories (p=.004). High restrained eaters chose significantly more types of sweet foods (p=.031) and beverages (p=.020) than low restrained eaters when comparing stressful and normal conditions. These findings suggest the majority of adults may experience changes in appetite with stress, specifically an increased appetite, and may choose more types of sweet and salty/crunchy foods. An individual's restraint level, gender, and age may also play a role in comfort food choice.
Department of Family and Consumer Sciences

In light of the limited and conflicting experimental data on food intake, body weight change and body energy metabolism following single-dose or long-term cocaine administration, the purpose of the present study was to further evaluate the dose-dependent acute and chronic (27 day) effects of two dose levels of cocaine on the following questions: i) Does chronic cocaine administration decrease food consumption and weight gain?; ii) To what extent does acute or chronic cocaine administration alter body carbohydrate stores (liver and skeletal muscle glycogen content)?; and iii). To what extent does acute or chronic cocaine administration affect plasma glucose and free fatty acid levels and thus hepatic glycogenolysis and adipose tissue lipolysis?

Obesity has increased dramatically in the past 25 years. The consumption of added sugar has increased significantly during the same time period. Previous research indicates a direct correlation between the consumption of added sugar and the prevalence of obesity. Sugar has been identified in multiple studies as having addictive or opiate-like qualities. Unquestionably, added sugar consumption has contributed to the current obesity epidemic. Here, we apply a reference price economic model to attempt to describe sugar consumption. Using consumption and price data from the Economic Research Service of the United States Department of Agriculture, we made a reference price estimation of domestic refined sugar (sucrose) consumption. Using time-series econometric techniques, we tested the effects of internal and external reference prices, in the form of first differenced own price and price of other nutrient classes, respectively, on sugar demand. Results indicate that internal and, particularly, external reference prices do indeed play a role in consumption decisions. However, the model lacks socioeconomic variables that may help to provide a more complete consumption picture.

During pregnancy, body fat stores increase in part to subsidize the high energy cost of lactation. One effect of exercise, on the other hand, is to lower percent body fat. The effect of exercise during pregnancy and lactation on body fat, and on body composition in general, is not well documented. There is also a paucity of data on the effect of exercise during these physiological states on food intake and body weight. If exercise during pregnancy decreases body fat stores, would lactation performance subsequently be compromised? This study was designed to determine the effect of moderately strenuous aerobic exercise, during rat pregnancy and lactation, on food intake, body weight, body composition and lactation performance. Virgin female Sprague-Dawley rats were divided into exercised (n=40) and sedentary (n=40) groups. Exercising rats were trained over three weeks to run on a treadmill at 30 m/min, 2 hours/day, 5 days/week. Within each group, two subgroups were then mated and three subgroups remained as virgin age controls (n=8 per subgroup). Of the mated subgroups, one was terminated within 24 hours of parturition and the other on day 14 of lactation. Subgroups of virgin sedentary and exercising controls were terminated at times corresponding to each of mating, parturition and day 14 of lactation of mated animals. Carcasses were assayed for fat, water, ash and protein. Ad libitum food intake and body weight were monitored throughout the study, as was the weight gain of pups of lactating dams. MANOVA showed the effect of activity to be significant on food intake at week three of training and during the pregnancy period (p<0.00l) and at week one (p<0.0l) and two (p<0.05) of lactation. The effect of activity was highly significant (p<0.00l) on body weight from week three of training and throughout the pregnancy and lactation periods, as well as on the percent fat, water and ash of the rat carcasses. Post hoc multimean comparisons (Scheffe) at the p<0.05 level revealed that exercise resulted in a significant increase in the food intake of virgin rats, and nonsignificant increases in the food intake of pregnant and lactating rats. Body weights of virgin, pregnant and lactating exercising rats were significantly greater than their respective sedentary controls. Despite their heavier body weights and greater food intake, the estimated carcass energy content of exercising animals was lower than that of sedentary animals. This finding was reflected in the carcass composition whereby exercising rats, whether virgin, pregnant or lactating, contained consistently less fat and more water than sedentary controls. At parturition, pregnant animals contained significantly less fat, more water and more ash than sedentary pregnant controls. After 14 days of lactation, there were no significant differences in carcass composition between exercising and sedentary dams. However, lactating rats, whether exercising or sedentary, catabolized approximately 50 percent of the body fat present at parturition. Pup weight gains were not significantly different between exercising and sedentary dams. From these findings it was concluded that the effect of exercise during pregnancy and lactation on food intake, body weight and body composition was comparable to its effect in non-gravid rats. Moderately strenuous exercise during pregnancy prevented the increase in body fat deposition normally present at this time. Despite these depleted fat stores, the energy supplied by the mobilization of the remaining fat and the increase in food intake was adequate to support normal pup growth.
Land and Food Systems, Faculty of
Graduate

Cognitive dietary restraint (CDR) reflects a perception of constantly monitoring or attempting to restrict food intake as a means to control body weight, rather than eating in response to physiological hunger cues. Higher salivary and urinary cortisol levels have been observed in women with high versus low CDR. This study assessed whether food and weight-related cues differentially activate the physiological stress response in 70 healthy women aged 19-35 with low (0-5; n = 35) or high (13-21; n = 35) scores on the Three Factor Eating Questionnaire Restraint subscale. Participants completed questionnaires on eating attitudes, stress, anxiety, depression and physical activity in the presence of food temptations. Concurrently, blood pressure, heart rate and salivary cortisol measures were obtained every 15 minutes over a 90 minute period. Results showed significant between-group differences in eating attitudes while anthropometric, general perceived stress, anxiety, depression and physical activity variables were similar. Although women with high CDR perceived the protocol as more stressful, physiological measures did not differ by CDR level. Participants also provided 4 saliva samples collected within 1 hour of awakening to assess the awakening cortisol response (ACR). ACR disturbances may be indicative of disrupted hypothalamic-pituitary-adrenal axis functioning, which may be responsible for the higher cortisol levels observed in high restraint women. Morning sampling procedures showed no between-group differences in the ACR. In conclusion, women with high and low CDR had similar physiological stress responses after cue exposure; however, this may have been the result of a weak stressor.

This thesis consists of a brief description on cancer, carcinogenesis, the changes in the type and level of dietary fat available in our diets over time and association with the development of certain diseases. The main focus of this research was on omega 6 and omega 3 essential fatty acids (EFA) and their interaction with regards to carcinogenesis.

The involvement of dopamine in anticipatory and consummatory aspects of feeding behaviors was investigated in the present thesis. All measurements of dopaminergic activity were taken by in vivo electrochemical techniques. In Experiment 1, dopamine efflux in the nucleus accumbens and caudate of male rats was monitored during sessions in which a small, unsignalled liquid meal was consumed. Increases in the electrochemical measure of dopamine activity, which were of similar temporal pattern and magnitude, were observed in both the nucleus accumbens and striatum following meal consumption. These data suggest a possible postingestional role of dopamine in these two brain structures. In Experiment 2, a conditioned feeding paradigm was utilized to study the role of dopamine during a discrete anticipatory phase of feeding. Rats were conditioned to discriminate between a positive conditioned stimulus (CS+) predictive of meal delivery, and a negative conditioned stimulus (CS-) that was not associated with food. Increases in dopamine activity, as determined by changes in electrochemical oxidation currents, were found to be greater during the CS+ than during the CS- in both the nucleus accumbens and caudate. In addition, the magnitude of increase was greater in the nucleus accumbens than the caudate, suggesting that the accumbens may be preferentially involved in the processing of external incentive stimuli. The results support a role for dopamine in both the nucleus accumbens and caudate during appetitive or anticipatory responding for food in the male rat.
Medicine, Faculty of
Graduate

Epidemiological studies have suggested that the consumption of fish may reduce the risk of cardiovascular disease. Compared to the number of studies using fish oils, few studies have used fish itself. Those which have used fish have generally used fattier fish such as mackerel and salmon as part of an uncontrolled diet. In this study, 23 healthy men consumed 200g each of Chinook salmon, Dover sole, and sablefish in a three-way crossover design for 18-day periods with three-week washout periods in between. The diets had the approximate composition of the 'Western' diet: 45% carbohydrates, 36% fat, and 16% protein with the sole diet containing 1.95 g omega-3 (n-3) fatty acids, the salmon diet 3.99 g n-3, and the sablefish diet 3.42 g n-3 fatty acids. Serum total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), bleeding time (BT), blood pressure (BP), platelet aggregation (PA) using ADP and collagen as agonists, platelet fatty acid profiles (FAP), thromboxane B2 (TXB2) , and apolipoprotein B (Apo B) were measured at the beginning and end of each period. TC, and HDL-C, and TG changed significantly when compared to the prefish diet while both LDL-C and apo B demonstrated diet effect. LDL-C increased on both the salmon and sablefish diets (p = 0.08) compared to the sole diet, and increased approximately 15% on the former two diets compared to the prefish diet. Bleeding time was significantly longer when the salmon diet was consumed (p = 0.06). The impact of the three diets on PA depended upon the agonist. With collagen, only the sablefish diet decreased aggregation compared to the prefish diet. When ADP was used, aggregation decreased on both the fattier fish diets compared to the low fat fish (sole). Similar results were demonstrated for TXB₂: the fattier fish produced statistically equivalent decreases (p = 0.06) among the diets, and lowered TXB₂ compared to the prefish diet. There were no significant differences among the diets for either systolic or diastolic BP though there was a significant decrease (p = 0.01) in diastolic pressure compared to the prefish diet when the salmon diet was consumed. Platelet fatty acid profiles reflected diet composition.
Graduation date: 1993

Arsenic is a naturally occurring toxic metal and its presence in food composites could be a potential risk to the health of both humans and animals. Arseniccontaminated groundwater is often used for food and animal consumption, irrigation of soils, which could potentially lead to arsenic entering the human food chain. Its side effects include multiple organ damage, cancers, heart disease, diabetes mellitus, hypertension, lung disease and peripheral vascular disease. Research investigations, epidemiologic surveys and total diet studies (market baskets) provide datasets, information and knowledge on arsenic content in foods. The determination of the concentration of arsenic in rice varieties is an active area of research. With the increasing capability to measure the concentration of arsenic in foods, there are volumes of varied and continuously generated datasets on arsenic in food groups. Visual analytics, which integrates techniques from information visualization and computational data analysis via interactive visual interfaces, presents an approach to enable data on arsenic concentrations to be visually represented. The goal of this doctoral research in Environmental Science is to address the need to provide visual analytical decision support tools on arsenic content in various foods with special emphasis on rice. The hypothesis of this doctoral thesis research is that software enabled visual representation and user interaction facilitated by visual interfaces will help discover hidden relationships between arsenic content and food categories. The specific objectives investigated were: (1) Provide insightful visual analytic views of compiled data on arsenic in food categories; (2) Categorize table ready foods by arsenic content; (3) Compare arsenic content in rice product categories and (4) Identify informative sentences on arsenic concentrations in rice. The overall research method is secondary data analyses using visual analytics techniques implemented through Tableau Software. Several datasets were utilized to conduct visual analytical representations of data on arsenic concentrations in foods. These consisted of (i) arsenic concentrations in 459 crop samples; (ii) arsenic concentrations in 328 table ready foods from multi-year total diet studies; (iii) estimates of daily inorganic arsenic intake for 49 food groups from multicountry total diet studies; (iv) arsenic content in rice product categories for 193 samples of rice and rice products; (v) 758 sentences extracted from PubMed abstracts on arsenic in rice. Several key insights were made in this doctoral research. The concentration of inorganic arsenic in instant rice was lower than those of other rice types. The concentration of Dimethylarsinic Acid (DMA) in wild rice, an aquatic grass, was notably lower than rice varieties (e.g. 0.0099 ppm versus 0.182 for a long grain white rice). The categorization of 328 table ready foods into 12 categories enhances the communication on arsenic concentrations. Outlier concentration of arsenic in rice were observed in views constructed for integrating data from four total diet studies. The 193 rice samples were grouped into two groups using a cut-off level of 3 mcg of inorganic arsenic per serving. The visual analytics views constructed allow users to specify cut-off levels desired. A total of 86 sentences from 53 PubMed abstracts were identified as informative for arsenic concentrations. The sentences enabled literature curation for arsenic concentration and additional supporting information such as location of the research. An informative sentence provided global “normal” range of 0.08 to 0.20 mg/kg for arsenic in rice. A visual analytics resource developed was a dashboard that facilitates the interaction with text and a connection to the knowledge base of the PubMed literature database. The research reported provides a foundation for additional investigations on visual analytics of data on arsenic concentrations in foods. Considering the massive and complex data associated with contaminants in foods, the development of visual analytics tools are needed to facilitate diverse human cognitive tasks. Visual analytics tools can provide integrated automated analysis; interaction with data; and data visualization critically needed to enhance decision making. Stakeholders that would benefit include consumers; food and health safety personnel; farmers; and food producers. Arsenic content of baby foods warrants attention because of the early life exposures that could have life time adverse health consequences. The action of microorganisms in the soil is associated with availability of arsenic species for uptake by plants. Genomic data on microbial communities presents wealth of data to identify mitigation strategies for arsenic uptake by plants. Arsenic metabolism pathways encoded in microbial genomes warrants further research. Visual analytics tasks could facilitate the discovery of biological processes for mitigating arsenic uptake from soil. The increasing availability of central resources on data from total diet studies and research investigations presents a need for personnel with diverse levels of skills in data management and analysis. Training workshops and courses on the foundations and applications of visual analytics can contribute to global workforce development in food safety and environmental health. Research investigations could determine learning gains accomplished through hardware and software for visual analytics. Finally, there is need to develop and evaluate informatics tools that have visual analytics capabilities in the domain of contaminants in foods.
Environmental Sciences
P. Phil. (Environmental Science)

Indiana University-Purdue University Indianapolis (IUPUI)
In order to elucidate the role of classical conditioning in food and alcohol co-consumption, the present study examined: (1) the effects of alcohol odor cues on alcohol and food cravings and attentional bias (bias in selective attention toward either food or alcohol pictures relative to neutral pictures); and (2) the role of alcohol odor cue elicited cravings and attentional biases on subsequent consumption. Participants (n = 77; mean age = 30.84, SD = 9.46; 51.9% female, 83.1% Caucasian) first completed the lab portion of the study. In this portion, they were exposed to alcohol and neutral odorants, after which their food and alcohol cravings and attentional bias were assessed. Participants then received an online survey the next day, on which they reported their level of food and alcohol consumption following the lab portion of the study. Using repeated measures analysis of covariance, alcohol odor cues were differentially effective in increasing food and alcohol attentional bias and cravings (Fs= 0.06 to 2.72, ps= 0.03 to 0.81). Using logistic and multiple regressions, alcohol odor cue elicited alcohol attentional bias, food attentional bias, and food cravings were associated with later alcohol consumption, but not with later food consumption or concurrent consumption (βs = -0.28 to 0.48, ps = 0.02 to 0.99; Exp(B)s = 0.95 to 1.83, ps = 0.33 to 0.91). Overall, alcohol odor cues can become conditioned stimuli that elicit conditioned food-related and alcohol-related responses, both of which persist long enough to motivate later alcohol consumption; however, these conditioned responses might not persist long enough to motivate later food or concurrent consumption. These findings serve as a first step in clarifying the role of classical conditioning in concurrent consumption. In particular, they suggest that additional empirical investigations are needed to: (1) clarify the classical conditioning mechanisms underlying concurrent consumption; and (2) examine whether interventions targeting classical conditioning mechanisms are effective for reducing alcohol use.

by Li Yung Yung.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.
Includes bibliographical references (leaves 105-121).
Abstracts in English and Chinese.
ACKNOWLEDGEMENTS --- p.i
ABSTRACT (ENGLISH VERSION) --- p.ii
ABSTRACT (CHINESE VERSION) --- p.iv
TABLE OF CONTENTS --- p.v
LIST OF TABLES --- p.x
LIST OF FIGURES --- p.xi
LIST OF ABBREVIATIONS --- p.xiii
Chapter CHAPTER ONE --- INTRODUCTION
Chapter 1.1 --- Seaweed --- p.1
Chapter 1.1.1 --- General Introduction --- p.1
Chapter 1.1.2 --- Classification and Use of Seaweed --- p.1
Chapter 1.1.3 --- Phycocolloids --- p.2
Chapter 1.1.4 --- Hong Kong Seaweed --- p.3
Chapter 1.1.4.1 --- Sargassum Species --- p.3
Chapter 1.1.4.2 --- Padina Species --- p.5
Chapter 1.2 --- Source and Production of Alginate --- p.8
Chapter 1.2.1 --- Function of Alginate in Seaweed --- p.8
Chapter 1.2.2 --- Chemical Structure of Alginate --- p.8
Chapter 1.2.3 --- Alginate Production --- p.9
Chapter 1.2.4 --- Isolation of Alginate --- p.13
Chapter 1.2.5 --- Commercial Methods --- p.13
Chapter 1.3 --- Application of Alginate --- p.14
Chapter 1.3.1 --- Industrial Application --- p.14
Chapter 1.3.2 --- Pharmaceutical Application --- p.16
Chapter 1.3.3 --- Food Application --- p.17
Chapter 1.3.3.1 --- Uses of Alginate in Food --- p.17
Chapter 1.3.3.2 --- Safety --- p.19
Chapter 1.4 --- Structure and Function Relationship of Alginate --- p.19
Chapter 1.4.1 --- Physico-Chemical Properties --- p.21
Chapter 1.4.1.1 --- M/G ratio --- p.21
Chapter 1.4.1.2 --- Solution Properties --- p.21
Chapter 1.4.1.3 --- Viscosity --- p.23
Chapter 1.4.1.4 --- Molecular Weight --- p.27
Chapter 1.4.2 --- Functional Properties --- p.27
Chapter 1.4.2.1 --- Emulsion --- p.27
Chapter 1.4.2.2 --- Gel Properties --- p.27
Chapter 1.4.2.3 --- Mechanism of Gelation --- p.29
Chapter 1.4.2.4 --- Gel Strength and Syneresis --- p.30
Chapter 1.5 --- Physiological Effects --- p.32
Chapter 1.5.1 --- Dietary Fibre --- p.32
Chapter 1.5.2 --- Minerals --- p.32
Chapter 1.6 --- Significance of the Present Study --- p.33
Chapter CHAPTER TWO --- MATERIALS AND METHODS
Chapter 2.1 --- Seaweed Collection --- p.36
Chapter 2.2 --- Sample Preparation --- p.36
Chapter 2.3 --- Alginate Extraction --- p.38
Chapter 2.3.1 --- Method A --- p.38
Chapter 2.3.2 --- Method B --- p.38
Chapter 2.3.3 --- Commercial Alginate --- p.39
Chapter 2.4 --- Chemical Composition of Alginate --- p.41
Chapter 2.4.1 --- Alginate Content --- p.41
Chapter 2.4.2 --- Moisture Content --- p.41
Chapter 2.4.3 --- Crude Protein Content --- p.41
Chapter 2.4.4 --- Ash Content --- p.42
Chapter 2.4.5 --- Monosaccharide Composition --- p.42
Chapter 2.4.5.1 --- Acid Deploymerisation --- p.42
Chapter 2.4.5.2 --- Neutral and Amino Sugar Derivatization --- p.42
Chapter 2.4.5.3 --- Determination of Neutral Sugars by Gas Chromatography --- p.43
Chapter 2.4.5.4 --- Uronic Acid Content --- p.44
Chapter 2.4.6 --- Uronic Acid Block Composition --- p.44
Chapter 2.4.6.1 --- "MG, MM and GG Block Determination" --- p.44
Chapter 2.4.6.2 --- M/G Ratio Determination --- p.45
Chapter 2.4.6.3 --- Phenol-Sulfuric Acid Method --- p.45
Chapter 2.5 --- Physico-Chemical Properties of Alginate --- p.46
Chapter 2.5.1 --- Viscosity --- p.46
Chapter 2.5.1.1 --- Ostwald Viscometer --- p.46
Chapter 2.5.1.2 --- Brookfield Viscometer --- p.47
Chapter 2.5.2 --- Molecular Weight --- p.47
Chapter 2.5.2.1 --- From Intrinsic Viscosity --- p.47
Chapter 2.5.2.2 --- Gel Permeation Chromatography-Laser Light Scattering (GPC-LLS) --- p.48
Chapter 2.6 --- Functional Properties of Alginate --- p.49
Chapter 2.6.1 --- Emulsifying Activity (EA) and Emulsion Stability (ES) --- p.49
Chapter 2.6.2 --- Gel Formation --- p.49
Chapter 2.6.3 --- Gel Strength and Syneresis --- p.50
Chapter 2.6.4 --- Application in Food ´ؤ Fruit Jelly --- p.52
Chapter 2.7 --- Data Analysis --- p.53
Chapter CHAPTER THREE --- RESULTS AND DISCUSSION
Chapter 3.1 --- Proximate Composition of Selected Seaweed --- p.54
Chapter 3.1.1 --- Moisture Content --- p.54
Chapter 3.1.2 --- Ash Content --- p.56
Chapter 3.1.3 --- Crude Protein Content --- p.57
Chapter 3.1.4 --- Carbohydrate Content --- p.58
Chapter 3.2 --- Chemical Composition of Alginate Extracted from Two Different Methods --- p.58
Chapter 3.2.1 --- Percentage Yield --- p.59
Chapter 3.2.2 --- Alginate Content --- p.61
Chapter 3.2.3 --- Moisture Content --- p.62
Chapter 3.2.4 --- Ash Content --- p.62
Chapter 3.2.5 --- Residual Protein Content --- p.63
Chapter 3.2.6 --- Monosaccharide Composition of Alginate --- p.63
Chapter 3.2.7 --- M/G Ratio --- p.66
Chapter 3.2.8 --- Summary --- p.69
Chapter 3.3 --- Comparative Studies of Physico-Chemical Composition of Alginate from Sargassum and Padina Species --- p.71
Chapter 3.3.1 --- Block Composition and M/G Ratio --- p.71
Chapter 3.3.2 --- Viscosity --- p.75
Chapter 3.3.2.1 --- Intrinsic Viscosity ´ؤ Capillary Viscometer --- p.75
Chapter 3.3.2.2 --- Solution Viscosity - Brookfield Viscometer --- p.79
Chapter 3.3.2.2.1 --- Effect of Temperature --- p.79
Chapter 3.3.2.2.2 --- Effect of Concentration --- p.81
Chapter 3.3.2.2.3 --- Shear Thinning and Time Independent Effect --- p.82
Chapter 3.3.3 --- Molecular Weight --- p.88
Chapter 3.3.3.1 --- From Intrinsic Viscosity --- p.88
Chapter 3.3.3.2 --- Gel Permeation Chromatograph-Laser Light Scattering (GPC-LLS) --- p.90
Chapter 3.4 --- Comparative Studies of the Functional Properties of Extracted Alginate with Commercial Alginate --- p.93
Chapter 3.4.1 --- Emulsifying Activity (EA) and Emulsifying Stability (ES) --- p.93
Chapter 3.4.2 --- Gelling Properties --- p.95
Chapter 3.4.2.1 --- Effect of Calcium Concentrations --- p.95
Chapter 3.4.2.2 --- Gel Strength and Syneresis --- p.97
Chapter 3.4.3 --- Application in Food --- p.99
Chapter CHAPTER FOUR --- CONCLUSIONS --- p.103
REFERENCES --- p.105
RELATED PUBLICATION --- p.120

This study explores the possible efficacy of a low carbohydrate and high fat nutritional intervention (LCHF) as a treatment possibility aiming to improve the ability of self-control and regulation in the context of carbohydrate-addiction. The study first outlines why increased simple carbohydrate consumption has been implicated as a risk-factor in numerous chronic conditions, and then explores the possibility that a reduction of such consumption could lower general medical expenditure in the healthcare sector of already overburdened institutions, especially in developing countries like South Africa. Since the neurobiological evidence for food addiction is compelling, this study investigates the impact of a low carbohydrate and high fat eating (LCHF) regimen by measuring the change in the severity of addictive behaviour in relation to a reduced carbohydrate consumption. Results indicate that a LCHF nutritional intervention lessened addictive behaviour after just 30 days, resulting in a statistically significant decrease in addiction symptoms from day 1 to day 30. The weight and BMI values of the participants recorded at the end of the study showed a reduction from those obtained during the pre- treatment stage, and the self-perceived ‘feeling in control’ also improved in all participants after the intervention. The introduction of a LCHF nutritional intervention presents a relatively cost-effective treatment and preventative measure to combat carbohydrate over-consumption and its numerous health complications, and it is therefore hoped that the positive findings of this study will foster further research, using larger samples, into this type of nutritional intervention against addictive eating behaviour.
Psychology
M.A. (Psychology)