Publications by authors named "Richard Tester"

The blood glucose response of savory slow energy-release crackers (GLY-HYP) were evaluated in volunteers carrying glycogen storage diseases (GSDs), Types I (Ia) and IV. The crackers have been shown previously to provide a "flat" slow glucose response in healthy volunteers, for up to 4 h. On average for the mixed-sex volunteer group aged 53 to 70 for Type I, the blood glucose concentration increased from baseline to a maximum of 9.

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There are dilemmas in the minds of consumers with respect to sugar consumption - they would like to consume sugars for sweetness, but in a healthy (and perhaps guilt free!) way. In a sense, consumers believe that if sugar does not appear as an ingredient on the product label, but is intrinsic in the food (and will appear as a nutrient), it is 'good'. As an ingredient, however, it is viewed as a 'bad chemical' associated with tooth decay and obesity.

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Scope: This review represents a focus on the structure and properties of the common nutritional disaccharides (lactose, maltose, and sucrose) in health and disease. The aim is to provide a comprehensive reference source related to the role of disaccharides in human nutrition.

Methods And Results: Key reference sources are searched, including Web of Science, PubMed, Science Direct, and Wiley Online, and key reference works are selected to support the factual basis of the text where interpretations and relevance of the works are discussed in the review.

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Background And Aims: Monosaccharides are important components of the diet, where the sweetness of these common sugars draw animals to eat the tissue within which they are located - especially fruits. Higher (larger) saccharides, within which they are constituents, are ubiquitous throughout nature too - and include disaccharides, oligosaccharides and polysaccharides. These may be converted (hydrolysed) to monosaccharides by the plant tissue enzymes during ripening and stimulate consumption by a predator (whereupon seeds within the fruit are dispersed).

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Background & Aims: The ketogenic diet is high in fat content, adequate with respect to protein but low in carbohydrate and designed to provide brain energy as ketone bodies rather than glucose. The consequence is that epilepsy can be managed and endurance (sport) related energy be derived from fat rather than ingested or stored (glycogen) carbohydrate. This review aims to set the diet in context for seizure related intervention, sport and potential modern variants with respect to glucose management - which have many medical (including epilepsy potentially) and activity related applications.

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Within the last ten years the utilisation of dietary fibre formats (non-starch polysaccharide and resistant starch) for diarrhoea therapy, have been evaluated. These polysaccharides ferment within the colon and generate short chain fatty acids which facilitate sodium absorption. Comparisons between polysaccharide structure/physico-chemical properties and fermentation capacity in the large intestine are presented.

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Diarrhoea therapies in general include a number of approaches (depending on local practise and the cause of the diarrhoea) aimed at: (i) removing the cause (e.g. lactose in the diet); (ii) treating the cause of infection if present (e.

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Starch granules contain an internal channel structure that can be used to encapsulate and deliver active ingredients such as nutrients, drugs, chemicals and microorganisms. Nature creates a broad range of starch granule sizes and compositions in different plants and this range of encapsulation matrices provides a great deal of commercial opportunity. Starch granules can be utilised for encapsulation in their native form or treated with amylases/amyloglucosidase to facilitate the entry of active ingredients into the granules.

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The reasons for (i) the presence and (ii) mechanisms of utilisation of glycogen by the lactic acid bacteria in the human vaginal tract are not well understood. It is probable that the vaginal epithelia produce both glycogen and α-amylase where the enzyme depolymerises the polysaccharide within the vagina itself. Only these depolymerised residues are then utilised for growth by the lactic acid bacteria.

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Glucomannans play a much broader role in human health then providing dietary fibre. They are biologically active molecules and can when added to the body imitate innate molecules found in different organs including surface carbohydrates on cells. This review considers the immunological role of exogenous glucomannans within animals and man.

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The impact of ingesting glucomannans on health is not limited to colonic-focused fermentation into short-chain fatty acids (SCFAs), which might have some local health benefits; it also helps in treating disease states and enhancing the body's immune system, both within the gut and in/on other parts of the body. The local and systemic roles of hydrolysed glucomannans, especially konjac glucomannans, in the mouth, oesophagus, stomach, small intestine, large intestine, gut-associated lymphoid tissue (GALT), skin and vagina, are highlighted. Therapeutic applications are discussed.

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Purpose: To compare the properties of buccal delivery matrices (wafers) made with dextrin, β-limit dextrin and pre-gelatinised starch.

Methods: The constituent α-glucans were tested for their mucoadhesive properties in solution plus their content of crystalline material (differential scanning calorimetry, DSC). Wafers were made by lyophilisation of aqueous solutions/dispersions of the α-glucans.

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Background: Glucomannan polysaccharides may be hydrolysed to lower molecular weight molecules using acids or enzymes, specifically mannanases or cellulases. Mannanases (β-mannanases) hydrolyse β-(1-4)-linked mannose residues randomly in mannans whilst cellulases (β-glucanase) hydrolyse β-(1-4)-linked glucose residues. The molecular weight of the hydrolysate is clearly dependent on the amount of hydrolysis.

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Purpose: β-Limit dextrin has been studied for many years as a means to investigate the internal structures of amylose and amylopectin. However its role as an excipient in the pharmaceutical industry has never been reported. This paper is the first one in a series to explore its potential use as an excipient to aid drug delivery.

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Commercially produced maize starches were treated with protease (Promod 25P) and their composition and properties were compared with untreated controls. It was found that, although protease treatment reduced the starch protein contents by 41%, 21% and 37% for the waxy, normal and amylomaize starches, respectively, it also caused some pits on the granule surfaces, which were evident by scanning electron microscopy (SEM), but no obvious decrease in granule dimensions (Coulter Counter Multisizer). The protein extraction was associated with decreases in starch lipid content by 42%, 40% and 45% (waxy, normal and amylomaize starches, respectively) and a decrease in total amylose content (30.

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Mesalamine (5-aminosalicylic acid) is the drug of choice for the treatment of Crohn's disease. A scheme for the synthesis of 5-aminosalicylic acid (5-ASA) conjugates of dextrans was developed with a focus on Crohn's disease applications. Dextrans were oxidised using sodium periodate (NaIO(4)), where the aldehyde groups formed were coupled with the alpha-amino (-NH(2)) group of 5-ASA.

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The relative molecular size distributions of a selection of starches (waxy maize, pea and maize) that had received differing amounts of damage from ball milling (as quantified by susceptibility to alpha-amylase) were compared using analytical ultracentrifugation. Starch samples were solubilised in 90% dimethyl sulfoxide, and relative size distributions were determined in terms of the apparent distribution of sedimentation coefficients g*(s) versus s(20,w). For comparison purposes, the sedimentation coefficients were normalised to standard conditions of density and viscosity of water at 20 degrees C, and measurements were made with a standard starch loading concentration of 8 mg/mL.

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Starches extracted from the sweet potato cultivars Sunnyred and Ayamurasaki grown at 15 or 33 degrees C (soil temperature) were annealed in excess water (3 mg starch/mL water) for different times (1, 4, 8 or 10h) at the temperatures 2-3 degrees K below the onset melting temperature. The structures of annealed starches, as well as their gelatinisation (melting) properties, were studied using high-sensitivity differential scanning calorimetry (HSDSC). In excess water, the single endothermic peak shifted to higher temperatures, while the melting (gelatinisation) enthalpy changed only very slightly, if any.

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Heteropolysaccharides isolated from liquid cultures of Tremella species were derivatised to alditol acetates and identified by GLC against derivatised sugar standards. From the sugar profiles it was evident that all of the polysaccharides contained essentially the same sugars but in different ratios. Some of the polysaccharides contained the five carbon sugars-fucose, ribose, xylose and arabinose together with six carbon sugars-mannose, galactose and glucose.

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