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Qi X, Ta MN, Tester RF. Savory Cracker Development for Blood Glucose Control and Management: Glycogen Storage Diseases. J Med Food 2024; 27:79-87. [PMID: 37967450 DOI: 10.1089/jmf.2023.0165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023] Open
Abstract
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 9.5 mmol/L at 60 min and remained above baseline for up to 210 min; overall, above 5 mmol/L for 4 h. In common with healthy individuals, a relatively flat blood glucose response was recorded. For Type IV, mixed-sex patients aged between 55 and 72, the blood glucose concentration reached maximum of 10.2 mmol/L at 45 min and then stayed above baseline for 150 min. Again, overall, above 5 mmol/L for 4 h. Altogether, these data indicate that these crackers would provide a valuable contribution to the nutritional needs of people of different age groups with GSDs (Clinical Registration Number: HRC10032021).
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Affiliation(s)
- Xin Qi
- Glycologic Limited, Reading, United Kingdom
| | - Minh N Ta
- Glycologic Limited, Reading, United Kingdom
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Affiliation(s)
- Xin Qi
- Glycologic Limited Glasgow G4 0BA UK
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Qi X, Tester RF. The 'epileptic diet'- ketogenic and/or slow release of glucose intervention: A review. Clin Nutr 2019; 39:1324-1330. [PMID: 31227228 DOI: 10.1016/j.clnu.2019.05.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/08/2019] [Accepted: 05/30/2019] [Indexed: 12/31/2022]
Abstract
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. METHODS The literature was reviewed using relevant data bases (e.g. Pubmed, Science Direct, Web of Science, Wiley on Line Library) and relevant articles were selected to provide historic and contemporary data for the text and associated Tables. RESULTS It is clear great health related benefits have been achieved by feeding the ketogenic to individuals subject to seizures where it helps manage the malaise. Sports applications are evident to. Glucose control diets provide health benefits of the ketogenic diet potentially and there is some evidence they are/can be very effective. CONCLUSIONS Key to epilepsy and sport performance is the control of blood glucose. The ketogenic diet has proven to be very effective in this regard but now other approaches to control blood glucose ae being evaluated which have advantages over the ketogenic diet. This therapeutic approach of clinical nutrition will undoubtedly move forwards over the next few years in view of the negative aspects of the ketogenic diet.
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Affiliation(s)
- Xin Qi
- Glycologic Limited, Glasgow, G4 0BA, UK.
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Qi X, Tester RF. Starch granules as active guest molecules or microorganism delivery systems. Food Chem 2019; 271:182-186. [DOI: 10.1016/j.foodchem.2018.07.177] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/18/2018] [Accepted: 07/25/2018] [Indexed: 11/26/2022]
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Abstract
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.g. antibiotics); (iii) reducing the effect of the cause (e.g. adsorbent); (iv) depressing gastric motility and secretions (e.g. various drugs); (v) probiotic bacteria with perhaps prebiotic energy sources and most importantly of all (vi) rehydration using rehydration salt solutions (oral rehydration therapy, ORT, using oral rehydration solutions, ORS). Glucose has been included in ORS formats for rapidly available energy since ORS formats were developed initially- but has the disadvantage of a high osmotic pressure. It is used in modern ORS formats to promote sodium absorption, however. The use of α-glucans (glucose containing oligo- or polysaccharides) in ORS formats is gaining ground in terms of utilisation for diarrhoea - a fairly recent approach to therapy in the western world. The use of different α-glucans in ORS formulations is discussed and strategies for the development further of therapies is investigated. This review is aimed at the scientific and medical communities.
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Affiliation(s)
- Xin Qi
- Glycologic Limited, 70 Cowcaddens Road, Glasgow, G4 0BA, UK.
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Affiliation(s)
- Xin Qi
- Glycologic Limited70 Cowcaddens RoadGlasgowG4 0BAUK
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Affiliation(s)
- Xin Qi
- Glycologic Limited70 Cowcaddens RoadGlasgow G4 0BAUK
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Tester RF, Al-Ghazzewi FH. Beneficial health characteristics of native and hydrolysed konjac (Amorphophallus konjac) glucomannan. J Sci Food Agric 2016; 96:3283-3291. [PMID: 26676961 DOI: 10.1002/jsfa.7571] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 06/05/2023]
Abstract
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. © 2015 Society of Chemical Industry.
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Affiliation(s)
- Xin Qi
- Glycologic Limited; Glasgow UK
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Affiliation(s)
- Xin Qi
- Glycologic Limited; Glasgow UK
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Affiliation(s)
- Xin Qi
- Glycologic Limited; Glasgow UK
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Al-Ghazzewi FH, Tester RF. Biotherapeutic agents and vaginal health. J Appl Microbiol 2016; 121:18-27. [PMID: 26757173 DOI: 10.1111/jam.13054] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 12/22/2015] [Accepted: 01/07/2016] [Indexed: 12/01/2022]
Abstract
Treatment of vaginal infection requires different drugs although the recurrence rate post treatment remains high due to adverse effects on the beneficial microbiota. Thus, there are clear clinical advantages for the use of biotherapeutic agents (prebiotics and/or probiotics) for treating these infections. Pre- and probiotic beneficial effects can be delivered topically or systemically. In general, both approaches have the potential to optimize, maintain and restore the ecology of the vaginal ecosystem. Specific carbohydrates provide a therapeutic approach for controlling infections by stimulating the growth of the indigenous lactobacilli but inhibiting the growth and adhesion of pathogens to the vaginal epithelial cells. Overall, little evidence exists to promote the prevention or treatment of vaginal disease with prebiotic carbohydrates in formulations such as pessaries, creams or douches. However, recent reports have promoted prebiotic applications in ecosystems other than the gut and include the mouth, skin and vagina. This review focuses on the utilization of pre- and probiotics for vaginal health.
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Abstract
This review discusses the role of pre- and probiotics with respect to improving skin health by modulating the cutaneous microbiota. The skin ecosystem is a complex environment covered with a diverse microbiota community. These are classified as either transient or resident, where some are considered as beneficial, some essentially neutral and others pathogenic or at least have the capacity to be pathogenic. Colonisation varies between different parts of the body due to different environmental factors. Pre- and probiotic beneficial effects can be delivered topically or systemically (by ingestion). The pre- and probiotics have the capacity to optimise, maintain and restore the microbiota of the skin in different ways. Topical applications of probiotic bacteria have a direct effect at the site of application by enhancing the skin natural defence barriers. Probiotics as well as resident bacteria can produce antimicrobial peptides that benefit cutaneous immune responses and eliminate pathogens. In cosmetic formulations, prebiotics can be applied to the skin microbiota directly and increase selectively the activity and growth of beneficial 'normal' skin microbiota. Little is known about the efficacy of topically applied prebiotics. Nutritional products containing prebiotics and/or probiotics have a positive effect on skin by modulating the immune system and by providing therapeutic benefits for atopic diseases. This review underlines the potential use of pre- and probiotics for skin health.
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Affiliation(s)
- F H Al-Ghazzewi
- Glycologic Limited, 70 Cowcaddens Road, Glasgow, G4 0BA, United Kingdom
| | - R F Tester
- Glycologic Limited, 70 Cowcaddens Road, Glasgow, G4 0BA, United Kingdom
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Affiliation(s)
- Prisana Suwannaporn
- Faculty of Agro-Industry; Department of Food Science and Technology; Kasetsart University; Bangkok Thailand
| | - Kamonphan Wiwattanawanich
- Faculty of Agro-Industry; Department of Food Science and Technology; Kasetsart University; Bangkok Thailand
| | - Richard F. Tester
- Department of Biological and Biomedical Sciences; Glasgow Caledonian University; Glasgow Scotland United Kingdom
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Al-Ghazzewi FH, Tester RF. Efficacy of cellulase and mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria. J Sci Food Agric 2012; 92:2394-2396. [PMID: 22495737 DOI: 10.1002/jsfa.5678] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
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. One use of such hydrolysates has been towards their capacity to function as prebiotics. The relative efficacy of cellulase and/or mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria (LAB) has been evaluated. RESULTS The LAB growth profiles (expressed in colony forming units, as a function of time) in UHT milk containing konjac glucomannan hydrolysed with cellulase were significantly greater than those containing glucose (control) or konjac glucomannan mannanase hydrolysates. An equivalent mixture (1:1) of cellulase-mannanase hydrolysates added to the UHT milk also showed significant improvement on the LAB growth profiles (compared to the glucose or mannanase alone hydrolysates). Different LAB strains showed some variation in growth profiles on the hydrolysates although this was not significant as a function of carbon source. CONCLUSIONS Glucomannan hydrolysates produced with either mannanase or cellulase enzymes were effective growth promoters (carbon sources) of LAB. However, cellulase hydrolysates were most effective.
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Al‐Ghazzewi FH, Tester RF, Alvani K. The synbiotic effects of konjac glucomannan hydrolysates (GMH) and lactobacilli on the growth ofStaphylococcus aureusandSalmonella typhimurium. ACTA ACUST UNITED AC 2012. [DOI: 10.1108/00346651211212051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Tester RF, Al‐Ghazzewi FH. A preliminary study of the synbiotic effects of konjac glucomannan hydrolysates (GMH) and lactobacilli on the growth of the oral bacteriumStreptococcus mutans. ACTA ACUST UNITED AC 2011. [DOI: 10.1108/00346651111151357] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
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. Methods. The bioadhesive properties of β-limit dextrin were studied using a texture analyser and compared with two well-known bioadhesive polymers – carbopol and chitosan (as controls). Results. The β-limit dextrin has significant mucoadhesive properties; similar to carbopol but superior to chitosan. Conclusions. The nature of β-limit dextrin (a starch derivative) makes it safe to consume and provides a natural alternative when compared with synthetic polymers. In addition, the polysaccharide can be digested by salivary amylase and thus provide a clean mouth feel.
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Tang M, Alvani K, Tester RF. Production and utilisation of gastric rafts from polysaccharide combinations to induce satiety. ACTA ACUST UNITED AC 2010. [DOI: 10.1108/00346651011029183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Khondkar P, Aidoo KE, Tester RF. The Effects of Temperature, pH, and Cations on the Rheological Properties of the Extracellular Polysaccharides of Medicinal Species of Genus Tremella Pers. (Heterobasidiomycetes). Int J Med Mushrooms 2010. [DOI: 10.1615/intjmedmushr.v12.i1.70] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Elamir AA, Tester RF, Al‐Ghazzewi FH, Kaal HY, Ghalbon AA, Elmegrahai NA, Piggott JR. Effects of konjac glucomannan hydrolysates on the gut microflora of mice. ACTA ACUST UNITED AC 2008. [DOI: 10.1108/00346650810906930] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Tester RF, Yousuf R, Karkalas J, Kettlitz B, Röper H. Properties of protease-treated maize starches. Food Chem 2008; 109:257-63. [DOI: 10.1016/j.foodchem.2008.01.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 01/07/2008] [Accepted: 01/22/2008] [Indexed: 10/22/2022]
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Bhattacharya K, Orton RC, Qi X, Mundy H, Morley DW, Champion MP, Eaton S, Tester RF, Lee PJ. A novel starch for the treatment of glycogen storage diseases. J Inherit Metab Dis 2007; 30:350-7. [PMID: 17514432 DOI: 10.1007/s10545-007-0479-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 01/10/2007] [Accepted: 02/12/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To determine whether a new starch offers better short-term metabolic control than uncooked cornstarch in patients with glycogen storage diseases (GSDs). STUDY DESIGN A short-term double-blind cross-over pilot study comparing uncooked physically modified cornstarch (WMHM20) with uncooked cornstarch in patients with GSD types Ia, Ib and III. Twenty-one patients (ages 3-47, 9 female) were given 2 g/kg cornstarch or WMHM20 mixed in water. Blood glucose, lactate and insulin, and breath hydrogen and (13)CO2 enrichment were measured, at baseline and after each load. The hourly biochemical evaluations terminated when blood glucose was < or = 3.0 mmol/L, when the study period had lasted 10 h or when the patient wished to end the test. The alternative starch was administered under similar trial conditions a median of 10 days later. RESULTS The median starch load duration was 9 h for WMHM20 versus 7 h for cornstarch. Glucose decreased more slowly (p = 0.05) and lactate was suppressed faster (p = 0.17) for WMHM20 compared with cornstarch. Peak hydrogen excretion was increased (p = 0.05) when cornstarch was taken. CONCLUSION These data indicate longer duration of euglycaemia and better short-term metabolic control in the majority of GSD patients with WMHM20 compared to cornstarch.
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Affiliation(s)
- K Bhattacharya
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
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Ahmad S, Tester RF, Corbett A, Karkalas J. Dextran and 5-aminosalicylic acid (5-ASA) conjugates: synthesis, characterisation and enzymic hydrolysis. Carbohydr Res 2006; 341:2694-701. [PMID: 16973138 DOI: 10.1016/j.carres.2006.08.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Revised: 08/14/2006] [Accepted: 08/17/2006] [Indexed: 11/22/2022]
Abstract
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. The resulting imine bonds were unstable in water and were consequently reduced to secondary amine groups. The effects of different aspects of the conjugation reaction were studied. These included the following: the molecular weight of the dextrans, the molar proportion of NaIO(4) to the dextrans (for periodate oxidation), the pH of the conjugation solutions, the ratio 5-ASA to oxidised polysaccharide and the relationship between the degree of conjugation and the amount of enzyme hydrolysis. Conjugates incubated in HCl were stable in 0.5 and 1.0M HCl, but they underwent degradation in 2.0 and 4.0M HCl. Dextrans (MW 20,000) with various degrees of oxidation (12%, 26%, 46%, 65%, 90% and 93%) were also prepared. Each oxidised dextran sample was conjugated with 5-ASA, and the product was quantified by high-performance liquid chromatography (HPLC). Dextrans with a maximum degree of oxidation (93%) unsurprisingly gave maximum conjugation of 5-ASA (49.1mg per 100mg of product) but were resistant to dextranase hydrolysis. Less oxidised dextrans (12%) conjugated proportionally less 5-ASA (15.1mg per 100mg of product) but were successfully hydrolysed by dextranase, suggesting their potential applications for the treatment of Crohn's disease in the distal ileum and proximal colon.
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Affiliation(s)
- Shavej Ahmad
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
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Abstract
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. The modal molecular size of the native unmilled alpha-glucans were found to be approximately 50S, 51S and 79S for the waxy maize, pea and maize amylopectin molecules, respectively, whilst the pea and maize amylose modal molecular sizes were approximately 14S and approximately 12S, respectively. As the amount of damaged starch increased, the amylopectin molecules were eventually fragmented, and several components appeared, with the smallest fractions approaching the sedimentation coefficient values of amylose. For the waxy maize starch, the 50S material (amylopectin) was gradually converted to 14S, and the degradation process included the appearance of 24S material. For the pea starch, the situation was more complicated than the waxy maize due to the presence of amylose. As the amylopectin molecules (51S) were depolymerised by damage within this starch, low-molecular-weight fragments added to the proportion of the amylose fraction (14S)--although tending towards the high-molecular-weight region of this fraction. As normal maize starch was progressively damaged, a greater number of fragments appeared to be generated compared to the other two starches. Here, the 79S amylopectin peak (native starch) was gradually converted into 61 and 46S material and eventually to 11S material with a molecular size comparable to amylose. Amylose did not appear to be degraded, implying that all the damage was focused on the amylopectin fraction in all three cases. Specific differences in the damage profiles for the pea and maize starches may reflect the effect of lipid-complexed amylose in the maize starch.
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Affiliation(s)
- Richard F Tester
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, UK.
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Tester RF, Ansell R, Snape CE, Yusuph M. Effects of storage temperatures and annealing conditions on the structure and properties of potato (Solanum tuberosum) starch. Int J Biol Macromol 2005; 36:1-8. [PMID: 15907996 DOI: 10.1016/j.ijbiomac.2005.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2004] [Revised: 02/04/2005] [Accepted: 02/04/2005] [Indexed: 11/23/2022]
Abstract
Starches were extracted from freshly harvested potatoes (12 cultivars, grown in Perthshire) and the properties of the starches of six cultivars were compared with starches extracted from the same samples but stored at 5, 25 or 55 degrees C for 7 days before extraction. The amylose (total) content of the freshly extracted starches from tubers stored at 5, 25 or 55 degrees C was on average 27.9+/-2.3, 28.3+/-1.7, 29.2+/-2.2 and 28.8+/-1.5%, respectively, with corresponding phosphorus representing 60+/-16, 64+/-9, 61+/-5 and 63+/-9 mg 100 g(-1). The unit chain distribution by chromatography of the amylopectin molecules from the starches extracted from the different conditions was very similar with an average degree of polymerisation (DP) of 26+/-2 where the two major fractions (F1 and F2) represented 54+/-2 and 19+/-1, respectively. Peak gelatinisation temperatures (Tp) and enthalpies (DeltaH) for the freshly extracted starches and from tubers stored at 5 or 25 degrees C were very similar (63.3+/-1.5 degrees C and 18.6+/-0.8 J g(-1); 63.1+/-1.0 degrees C and 17.7+/-1.5 J g(-1) and; 62.9+/-0.7 degrees C and 18.7+/-1.1 J g(-1), respectively) although starches stored at 55 degrees C were annealed, where Tp represented 71.1+/-1.1 degrees C and DeltaH 18.1+/-1.4 J g(-1). These in situ-annealed starches were comparable in terms of gelatinisation characteristics to annealed freshly extracted starches where on average, T(p) represented 72.7+/-1.0 degrees C and DeltaH 20.8+/-1.0 J g(-1). Annealing of tubers in situ prior to processing might be beneficial with respect to developing new potato-based products.
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Affiliation(s)
- R F Tester
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Food Research Laboratories, School of Biological and Biomedical Sciences, Cowcaddens Road, City Campus, Glasgow G4 0BA, UK.
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Abstract
Forty-nine samples of raw cow's milk and 20 samples of fresh white soft cheese were collected directly from 20 local dairy factories in the north-west of Libya and analysed for the presence of aflatoxin M1 (AFM1). The samples were analysed using a high-performance liquid chromatography technique for toxin detection and quantification. Thirty-five of the 49 milk samples (71.4%) showed AFM1 levels between 0.03 and 3.13 ng ml(-1) milk. Multiple analyses of five milk samples free of AFM1 artificially contaminated with concentrations of AFM1 at 0.01, 0.05, 0.1, 1.0 and 3.0 ng ml(-1) showed average recoveries of 66.85, 72.41, 83.29, 97.94 and 98.25%, with coefficients of variations of 3.77, 4.11, 1.57, 1.29 and 0.54%, respectively. Fifteen of 20 white soft cheese samples (75.0%) showed the presence of AFM1 in concentrations between 0. 11 and 0.52 ng g(-1) of cheese. Multiple assays of five cheese samples free of AFM1 spiked with different concentration of AFM1 (0.1, 0.5, 1.0 and 3.0 ng g(-1)) showed average recoveries of 63.23, 78.14,83.29 and 88.68%, with coefficients of variation of 1.53, 9.90, 4.87 and 3.79%, respectively. The concentrations of AFM1 were lower in the cheese products than in the raw milk samples.
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Affiliation(s)
- A M Elgerbi
- Food Research Laboratory, School of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, G4 OBA, UK
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Genkina NK, Wasserman LA, Noda T, Tester RF, Yuryev VP. Effects of annealing on the polymorphic structure of starches from sweet potatoes (Ayamurasaki and Sunnyred cultivars) grown at various soil temperatures. Carbohydr Res 2004; 339:1093-8. [PMID: 15063196 DOI: 10.1016/j.carres.2004.01.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2003] [Accepted: 01/21/2004] [Indexed: 11/24/2022]
Abstract
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. The elevation of gelatinisation temperature was associated with increasing order/thickness of the crystalline lamellae. The only DSC endotherm identified in 0.6 M KCl for Sunnyred starch grown at 33 degrees C was attributed to A-type polymorphic structure. The multiple endothermic forms observed by DSC performed in 0.6M KCl for annealed starches from both cultivars grown at 15 degrees C provided evidence of a complex C-type (A- plus B-type) polymorphic structure of crystalline lamellae. The A:B-ratio of two polymorphic forms increased upon annealing due to partial transformation of B- to A-polymorph, which was time dependent. Long heating periods facilitated the maximal transformation of B- to A-polymorph associated with limited A:B ratio.
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Affiliation(s)
- Natalia K Genkina
- Institute of Biochemical Physics, Russian Academy of Sciences, Kosygina str. 4, 119991 Moscow, Russia
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Tester RF, Qi X. Molecular basis of the gelatinisation and swelling characteristics of waxy barley starches grown in the same location during the same season. Part I. Composition and alpha-glucan fine structure. J Cereal Sci 2004. [DOI: 10.1016/s0733-5210(03)00065-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Affiliation(s)
- Kofi E. Aidoo
- Department of Biological Science (Food Science), Glasgow Caledonian University, Southbrae Campus, Southbrae Drive, Glasgow G13 1PP, UK
| | - Richard F. Tester
- Department of Biological Science (Food Science), Glasgow Caledonian University, Southbrae Campus, Southbrae Drive, Glasgow G13 1PP, UK
| | - Janet E. Morrison
- Department of Biological Science (Food Science), Glasgow Caledonian University, Southbrae Campus, Southbrae Drive, Glasgow G13 1PP, UK
| | - David MacFarlane
- Department of Biological Science (Food Science), Glasgow Caledonian University, Southbrae Campus, Southbrae Drive, Glasgow G13 1PP, UK
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Yusuph M, Tester RF, Ansell R, Snape CE. Composition and properties of starches extracted from tubers of different potato varieties grown under the same environmental conditions. Food Chem 2003. [DOI: 10.1016/s0308-8146(02)00549-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Genkina NK, Noda T, Koltisheva GI, Wasserman LA, Tester RF, Yuryev VP. Effects of Growth Temperature on Some Structural Properties of Crystalline Lamellae in Starches Extracted from Sweet Potatoes (Sunnyred andAyamurasaki). STARCH-STARKE 2003. [DOI: 10.1002/star.200300145] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
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. The uronic acid content of Tremella heteropolysaccharides also varied according to species. In addition, carbon source (arabinose, xylose, glucose, fructose and galactose) affected the sugar (including uronic acid content) ratio within the polysaccharides.
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Affiliation(s)
- Proma Khondkar
- School of Biological and Biomedical Sciences, Glasgow Caledonian University, UK
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40
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Abstract
Annealing processes, involving specific heating protocols, have been used by man for centuries to impart desirable properties to materials - especially metals and particularly tools and weapons. The terminology has also been applied to biopolymers such as starches, where the effects of the processing have been known for decades although the molecular basis has not been at all well understood. Because of the marked effect the annealing process has on starch functionality and consequently industrial applications, it is critical that the underlying molecular events are understood. This review is an attempt to clarify the process of starch annealing with an emphasis on data generated in the authors' laboratory.
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Affiliation(s)
- R F Tester
- Food Research Laboratories, School of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK
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41
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Abstract
Air equilibrated barley starch comprises amylopectin, amylose, lipid and water. The structure of amylose and amylopectin, and the proportion of amylose in granules is under genetic control and is therefore subject to genotypic variation. The amount of lipid (which is essentially all lysophospholipid) is similarly under genetic control. Environment and especially environmental temperature do, however, have a regulatory effect on the size of starch granules, the amylose to amylopectin ratio and the amount of lipid (which is essentially all complexed with amylose) within barley starch. High growth temperatures probably facilitate amylopectin crystallisation and increase gelatinisation temperatures, (and to some extent the enthalpy of gelatinisation), but delay the onset and depress the extent of swelling of granules when heated in water.
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Affiliation(s)
- R F Tester
- Glasgow Caledonian University, Department of Biological Sciences (Food Science), Southbrae Campus, Scotland, UK
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