151
|
Dhital S, Lin AHM, Hamaker BR, Gidley MJ, Muniandy A. Mammalian mucosal α-glucosidases coordinate with α-amylase in the initial starch hydrolysis stage to have a role in starch digestion beyond glucogenesis. PLoS One 2013; 8:e62546. [PMID: 23638112 PMCID: PMC3636141 DOI: 10.1371/journal.pone.0062546] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 03/22/2013] [Indexed: 11/19/2022] Open
Abstract
Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing predominantly α-amylase, and intestinal extract containing a combination of α-amylase and mucosal α-glucosidase activities, were applied to three granular maize starches with different amylose contents in an in vitro system. Relative glucogenesis, released maltooligosaccharide amounts, and structural changes of degraded residues were examined. Pancreatic extract-treated starches showed a hydrolysis limit over the 12 h incubation period with residues having a higher gelatinization temperature than the native starch. α-Amylase combined with the mucosal α-glucosidases in the intestinal extract showed higher glucogenesis as expected, but also higher maltooligosaccharide amounts indicating an overall greater degree of granular starch breakdown. Starch residues after intestinal extract digestion showed more starch fragmentation, higher gelatinization temperature, higher crystallinity (without any change in polymorph), and an increase of intermediate-sized or small-sized fractions of starch molecules, but did not show preferential hydrolysis of either amylose or amylopectin. Direct digestion of granular starch by mammalian recombinant mucosal α-glucosidases was observed which shows that these enzymes may work either independently or together with α-amylase to digest starch. Thus, mucosal α-glucosidases can have a synergistic effect with α-amylase on granular starch digestion, consistent with a role in overall starch digestion beyond their primary glucogenesis function.
Collapse
Affiliation(s)
- Sushil Dhital
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana, United States of America
- Centre for Nutrition and Food Sciences and Australian Research Council Centre of Excellence in Plant Cell Walls, The University of Queensland, Brisbane, Queensland, Australia
| | - Amy Hui-Mei Lin
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana, United States of America
| | - Bruce R. Hamaker
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana, United States of America
| | - Michael J. Gidley
- Centre for Nutrition and Food Sciences and Australian Research Council Centre of Excellence in Plant Cell Walls, The University of Queensland, Brisbane, Queensland, Australia
| | - Anbuhkani Muniandy
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana, United States of America
| |
Collapse
|
152
|
Fredericks CH, Fanning KJ, Gidley MJ, Netzel G, Zabaras D, Herrington M, Netzel M. High-anthocyanin strawberries through cultivar selection. J Sci Food Agric 2013; 93:846-852. [PMID: 22887449 DOI: 10.1002/jsfa.5806] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 06/15/2012] [Accepted: 06/16/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Diets high in fruit and vegetables are known to have significant health benefits. This is in part due to the presence of phytochemicals, which possess potential protective health benefits. This study focuses on the ability of strawberries to be bred for higher anthocyanin content. This is a major contributor to the characteristic colour and nutritional value of ripe strawberries, together with phenolic acids, ascorbic acid and total antioxidant capacity. RESULTS Anthocyanins in five commercial strawberry cultivars and three breeding lines were assessed. This led to the discovery of one breeding line (BL 2006-221) as an exceptional source of anthocyanins (~1 g kg(-1) fresh weight), with approximately double the levels of current commercial cultivars. Temperature was shown to influence anthocyanin extraction, with 40 °C being the best extraction temperature using the accelerated solvent extraction (ASE) method. Hue angle and anthocyanin concentration showed a good correlation (r(2) = 0.69). CONCLUSION The new breeding line BL 2006-221 has the potential to be used in the development of phytochemically rich strawberry cultivars. Using hue angle as a screening tool for total anthocyanin concentration and extraction of anthocyanins from strawberries by ASE at 40 °C would support such cultivar development.
Collapse
Affiliation(s)
- Charissa H Fredericks
- School of Land, Crop and Food Sciences, The University of Queensland, St Lucia, QLD, Australia
| | | | | | | | | | | | | |
Collapse
|
153
|
Taing MW, Pierson JT, Shaw PN, Dietzgen RG, Roberts-Thomson SJ, Gidley MJ, Monteith GR. Mango (Mangifera indica L.) peel extract fractions from different cultivars differentially affect lipid accumulation in 3T3-L1 adipocyte cells. Food Funct 2013; 4:481-91. [DOI: 10.1039/c2fo30224a] [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: 12/18/2022]
|
154
|
Padayachee A, Netzel G, Netzel M, Day L, Mikkelsen D, Gidley MJ. Lack of release of bound anthocyanins and phenolic acids from carrot plant cell walls and model composites during simulated gastric and small intestinal digestion. Food Funct 2013; 4:906-16. [DOI: 10.1039/c3fo60091b] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
155
|
Gunness P, Flanagan BM, Shelat K, Gilbert RG, Gidley MJ. Kinetic analysis of bile salt passage across a dialysis membrane in the presence of cereal soluble dietary fibre polymers. Food Chem 2012; 134:2007-13. [DOI: 10.1016/j.foodchem.2012.03.131] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 03/16/2012] [Accepted: 03/29/2012] [Indexed: 11/30/2022]
|
156
|
Mavroudis NE, Gidley MJ, Sjöholm I. Osmotic processing: Effects of osmotic medium composition on the kinetics and texture of apple tissue. Food Res Int 2012. [DOI: 10.1016/j.foodres.2012.06.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
157
|
Haque E, Whittaker AK, Gidley MJ, Deeth HC, Fibrianto K, Bhandari BR. Kinetics of enthalpy relaxation of milk protein concentrate powder upon ageing and its effect on solubility. Food Chem 2012; 134:1368-73. [DOI: 10.1016/j.foodchem.2012.03.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 02/20/2012] [Accepted: 03/07/2012] [Indexed: 12/01/2022]
|
158
|
Shrestha AK, Blazek J, Flanagan BM, Dhital S, Larroque O, Morell MK, Gilbert EP, Gidley MJ. Molecular, mesoscopic and microscopic structure evolution during amylase digestion of maize starch granules. Carbohydr Polym 2012; 90:23-33. [DOI: 10.1016/j.carbpol.2012.04.041] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 04/10/2012] [Accepted: 04/12/2012] [Indexed: 10/28/2022]
|
159
|
Padayachee A, Netzel G, Netzel M, Day L, Zabaras D, Mikkelsen D, Gidley MJ. Binding of polyphenols to plant cell wall analogues - Part 2: Phenolic acids. Food Chem 2012; 135:2287-92. [PMID: 22980803 DOI: 10.1016/j.foodchem.2012.07.004] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [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: 03/21/2012] [Revised: 06/02/2012] [Accepted: 07/02/2012] [Indexed: 11/19/2022]
Abstract
Bacterial cellulose and cellulose-pectin composites were used as well-defined model plant cell wall (PCW) systems to study the interaction between phenolic acids (PA) derived from purple carrot juice concentrate (PCJC) and PCW components. Significant PA depletion from solution occurred, with pure cellulose initially (30s-1h) absorbing more than cellulose-pectin composites in the first hour (ca 20% cf 10-15%), but with all composites absorbing similar levels (ca 30%) after several days. Individual PAs bound to different relative extents with caffeic acid>chlorogenic acid>ferulic acid. Extrapolation of data for these model systems to carrot puree suggests that nutritionally-significant amounts of PAs could bind to cell walls, potentially restricting bioavailability in the small intestine and, as a consequence, delivering PAs to the large intestine for fermentation and metabolism by gut bacteria.
Collapse
Affiliation(s)
- A Padayachee
- ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD 4072, Australia
| | | | | | | | | | | | | |
Collapse
|
160
|
Regina A, Blazek J, Gilbert E, Flanagan BM, Gidley MJ, Cavanagh C, Ral JP, Larroque O, Bird AR, Li Z, Morell MK. Differential effects of genetically distinct mechanisms of elevating amylose on barley starch characteristics. Carbohydr Polym 2012; 89:979-91. [PMID: 24750889 DOI: 10.1016/j.carbpol.2012.04.054] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 04/11/2012] [Accepted: 04/12/2012] [Indexed: 11/25/2022]
Abstract
The relationships between starch structure and functionality are important in underpinning the industrial and nutritional utilisation of starches. In this work, the relationships between the biosynthesis, structure, molecular organisation and functionality have been examined using a series of defined genotypes in barley with low (<20%), standard (20-30%), elevated (30-50%) and high (>50%) amylose starches. A range of techniques have been employed to determine starch physical features, higher order structure and functionality. The two genetic mechanisms for generating high amylose contents (down-regulation of branching enzymes and starch synthases, respectively) yielded starches with very different amylopectin structures but similar gelatinisation and viscosity properties driven by reduced granular order and increased amylose content. Principal components analysis (PCA) was used to elucidate the relationships between genotypes and starch molecular structure and functionality. Parameters associated with granule order (PC1) accounted for a large percentage of the variance (57%) and were closely related to amylose content. Parameters associated with amylopectin fine structure accounted for 18% of the variance but were less closely aligned to functionality parameters.
Collapse
Affiliation(s)
- Ahmed Regina
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Jaroslav Blazek
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Elliot Gilbert
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Bernadine M Flanagan
- Centre for Nutrition and Food Sciences, University of Queensland, St. Lucia, Qld 4072, Australia
| | - Michael J Gidley
- Centre for Nutrition and Food Sciences, University of Queensland, St. Lucia, Qld 4072, Australia
| | - Colin Cavanagh
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Jean-Philippe Ral
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Oscar Larroque
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Anthony R Bird
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Food and Nutritional Sciences, Kintore Avenue, Adelaide, SA, Australia
| | - Zhongyi Li
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Matthew K Morell
- CSIRO Food Futures National Research Flagship, GPO Box 1600, Canberra, ACT 2601, Australia; CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| |
Collapse
|
161
|
Day L, Gomez J, Øiseth SK, Gidley MJ, Williams BA. Faster fermentation of cooked carrot cell clusters compared to cell wall fragments in vitro by porcine feces. J Agric Food Chem 2012; 60:3282-3290. [PMID: 22385330 DOI: 10.1021/jf204974s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Plant cell walls are the major structural component of fruits and vegetables, which break down to cell wall particles during ingestion (oral mastication) or food processing. The major health-promoting effect of cell walls occurs when they reach the colon and are fermented by the gut microbiota. In this study, the fermentation kinetics of carrot cell wall particle dispersions with different particle size and microstructure were investigated in vitro using porcine feces. The cumulative gas production and short-chain fatty acids (SCFAs) produced were measured at time intervals up to 48 h. The results show that larger cell clusters with an average particle size (d(0.5)) of 298 and 137 μm were more rapidly fermented and produced more SCFAs and gas than smaller single cells (75 μm) or cell fragments (50 μm), particularly between 8 and 20 h. Confocal microscopy suggests that the junctions between cells provides an environment that promotes bacterial growth, outweighing the greater specific surface area of smaller particles as a driver for more rapid fermentation. The study demonstrates that it may be possible, by controlling the size of cell wall particles, to design plant-based foods for fiber delivery and promotion of colon fermentation to maximize the potential for human health.
Collapse
Affiliation(s)
- Li Day
- CSIRO Food and Nutritional Sciences, 671 Sneydes Road, Werribee, Victoria 3030, Australia.
| | | | | | | | | |
Collapse
|
162
|
Taing MW, Pierson JT, Hoang VLT, Shaw PN, Dietzgen RG, Gidley MJ, Roberts-Thomson SJ, Monteith GR. Mango fruit peel and flesh extracts affect adipogenesis in 3T3-L1 cells. Food Funct 2012; 3:828-36. [DOI: 10.1039/c2fo30073g] [Citation(s) in RCA: 24] [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: 11/21/2022]
|
163
|
Pierson JT, Dietzgen RG, Shaw PN, Roberts-Thomson SJ, Monteith GR, Gidley MJ. Major Australian tropical fruits biodiversity: Bioactive compounds and their bioactivities. Mol Nutr Food Res 2011; 56:357-87. [DOI: 10.1002/mnfr.201100441] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/30/2011] [Accepted: 09/20/2011] [Indexed: 01/03/2023]
|
164
|
Haque E, Bhandari BR, Gidley MJ, Deeth HC, Whittaker AK. Ageing-induced solubility loss in milk protein concentrate powder: effect of protein conformational modifications and interactions with water. J Sci Food Agric 2011; 91:2576-2581. [PMID: 21656776 DOI: 10.1002/jsfa.4478] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 04/10/2011] [Accepted: 04/18/2011] [Indexed: 05/30/2023]
Abstract
BACKGROUND Protein conformational modifications and water-protein interactions are two major factors believed to induce instability of protein and eventually affect the solubility of milk protein concentrate (MPC) powder. To test these hypotheses, MPC was stored at different water activities (a(w) 0.0-0.85) and temperatures (25 and 45 °C) for up to 12 weeks. Samples were examined periodically to determine solubility, change in protein conformation by Fourier transform infrared (FTIR) spectroscopy and water status (interaction of water with the protein molecule/surface) by measuring the transverse relaxation time (T(2) ) with proton nuclear magnetic resonance ((1) H NMR). RESULTS The solubility of MPC decreased significantly with ageing and this process was enhanced by increasing water activity (a(w) ) and temperature. Minor changes in protein secondary structure were observed with FTIR which indicated some degree of unfolding of protein molecules. The NMR T(2) results indicated the presence of three distinct populations of water molecules and the proton signal intensity and T(2) values of proton fractions varied with storage condition (humidity) and ageing. CONCLUSION Results suggest that protein/protein interactions may be initiated by unfolding of protein molecules that eventually affects solubility.
Collapse
Affiliation(s)
- Enamul Haque
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | | | | | | | | |
Collapse
|
165
|
Shelat KJ, Vilaplana F, Nicholson TM, Gidley MJ, Gilbert RG. Diffusion and rheology characteristics of barley mixed linkage β-glucan and possible implications for digestion. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.07.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
166
|
Butardo VM, Fitzgerald MA, Bird AR, Gidley MJ, Flanagan BM, Larroque O, Resurreccion AP, Laidlaw HKC, Jobling SA, Morell MK, Rahman S. Impact of down-regulation of starch branching enzyme IIb in rice by artificial microRNA- and hairpin RNA-mediated RNA silencing. J Exp Bot 2011; 62:4927-41. [PMID: 21791436 PMCID: PMC3193005 DOI: 10.1093/jxb/err188] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [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: 02/06/2011] [Revised: 05/10/2011] [Accepted: 05/13/2011] [Indexed: 05/19/2023]
Abstract
The inactivation of starch branching IIb (SBEIIb) in rice is traditionally associated with elevated apparent amylose content, increased peak gelatinization temperature, and a decreased proportion of short amylopectin branches. To elucidate further the structural and functional role of this enzyme, the phenotypic effects of down-regulating SBEIIb expression in rice endosperm were characterized by artificial microRNA (amiRNA) and hairpin RNA (hp-RNA) gene silencing. The results showed that RNA silencing of SBEIIb expression in rice grains did not affect the expression of other major isoforms of starch branching enzymes or starch synthases. Structural analyses of debranched starch showed that the doubling of apparent amylose content was not due to an increase in the relative proportion of amylose chains but instead was due to significantly elevated levels of long amylopectin and intermediate chains. Rices altered by the amiRNA technique produced a more extreme starch phenotype than those modified using the hp-RNA technique, with a greater increase in the proportion of long amylopectin and intermediate chains. The more pronounced starch structural modifications produced in the amiRNA lines led to more severe alterations in starch granule morphology and crystallinity as well as digestibility of freshly cooked grains. The potential role of attenuating SBEIIb expression in generating starch with elevated levels of resistant starch and lower glycaemic index is discussed.
Collapse
Affiliation(s)
- Vito M. Butardo
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia
- Grain Quality and Nutrition Centre, International Rice Research Institute, Los Baños, Laguna 4031, Philippines
- Centre for Nutrition and Food Sciences, University of Queensland, Brisbane, Qld 4072, Australia
| | - Melissa A. Fitzgerald
- Grain Quality and Nutrition Centre, International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | - Anthony R. Bird
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Food and Nutritional Sciences, PO Box 10041, Adelaide SA 5000, Australia
| | - Michael J. Gidley
- Centre for Nutrition and Food Sciences, University of Queensland, Brisbane, Qld 4072, Australia
| | - Bernadine M. Flanagan
- Centre for Nutrition and Food Sciences, University of Queensland, Brisbane, Qld 4072, Australia
| | - Oscar Larroque
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia
| | - Adoracion P. Resurreccion
- Grain Quality and Nutrition Centre, International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | - Hunter K. C. Laidlaw
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia
| | - Stephen A. Jobling
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia
| | - Matthew K. Morell
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia
| | - Sadequr Rahman
- CSIRO Food Futures Flagship, GPO Box 93, North Ryde, NSW 1670, Australia
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia
| |
Collapse
|
167
|
Møller SM, Whittaker AK, Stokes JR, Gidley MJ, Andersen U, Bertram HC. Molecular water motions of skim milk powder solutions during acidification studied by 17O and 1H nuclear magnetic resonance and rheology. J Agric Food Chem 2011; 59:10097-10103. [PMID: 21854070 DOI: 10.1021/jf202258h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The molecular motion of water was studied in glucono-δ-lactone-acidified skim milk powder (SMP) solutions with various pH values and dry matter contents. NMR relaxometry measurements revealed that lowering the pH in SMP solutions affected 17O and 1H T2 relaxation rates almost identically. Consequently, the present study indicates that the proteins present in the samples do not affect the 1H relaxation behavior markedly, even at relatively high SMP concentrations (15-25%). Comparison of rheological measurements and NMR measurements suggested that the collapse of κ-casein during acidification could contribute to the initial decrease in 17O and 1H relaxation rate in the pH range between 6.6 and 5.5 for 15% SMP and in the pH range between 6.6 and 5.9 for 25% SMP. However, below pH 5.5 the viscosity and 17O and 1H NMR relaxation rates did not correlate, revealing that the aggregation of casein micelles, which increases viscosity below pH 5.5, does not involve major repartitioning of water.
Collapse
Affiliation(s)
- Sandie M Møller
- Department of Food Science, Faculty of Science and Technology, Aarhus University, Research Centre Aarslev, Kirstinebjergvej 10, DK-5792 Årslev, Denmark
| | | | | | | | | | | |
Collapse
|
168
|
Dhital S, Shrestha AK, Hasjim J, Gidley MJ. Physicochemical and structural properties of maize and potato starches as a function of granule size. J Agric Food Chem 2011; 59:10151-61. [PMID: 21838326 DOI: 10.1021/jf202293s] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Chemical composition, molecular structure and organization, and thermal and pasting properties of maize and potato starches fractionated on the basis of granule size were investigated to understand heterogeneity within granule populations. For both starches, lipid, protein, and mineral contents decreased and apparent amylose contents increased with granule size. Fully branched (whole) and debranched molecular size distributions in maize starch fractions were invariant with granule size. Higher amylose contents and amylopectin hydrodynamic sizes were found for larger potato starch granules, although debranched molecular size distributions did not vary. Larger granules had higher degrees of crystallinity and greater amounts of double and single helical structures. Systematic differences in pasting and thermal properties were observed with granule size. Results suggest that branch length distributions in both amylose and amylopectin fractions are under tighter biosynthetic control in potato starch than either molecular size or amylose/amylopectin ratio, whereas all three parameters are controlled during the biosynthesis of maize starch.
Collapse
Affiliation(s)
- Sushil Dhital
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | | | | | | |
Collapse
|
169
|
Huson MG, Strounina EV, Kealley CS, Rout MK, Church JS, Appelqvist IAM, Gidley MJ, Gilbert EP. Effects of thermal denaturation on the solid-state structure and molecular mobility of glycinin. Biomacromolecules 2011; 12:2092-102. [PMID: 21480635 DOI: 10.1021/bm200080h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effects of moisture and thermal denaturation on the solid-state structure and molecular mobility of soy glycinin powder were investigated using multiple techniques that probe over a range of length and time scales. In native glycinin, increased moisture resulted in a decrease in both the glass transition temperature and the denaturation temperature. The sensitivity of the glass transition temperature to moisture is shown to follow the Gordon-Taylor equation, while the sensitivity of the denaturation temperature to moisture is modeled using Flory's melting point depression theory. While denaturation resulted in a loss of long-range order, the principal conformational structures as detected by infrared are maintained. The temperature range over which the glass to rubber transition occurred was extended on the high temperature side, leading to an increase in the midpoint glass transition temperature and suggesting that the amorphous regions of the newly disordered protein are less mobile. (13)C NMR results supported this hypothesis.
Collapse
Affiliation(s)
- Mickey G Huson
- CSIRO Food Futures Flagship, North Ryde, NSW 2113, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
170
|
Waramboi JG, Dennien S, Gidley MJ, Sopade PA. Characterisation of sweetpotato from Papua New Guinea and Australia: Physicochemical, pasting and gelatinisation properties. Food Chem 2011; 126:1759-70. [DOI: 10.1016/j.foodchem.2010.12.077] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 11/09/2010] [Accepted: 12/15/2010] [Indexed: 11/15/2022]
|
171
|
Mikkelsen D, Gidley MJ, Williams BA. In vitro fermentation of bacterial cellulose composites as model dietary fibers. J Agric Food Chem 2011; 59:4025-4032. [PMID: 21417282 DOI: 10.1021/jf104855e] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Plant cell walls within the human diet are compositionally heterogeneous, so defining the basis of nutritive properties is difficult. Using a pig fecal inoculum, in vitro fermentations of soluble forms of arabinoxylan, mixed-linkage glucan, and xyloglucan were compared with the same polymers incorporated into bacterial cellulose composites. Fermentation rates were highest and similar for the soluble polysaccharides. Cellulose composites incorporating those polysaccharides fermented more slowly and at similar rates to wheat bran. Bacterial cellulose and cotton fermented most slowly. Cellulose composite fermentation resulted in a different short-chain fatty acid profile, compared with soluble polysaccharides, with more butyrate and less propionate. The results suggest that physical form is more relevant than the chemistry of plant cell wall polysaccharides in determining both rate and end-products of fermentation using fecal bacteria. This work also establishes bacterial cellulose composites as a useful model system for the fermentation of complex cell wall dietary fiber.
Collapse
Affiliation(s)
- Deirdre Mikkelsen
- Center for Nutrition and Food Sciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
| | | | | |
Collapse
|
172
|
Dhital S, Shrestha AK, Flanagan BM, Hasjim J, Gidley MJ. Cryo-milling of starch granules leads to differential effects on molecular size and conformation. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.01.002] [Citation(s) in RCA: 53] [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: 12/01/2022]
|
173
|
Abstract
Gluconacetobacter xylinus synthesises cellulose in an analogous fashion to plants. Through fermentation of Ga. xylinus in media containing cell wall polysaccharides from the hemicellulose and/or pectin families, composites with cellulose can be produced. These serve as general models for the assembly, structure, and properties of plant cell walls. By studying structure/property relationships of cellulose composites, the effects of defined hemicellulose and/or pectin polysaccharide structures can be investigated. The macroscopic nature of the composites also allows composite mechanical properties to be characterised. The method for producing cellulose-based composites involves reviving and then culturing Ga. xylinus in the presence of desired hemicelluloses and/or pectins. Different conditions are required for construction of hemicellulose- and pectin-containing composites. Fermentation results in a floating mat or pellicle of cellulose-based composite that can be recovered, washed, and then studied under hydrated conditions without any need for intermediate drying.
Collapse
Affiliation(s)
- Deirdre Mikkelsen
- Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | | |
Collapse
|
174
|
Wilkinson AS, Flanagan BM, Pierson JT, Hewavitharana AK, Dietzgen RG, Shaw PN, Roberts-Thomson SJ, Monteith GR, Gidley MJ. Bioactivity of Mango Flesh and Peel Extracts on Peroxisome Proliferator-Activated Receptor γ[PPARγ] Activation and MCF-7 Cell Proliferation: Fraction and Fruit Variability. J Food Sci 2010; 76:H11-8. [DOI: 10.1111/j.1750-3841.2010.01899.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
175
|
Hasjim J, Lavau GC, Gidley MJ, Gilbert RG. In Vivo and In Vitro Starch Digestion: Are Current in Vitro Techniques Adequate? Biomacromolecules 2010; 11:3600-8. [DOI: 10.1021/bm101053y] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jovin Hasjim
- The University of Queensland, Centre for Nutrition and Food Sciences, Brisbane, QLD 4072, Australia
| | - Gautier Cesbron Lavau
- The University of Queensland, Centre for Nutrition and Food Sciences, Brisbane, QLD 4072, Australia
| | - Michael J. Gidley
- The University of Queensland, Centre for Nutrition and Food Sciences, Brisbane, QLD 4072, Australia
| | - Robert G. Gilbert
- The University of Queensland, Centre for Nutrition and Food Sciences, Brisbane, QLD 4072, Australia
| |
Collapse
|
176
|
Ginjom IR, D'Arcy BR, Caffin NA, Gidley MJ. Phenolic contents and antioxidant activities of major Australian red wines throughout the winemaking process. J Agric Food Chem 2010; 58:10133-10142. [PMID: 20804125 DOI: 10.1021/jf100822n] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Three Australian red wine types (Shiraz, Cabernet Sauvignon, and Merlot) were analyzed for antioxidant activity and a range of phenolic component contents using various spectral methods. More than half of the total phenolic compounds were tannins, whereas monomeric anthocyanins and flavonols were present in much lesser amounts (<10%). The evolution of phenolic contents and the respective antioxidant activities in wine samples from all stages of winemaking showed progressive changes toward those of commercial wines. The antioxidant activity of the wines in DPPH and ABTS assays was positively correlated with total phenolic contents and tannins. Comparisons of the three wine varieties based on their individual phenolic component groups and antioxidant activities showed limited differences between the different varieties. However, when all of the variables were combined in a principal component analysis, variety differentiation was observed. The three varieties of red wines all contained similar and high concentrations of antioxidants despite differences in grape variety/maturity and winemaking process, suggesting that related health benefits would accrue from all of the red wines studied.
Collapse
Affiliation(s)
- Irine R Ginjom
- School of Land, Crop and Food Sciences, The University of Queensland, Brisbane, QLD, Australia
| | | | | | | |
Collapse
|
177
|
Tydeman EA, Parker ML, Wickham MSJ, Rich GT, Faulks RM, Gidley MJ, Fillery-Travis A, Waldron KW. Effect of carrot (Daucus carota) microstructure on carotene bioaccessibilty in the upper gastrointestinal tract. 1. In vitro simulations of carrot digestion. J Agric Food Chem 2010; 58:9847-9854. [PMID: 20698537 DOI: 10.1021/jf101034a] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Studies investigating carotene bioaccessibility (release from the food matrix to a solubilized form) directly from plant material during the process of digestion are scarce, mainly due to the difficulties associated with obtaining such material. Therefore, this paper examines the relationship between tissue microstructure and carotene bioaccessibility using an in vitro digestion model. Dietary oil provides a pool for the initial solubilization. Therefore, carotene partitioning into an emulsified oil phase was assessed using raw carrot tissue and carrot tissue subjected to various degrees of heating and particle size reduction and, in all cases, was found to be greatly reduced compared with juiced carrot. Carotene bioaccessibility was found to be greater from raw tissues than heated tissues of the same size. This is because heating increases the propensity for intact cells to separate, effectively encapsulating the carotene. Although the gross structure of the tissues was found to be relatively unaffected by in vitro digestion, at the cellular level some cell-wall swelling and cell death were observed, particularly close to the surfaces of the tissue. This study suggests that cell-wall rupture prior to digestion is an absolute requirement for carotene bioaccessibility in the upper intestine and that heating does not enhance carotene release from intact cells.
Collapse
Affiliation(s)
- Elizabeth A Tydeman
- Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
178
|
Tydeman EA, Parker ML, Faulks RM, Cross KL, Fillery-Travis A, Gidley MJ, Rich GT, Waldron KW. Effect of carrot (Daucus carota) microstructure on carotene bioaccessibility in the upper gastrointestinal tract. 2. In vivo digestions. J Agric Food Chem 2010; 58:9855-60. [PMID: 20806973 DOI: 10.1021/jf1010353] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Nutrient bioaccessibility and subsequent absorption will be directly influenced by changes in food structure during gastrointestinal processing. The accompanying paper (Tydeman et al. J. Agric. Food Chem. 2010, 58, doi: 10.1021/jf101034a) reported results on the effect of carrot processing on the release of carotene into lipid phases during in vitro gastric and small intestinal digestions. This paper describes results from in vivo digestion of two of the types of processed carrot used previously, raw grated carrot and cooked carrot mashed to a puree. Ileostomy effluents from human volunteers fed meals containing the carrot material were used to study tissue microstructure and carotene release. Raw carrot shreds and intact cells that had survived the pureeing process were identifiable in ileal effluent. The gross tissue structure in the shreds had not changed following digestion. Carotene-containing particles remained encapsulated in intact cells, but were absent from ruptured cells. Microscopy revealed marked changes to the cell walls including swelling and pectin solubilization, which increased in severity with increasing residence time in the upper gut. These observations were entirely consistent with the in vitro observations. It was concluded that a single intact cell wall is sufficient to reduce carotene bioaccessibility from a cell by acting as a physical barrier, which is not broken down during upper gut digestion.
Collapse
Affiliation(s)
- Elizabeth A Tydeman
- Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
179
|
|
180
|
Singh DP, Liu LH, Øiseth SK, Beloy J, Lundin L, Gidley MJ, Day L. Influence of boron on carrot cell wall structure and its resistance to fracture. J Agric Food Chem 2010; 58:9181-9189. [PMID: 23654242 DOI: 10.1021/jf100688t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Plant cell wall structure integrity and associated tissue mechanical properties is one of key determinants for the perceived texture of plant-based foods. Carrots (Daucus carota) were used to investigate the effect of mineral supply of boron (B) and/or calcium (Ca), during plant growth, on the plant cell wall structure and mechanical properties of matured root tissues. Five commercial cultivars of carrots, Kuroda (orange), Dragon Purple, Kuttiger White, Yellow, and Nutri-Red, were cultivated under controlled glasshouse conditions over two seasons. Significant increases in the accumulation of B and Ca were found for all cultivars of carrots when additional B and Ca were included in the nutrient feeding solutions throughout the plant growth period. Elevated levels of B in carrot root tissue reduced the uptake of Ca and other mineral nutrients and enhanced plant cell wall structural integrity, its resistance to fracture, and the weight and size (both diameter and length) of carrots. Although higher amounts of Ca were accumulated in the plant materials, the additional supply of Ca did not have a significant effect on the mechanical properties of mature plant tissues or on the uptake of B by the plant. The results suggest that B cross-linking of pectin (rhamnogalacturonan II) has a greater influence on mature tissue mechanical properties than Ca cross-linking of pectin (homogalacturonan) when supplied during plant growth.
Collapse
|
181
|
Witt T, Gidley MJ, Gilbert RG. Starch digestion mechanistic information from the time evolution of molecular size distributions. J Agric Food Chem 2010; 58:8444-8452. [PMID: 20572670 DOI: 10.1021/jf101063m] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Size-exclusion chromatography [SEC, also termed gel permeation chromatography (GPC)] is used to measure the time evolution of the distributions of molecular size and of branch length as starch is subjected to in vitro digestion, including studying the development of enzyme-resistant starch. The method is applied to maize starches with varying amylose contents; the starches were extruded so as to provide an analogue for processed food. The initial rates of digestion of amylose and amylopectin components were found to be the same for high-amylose starches. A small starch species, not present in the original starting material, was formed during the digestion process; this new species has a slower digestion rate and is probably formed by retrogradation of longer branches of amylose and amylopectin as they are partially or wholly liberated from their parent starch molecule during the digestion process. The data suggest that the well-known connection between high amylose content and resistant starch arises from the greater number of longer branches, which can form the small retrograded species. The method is useful for the purpose of comparisons between different starches undergoing the process of digestion, by observing the changes in their molecular structures, as an adjunct to detailed studies of the enzyme-resistant fraction.
Collapse
Affiliation(s)
- Torsten Witt
- Centre for Nutrition & Food Sciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | | | | |
Collapse
|
182
|
Haque E, Bhandari BR, Gidley MJ, Deeth HC, Møller SM, Whittaker AK. Protein conformational modifications and kinetics of water-protein interactions in milk protein concentrate powder upon aging: effect on solubility. J Agric Food Chem 2010; 58:7748-7755. [PMID: 20536137 DOI: 10.1021/jf1007055] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Protein conformational modifications and water-protein interactions are two major factors believed to induce instability of protein and eventually affect the solubility of milk protein concentrate (MPC) powder. To test these hypotheses, MPC was stored at different water activities (a(w) 0.0-0.85) and temperatures (25 and 45 degrees C) for up to 12 weeks. Samples were examined periodically to determine solubility, change in protein conformation by Fourier transform infrared (FTIR) spectroscopy and principal component analysis (PCA), and water status (interaction of water with the protein molecule/surface) by measuring the transverse relaxation time (T(2)) with proton nuclear magnetic resonance ((1)H NMR). The solubility of MPC decreased significantly with aging, and this process was enhanced by increasing water activity (a(w)) and storage temperature. Minor changes in protein secondary structure were observed with FTIR, which indicated some degree of unfolding of protein molecules. PCA of the FTIR data was able to discriminate samples according to moisture content and storage period. Partial least-squares (PLS) analysis showed some correlation between FTIR spectral feature and solubility. The NMR T(2) results indicated the presence of three distinct populations of water molecules, and the proton signal intensity and T(2) values of proton fractions varied with storage conditions (humidity, temperature) and aging. Results suggest that protein/protein interactions may be initiated by unfolding of protein molecules that eventually affects solubility.
Collapse
Affiliation(s)
- Enamul Haque
- School of Land, Crop and Food Sciences, University of Queensland, QLD 4072 Australia
| | | | | | | | | | | |
Collapse
|
183
|
Daud NH, Aung CS, Hewavitharana AK, Wilkinson AS, Pierson JT, Roberts-Thomson SJ, Shaw PN, Monteith GR, Gidley MJ, Parat MO. Mango extracts and the mango component mangiferin promote endothelial cell migration. J Agric Food Chem 2010; 58:5181-5186. [PMID: 20349963 DOI: 10.1021/jf100249s] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This study tested the hypothesis that mango extracts contain bioactive molecules capable of modulating endothelial cell migration, an essential step in the formation of new blood vessels or angiogenesis. The formation of new blood vessels is an important therapeutic target for diseases such as limb ischemia, coronary infarction or stroke. We examined the effect of mango peel and flesh extracts as well as the individual polyphenolic molecules, mangiferin and quercetin, on bovine aortic cell migration using a modified Boyden chamber assay. Our results show that mangiferin, and extracts rich in mangiferin, increase endothelial cell migration. The dose-effect relationship for various extracts further suggests that this action of mangiferin is modulated by other components present in the extracts. The promigratory effect of mango extracts or mangiferin was unrelated to an effect on cell proliferation, and did not involve a change in the production of matrix metalloprotease-2 or -9 by the endothelial cells. Taken together, these results suggest that mangiferin present in mango extracts may have health promoting effects in diseases related to the impaired formation of new blood vessels.
Collapse
Affiliation(s)
- Noor Huda Daud
- School of Pharmacy, University of Queensland, Woolloongabba, Queensland, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
184
|
Nguyen VT, Flanagan B, Mikkelsen D, Ramirez S, Rivas L, Gidley MJ, Dykes GA. Spontaneous mutation results in lower cellulose production by a Gluconacetobacter xylinus strain from Kombucha. Carbohydr Polym 2010. [DOI: 10.1016/j.carbpol.2009.11.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
185
|
|
186
|
Mimouni A, Deeth HC, Whittaker AK, Gidley MJ, Bhandari BR. Rehydration of high-protein-containing dairy powder: Slow- and fast-dissolving components and storage effects. ACTA ACUST UNITED AC 2010. [DOI: 10.1051/dst/2010002] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
187
|
Gidley MJ, Hanashiro I, Hani NM, Hill SE, Huber A, Jane JL, Liu Q, Morris GA, Rolland-Sabaté A, Striegel AM, Gilbert RG. Reliable measurements of the size distributions of starch molecules in solution: Current dilemmas and recommendations. Carbohydr Polym 2010. [DOI: 10.1016/j.carbpol.2009.07.056] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
188
|
Mimouni A, Deeth HC, Whittaker AK, Gidley MJ, Bhandari BR. Rehydration process of milk protein concentrate powder monitored by static light scattering. Food Hydrocoll 2009. [DOI: 10.1016/j.foodhyd.2009.01.010] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
189
|
Al-Rabadi GJ, Gilbert RG, Gidley MJ. Effect of particle size on kinetics of starch digestion in milled barley and sorghum grains by porcine alpha-amylase. J Cereal Sci 2009. [DOI: 10.1016/j.jcs.2009.05.001] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
190
|
Cave RA, Seabrook SA, Gidley MJ, Gilbert RG. Characterization of Starch by Size-Exclusion Chromatography: The Limitations Imposed by Shear Scission. Biomacromolecules 2009; 10:2245-53. [DOI: 10.1021/bm900426n] [Citation(s) in RCA: 266] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Richard A. Cave
- The University of Queensland, Centre for Nutrition and Food Sciences, LCAFS, Brisbane, Qld 4072, Australia
| | - Shane A. Seabrook
- The University of Queensland, Centre for Nutrition and Food Sciences, LCAFS, Brisbane, Qld 4072, Australia
| | - Michael J. Gidley
- The University of Queensland, Centre for Nutrition and Food Sciences, LCAFS, Brisbane, Qld 4072, Australia
| | - Robert G. Gilbert
- The University of Queensland, Centre for Nutrition and Food Sciences, LCAFS, Brisbane, Qld 4072, Australia
| |
Collapse
|
191
|
|
192
|
Mikkelsen D, Flanagan BM, Dykes GA, Gidley MJ. Influence of different carbon sources on bacterial cellulose production by Gluconacetobacter xylinus strain ATCC 53524. J Appl Microbiol 2009; 107:576-83. [PMID: 19302295 DOI: 10.1111/j.1365-2672.2009.04226.x] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS To determine the effect of carbon sources on cellulose produced by Gluconacetobacter xylinus strain ATCC 53524, and to characterize the purity and structural features of the cellulose produced. METHODS AND RESULTS Modified Hestrin Schramm medium containing the carbon sources mannitol, glucose, glycerol, fructose, sucrose or galactose were inoculated with Ga. xylinus strain ATCC 53524. Plate counts indicated that all carbon sources supported growth of the strain. Sucrose and glycerol gave the highest cellulose yields of 3.83 and 3.75 g l(-1) respectively after 96 h fermentation, primarily due to a surge in cellulose production in the last 12 h. Mannitol, fructose or glucose resulted in consistent rates of cellulose production and yields of >2.5 g l(-1). Solid state (13)C CP/MAS NMR revealed that irrespective of the carbon source, the cellulose produced by ATCC 53524 was pure and highly crystalline. Scanning electron micrographs illustrated the densely packed network of cellulose fibres within the pellicles and that the different carbon sources did not markedly alter the micro-architecture of the resulting cellulose pellicles. CONCLUSIONS The production rate of bacterial cellulose by Ga. xylinus (ATCC 53524) was influenced by different carbon sources, but the product formed was indistinguishable in molecular and microscopic features. SIGNIFICANCE AND IMPACT OF THE STUDY Our studies for the first time examined the influence of different carbon sources on the rate of cellulose production by Ga. xylinus ATCC 53524, and the molecular and microscopic features of the cellulose produced.
Collapse
Affiliation(s)
- D Mikkelsen
- Centre for Nutrition and Food Sciences, The University of Queensland, Brisbane, Qld, Australia.
| | | | | | | |
Collapse
|
193
|
Kealley CS, Rout MK, Dezfouli MR, Strounina E, Whittaker AK, Appelqvist IAM, Lillford PJ, Gilbert EP, Gidley MJ. Structure and molecular mobility of soy glycinin in the solid state. Biomacromolecules 2008; 9:2937-46. [PMID: 18808181 DOI: 10.1021/bm800721d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a multitechnique study of structural organization and molecular mobility for soy glycinin at a low moisture content (<30% w/w) and relate these to its glass-to-rubber transition. Small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy are used to probe structure and mobility on different length and time scales. NMR (approximately 10(-6) to 10(-3) s) reveals transitions at a higher moisture content (>17%) than DSC or SAXS, which sample for much longer times (approximately 10 to 10(3) s) and where changes are detected at >13% water content at 20 degrees C. The mobility transitions are accompanied by small changes in unit-cell parameters and IR band intensities and are associated with the enhanced motion of the polypeptide backbone. This study shows how characteristic features of the ordered regions of the protein (probed by SAXS and FTIR) and mobile segments (probed by NMR and DSC) can be separately monitored and integrated within a mobility transformation framework.
Collapse
Affiliation(s)
- Catherine S Kealley
- Bragg Institute, Australian Nuclear Science and Technology Organization, PMB 1, Menai, NSW 2234 Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
194
|
Zalifah M, Greenway DR, Caffin NA, D’Arcy BR, Gidley MJ. Application of labelled magnitude satiety scale in a linguistically-diverse population. Food Qual Prefer 2008. [DOI: 10.1016/j.foodqual.2008.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
195
|
Abstract
Hydrocolloid gel particles of micron and sub-micron size are particularly attractive for use in many applications in the food, agricultural, pharmaceutical, and chemical industries, due to their biocompatibility, perception as "natural" materials, and soft-solid texture. Industrial applications for such particles include uses as texturizers in confectionery and cosmetic products, slow-release encapsulation agents for flavors, nutrients, and pharmaceutical products, and thickeners in soups and sauces. Properties such as particle size, hardness, shape, texture, and molecular release rates can be important for individual applications. In addition, product formats will determine specific needs for physical form (e.g. dry or wet) and compatibility with other components. The diverse range of potential applications for hydrocolloid gel particles provide a driver for understanding-led tailoring of raw material and process conditions. This review introduces some of the materials that are used to form hydrocolloid gel particles and the corresponding gel formation mechanisms. One issue of importance in the production of hydrocolloid gel particles is the control of particle properties, such as release profiles, strength, and detectability within products. An alternative technique to traditional methods of hydrocolloid gel particle production is evaluated and a model for control of particle size, and subsequently other particle properties, is proposed. Key properties of hydrocolloid gel particles are identified and characterization methods for evaluating these properties are described.
Collapse
Affiliation(s)
- P Burey
- Centre for Nutrition and Food Sciences, The University of Queensland, Brisbane, Australia.
| | | | | | | |
Collapse
|
196
|
Lopez-Rubio A, Flanagan BM, Gilbert EP, Gidley MJ. A novel approach for calculating starch crystallinity and its correlation with double helix content: a combined XRD and NMR study. Biopolymers 2008; 89:761-8. [PMID: 18428208 DOI: 10.1002/bip.21005] [Citation(s) in RCA: 440] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A peak fitting procedure has been implemented for calculating crystallinity in granular starches. This methodology, widely used for synthetic polymers, is proposed to better reflect the crystalline content of starches than the method normally used, in which it is assumed that relatively perfect crystalline domains are interspersed with amorphous regions. The new approach takes into account irregularities in crystals that are expected to exist in semicrystalline materials. Therefore, instead of assuming that the amorphous background extends up to the base of diffraction peaks, the whole X-ray diffraction (XRD) profile is fitted to an amorphous halo and several discrete crystalline diffraction peaks. The crystallinity values obtained from the XRD patterns of a wide range of native starches using this fitting technique are very similar to the double helix contents as measured by (13)C solid state NMR, suggesting that double helices in granular starches are present within irregular crystals. This contrasts with previous descriptions of crystalline and noncrystalline double helices that were based on the analysis of XRD profiles as perfect crystals interspersed in a noncrystalline background. Furthermore, with this fitting methodology it is possible to calculate the contribution from the different crystal polymorphs of starch to the total crystallinity.
Collapse
Affiliation(s)
- Amparo Lopez-Rubio
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Menai, NSW, Australia.
| | | | | | | |
Collapse
|
197
|
Nguyen VT, Flanagan B, Gidley MJ, Dykes GA. Characterization of cellulose production by a Gluconacetobacter xylinus strain from Kombucha. Curr Microbiol 2008; 57:449-53. [PMID: 18704575 DOI: 10.1007/s00284-008-9228-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 06/17/2008] [Indexed: 12/01/2022]
Abstract
The aims of this work were to characterize and improve cellulose production by a Gluconoacetobacter xylinus strain isolated from Kombucha and determine the purity and some structural features of the cellulose from this strain. Cellulose yield in tea medium with both black tea and green tea and in Hestrin and Schramm (HS) medium under both static and agitated cultures was compared. In the tea medium, the highest cellulose yield was obtained with green tea (approximately 0.20 g/L) rather than black tea (approximately 0.14 g/L). Yield in HS was higher (approximately 0.28 g/L) but did not differ between static and agitated incubation. (1)H-NMR and (13)C-NMR spectroscopy indicated that the cellulose is pure (free of acetan) and has high crystallinity, respectively. Cellulose yield was improved by changing the type and level of carbon and nitrogen source in the HS medium. A high yield of approximately 2.64 g/L was obtained with mannitol at 20 g/L and corn steep liquor at 40 g/L in combination. In the tea medium, tea at a level of 3 g/L gave the highest cellulose yield and the addition of 3 g/L of tea to the HS medium increased cellulose yield to 3.34 g/L. In conclusion, the G. xylinus strain from Kombucha had different cellulose-producing characteristics than previous strains isolated from fruit. Cellulose was produced in a pure form and showed high potential applicability. Our studies extensively characterized cellulose production from a G. xylinus strain from Kombucha for the first time, indicating both similarities and differences to strains from different sources.
Collapse
Affiliation(s)
- Vu Tuan Nguyen
- School of Land, Crop and Food Sciences, University of Queensland, St Lucia, Queensland, Australia
| | | | | | | |
Collapse
|
198
|
Lopez-Rubio A, Flanagan BM, Shrestha AK, Gidley MJ, Gilbert EP. Molecular Rearrangement Of Starch During In Vitro Digestion: Toward A Better Understanding Of Enzyme Resistant Starch Formation In Processed Starches. Biomacromolecules 2008; 9:1951-8. [DOI: 10.1021/bm800213h] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amparo Lopez-Rubio
- Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia, Centre for Nutrition and Food Sciences, University of Queensland, St Lucia, QLD 4072, Australia, and Commonwealth Scientific and Industrial Research Organisation, Food Futures National Research Flagship, Riverside Corporate Park, North Ryde, NSW, Australia
| | - Bernadine M. Flanagan
- Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia, Centre for Nutrition and Food Sciences, University of Queensland, St Lucia, QLD 4072, Australia, and Commonwealth Scientific and Industrial Research Organisation, Food Futures National Research Flagship, Riverside Corporate Park, North Ryde, NSW, Australia
| | - Ashok K. Shrestha
- Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia, Centre for Nutrition and Food Sciences, University of Queensland, St Lucia, QLD 4072, Australia, and Commonwealth Scientific and Industrial Research Organisation, Food Futures National Research Flagship, Riverside Corporate Park, North Ryde, NSW, Australia
| | - Michael J. Gidley
- Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia, Centre for Nutrition and Food Sciences, University of Queensland, St Lucia, QLD 4072, Australia, and Commonwealth Scientific and Industrial Research Organisation, Food Futures National Research Flagship, Riverside Corporate Park, North Ryde, NSW, Australia
| | - Elliot P. Gilbert
- Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia, Centre for Nutrition and Food Sciences, University of Queensland, St Lucia, QLD 4072, Australia, and Commonwealth Scientific and Industrial Research Organisation, Food Futures National Research Flagship, Riverside Corporate Park, North Ryde, NSW, Australia
| |
Collapse
|
199
|
Wilkinson AS, Monteith GR, Shaw PN, Lin CN, Gidley MJ, Roberts-Thomson SJ. Effects of the mango components mangiferin and quercetin and the putative mangiferin metabolite norathyriol on the transactivation of peroxisome proliferator-activated receptor isoforms. J Agric Food Chem 2008; 56:3037-3042. [PMID: 18393431 DOI: 10.1021/jf800046n] [Citation(s) in RCA: 37] [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] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mangos are a source of bioactive compounds with potential health-promoting activity. This study evaluated the abilities of the mango components quercetin and mangiferin and the aglycone derivative of mangiferin, norathyriol, to modulate the transactivation of peroxisome proliferator-activated receptor isoforms (PPARs). PPARs are transcription factors important in many human diseases. Through the use of a gene reporter assay it was shown that quercetin inhibited the activation of all three isoforms of PPARs (PPARgamma IC(50) = 56.3 microM; PPARalpha IC(50) = 59.6 microM; PPARbeta IC(50) = 76.9 microM) as did norathyriol (PPARgamma IC(50) = 153.5 microM; PPARalpha IC(50) = 92.8 microM; PPARbeta IC(50) = 102.4 microM), whereas mangiferin did not inhibit the transactivation of any isoform. These findings suggest that mango components and metabolites may alter transcription and could contribute to positive health benefits via this or similar mechanisms.
Collapse
Affiliation(s)
- Ashley S Wilkinson
- School of Pharmacy and Centre for Nutrition and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | | | | | | | | | | |
Collapse
|
200
|
Hernández JM, Gaborieau M, Castignolles P, Gidley MJ, Myers AM, Gilbert RG. Mechanistic Investigation of a Starch-Branching Enzyme Using Hydrodynamic Volume SEC Analysis. Biomacromolecules 2008; 9:954-65. [DOI: 10.1021/bm701213p] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Javier M. Hernández
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Marianne Gaborieau
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Patrice Castignolles
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Michael J. Gidley
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Alan M. Myers
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Robert G. Gilbert
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| |
Collapse
|