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Nakamura Y. A model for the reproduction of amylopectin cluster by coordinated actions of starch branching enzyme isoforms. PLANT MOLECULAR BIOLOGY 2023:10.1007/s11103-023-01352-6. [PMID: 37294528 DOI: 10.1007/s11103-023-01352-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/10/2023] [Indexed: 06/10/2023]
Abstract
Amylopectin is a highly branched glucan which accounts for approximately 65-85% of starch in most plant tissues. It is crucially important to understand the biosynthetic process of this glucan in regulating the structure and functional properties of starch granules. Currently, the most accepted ideas of structural feature and biosynthesis of amylopectin are that amylopectin is composed of a branched element called "cluster" and that the essential process of amylopectin biosynthesis is to reproduce a new cluster from the existing cluster. The present paper proposes a model explaining the whole process of amylopectin biosynthesis as to how the new cluster is reproduced by concerted actions of multiple isoforms of starch biosynthetic enzymes, particularly by combinations of distinct roles of starch branching enzyme (BE) isoforms. This model proposes for the first time the molecular mechanism as to how the formation of a new cluster is initiated, and the reason why BEI can play a major role in this step. This is because BEI has a rather broad chain-length preference compared to BEIIb, because a low preference of BEI for the substrate chain-length is advantageous for branching a couple of elongated chains that are not synchronously formed and thus these chains having varied lengths could be safely attacked by this isoform. On the contrary, it is unlikely that BEIIb is involved in this reaction because it can react to only short chains having degree of polymerization of 12-14. BEIIa is possibly able to complement the role of BEI to some extent, because BEIIa can attack basically short chains but its chain-length preference is lower compared with BEIIb. The model implies that the first branches mainly formed by BEI to construct the amorphous lamellae whereas the second branches predominantly formed by BEIIb are located mainly in the crystalline lamellae. This paper provides new insights into the roles of BEI, BEIIb, and BEIIa in amylopectin biosynthesis in cereal endosperm.
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Affiliation(s)
- Yasunori Nakamura
- Starch Technologies Co., Ltd, Akita Prefectural University, Shimoshinjo-Nakano, Akita-City, Akita, 010-0195, Japan.
- Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-Nakano, Akita-City, Akita, 010-0195, Japan.
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2
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Ogawa Y, Putaux JL, Nishiyama Y. Crystallography of polysaccharides: Current state and challenges. Curr Opin Chem Biol 2022; 70:102183. [PMID: 35803025 DOI: 10.1016/j.cbpa.2022.102183] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/27/2022] [Accepted: 06/07/2022] [Indexed: 11/25/2022]
Abstract
Polysaccharides are the most abundant class of biopolymers, holding an important place in biological systems and sustainable material development. Their spatial organization and intra- and intermolecular interactions are thus of great interest. However, conventional single crystal crystallography is not applicable since polysaccharides crystallize only into tiny crystals. Several crystallographic methods have been developed to extract atomic-resolution structural information from polysaccharide crystals. Small-probe single crystal diffractometry, high-resolution fiber diffraction and powder diffraction combined with molecular modeling brought new insights from various types of polysaccharide crystals, and led to many high-resolution crystal structures over the past two decades. Current challenges lie in the analysis of disorder and defects by further integrating molecular modeling methods for low-resolution diffraction data.
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Affiliation(s)
- Yu Ogawa
- Univ. Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France.
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3
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Junejo SA, Flanagan BM, Zhang B, Dhital S. Starch structure and nutritional functionality - Past revelations and future prospects. Carbohydr Polym 2022; 277:118837. [PMID: 34893254 DOI: 10.1016/j.carbpol.2021.118837] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/17/2021] [Accepted: 10/28/2021] [Indexed: 02/08/2023]
Abstract
Starch exists naturally as insoluble semi-crystalline granules assembled by amylose and amylopectin. Acknowledging the pioneers, we have reviewed the major accomplishments in the area of starch structure from the early 18th century and further established the relation of starch structure to nutritional functionality. Although a huge array of work is reported in the area, the review identified that some features of starch are still not fully understood and needs further elucidation. With the rise of diet-related diseases, it has never been more important to understand starch structure and use that knowledge to improve the nutritional value of the world's principal energy source.
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Affiliation(s)
- Shahid Ahmed Junejo
- School of Food Science and Engineering, Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health, South China University of Technology, Guangzhou 510640, China
| | - Bernadine M Flanagan
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Bin Zhang
- School of Food Science and Engineering, Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health, South China University of Technology, Guangzhou 510640, China.
| | - Sushil Dhital
- Department of Chemical Engineering, Monash University, Clayton Campus, VIC 3800, Australia.
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Tetlow IJ, Bertoft E. A Review of Starch Biosynthesis in Relation to the Building Block-Backbone Model. Int J Mol Sci 2020; 21:E7011. [PMID: 32977627 PMCID: PMC7582286 DOI: 10.3390/ijms21197011] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 01/31/2023] Open
Abstract
Starch is a water-insoluble polymer of glucose synthesized as discrete granules inside the stroma of plastids in plant cells. Starch reserves provide a source of carbohydrate for immediate growth and development, and act as long term carbon stores in endosperms and seed tissues for growth of the next generation, making starch of huge agricultural importance. The starch granule has a highly complex hierarchical structure arising from the combined actions of a large array of enzymes as well as physicochemical self-assembly mechanisms. Understanding the precise nature of granule architecture, and how both biological and abiotic factors determine this structure is of both fundamental and practical importance. This review outlines current knowledge of granule architecture and the starch biosynthesis pathway in relation to the building block-backbone model of starch structure. We highlight the gaps in our knowledge in relation to our understanding of the structure and synthesis of starch, and argue that the building block-backbone model takes accurate account of both structural and biochemical data.
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Affiliation(s)
- Ian J. Tetlow
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, ON N1G 2W1, Canada
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Starch and Glycogen Analyses: Methods and Techniques. Biomolecules 2020; 10:biom10071020. [PMID: 32660096 PMCID: PMC7407607 DOI: 10.3390/biom10071020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 01/16/2023] Open
Abstract
For complex carbohydrates, such as glycogen and starch, various analytical methods and techniques exist allowing the detailed characterization of these storage carbohydrates. In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included.
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6
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Vamadevan V, Blennow A, Buléon A, Goldstein A, Bertoft E. Distinct Properties and Structures Among B-Crystalline Starch Granules. STARCH-STARKE 2017. [DOI: 10.1002/star.201700240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Andreas Blennow
- Department of Plant and Environmental Sciences, University of Copenhagen; Frederiksberg C Denmark
| | - Alain Buléon
- UR1268 Biopolymères Interactions Assemblages, INRA; Nantes France
| | - Avi Goldstein
- Department of Food Science and Nutrition, University of Minnesota; St Paul MN USA
| | - Eric Bertoft
- Department of Food Science and Nutrition, University of Minnesota; St Paul MN USA
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Pérez S, de Sanctis D. Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience. Beilstein J Org Chem 2017; 13:1145-1167. [PMID: 28684994 PMCID: PMC5480326 DOI: 10.3762/bjoc.13.114] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/17/2017] [Indexed: 11/29/2022] Open
Abstract
Synchrotron radiation is the most versatile way to explore biological materials in different states: monocrystalline, polycrystalline, solution, colloids and multiscale architectures. Steady improvements in instrumentation have made synchrotrons the most flexible intense X-ray source. The wide range of applications of synchrotron radiation is commensurate with the structural diversity and complexity of the molecules and macromolecules that form the collection of substrates investigated by glycoscience. The present review illustrates how synchrotron-based experiments have contributed to our understanding in the field of structural glycobiology. Structural characterization of protein–carbohydrate interactions of the families of most glycan-interacting proteins (including glycosyl transferases and hydrolases, lectins, antibodies and GAG-binding proteins) are presented. Examples concerned with glycolipids and colloids are also covered as well as some dealing with the structures and multiscale architectures of polysaccharides. Insights into the kinetics of catalytic events observed in the crystalline state are also presented as well as some aspects of structure determination of protein in solution.
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Affiliation(s)
- Serge Pérez
- Department of Molecular Pharmacochemistry, CNRS-University Grenoble Alpes, France
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8
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Crystallite orientation maps in starch granules from polarized Raman spectroscopy (PRS) data. Carbohydr Polym 2016; 154:70-6. [DOI: 10.1016/j.carbpol.2016.08.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/06/2016] [Accepted: 08/09/2016] [Indexed: 11/20/2022]
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9
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Santucci SC, Cojoc D, Amenitsch H, Marmiroli B, Sartori B, Burghammer M, Schoeder S, DiCola E, Reynolds M, Riekel C. Optical tweezers for synchrotron radiation probing of trapped biological and soft matter objects in aqueous environments. Anal Chem 2011; 83:4863-70. [PMID: 21542583 DOI: 10.1021/ac200515x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Investigations of single fragile objects manipulated by optical forces with high brilliance X-ray beams may initiate the development of new research fields such as protein crystallography in an aqueous environment. We have developed a dedicated optical tweezers setup with a compact, portable, and versatile geometry for the customary manipulation of objects for synchrotron radiation applications. Objects of a few micrometers up to a few tens of micrometers size can be trapped for extended periods of time. The selection and positioning of single objects out of a batch of many can be performed semi-automatically by software routines. The performance of the setup has been tested by wide-angle and small-angle X-ray scattering experiments on single optically trapped starch granules, using a synchrotron radiation microbeam. We demonstrate here for the first time the feasibility of microdiffraction on optically trapped protein crystals. Starch granules and insulin crystals were repeatedly raster-scanned at about 50 ms exposure/raster-point up to the complete loss of the structural order. Radiation damage in starch granules results in the appearance of low-angle scattering due to the breakdown of the polysaccharide matrix. For insulin crystals, order along the densely packed [110] direction is preferentially maintained until complete loss of long-range order.
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Affiliation(s)
- Silvia C Santucci
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France.
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10
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Bayés-García L, Calvet T, Cuevas-Diarte MÀ, Ueno S, Sato K. Heterogeneous microstructures of spherulites of lipid mixtures characterized with synchrotron radiation microbeam X-ray diffraction. CrystEngComm 2011. [DOI: 10.1039/c1ce05667k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Pérez S, Bertoft E. The molecular structures of starch components and their contribution to the architecture of starch granules: A comprehensive review. STARCH-STARKE 2010. [DOI: 10.1002/star.201000013] [Citation(s) in RCA: 897] [Impact Index Per Article: 64.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Peroni-Okita FH, Simão RA, Cardoso MB, Soares CA, Lajolo FM, Cordenunsi BR. In vivo degradation of banana starch: Structural characterization of the degradation process. Carbohydr Polym 2010. [DOI: 10.1016/j.carbpol.2010.02.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Arima S, Ueno S, Ogawa A, Sato K. Scanning microbeam small-angle X-ray diffraction study of interfacial heterogeneous crystallization of fat crystals in oil-in-water emulsion droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:9777-9784. [PMID: 19588887 DOI: 10.1021/la901115x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We performed scanning microbeam small-angle X-ray diffraction (micro-SAXD) experiments, differential scanning calorimetry (DSC) analysis, and optical microscopic observation of palm mid fraction (PMF) crystals in oil-in-water emulsion droplets. The scanning micro-SAXD experiment was performed by irradiating a synchrotron radiation X-ray microbeam having an area of 5 x 5 microm(2) onto different positions on a 50 microm diameter emulsion droplet after the crystallization of PMF by chilling the emulsion at 5 degrees C. The micro-SAXD patterns were recorded with a two-dimensional (2D) detector, which enabled spatial analysis of polymorphic structures and the orientation of lamella planes of PMF crystals at different positions inside the emulsion droplet. Particular attention was paid to compare the crystallization of PMF in two types of emulsion droplets, hydrophilic polyoxyethylene sorbitan mono-oleate (Tween 80) alone (Tween 80 emulsion) and Tween 80 and hydrophobic sucrose palmitic acid oligoester (P-170) (Tween 80+P-170 emulsion). The DSC study revealed that the PMF crystallization temperature in the Tween 80+P-170 emulsion droplets increased by 3 degrees C compared to that of the Tween 80 emulsion because of the effects of the P-170 additive in promoting PMF crystallization. The micro-SAXD studies revealed the following results. (1) The lamella planes of PMF crystals near the outer edges of the droplet in the Tween 80+P-170 emulsion were mostly parallel to an oil-water interface, whereas the lamella planes of PMF crystals were not always aligned with the oil-water interface in the Tween 80 emulsion droplet. (2) The degree of orientation of the lamellar planes of PMF crystals, which was evaluated from the values of full width at half-maximum of 2D micro-SAXD patterns with respect to azimuthal angle extension, was remarkably higher in the Tween 80+P-170 emulsion than in the Tween 80 emulsion. (3) Polymorphic transformation of PMF from alpha to beta' in the Tween 80+P-170 emulsion was retarded compared to that in the Tween 80 emulsion. These results confirmed that the P-170 additive caused interfacial heterogeneous nucleation through hydrophobic interactions at the oil-water interfaces in the emulsion, which subsequently influenced the arrangements of fat crystals so that the lamellar planes of fat crystals were parallel to the oil-water interface.
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Affiliation(s)
- S Arima
- Technical Development Center, Mitsubishi-Kagaku Foods Co., 1000 Kamoshida, Aoba-ku, Yokohama 227-0033, Japan
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15
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Popov D, Buléon A, Burghammer M, Chanzy H, Montesanti N, Putaux JL, Potocki-Véronèse G, Riekel C. Crystal Structure of A-amylose: A Revisit from Synchrotron Microdiffraction Analysis of Single Crystals. Macromolecules 2009. [DOI: 10.1021/ma801789j] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. Popov
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - A. Buléon
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - M. Burghammer
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - H. Chanzy
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - N. Montesanti
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - J.-L. Putaux
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - G. Potocki-Véronèse
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
| | - C. Riekel
- European Synchrotron Radiation Facility, BP 220, F-30843, Grenoble Cedex, France; INRA, Rue de la Géraudière, BP 71627, 44316, Nantes Cedex 3, France; Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France; and Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP), UMR 5504 INSA-CNRS, UMR 792 INSA-INRA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 4, France
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Fundaments of Soft Condensed Matter Scattering and Diffraction with Microfocus Techniques. APPLICATIONS OF SYNCHROTRON LIGHT TO SCATTERING AND DIFFRACTION IN MATERIALS AND LIFE SCIENCES 2009. [DOI: 10.1007/978-3-540-95968-7_4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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17
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Kasemwong K, Piyachomkwan K, Wansuksri R, Sriroth K. Granule Sizes of Canna (Canna edulis) Starches and their Reactivity Toward Hydration, Enzyme Hydrolysis and Chemical Substitution. STARCH-STARKE 2008. [DOI: 10.1002/star.200800229] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Thys RCS, Westfahl H, Noreña CPZ, Marczak LDF, Silveira NP, Cardoso MB. Effect of the alkaline treatment on the ultrastructure of C-type starch granules. Biomacromolecules 2008; 9:1894-901. [PMID: 18517249 DOI: 10.1021/bm800143w] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of alkaline treatment on the ultrastructure of C-type starch granules was investigated during the alkaline extraction of Araucaria angustifolia (pinhao) starch. The efficiency in protein removal was evaluated using intrinsic fluorescence and Kjeldahl's method. In parallel, morphological changes of starch granules were observed using scanning electron microscopy and atomic force microscopy. The starch crystallinity was monitored by wide-angle X-ray scattering and the lamellar structure was studied by small-angle X-ray scattering (SAXS). The paracrystalline model was employed to interpret the SAXS curves. It was found that the granular organization was significantly altered when alkaline solutions were used during the extraction. A partial degradation of B-type allomorph of starch and a significant compression of semicrystalline growth rings were observed.
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Affiliation(s)
- Roberta C S Thys
- Programa de Pos-Graduacao em Engenharia Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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19
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Koch MHJ, Bras W. Synchrotron radiation studies of non-crystalline systems. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b703892p] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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20
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Gebhardt R, Hanfland M, Mezouar M, Riekel C. High-Pressure Potato Starch Granule Gelatinization: Synchrotron Radiation Micro-SAXS/WAXS Using a Diamond Anvil Cell. Biomacromolecules 2007; 8:2092-7. [PMID: 17550289 DOI: 10.1021/bm070156s] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Potato starch granules have been examined by synchrotron radiation small- and wide-angle scattering in a diamond anvil cell (DAC) up to 750 MPa. Use of a 1 microm synchrotron radiation beam allowed the mapping of individual granules at several pressure levels. The data collected at 183 MPa show an increase in the a axis and lamellar period from the edge to the center of the granule, probably due to a gradient in water content of the crystalline and amorphous lamellae. The average granules radius increases up to the onset of gelatinization at about 500 MPa, but the a axis and the lamellar periodicity remain constant or even show a decrease, suggesting an initial hydration of amorphous growth rings. The onset of gelatinization is accompanied by (i) an increase in the average a axis and lamellar periodicity, (ii) the appearance of an equatorial SAXS streak, and (iii) additional short-range order peaks.
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Affiliation(s)
- R Gebhardt
- European Synchrotron Radiation Facility, Grenoble Cedex, France
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21
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Lopez-Rubio A, Htoon A, Gilbert EP. Influence of Extrusion and Digestion on the Nanostructure of High-Amylose Maize Starch. Biomacromolecules 2007; 8:1564-72. [PMID: 17394285 DOI: 10.1021/bm061124s] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An in-depth characterization of the structural changes undergone by high-amylose starch after extrusion and digestion with a pancreatic alpha-amylase has been carried out. The combination of USAXS, SAXS, XRD, and SEM techniques has provided a wide "picture" of the morphological transformations of starch, covering a length scale from approximately 0.3 nm to approximately 230 microm. Depending on the extrusion conditions, either gelatinization was attained ("mild" conditions) or single-amylose helix formation was induced ("extreme" conditions). SAXS experiments demonstrated that upon contacting the extruded materials with water, retrogradation took place. A new type of molecular organization with a characteristic repeat length of 5 nm was observed in the dry resistant starch fractions from the extruded high-amylose starch. The crystalline morphology of the resistant starch fractions, as observed by XRD, varied from B-type crystallinity for the "mild" extruded starch to a mixture of C- and V-type crystallinity in the case of "extreme" extrusion.
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Affiliation(s)
- Amparo Lopez-Rubio
- Bragg Institute, Australian Nuclear Science and Technology Organization, PMB 1, Menai, NSW 2234, Australia.
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