Computing and Library Services - delivering an inspiring information environment

A hydrodynamic study of the depolymerisation of a high methoxy pectin at elevated temperatures

Morris, Gordon, Foster, T. J. and Harding, S. E. (2002) A hydrodynamic study of the depolymerisation of a high methoxy pectin at elevated temperatures. Carbohydrate Polymers, 48 (4). pp. 361-367. ISSN 0144-8617

Metadata only available from this repository.


The hydrodynamic properties (intrinsic viscosity, [η]; infinite dilution sedimentation coefficient, s20,w0; weight average molecular weight, Mw and translational frictional ratio, f/f0) of a high methoxy pectin have been evaluated at various temperatures (20-60°C). A reduction in the value of all four hydrodynamic parameters is indicative of depolymerisation and is in agreement with an earlier study using viscometry [Axelos, M.A.V., & Branger, M., (1993). Food Hydrocolloids, 7, 91-102]. The apparent linearity of the Mark - Houwink plot of log[η] vs log Mw suggests that the conformation of the pectin molecule does not change significantly over the temperature range studied. The evaluation of the Mark-Houwink viscosity exponent (a = 0.84) indicates a moderately extended structure. This then allows the calculation of the number of Kuhn statistical lengths per chain from the adapted 'blob' theory of Dondos [Dondos A. (2001). Polymer, 42, 897-901]. The weight average number of Kuhn statistical lengths per chain is reduced from (170 ± 10) to (125 ± 10) when the temperature is increased from 20-60°C. This may be of significance as many high methoxy pectins are exposed to high temperatures during processing in both the food and pharmaceutical industries. © 2002 Elsevier Science Ltd. All rights reserved.

Item Type: Article
Uncontrolled Keywords: β-elimination Adapted 'blob' theory Depolymerisation Elevated temperature analytical ultracentrifugation High methoxy pectin Kuhn statistical chain length Conformations Depolymerization High temperature effects Hydrodynamics Molecular weight Viscosity Biopolymers
Subjects: Q Science > QD Chemistry
Schools: School of Applied Sciences
Related URLs:

Language of Original Document: English
Correspondence Address: Morris, G.A.; Industrial Research Limited, Gracefield Road, Lower Hutt, New Zealand; email:
References: Abel-Azim, A.-A.A., Atta, A.M., Farahat, M.S., Boutros, W., Determination of the intrinsic viscosity of polymeric compounds through a single specific viscosity measurement (1998) Polymer, 39, pp. 6827-6833; Axelos, M.A., Branger, M., The effect of degree of esterification on the thermal-stability and chain conformation of pectins (1993) Food Hydrocolloids, 7, pp. 91-102; Berth, G., Anger, H., Linow, F., Light-scattering and viscometric studies for molecular weight determination of pectin in aqueous solutions (1977) Nahrung, 21, pp. 939-950; Dondos, A., A new relationship between the intrinsic viscosity and the molecular mass of polymers derived from the blob model: Determination of the statistical length of flexible polymers (2001) Polymer, 42, pp. 897-901; Gralén, N., (1944) Sedimentation and diffusion measurements on cellulose and cellulose derivatives, , PhD Dissertation, University of Uppsala, Sweden; Green, A.A., The preparation of acetate and phosphate buffer solutions of known pH and ionic strength (1933) Journal of the American Chemical Society, 55, p. 2331; Harding, S.E., The intrinsic viscosity of biological macromolecules. Progress in measurement, interpretation and application to structure in dilute solutions (1997) Progress in Biophysics and Molecular Biology, 68, pp. 207-262; Harding, S.E., Vårum, K.M., Stokke, B.T., Smidsrød, O., Molecular weight determination of polysaccharides (1991) Advances in Carbohydrate Analysis, 1, pp. 63-144; Harding, S.E., Berth, G., Ball, A., Mitchell, J.R., Garcia de la Torre, J., The molecular-weight distribution and conformation of citrus pectins in solutions studied by hydrodynamics (1991) Carbohydrate Polymers, 16, pp. 1-15; Jumel, K., (1994) Molecular size of interacting and degrading polysaccharides, , PhD Dissertation, University of Nottingham; Jumel, K., Browne, P., Kennedy, J.F., The use of low angle laser light scattering with gel permeation chromatography for the molecular weight determination of biomolecules (1992) Laser light scattering in biochemistry, pp. 23-34. , S. E. Harding, D. B. Sattelle & V. A. Bloomfield. Cambridge: Royal Society of Chemistry, Chapter 2; Kratky, O., Leopold, H., Stabinger, H., The determination of the partial specific volume of proteins by the mechanical oscillator technique (1973) Methods in Enzymology, 27 D, pp. 98-110; Kravtchencko, T.P., Pilnik, W., A simplified method for the determination of the intrinsic viscosity of pectin solutions by classical viscometry (1990) Gums and stabilisers for the food industry, 5. , G. O. Phillips, P. A. Williams & D. J. Wedlock, Oxford: IRL Press; Lapasin, R., Pricl, S., (1995) Rheology of industrial polysaccharides, theory and applications, , London, UK: Blackie; Morris, G.A., (2001) Hydrodynamic investigation of polysaccharides and their interactions with casein, , PhD Dissertation, University of Nottingham, UK; Morris, G.A., Butler, S.N.G., Foster, T.J., Jumel, K., Harding, S.E., Elevated temperature analytical ultracentrifugation of a low-methoxy polyuronide (1999) Progress in Colloid and Polymer Science, 113, pp. 205-208; Morris, G.A., Foster, T.J., Harding, S.E., The effect of degree of esterification on the hydrodynamic properties of citrus pectin (2000) Food Hydrocolloids, 14, pp. 227-235; Pavlov, G.M., The concentration dependence of sedimentation for polysaccharides (1997) European Biophysics Journal, 25, pp. 385-398; Pavlov, G.M., Korneeva, E.V., Harding, S.E., Vichoreva, G.A., Dilute solution properties of carboxymethylchitins in high ionic-strength solvent (1998) Polymer, 39, pp. 6951-6961; Pilgrim, G.W., Walter, R.H., Oakenfull, D.G., Jams, jellies and preserves (1991) The chemistry and technology of pectin, pp. 23-50. , R. H. Walter (Ed.). San Diego: Academic Press. Chapter 2; Ralston, G., (1993) Introduction to analytical ultracentrifugation, , California: Beckman Instruments Inc; Rowe, A.J., Concentration-dependence of transport processes - General description applicable to sedimentation, translational diffusion, and viscosity coefficients of macromolecular solutes (1977) Biopolymers, 16, pp. 2595-2611; Smidsrod, O., Andresen, L., (1979) Biopolymerkjemi, , Trondheim, Norway: Tapir Press; Tanford, C., (1961) Physical chemistry of macromolecules, , New York: John Wiley and Sons; Theisen, A., Johann, C., Deacon, M.P., Harding, S.E., (2000) Refractive increment data-book for polymer and biomolecular scientists, , Nottingham: Nottingham University Press; Tombs, M.P., Harding, S.E., (1998) An introduction to polysaccharide biotechnology, , London: Taylor and Francis, Chapter 2; Van Holde, K.E., (1985) Physical Biochemistry, (2nd ed), , New Jersey: Prentice-Hall; Walter, R.H., Function of pectin in plant tissue structure and firmness (1991) The chemistry and technology of pectin, pp. 1-22. , R.H. Walter, (Ed.). San Diego: Academic Press. Chapter 1; Wyatt, P.J., Combined differential light scattering with various liquid chromatography separation techniques (1992) Laser light scattering in biochemistry, pp. 35-38. , S. E. Harding, D. B. Sattelle & V. A. Bloomfield, Cambridge: Royal Society of Chemistry, Chapter 3

Depositing User: Gordon Morris
Date Deposited: 13 May 2011 11:27
Last Modified: 04 Jul 2011 14:09

Item control for Repository Staff only:

View Item

University of Huddersfield, Queensgate, Huddersfield, HD1 3DH Copyright and Disclaimer All rights reserved ©