Department of Food Science & Engineering, Faculty of Biosystem Engineering, University of Tehran, Karadj, I.R. IRAN
The effects of some synthetic sweeteners on the rheological and physical properties of guar gum in dilute solutions were investigated.Measurements include the determination of intrinsic viscosity and the particle size, surface weighted mean [D3, 2], volume weighted mean [D4,3] and specificsurface area ofguar gum andsyntheticsweeteners mixtures. The concentration of these sweeteners were 0, 0.1, 0.2 % w/w for aspartame, acesulfame-k and cyclamate, and 0, 0.001, 0.002 % w/w for neotame. Gum was evaluated for intrinsic viscosity by various models i.e. Huggins, Kraemer, Tanglertpaibul and Rao equations. The results showed that the values obtained for intrinsic viscosity were different upon various equations used. The plot of relative viscosity versus concentration, obtained from Tanglertpaibul and Rao model described best the phenomenon. Sweeteners had no significant effect on intrinsic viscosity of guar gum solutions.
 Sinha, V. R. and Kumria, R., Polysaccharides in Colon-Specific Drug Delivery, International Journal of Pharmaceutics, 224, 19 (2001).
 Skinner, G.W., Harcum, W.W., Barnum, P.E., Guo, J.H., Evaluation of Water Soluble Polymers in a Phenylpropanol Amine Sustained Release Tablet, in: Proceedings of the Annual Meeting of the American Association of Pharmaceutical Scientists, p. S14 (1998).
 Rubinstein, A. and Gliko-Kabir, I., Synthesis and Swelling Dependent Enzymatic Degradation of Borax Modified Guar Gum for Colonic Delivery Purposes, S.T.P. Pharma Science, 5, 41 (1995).
 Wong, D., Larabee, S., Clifford, K., Tremblay, J. and Friend, D. R., USP Dissolution Apparatus III (reciprocating cylinder) for Screening of Guar-Based Colonic Delivery Formulations, Journal of Controlled Release, 47, 173 (1997).
 Bayliss, C. E. and Houston, A. P., Degradation of Guar Gum by Faecal Bacteria, Applied Environmental Microbiology, 48, 626 (1986).
 Macfarlane, G. T., Hay, S., Macfarlane, S. and Gibson, G. R., Effect of Different Carbohydrates on Growth, Polysaccharidase and Glycosidase Production of Bacteroides Ovatusin Batch and Continuous Culture, Journal of Applied Bacteriology, 68, 179 (1990).
 Morris, E. R., “Mixed Polymer Gels”, Harris, P. (Ed.), Food Gels, London: Elsevier Applied Science pp. 291-360 (1990).
 Dea, I. C. M., Morris, E. R., Rees, D. A., Welsh, J., Barnes, H. A. and Price, J., Associatations of Like and Unlike Polysaccharides: Mechanism and Specificity in Galactomannans, Interacting Bacterial Polysaccharides, and Related Systems, Carbo-hydrate Reesearch, 57, 249 (1977).
 McCleary, B. V., Clark, A. H., Dea, I. C. M. and Ress, D. A., The Fine Structures of Carob and Guar Galactomannans, Carbohydrate Research, 139, 237 (1985).
 McCleary, B. V., Enzymic Hydrolysis, Fine Structure, and Gelling Interaction Properties of Galactomannans, CarbohydrateResearch, 71, 205 (1979).
 Launay, B., Doublier, J. R. and Cuvelier, G.,” Flow Properties of Aqueous Solutions and Dispersions of Polysaccharides”, Mitchell, J. R. and Ledward, D. A., (Eds.), Functional Properties of Food Macro-molecules, London: Elsevier Applied Science pp. 1-78 (1986).
 Richardson, H. P., Willmer, J. and Foster, J. T., Dilute Solution Properties of Guar and Locust Bean Gum in Sucrose Solutions, Food Hydrocolloids, 12, 339 (1998).
 Bohdanecky, M. and Kovar, J., The Viscosity of Polymer Solutions of Finite Concentration, Jenkins, A. D. (Ed.), “Viscosity of Polymer Solutions”, Chap. 3, pp. 166-220, Polymer Science Library 2, Amsterdam: Elsivier (1982).
 Goycoolea, F. M., Morris, E. R., Gidely, M. J., Viscosity of Galactomannans at Alkaline and Neutral pH: Evidence of ‘Hyperentanglment’ in Solution, Carbohydrate Polymers, 27, 69 (1995).
 Elfak, A. M., Pass, G., Philips, G. O. and Morley, R. G., The Viscosity of Dilute Solutions of Guar Gum and Locust Bean Gum with and without Added Sugar, J. Sci. Fd Agric., 28(10), 895 (1977).
 Launay, B., Cuvelier, G. and Martinez-Reyes, S., Viscosity of Locust Bean, Guar, and Xanthan Gum Solutions in the Newtonian Domain: A Critical Examination of the Log (ηsp)o - logC(η)o Master Curves, Carbohydrate Polymers, 34, 385 (1997).
 Bayarri, S., Duran, L. and Costell, E., Influence of Sweeteners on the Viscoelasticity of Hydrocolloids Gelled Systems, Food Hydrocolloids, 18, 611 (2003).
 Lai, L. S. and Chiang, H. F., Rheology of Decolorized Hsian-Tsao Leaf Gum in the Dilute Domain, Food Hydrocolloids, 16, 427 (2002).
 Higiro, J., Herald, T. J., Alavi, S. and Bean. S., Rheological Study of Xanthan and Locust Bean Gum Interaction in Dilute Solution: Effect of Salts, Food Research Iinternational, 40, 435 (2006).
 Heitmann, D.I. T. and Mersmann, A., Determination of the Intrinsic Viscosity of Native Potato Starch, Starch/Sta¨ rke, 47, 426 (1995).
 McMillan, D. E., A Comparison of Five Methods for Obtaining the Intrinsic Viscosity of Bovine Serum Albumin, Biopolymers, 13, 1367 (1974).
 Huggins, M. L., The Viscosity of Dilute Solutions of Long-Chain Molecules, IV. Dependence on Concentration, Journal of the American Chemical Society, 64, 2716 (1942).
 Da Silva, J. La. L. and Rao, M. A., Viscoelastic Properties of Food Hydrocolloid Dispersions, In Rao, M. A. and Steffe, J. F., (Eds.), Viscoelastic Properties of Foods, New York: Elsevier Applied Science, pp. 285-315 (1992).
 Kraemer, E. O., Molecular Weights of Celluloses and Cellulose Derivatives,IndustrialandEngineering Chemistry, 30, 1200 (1938).
 Sornsrivichai, T., A Study on Rheological Properties of Tomato Concentrates as Affected by Concen-tration Methods, Processing Conditions, and Pulp Content, Ph.D. Thesis, CornellUniversity, Ithaca, New York (1986).
 Tanglertpaibul, T. and Rao, M. A., Intrinsic Viscosity of Tomato Serum as Affected by Methods of Determination and Methods of Processing Concentrates, Journal of Food Science, 52(6), 1642 (1987).
 Chou, T.D. and Kokini, J. L., Rheological Properties and Conformation of Tomato Paste Pectins, Citrus, and Apple Pectins, Journal of Food Science, 52, 1658 (1987).
 Lapasin, R. and Pricl, S., Rheologyof Industrial Polysaccharides: Theory and Applications (Eds). Glasgow, Blackie Academic and Professional, pp. 250-494 (1995).
 Pals, D. T. and Hermans, J. J., Sodium Salts of Pectin and Carboxymethyl Cellulose in Aqueous Sodium Chloride, Recueil des Travaux Chimiques du Pays-Bas, 71, 433 (1952).
 Morris, E. R., Polysaccharide Rheology and in-Mouth Perception, In Stephen, A. M., (Ed.), Food Polysaccharides and Their Applications, New York: Marcel Dekker, Inc., pp. 517-546 (1995).
 Morris, E. R., Cutler, A. N., Ross-Murphy, S. B. and Rees, D. A., Concentration and Shear Rate Dependence of Viscosity in Random Coil Polysaccharide Solutions, Carbohydrate Polymers, 1, 5 (1995b).