Dysphagia

, Volume 27, Issue 1, pp 10–19

The Effect of Saliva on the Viscosity of Thickened Drinks

  • Ben Hanson
  • Mark T. O’Leary
  • Christina H. Smith
Original Article

DOI: 10.1007/s00455-011-9330-8

Cite this article as:
Hanson, B., O’Leary, M.T. & Smith, C.H. Dysphagia (2012) 27: 10. doi:10.1007/s00455-011-9330-8

Abstract

Powdered thickeners are used to modify drink consistency in the clinical management of dysphagia. These thickeners are composed of primarily modified maize starch; some varieties also incorporate powdered gums. Amylase is a digestive enzyme found in saliva that initiates the breakdown of starch. To determine the significance of this process in dysphagia management, we measured the effects of human saliva on the viscosity of thickened drinks. Two thickeners were studied: one comprising modified maize starch alone and one that included additional gums. These were added to drinks with neutral and acidic pH: water and orange juice. Two clinical scenarios were simulated: (1) the effect of saliva on fluid as it is swallowed and (2) the effect when saliva enters a cup and contaminates a drink. Saliva was found to reduce the viscosity of water thickened with maize starch in both scenarios: (1) 90% reduction after 10 s and (2) almost 100% reduction in viscosity after 20 min. The thickener composed of gums and maize starch showed a significant reduction but retained a level of thickening. In contrast, thickened orange juice (pH 3.8) was not observed to undergo any measurable reduction in viscosity under the action of saliva.

Keywords

Dysphagia Saliva Amylase Viscosity Thickener Deglutition Deglutition disorders 

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Ben Hanson
    • 1
  • Mark T. O’Leary
    • 1
  • Christina H. Smith
    • 2
  1. 1.Department of Mechanical EngineeringUniversity College London (UCL)LondonUK
  2. 2.Department of Human Communication ScienceUniversity College London (UCL)LondonUK

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