European Food Research and Technology

, Volume 231, Issue 6, pp 977–984

Evaluation of the operationally defined soluble, insoluble, and complexing copper consumed through drinking water in human saliva

  • Jae Hee Hong
  • Susan E. Duncan
  • Andrea M. Dietrich
  • Sean F. O’Keefe
Original Paper

DOI: 10.1007/s00217-010-1352-1

Cite this article as:
Hong, J.H., Duncan, S.E., Dietrich, A.M. et al. Eur Food Res Technol (2010) 231: 977. doi:10.1007/s00217-010-1352-1

Abstract

Previous studies suggest that different copper species formed in saliva have different reactivity in chemical reactions that may be associated with perception of metallic sensation occurring in the oral cavity. This study was performed to understand copper speciation in human saliva, which will help to understand the perception mechanism of metallic taste. Saliva samples were treated with CuSO4·5H2O at the levels of 0, 2.5, 10, 20, or 40 mg/L as Cu in vitro. Also saliva is collected before and after drinking 20 mL of 0, 2.5, and 5 mg/L copper in water (in vivo treatment). Copper speciation was operationally determined based on apparent molecular size using ultrafiltration coupled with inductively coupled plasma mass spectrometry. For in vitro copper treatment, 50–70% of copper was soluble at Cu ≤ 10 mg/L, whereas 60–70% of copper was in complex or insoluble form at Cu > 20 mg/L. For in vivo copper treatment, 90–95% of copper was soluble in saliva. These results suggest that copper is in the soluble unbound form in saliva at low concentrations. At higher concentrations, copper either becomes insoluble or binds with salivary components.

Keywords

Copper Metallic taste Astringency Saliva Ultrafiltration Drinking water 

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Jae Hee Hong
    • 1
  • Susan E. Duncan
    • 2
  • Andrea M. Dietrich
    • 3
  • Sean F. O’Keefe
    • 2
  1. 1.School of Food ScienceKyungil UniversityGyeongsan-siKorea
  2. 2.Department of Food Science and TechnologyVirginia Polytechnic Institute and State UniversityBlacksburgUSA
  3. 3.Department of Civil and Environmental EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgUSA