science program
IPWR Research Investigator: Andrea Dietrich, Ph.D.
Location:
Virginia Polytechnic Institute & State University
Amount: $200,000 for two years
Project: Mechanism of Metallic Flavor from Drinking Water
Our research will provide critical information on the perception of metallic flavor and its impact on human nutrition and consumption of water. Metallic flavor can be a problem in drinking water and may reduce water consumption by the public. We hypothesize that the metallic flavor formation is not only due to the taste of metal ions but also due to production of metal-catalyzed odors in the mouth that create a retronasal effect. Specifically, lipid oxidation of oral cell membrane phospholipids by the metal ions can produce volatile carbonyls which cause metallic flavors and odors.
Our interdisciplinary approach combines expertise in food oxidation and off-flavors, water chemistry, cell biology, and human perception. We will investigate the role of the micronutrients iron and copper in oral lipid oxidation and associated carbonyl formation from drinking water with these metals. Determination of volatile compounds in the mouth will require analysis with solid-phase microextraction in conjunction with gas chromatography coupled to mass spectrometry and odor detector. Studies with human subjects will be augmented with in-vitro experiments with cultured epithelial cells. The research will also evaluate preventative measures with antioxidants to prevent metallic flavor production. Lastly, the research will compare the sensory thresholds, recommended nutritional levels, and adverse health effect levels of iron and copper in water to evaluate needs and inconsistencies.
Articles Published or accepted to Refereed Journals
Hong, JH. Ömür-Özbek, P., Stanek, B.T., Dietrich, A.M., Duncan, S.E., Lee, YW., Lesser, G. Taste and smell abnormalities in cancer patients, Journal of Supportive Oncology, 7:2: Mar/Apr 2009. (IN PRESS)
Article In-Review at Refereed Journal
Dietrich, A.M. The sense of smell: contributions of orthonasal and retronasal perception applied to metallic flavor of drinking water, Journal of Water Supply: Research and Technology AQUA.
Presentations with Conference Proceedings
Ömür-Özbek, P., A.M. Dietrich, S.E. Duncan. YW Lee. Metallic flavor of iron and copper in drinking water. 2008 International Water Association Off-Flavours in the Aquatic Environment Symposium, Daejeon, Korea, October 8-11, 2008.
Ömür-Özbek, P., A.M. Dietrich. Metallic flavored drinking water with iron and copper. 2008 Water Jam, joint meeting of the Virginia American Water Works Association and Virginia Water Environment Association, Virginia Beach, Virginia, September 10-12, 2008.
Ömür-Özbek; P. and A.M. Dietrich. Hexanal as an Odor Standard. Proceedings of the American Water Works Water Association Water Quality Technology Conference, Charlotte, NC, Nov. 4-7, 2007.
Presentations Only
Ömür-Özbek, P., A.M. Dietrich, S.E. Duncan, Y-W Lee. Metallic Flavor Resulting from Lipid Oxidation in Mouth”, Macromolecular Interfaces with Life Sciences Symposium, Blacksburg, VA, October 21, 2007.
J. H. Hong, P. Omur-Ozbek, B. T. Stanek, A. M. Dietrich, Y. W. Lee and S. E. Duncan. Implication of Metallic Flavor Mechanisms and Suppression on Human Health; Virginia Tech Dean’s Forum on Nutrition and Health, November 5, 2007, Blacksburg, VA.
Ömür-Özbek, P. , YW Lee, S. Duncan, A.M. Dietrich. Role of Metals in Drinking Water on Flavor and Health, Association of Environmental Engineering and Science Professor Education and Research Conference, Blacksburg, VA, July 28-August 1, 2007.
