Many, indeed most, foods contain luminescent compounds, molecules that absorb UV or visible light and remit light of a longer wavelength (lower energy). These compounds include both natural (chlorophyll) and artificial (red dye # 3) colors, flavors (vanillin), vitamins (riboflavine), and many others. Luminescence, both prompt fluorescence and delayed phosphorescence, from molecules is often very sensitive to the local chemical and physical properties of the liquid or solid matrix in which the molecule is embedded. Depending upon its specific molecular structure and thus photophysical properties, the luminescent molecule may be sensitive to physical properties of the environment (such as pH, temperature, water activity, polarity, viscosity, etc.), it may be sensitive to the presence of specific molecules (metal ions, organic molecules, etc.) in its local environment, or it may partition into specific phases (liquid, oil, etc.) of the food. This project will identify luminescent molecules found in foods, characterize the ways that their luminescence responds to chemical and physical properties of foods and biomaterials, and then determine how the luminescence can be used to sense specific physical properties of the food related to quality and stability.
|Effective start/end date||9/1/13 → 2/28/15|