Optical and Thermal Properties of Coffee and Caffeine
| dc.contributor.advisor | Asfaw Araya (PhD) | |
| dc.contributor.author | Ture Kassahun | |
| dc.date.accessioned | 2018-07-18T07:47:35Z | |
| dc.date.accessioned | 2023-11-09T11:25:31Z | |
| dc.date.available | 2018-07-18T07:47:35Z | |
| dc.date.available | 2023-11-09T11:25:31Z | |
| dc.date.issued | 2005-06 | |
| dc.description.abstract | In this project, the thermal and optical propeliies of coffee and caffeine are investigated. Characteristics involved are solvatochromic effect, fluorescence, chemical structures (bonds) and thermal propeliies of both coffee and caffeine. The UVNis absorption band of caffeine in different solvents shows very small solvatochromic effect, indicating only local transitions of electrons. This founding is similar to that found for QM-calculations. Fluorescence measurements revealed no fluorescence emission by caffeine, but deactivation of fluorescien fluorescence intensity. However, simple cOlTelation between the deactivation produced by caffeine and coffee on the fluorescence of fluorescein could not be drawn with out the detailed know ledge of other components. From FT -IR results, the fluorescence deactivation mechanism is found to incorporate carbonyl groups of both caffeine and coffee. The observed thelTl1al (TGA) results showed coffee is thermally unstable and decomposes steadly.This shows the inherent discrepancy of the temperature dependent measurement, which makes exact measurement of caffeine at various temperature intervals unrealistic. The DSC result shows crystallization, heat absorption melting and heat release of coffee at various temperature regions Key Words: Coffee, Caffeine, Fluorescence, Solventochromism, Thermal, UVNis | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/9180 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Coffee | en_US |
| dc.subject | Caffeine | en_US |
| dc.subject | Fluorescence | en_US |
| dc.subject | Solventochromism | en_US |
| dc.subject | Thermal | en_US |
| dc.subject | UVNis | en_US |
| dc.title | Optical and Thermal Properties of Coffee and Caffeine | en_US |
| dc.type | Thesis | en_US |