Determination of Caffeine Content of Bale Coffee Using HPLC Analysis

摘要

Ethiopia is the home land of biodiversity of coffea arabica seeds. The major and most known coffee producing regions in the country are Oromiya and Southern Nations Nationalities and Peoples Region. The objective of this study was to determine the caffeine content of coffee bean samples obtained from coffee growing areasof Bale zone, Oromia region. The samples were collected from farmers’ union that supplies coffee to Ethiopian Commodity Exchange (ECX) or exporters. The collected samples were roasted and powdered to facilitate the extraction. The powders were then boiled with water, filtered and subjected to liquid-liquid extraction using dichloromethane. The extracts were subjected to High Performance Liquid Chromatographic analysis. The results revealed that caffeine levels to be 1.31 ± 0.14% for Gololcha coffee, 1.32 ± 0.03% for Harena Buluk forest coffee, 1.33 ± 0.08% for Mena forest coffee, 1.34 ± 0.21% for Berbere coffee, 1.36 ± 0.02% for Harena Buluk cultivated coffee and 1.36 ± 0.16% for Mena cultivated coffee (on dry matter basis). The finding also showed that there are no significant differences in the caffeine contents of the coffee samples used in the study. Moreover, the caffeine contents were in the range of export standards of Ethiopia.