Biochemical composition of Ethiopian coffees (Coffea arabica L.) as influenced by variety and postharvest processing methods

This study investigated the influence of variety, processing methods and their possible interactions on the biochemical composition of green coffee beans. The results revealed that the biochemical composition was significantly affected by the interaction effect of variety and processing methods. As compared to coffees processed in semi-washed and dry method, the highest total chlorogenic acid (TCGA) content was obtained in coffee varieties 74-112, 74-110 and 74-165, processed by washed method. The washed processing method also enhanced the caffeine content of the coffee beans. The highest value was observed in the coffee varieties 74-4, 74-112 and 74-165. The dry method, on the other hand, increased the sucrose content and the highest value was obtained in the varieties 74-110, 74-140 and 74-148. In general, the present study indicated the existence of variation in biochemical composition of Ethiopian Arabica coffee varieties and is influenced by the different processing methods. This study, however, was carried out with coffee varieties grown under same growing conditions and did not consider season variation. Therefore, it is advisable to further evaluate with more number of coffee varieties grown in different growing environments and seasons.   Key words: Processing methods, green beans, caffeine, chlorogenic acid, sucrose.