Effect of variety and farm altitude on chemical content of Arabica coffee (Coffea arabica) grown in Gayo Highland, Indonesia

Abstract

Arabica coffee grown in the Gayo Highlands, Aceh, by small holder farmers has been well known for its excellent quality and distinctive taste. Its physical and organoleptic qualities have been included in several reports. However, the literature on its chemical content, such as chlorogenic acid, caffeine, and antioxidant activity is very limited. The aims of this research are to investigate the effect of difference varieties and farm altitudes on the coffee chemical content, especially chlorogenic acid, caffeine, and antioxidant activity. This research used a factorial randomized block design with two factors, namely variety (V) and farm altitude (T). Coffee Varieties (V) consist of three most widely planted varieties in the Highlands, namely, Timtim (V1), Borbor (V2), and Ateng Super (V3). Farm altitude (T) consists of three levels, namely farm altitude between 1000-1200 m above sea level (asl), represented by Celala (T1), farm altitude between 1201-1400 m asl, represented by Pegasing (T2) and farm altitude between 1401-1600 m asl, which is represented by Permata (T3). The analysis of variance (ANOVA) showed that coffee varieties, farm altitudes and the interaction between the two factors had no significant effect on the parameters observed. However, the data show a tendency that caffeine content and antioxidant activity in ground coffee tends to increase as farm altitude increase, while the chlorogenic acid content tends to decrease. Overall, the chlorogenic acid content in ground coffee ranged between 3.36% - 7.82%, with an average of 5.78% ± 1.52%, caffeine content ranged between 1.35% - 1.82% with an average of 1.61% ± 0.24%, and antioxidant activity ranged between 62.55% - 79.32% inhibition, with an average of 69.23% ± 4.42%.