Robusta coffee beans found to have higher caffeine content than Arabica
Caffeine metabolism in coffee plants was studied to understand why Robusta coffee has more caffeine than Arabica. Researchers found that specific genes control caffeine levels in leaves and beans. In Robusta, genes CcXMT1 and CcDXMT are key for high caffeine levels, especially in leaves. In Arabica, genes CaXMT1 and CaDXMT2 play a role, but overall gene activity is lower during bean growth. This shows that caffeine levels in coffee plants are influenced by how genes are turned on and off, and by differences between Arabica and Robusta coffee plants.