Proteomic analysis of higher & lower altitude cultivars of Coffea arabica reveals differences related to environmental adaptations and coffee bean flavour.

Coffee ranks among the most popular beverages worldwide and is an important commodity in developing nations. While coffee beans harvested from Coffea arabica are considered to have a superior rich and balanced flavour, they are susceptible to disease and climatic variables like temperature, precipitation, and oxygen availability, each of which varies with altitude. We performed a comprehensive proteomic comparison of two C. arabica cultivars, the high-altitude Rwanda Shyira (RS) and the lower-altitude Brazil Flor de Ipe (BFDI), using liquid chromatography MS/MS analysis. Five of the identified 531 proteins exhibited statistically significant differences in expressional intensity between the two cultivars. These differences may correspond to bitter flavonoid concentrations along with adaptations to cold, hypoxic, and disease stressors at different altitudes and geographic niches. These substantial proteomic differences identified between these elevations provide a greater understanding of the effects of altitude on the C. arabica plant and its coffee, which has implications for the global market.