By analyzing green coffee beans from 20 locations across varying altitudes and climates, researchers found strong links between growing conditions—especially elevation and temperature—and key quality indicators such as bean weight, moisture, fat content, and acidity. Using principal component analysis, the study demonstrated how coffee-growing environments significantly influence biochemical profiles, including trigonelline, chlorogenic acid, and sucrose levels.
Coffee quality depends on numerous factors—from bean size and shape to flavor and aroma—each driven by underlying biochemical compounds like caffeine, chlorogenic acids, trigonelline, and sucrose. These compounds are shaped not only by coffee genetics but also by environmental elements such as altitude, temperature, soil, and post-harvest practices. Ethiopia, the genetic birthplace of Coffea arabica, boasts a rich variety of agro-ecologies that result in distinct regional flavor profiles, from Sidamo’s spice to Harar’s mocha notes. While prior studies have examined how climate and geography affect individual aspects of coffee chemistry, few have systematically linked both physicochemical and biochemical bean traits to the full spectrum of environmental variables across Ethiopia’s coffee belt.
A study (DOI: 10.48130/bpr-0024-0021) published in Beverage Plant Research on 17 June 2024 by Markos Makiso Urugo’s team, Jimma University, deepens our understanding of the complex relationships between terroir and coffee quality, providing a foundation for more targeted cultivation, breeding, and marketing of Ethiopia’s prized specialty coffees.
The study collected green Arabica coffee beans from 20 distinct agro-ecological zones across Ethiopia and evaluated their physicochemical characteristics (including bean weight, moisture, crude fat, and pH) and biochemical composition (caffeine, chlorogenic acid, trigonelline, and sucrose). The results revealed strong correlations between altitude and several key bean traits. Hundred-bean weight, moisture content, crude fat, trigonelline, and sucrose all increased with elevation, while average temperature showed a negative correlation with these variables. These patterns suggest that cooler, high-altitude environments promote slower fruit maturation, enabling prolonged bean filling and accumulation of lipids and sugars. Conversely, chlorogenic acid content decreased with altitude and rose with temperature, likely reflecting more rapid ripening and metabolic shifts in warmer climates. pH showed an inverse relationship with altitude, supporting previous findings that higher elevations enhance coffee acidity and flavor complexity. Notably, neither bean weight, pH, moisture, nor biochemical composition showed any significant correlation with annual rainfall, underscoring that altitude and temperature are more decisive environmental factors. Caffeine content varied considerably across samples but was not significantly linked to any specific environmental variable, pointing to genetic or other ecological influences. PCA further emphasized the clustering of high-quality traits—high bean weight, fat, sucrose, and trigonelline—in samples from higher altitudes. These findings collectively highlight the multifactorial nature of coffee quality and underscore the critical role of elevation and thermal regimes in shaping the physical and chemical profile of green Arabica beans.
These findings offer valuable insights for farmers, exporters, and specialty coffee roasters aiming to optimize quality through environmental selection. By understanding how altitude and climate affect bean chemistry, producers can better match cultivars to their environments or fine-tune cultivation practices to achieve desirable traits. In a warming world, this data also provides a basis for climate adaptation strategies in coffee agriculture. Moreover, marketers can use this eco-biochemical information to authenticate origin and develop region-specific flavor profiles, enhancing traceability and value in global markets.
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References
DOI
10.48130/bpr-0024-0021
Original Source URL
https://doi.org/10.48130/bpr-0024-0021
About Beverage Plant Research
Beverage Plant Research (e-ISSN 2769-2108) is the official journal of Tea Research Institute, Chinese Academy of Agricultural Sciences and China Tea Science Society. Beverage Plant Research is an open access, online-only journal published by Maximum Academic Press which publishing original research, methods, reviews, editorials, and perspectives, which advance the biology, chemistry, processing, and health functions of tea and other important beverage plants.