Effect of altitude of coffee plants on the composition of fatty acids of green coffee beans

BACKGROUND: The fatty acids of green coffee beans are one of the major components that determine the quality of coffee. Fatty acids composition of green coffee beans is affected by soil composition and altitude of coffee plants. This study was aimed to evaluate the effect of altitude of the coffee plants on the composition of fatty acids in green coffee beans. METHODS: Fatty acids contents of 40 green coffee beans samples collected from the coffee plants grown at different altitudes (group 1: 1500–1700, group 2: 1701–1900 and group 3: > 1900 m.a.s.l.) in Ethiopia were determined using gas chromatography-mass spectrometry (GC–MS). Chemometric data analyses were performed to determine the effects of altitude on the fatty acid composition of the green coffee beans. RESULTS: The green coffee beans contained main saturated fatty acid, palmitic acid with an average value of 55.5 mg/g and unsaturated fatty acid, linoleic acid with an average value of 51.6 mg/g. The other major constituents of fatty acids present in green coffee beans were stearic and oleic acids with the value of 12.3 mg/g and 8.92 mg/g, respectively. Palmitic acid content in lowland green coffee beans is significantly different than in the other two regions. On the other hand, stearic and oleic acids contents in the green coffee beans did not show a significant difference between the three topographical regions. While linoleic acid content in the green coffee beans showed significant difference between group 1 and 3 but did not show significant differences between group 1 and 2 and between group 2 and 3. The four major fatty acids, palmitic (R = − 0.574), linoleic (R = − 0.506), stearic (R = − 0.43) and oleic acids (R = − 0.291) in green coffee beans showed a moderate negative correlation with the altitude of coffee plants. CONCLUSION: The fatty acids contents decreases with increasing altitude of the coffee plants and hence affects the quality of coffee. The fatty acid composition of green coffee beans can also be used to determine the topographical origin of coffee plants.