Correlation between caffeine contents of green coffee beans and altitudes of the coffee plants grown in southwest Ethiopia

Abstract

ABSTRACT. Caffeine contents of 45 green coffee bean samples collected from coffee plants grown at different altitudes in Southwest Ethiopia was determined by UV-Vis spectrophotometry. The caffeine contents were found in the range of 0.62 -1.2% (w/w). A moderate negative correlation (R = 0.5463) was found between the caffeine contents of green coffee beans and the altitudes at which the coffee plants were grown. The caffeine contents of 9 of the green coffee bean samples analyzed by high performance liquid chromatography (HPLC) provided comparable results in the range of 0.60−1.1% (w/w). Statistical analysis of data (t-test) indicated absence of significant differences between the caffeine contents obtained by the two methods. Nonetheless, HPLC method is precise, accurate and reliable in determining caffeine content in green coffee bean samples while the UV-Vis spectrophotometry is simple, rapid, precise and more economical.

Influence of Altitudes of Coffee Plants on the Alkaloids Contents of Green Coffee Beans

“…Coffee is the most widely consumed beverage in the world due to its pleasant taste, aroma and stimulant effect and health benefits. The name coffee was originated from the Coffee grows at various altitudes, ranging from 550 to 2750 meters above sea level (Hagos et al, 2018). However, Arabica coffee best thrives and is produced between altitudes of 1300 and 1800 meters, with annual rainfall amount ranging from 1500 to 2500 mm with an ideal minimum and maximum air temperatures of 15 and 25 o C, respectively.…”

Influence of altitudes of coffee plants on the alkaloids contents of green coffee beans

“…The data obtained in this study is compared with the data reported in the literature ( Table 2). The trigonelline contents in Arabica green coffee beans were reported in the range of 0.6-1.2% (w/w) (Belitz et al, 2009), 0.74-1.12% (w/w) (Duarte et al, 2010), 0.98-1.32% (w/w) (Mehari et al, 2016c) and 1.00-1.10% (w/w) (Hagos et al, 2018). Therefore, these values are in reasonable degree of agreement with the findings of the present work.…”

“…Many analytical methods have been reported for the determination of alkaloids in green coffee beans such as ultraviolet visible spectroscopy (Belay et al, 2008;Zewdu et al, 2016;Demissie et al, 2016), fluorescence spectroscopy (Yisak et al, 2018a), FT-IR-ATR (Weldegebreal et al, 2016;Yisak et al, 2018b), high performance liquid chromatography (Belitz et al, 2009;Gopinandhan et al, 2014;Mehari et al, 2016c;Hagos et al, 2018), gas chromatography (McCusker et al, 2003;McCusker et al, 2006;Sereshti and Samadi, 2014). However, the literature survey also revealed that there is limited reports available on study of the simultaneous determination of alkaloids in green coffee beans for a given set of samples and effect of altitude and soil composite (Belitz et al, 2009;Mehari et al, 2016c;Hagos et al, 2018). Therefore, the aim of this study was the simultaneous determination of amount of alkaloids (caffeine, theobromine, trigonelline, theophylline) in green coffee bean samples from South east region (Sidama) and South west region (Illubabor, Jimma, Wellega and Gedeo) of Ethiopia by high performance liquid chromatography and to investigate the influence of altitude and the soil pH and organic carbon on alkaloids content and to compare the results of this study with the results reported in the literature.…”

Volatile profile of green coffee beans from Coffea arabica L. plants grown at different altitudes in Ethiopia

“…Coffee beans are the seeds of a shrub in the genus Coffea and belonging to the family Rubiaceae. It has over sixty different species of which only three (Coffea arabica, Coffea robusta (canephora), and Coffea liberica) have globally commercial values [3]. Coffea arabica and Coffea canephora are the most important commercial species [4,5].…”

“…Sherge et al [15] have studied the influence of growing altitude, shade and harvest period on quality and biochemical composition of Ethiopian specialty coffee. Hagos et al [3] have studied the correlation between caffeine contents in green coffee beans and altitudes of the coffee plants grown in southwest Ethiopia. Mintesnot and Dechassa [16] have studied the effect of altitude, shade, and processing methods on the quality and biochemical composition (caffeine, trigonelline, and chlorogenic acids) of green coffee beans in Ethiopia.…”