Caffeine content variation in single green Arabica coffee seeds

Abstract

Coffea arabica L. is highly homozygotic and caffeine content in most cultivars is reported to be similar (approximately 1%). The caffeine content was analysed using individual seeds of cultivars Catuaí Vermelho, Mundo Novo and Bourbon Vermelho, and varieties Mokka and Laurina of C. arabica. Seeds were cut transversely in half, a thin slice from each was extracted in a mixture of chloroform and methanol, and caffeine was measured by high performance liquid chromatography. The extraction procedure was validated by comparison with two conventional methods less suited for analysing large numbers of seeds. The results revealed an unexpectedly large variation [Catuaí Vermelho: 3.72 -25.9 mg g 21 (seeds); Mundo Novo: 5.06 -18.59 mg g 21 ; Bourbon Vermelho: 6.76 -16.59 mg g 21 ] even in types naturally low in caffeine such as Laurina (1.17 -9.97 mg g 21 ) and Mokka (2.01 -9.64 mg g 21 ). The mean values for all cultivars were always in the range of the caffeine content found in the literature. Several studies showed that C. arabica has approximately 10% cross-pollination, but the variation observed in caffeine content in individual seeds was too large to be explained by cross-pollination.

Caffeine Consumption through Coffee: Content in the Beverage, Metabolism, Health Benefits and Risks

“…The effect of environment, agricultural practices, including the use of fertilizers, and post-harvest processing on methylxanthines contents seems to be less important than genetic aspects, except in the case of secondary processing, such as decaffeination [38][39][40]. The range of caffeine contents reported for green C. arabica L. vary in the literature between 0.7 and 1.7 g/100 g (dry matter-dm) [15,26,38,[41][42][43][44][45][46][47][48][49][50][51][52], while those for C. canephora vary in the range between 1.4 and 3.3 g/100 g (dm) [26,38,41,42,45,49,50,[52][53][54][55][56]. However, common values are in a narrower range, between 1.0 and 1.2 g/100 g, dw, for C. arabica [15,44,[46][47][48][49][50][51]54], and between 1.7 and 2.1 g/100 g (dm) for C. canephora [26,39,43,51,55,56].…”

Functional properties of coffee and coffee by-products

“…The purine caffeine is the main alkaloid in coffee beans, accounting for 1 to 4% (dry basis), with large variation within cultivars and among them (Belitz et al, 2009;Dessalegn, Labuschagne, Osthoff, & Herselman, 2008;Mazzafera & Silvarolla, 2010). Caffeine contents are strongly related to the quality of coffee beverages, because it contributes to its bitterness (Farah, Monteiro, Calado, Franca, & Trugo, 2006).…”

An examination of consumer exposure to caffeine from commercial coffee and coffee-flavoured milk

“…It is recognised that beverages with caffeine as a natural component will have a wide range of caffeine levels. These variances are probably the result of many factors which include the species of plant origin (Mazzafera and Silvarolla, 2010), growing environment, effects of commercial processing and storage along with variances at the retail level such as amount of coffee or tea used, the extraction method (e.g. percolated, drip etc.)…”