Expression of Coffee Carotenoid Genes Examined

Roasted coffee holds an intricate collection of volatile organic compounds (VOCs) responsible for the characteristic taste and smell of brewed coffee. The strong aroma component of coffee like beta-damascenone has been attributed as derived from carotenoid precursors. To further analyze the probable relationship of carotenoids and coffee aroma profiles, Andrew Simkin of Centre de Recherche Nestlé and colleagues measured the carotenoid content of developing coffee grain.

Results of their study verify that the presence of lutein in the grain, and that the underdeveloped coffee grain has significant amounts of beta and alpha carotene, violaxanthin, and neoxanthin. Complimentary quantitative gene expression analysis also elucidated that all carotenoid biosynthetic genes studied are expressed in the grain, and that the transcript levels are gene and stage dependent. As the grain approaches ripening, the carotenoid levels decrease as well as the transcript levels. Thus, the highest transcript levels were found at the green-yellow stages, the same period when there is potentially maximum carotenoid synthesis.

Read the abstract of this study at http://dx.doi.org/10.1016/j.plaphy.2010.02.007.