Quantitative studies on roast kinetics for bioactives in coffee

Quantitative analysis of the bioactives trigonelline (1), N-methylpyridinium (2), caffeine (3), and caffeoylquinic acids (4) in a large set of roasted Arabica (total sample size n = 113) and Robusta coffees (total sample size n = 38) revealed that the concentrations of 1 and 4 significantly correlated with the roasting color (P less than 0.001, two tailed), whereas that of 2 significantly correlated inversely with the color (P less than 0.001, two tailed). As dark-roasted coffees were rich in N-methylpyridinium whereas light-roasted coffees were rich in trigonelline and caffeoylquinic acids, manufacturing of roast coffees rich in all four bioactives would therefore necessitate blending of two or even more coffees of different roasting colors. Additional experiments on the migration rates during coffee brewing showed that all four bioactives were nearly quantitatively extracted in the brew (more than 90%) when a water volume/coffee powder ratio of more than 16 was used.

Content

Subjects

caffeine

caffeoylquinic acids

coffee

N-methylpyridinium

roasting color

trigonelline

DDC Class

540: Chemie

570: Biowissenschaften, Biologie

580: Pflanzen (Botanik)

630: Landwirtschaft, Veterinärmedizin

Funding References

More Funding Information

Deutschland, Bundesministerium für Bildung und Forschung (Grant 0315692/01EA1365)