Figure 2. Densitogram of caffeine extracted from the coffee powder (a), instant coffee (b) and brewed coffee (c)

From

The Caffeine Content in Coffee Beverages Commercially Distributed in Indonesia

Sukrasno, Irena Aria Rivera, Komar Ruslan Wirasutisna

Journal of Food and Nutrition Research. 2018, 6(8), 513-517 doi:10.12691/jfnr-6-8-5