Fig. 2.

Acid concentrations for A) Chlorogenic acid, B) Citric acid, C) Malic acid, D) Quinic acid, E) Acetic acid, F) Phosphoric acid, G) Glycolic acid, H) Lactic acid, and I) Formic acid for measured coffee samples (Brazil 1, light green, Brazil 2, dark green, Bolivia, yellow, Kenya 1, orange, Kenya 2, pink, and the mean for all coffees, black) for varying roast levels. Letters indicate significant differences (p < 0.05) between roast levels. Please note that the scales are different (horizontal lines are separated by 0.1 mg/mL for all acids). * on graphs for chlorogenic and citric acid denotes p < 0,001 for sample difference.