Table 2.

Acid concentrations and p-values. Mean acid concentration for each roast level, and p-values associated with comparison of roast level (fixed factor: lighter, medium, darker). Letters indicate significant differences (p < 0.05) between roast levels.

ACID	ROASTING
	Lighter		Medium		Darker		p-value
	mean	std	mean	std	mean	std
	(mg/mL)		(mg/mL)		(mg/mL)
Chlorogenic	1.207	0.212	0.792	0.198	0.423	0.152
	A		B		C		<0.0001
Quinic	0.644	0.039	0.661	0.032	0.731	0.097
	B		B		A		0.0055
Citric	0.493	0.100	0.396	0.092	0.316	0.085
	A		B		C		<0.0001
Acetic	0.235	0.021	0.288	0.017	0.310	0.012
	C		B		A		<0.0001
Phosphoric	0.244	0.014	0.274	0.012	0.286	0.019
	B		A		A		0.0024
Formic	0.168	0.012	0.177	0.010	0.172	0.013
	NS		NS		NS		0.0758
Lactic	0.144	0.013	0.169	0.013	0.186	0.020
	B		A		A		0.0006
Malic	0.204	0.014	0.156	0.015	0.118	0.020
	A		B		C		<0.0001
Glycogenic	0.067	0.007	0.094	0.008	0.121	0.015
	C		B		A		<0.0001
Total acids	3.404	0.240	3.007	0.223	2.660	0.204
	A		AB		B		0.0040
Total OAs	1.954	0.112	1.942	0.102	1.952	0.134
	NS		NS		NS		0.9870