Table 6 Contents of phenolic and nitrogenous compounds, acidity and antioxidant activities of roasted coffee samples

Sample name	TPC (mg GAE/g, d.m.)1)	RSA (%)	TTA		pH	Caffeine (mg/g, d.m.)	Trigonelline (mg/g, d.m.) CQA	CQA (mg/g, d.m.)
			(% CA, d.m.)2)	(mL/g, d.m.)				3-CQA	4-CQA	5-CQA	Total
WRS	28.4±0.46abc	89.6±0.27b	1.64±0.05ab	2.56±0.08ab	4.82±0.01c	15.0±0.15de	10.2±0.35e	6.65±0.07g	0.51±0.03a	25.6±0.36h	32.7h
WRT	29.0±0.84ab	90.1±0.61b	1.64±0.02ab	2.56±0.03ab	4.72±0.01g	15.6±0.15c	10.4±0.09de	9.09±0.14c	0.47±0.01bc	34.9±0.48c	44.4c
WRB	28.3±0.63abc	89.5±0.31b	1.58±0.04b	2.47±0.06b	4.83±0.00c	16.3±0.02b	10.3±0.04e	7.24±0.02f	0.49±0.03ab	26.4±0.05g	34.2g
SKK	26.4±1.25bc	90.1±0.77b	1.60±0.03ab	2.50±0.04ab	4.83±0.01c	16.4±0.11b	10.6±0.06c	7.24±0.08f	0.46±0.02bc	26.8±0.23fg	34.5fg
SKN	28.7±0.38abc	89.5±0.31b	1.66±0.09a	2.59±0.14a	4.79±0.01d	15.4±0.07c	10.6±0.07cd	7.31±0.08f	0.46±0.04bc	27.1±0.33f	34.9f
NGK	29.7±1.25a	89.8±0.55b	1.66±0.03a	2.59±0.04a	4.79±0.01d	16.4±0.03b	11.9±0.03a	8.0±0.07e	0.44±0.00cd	31.1±0.15e	39.5e
NRL	30.6±0.81a	89.5±0.81b	1.63±0.00ab	2.54±0.04ab	4.75±0.00f	14.8±0.21e	10.2±0.16e	9.21±0.20c	0.45±0.01c	35.1±0.53c	44.8c
ERW	26.6±4.06bc	89.5±0.41b	1.60±0.01ab	2.50±0.02ab	4.77±0.00e	14.9±0.08e	10.3±0.03de	8.85±0.11d	0.45±0.01c	33.0±0.35d	42.3d
ETH	28.1±0.81abc	91.1±0.55a	1.36±0.01c	2.13±0.02c	4.89±0.01b	15.2±0.07d	11.9±0.07a	11.10±0.06a	0.47±0.01bc	42.7±0.17a	54.3a
BRA	25.8±0.69c	91.5±0.46a	1.23±0.03d	1.92±0.05d	5.02±0.00a	19.8±0.17a	11.1±0.10b	10.26±0.09b	0.41±0.00d	37.8±0.33b	48.5b

All values are means ± standard deviations of at least three measurements
Milligram of gallic acid equivalent per gram, on dry matter basis
Citric acid
Values with different superscripts in the same column are significantly different (p<0.05).