Effect of cocoa roasting time on volatile composition of dark chocolates from different origins determined by HS-SPME/GC-MS

Figures & data

Figure 1. Characteristic chromatograms of the volatile compounds obtained using chromatography-mass spectrometry: (a) Ghana and (b) Ecuador. Identification of volatile compounds in Table 1.

Figura 1. Cromatograma de los compuestos volátiles característicos obtenido mediante cromatografía de gases-espectrometría de masas: (a) Ghana y (b) Ecuador. Identificación de compuestos volátiles en la Tabla 1.

Table 1. Two-way analysis of variance (origin and roasting time) with interactions for volatile compounds identified in dark chocolates samples.

Tabla 1. Análisis de la varianza de dos factores (origen y tiempo de tostado) con interacciones para los compuestos volátiles identificados en las muestras de chocolate negro

Familie	Compound	ID	F origin			F roasting			F interaction			Group
Acids	Acetic acid	A1	164.70	< 0.0001	**	202.46	< 0.0001	**	3.50	0.098272	ns	G6
	Propanoic acid	A2	13.47	0.010456922	*	124.75	< 0.0001	**	19.02	0.002528	*	G1
	2-methyl propanoic acid	A3	0.48	0.512863594	ns	45.70	0.000233764	**	26.02	0.001105	*	G1
	Butanoic acid	A4	339.14	< 0.0001	**	339.14	< 0.0001	**	339.14	< 0.0001	**	G1
	Pentanoic acid	A5	28.53	0.001759295	*	218.28	< 0.0001	**	83.27	< 0.0001	**	G6
	4-Methyl pentanoic acid	A6	200.71	< 0.0001	**	97.61	< 0.0001	**	211.09	< 0.0001	**	G3
	Hexanoic acid	A7	16.68	0.006474375	*	40.56	0.000326638	**	13.01	0.006577	*	G6
	Hexanedioic acid	A8	92.84	< 0.0001	**	92.84	< 0.0001	**	92.84	< 0.0001	**	G6
	Nonanoic acid	A9	161.95	< 0.0001	**	478.96	< 0.0001	**	161.95	< 0.0001	**	G6
	Undecanoic acid	A10	1.43	0.277051476	ns	1.43	0.310809332	ns	1.43	0.310809	ns
	Benzoic acid	A11	157,246.65	< 0.0001	**	157,246.65	< 0.0001	**	157,246.65	< 0.0001	**	G1
	Benzeneacetic acid	A12	12.32	0.012666486	*	12.32	0.007505642	*	12.32	0.007506	*	G1
Alcohols	1-Pentanol	OH1	106,366.30	< 0.0001	**	106,366.30	< 0.0001	**	106,366.30	< 0.0001	**
	4-Heptanol	OH2	3695.79	< 0.0001	**	3695.79	< 0.0001	**	3695.79	< 0.0001	**
	1-Octanol	OH3	490.41	< 0.0001	**	148.17	< 0.0001	**	148.17	< 0.0001	**	G6
	2-Nonanol	OH4	0.79	0.408136998	ns	146.13	< 0.0001	**	0.79	0.495705	ns	G1
	2-Hexadecanol	OH5	58.75	0.000257833	**	58.75	0.000114685	**	58.75	0.000115	**
	2,3-Butanediol	OH6	359.54	< 0.0001	**	220.06	< 0.0001	**	220.06	< 0.0001	**	G3
	2,6-Dimethyl-7-octen-2-ol	OH7	25.61	0.002310011	*	25.61	0.001153363	*	25.61	0.001153	*	G1
	3,7-Dimethyl-1,6-octadien-3-ol (linalool)	OH8	64.07	0.000202805	**	26.13	0.001092622	*	54.38	0.000143	**	G5
	2E-undecen-1-ol	OH9	17.92	0.005477833	*	17.92	0.002947315	*	17.92	0.002947	*	G1
	Phenol	OH10	78.45	0.00011521	**	78.45	< 0.0001	**	78.45	< 0.0001	**	G3
	2,4-bis(1,1-dimethylethyl) phenol	OH11	17,704.16	< 0.0001	**	17,704.16	< 0.0001	**	17,704.16	< 0.0001	**	G1
	2,6-bis(1,1-dimethylethyl)-4-(1-methylpropyl) phenol	OH12	2.31	0.179083236	ns	0.58	0.590013705	ns	1.85	0.236189	ns
	2-(1,1-dimethylethyl)-4-(1-methyl-1-phenylethyl) phenol	OH13	1740.75	< 0.0001	**	2020.67	< 0.0001	**	1740.75	< 0.0001	**	G1
	Benzyl alcohol	OH14	3.20	0.124022319	ns	17.32	0.003215778	*	27.62	0.000941	**
	2-Phenylethanol (Phenylethyl alcohol)	OH15	78.57	0.000114694	**	0.08	0.921801611	ns	8.64	0.017103	*	G4
Aldehydes	Nonanal	AD1	197.18	< 0.0001	**	3.63	0.092671233	ns	3.63	0.092671	ns	G4
	Dodecanal	AD2	417.15	< 0.0001	**	106.31	< 0.0001	**	106.31	< 0.0001	**	G4
	2-Dodecenal	AD3	9324.88	< 0.0001	**	2384.88	< 0.0001	**	2384.88	< 0.0001	**	G4
	10-Octadecenal	AD4	5199.77	< 0.0001	**	5199.77	< 0.0001	**	5199.77	< 0.0001	**	G1
	Benzaldehyde	AD5	31.96	0.001314925	*	30.12	0.000742911	**	20.73	0.002021	*	G3
	2-Phenyl-2-butenal	AD6	45.85	0.000506689	**	40.01	0.000339375	**	54.92	0.000139	**	G5
	4-Methyl-2-phenyl-2-pentenal	AD7	32.85	0.001224319	*	32.85	0.000585783	**	32.85	0.000586	**	G1
	2-Methyl-2-phenyl-2-hexenal	AD8	463.30	< 0.0001	**	128.66	< 0.0001	**	128.66	< 0.0001	**	G4
	5-Methyl-2-phenyl-2-hexenal	AD9	345.10	< 0.0001	**	17.08	0.003333383	*	57.49	0.000122	**	G4
	Benzeneacetaldehyde	AD10	9.57	0.021307972	*	9.57	0.013606639	*	9.57	0.013607	*	G1
	4-Hydroxy-3-metoxibenzaldehyde (Vainillin)	AD11	53.70	0.000329953	**	6.27	0.033943277	*	32.45	0.000606	**	G4
Alkanes	Nonadecane	AK1	74.24	0.000	**	74.24	< 0.0001	**	74.24	< 0.0001	**
	2,3,5-Trimethyldecane	AK2	1256.61	< 0.0001	**	1256.61	< 0.0001	**	1256.61	< 0.0001	**
	6-ethyl-2-methyldecane	AK3	24.29	0.003	*	24.29	0.001	*	24.29	0.001	*
	3-methylpentadecane	AK4	15.14	0.008	*	15.14	0.005	*	15.14	0.005	*
	Eicosane	AK5	363.92	< 0.0001	**	363.92	< 0.0001	**	363.92	< 0.0001	**
Esters	Methyl acetate	E1	14.88	0.008392286	*	14.88	0.004726799	*	14.88	0.004727	*	G1
	Ethyl acetate	E2	3968.86	< 0.0001	**	3968.86	< 0.0001	**	3968.86	< 0.0001	**	G1
	Methyl benzeneacetate	E3	10,869.96	< 0.0001	**	10,869.96	< 0.0001	**	10,869.96	< 0.0001	**
	Ethyl benzeneacetate	E4	16.77	0.00639548	*	19.51	0.002365757	*	14.20	0.005305	*	G5
	2-phenylethyl acetate	E5	9.94	0.019760812	*	3.42	0.102182994	ns	2.81	0.137963	ns	G5
	1-methylethyl propanoate	E6	338.17	< 0.0001	**	338.17	< 0.0001	**	338.17	< 0.0001	**	G3
	1-methylpropyl propanoate	E7	7687.16	< 0.0001	**	7687.16	< 0.0001	**	7687.16	< 0.0001	**
	Ethyl octanoate	E8	150.73	< 0.0001	**	14.66	0.004902466	*	6.77	0.028978	*	G5
	Ethyl decanoate	E9	105.79	< 0.0001	**	4.61	0.061200021	ns	7.48	0.023451	*	G4
	Ethyl dodecanoate	E10	124.55	< 0.0001	**	11.32	0.009202063	*	19.54	0.002359	*	G5
	Methyl hexadecanoate	E11	3.74	0.101297084	ns	80.79	< 0.0001	**	3.74	0.088186	ns	G1
	Ethyl hexadecanoate	E12	90.60	< 0.0001	**	90.60	< 0.0001	**	90.60	< 0.0001	**	G1
	Methyl 7-octadecanoate	E13	1.50	0.267134715	ns	1.50	0.297076312	ns	1.50	0.297076	ns
	Methyl 9-octadecenoate	E14	6975.44	< 0.0001	**	6975.44	< 0.0001	**	6975.44	< 0.0001	**
	Methyl 11-octadecenoate	E15	38.33	0.000817589	**	38.33	0.000382393	**	38.33	0.000382	**	G6
	Ethyl 9-octadecenoate	E16	2568.07	< 0.0001	**	2568.07	< 0.0001	**	2568.07	< 0.0001	**	G1
	Phenylmethyl 9-octadecenoate	E17	1.00	0.355917684	ns	1.00	0.421875	ns	1.00	0.421875	ns
	Methyl eicosanoate	E18	2795.60	< 0.0001	**	2795.60	< 0.0001	**	2795.60	< 0.0001	**
	Methyl docasanoate	E19	6.09	0.048624795	*	6.09	0.035967165	*	6.09	0.035967	*	G6
	Methyl tetracosanoate	E20	4330.23	< 0.0001	**	4330.23	< 0.0001	**	4330.23	< 0.0001	**	G6
	1-methylpropyl benzoate	E21	52.16	0.000357186	**	52.16	0.000160838	**	52.16	0.000161	**
	2-methylpropyl benzoate (isobutyl benzoate)	E22	7.81	0.031361859	*	55.69	0.000133566	**	16.60	0.003585	*
	Penthyl benzoate	E23	3192.57	< 0.0001	**	3192.57	< 0.0001	**	3192.57	< 0.0001	**	G1
	Diethyl 1,2-benzenedicarboxilate	E24	446.08	< 0.0001	**	446.08	< 0.0001	**	446.08	< 0.0001	**	G1

Values of compounds come from three separate determinations. * Significant differences (p < 0.05). ** Significant differences (p < 0.001). ns = non-significant differences / Los valores de los compuestos provienen de tres determinaciones distintas. * Diferencias significativas (p < 0.05). ** Diferencias significativas (p < 0,001). ns = diferencias no significativas

Identification of volatile compunds / Identificación de los compuestos volátiles:a) 1: AK2; 2: A1; 3PZ5; 4: OH12; 5: OH15; 6: A11; 7: E16; 8: P2; 9: AD11; 10: OH13; 11: P5 and b) 1: PZ4; 2: A1; 3: PZ5; 4: AD5; 5: OH8; 6: A3; 7: F4; 8: OH12; 9: OH15; 10: PY1; 11: PY4; 12: A9; 13: P2; 14: F13; 15: AD11; 16: A5; 17: P5; 18: P1; 19: E13; 20: E14

Table 1. Two-way analysis of variance (origin and roasting time) with interactions for volatile compounds identified in dark chocolates samples.

Tabla 1. Análisis de la varianza de dos factores (origen y tiempo de tostado) con interacciones para los compuestos volátiles identificados en las muestras de chocolate negro

Familie	Compound	ID	F origin			F roasting			F interaction			Group
Acids	Acetic acid	A1	164.70	< 0.0001	**	202.46	< 0.0001	**	3.50	0.098272	ns	G6
	Propanoic acid	A2	13.47	0.010456922	*	124.75	< 0.0001	**	19.02	0.002528	*	G1
	2-methyl propanoic acid	A3	0.48	0.512863594	ns	45.70	0.000233764	**	26.02	0.001105	*	G1
	Butanoic acid	A4	339.14	< 0.0001	**	339.14	< 0.0001	**	339.14	< 0.0001	**	G1
	Pentanoic acid	A5	28.53	0.001759295	*	218.28	< 0.0001	**	83.27	< 0.0001	**	G6
	4-Methyl pentanoic acid	A6	200.71	< 0.0001	**	97.61	< 0.0001	**	211.09	< 0.0001	**	G3
	Hexanoic acid	A7	16.68	0.006474375	*	40.56	0.000326638	**	13.01	0.006577	*	G6
	Hexanedioic acid	A8	92.84	< 0.0001	**	92.84	< 0.0001	**	92.84	< 0.0001	**	G6
	Nonanoic acid	A9	161.95	< 0.0001	**	478.96	< 0.0001	**	161.95	< 0.0001	**	G6
	Undecanoic acid	A10	1.43	0.277051476	ns	1.43	0.310809332	ns	1.43	0.310809	ns
	Benzoic acid	A11	157,246.65	< 0.0001	**	157,246.65	< 0.0001	**	157,246.65	< 0.0001	**	G1
	Benzeneacetic acid	A12	12.32	0.012666486	*	12.32	0.007505642	*	12.32	0.007506	*	G1
Alcohols	1-Pentanol	OH1	106,366.30	< 0.0001	**	106,366.30	< 0.0001	**	106,366.30	< 0.0001	**
	4-Heptanol	OH2	3695.79	< 0.0001	**	3695.79	< 0.0001	**	3695.79	< 0.0001	**
	1-Octanol	OH3	490.41	< 0.0001	**	148.17	< 0.0001	**	148.17	< 0.0001	**	G6
	2-Nonanol	OH4	0.79	0.408136998	ns	146.13	< 0.0001	**	0.79	0.495705	ns	G1
	2-Hexadecanol	OH5	58.75	0.000257833	**	58.75	0.000114685	**	58.75	0.000115	**
	2,3-Butanediol	OH6	359.54	< 0.0001	**	220.06	< 0.0001	**	220.06	< 0.0001	**	G3
	2,6-Dimethyl-7-octen-2-ol	OH7	25.61	0.002310011	*	25.61	0.001153363	*	25.61	0.001153	*	G1
	3,7-Dimethyl-1,6-octadien-3-ol (linalool)	OH8	64.07	0.000202805	**	26.13	0.001092622	*	54.38	0.000143	**	G5
	2E-undecen-1-ol	OH9	17.92	0.005477833	*	17.92	0.002947315	*	17.92	0.002947	*	G1
	Phenol	OH10	78.45	0.00011521	**	78.45	< 0.0001	**	78.45	< 0.0001	**	G3
	2,4-bis(1,1-dimethylethyl) phenol	OH11	17,704.16	< 0.0001	**	17,704.16	< 0.0001	**	17,704.16	< 0.0001	**	G1
	2,6-bis(1,1-dimethylethyl)-4-(1-methylpropyl) phenol	OH12	2.31	0.179083236	ns	0.58	0.590013705	ns	1.85	0.236189	ns
	2-(1,1-dimethylethyl)-4-(1-methyl-1-phenylethyl) phenol	OH13	1740.75	< 0.0001	**	2020.67	< 0.0001	**	1740.75	< 0.0001	**	G1
	Benzyl alcohol	OH14	3.20	0.124022319	ns	17.32	0.003215778	*	27.62	0.000941	**
	2-Phenylethanol (Phenylethyl alcohol)	OH15	78.57	0.000114694	**	0.08	0.921801611	ns	8.64	0.017103	*	G4
Aldehydes	Nonanal	AD1	197.18	< 0.0001	**	3.63	0.092671233	ns	3.63	0.092671	ns	G4
	Dodecanal	AD2	417.15	< 0.0001	**	106.31	< 0.0001	**	106.31	< 0.0001	**	G4
	2-Dodecenal	AD3	9324.88	< 0.0001	**	2384.88	< 0.0001	**	2384.88	< 0.0001	**	G4
	10-Octadecenal	AD4	5199.77	< 0.0001	**	5199.77	< 0.0001	**	5199.77	< 0.0001	**	G1
	Benzaldehyde	AD5	31.96	0.001314925	*	30.12	0.000742911	**	20.73	0.002021	*	G3
	2-Phenyl-2-butenal	AD6	45.85	0.000506689	**	40.01	0.000339375	**	54.92	0.000139	**	G5
	4-Methyl-2-phenyl-2-pentenal	AD7	32.85	0.001224319	*	32.85	0.000585783	**	32.85	0.000586	**	G1
	2-Methyl-2-phenyl-2-hexenal	AD8	463.30	< 0.0001	**	128.66	< 0.0001	**	128.66	< 0.0001	**	G4
	5-Methyl-2-phenyl-2-hexenal	AD9	345.10	< 0.0001	**	17.08	0.003333383	*	57.49	0.000122	**	G4
	Benzeneacetaldehyde	AD10	9.57	0.021307972	*	9.57	0.013606639	*	9.57	0.013607	*	G1
	4-Hydroxy-3-metoxibenzaldehyde (Vainillin)	AD11	53.70	0.000329953	**	6.27	0.033943277	*	32.45	0.000606	**	G4
Alkanes	Nonadecane	AK1	74.24	0.000	**	74.24	< 0.0001	**	74.24	< 0.0001	**
	2,3,5-Trimethyldecane	AK2	1256.61	< 0.0001	**	1256.61	< 0.0001	**	1256.61	< 0.0001	**
	6-ethyl-2-methyldecane	AK3	24.29	0.003	*	24.29	0.001	*	24.29	0.001	*
	3-methylpentadecane	AK4	15.14	0.008	*	15.14	0.005	*	15.14	0.005	*
	Eicosane	AK5	363.92	< 0.0001	**	363.92	< 0.0001	**	363.92	< 0.0001	**
Esters	Methyl acetate	E1	14.88	0.008392286	*	14.88	0.004726799	*	14.88	0.004727	*	G1
	Ethyl acetate	E2	3968.86	< 0.0001	**	3968.86	< 0.0001	**	3968.86	< 0.0001	**	G1
	Methyl benzeneacetate	E3	10,869.96	< 0.0001	**	10,869.96	< 0.0001	**	10,869.96	< 0.0001	**
	Ethyl benzeneacetate	E4	16.77	0.00639548	*	19.51	0.002365757	*	14.20	0.005305	*	G5
	2-phenylethyl acetate	E5	9.94	0.019760812	*	3.42	0.102182994	ns	2.81	0.137963	ns	G5
	1-methylethyl propanoate	E6	338.17	< 0.0001	**	338.17	< 0.0001	**	338.17	< 0.0001	**	G3
	1-methylpropyl propanoate	E7	7687.16	< 0.0001	**	7687.16	< 0.0001	**	7687.16	< 0.0001	**
	Ethyl octanoate	E8	150.73	< 0.0001	**	14.66	0.004902466	*	6.77	0.028978	*	G5
	Ethyl decanoate	E9	105.79	< 0.0001	**	4.61	0.061200021	ns	7.48	0.023451	*	G4
	Ethyl dodecanoate	E10	124.55	< 0.0001	**	11.32	0.009202063	*	19.54	0.002359	*	G5
	Methyl hexadecanoate	E11	3.74	0.101297084	ns	80.79	< 0.0001	**	3.74	0.088186	ns	G1
	Ethyl hexadecanoate	E12	90.60	< 0.0001	**	90.60	< 0.0001	**	90.60	< 0.0001	**	G1
	Methyl 7-octadecanoate	E13	1.50	0.267134715	ns	1.50	0.297076312	ns	1.50	0.297076	ns
	Methyl 9-octadecenoate	E14	6975.44	< 0.0001	**	6975.44	< 0.0001	**	6975.44	< 0.0001	**
	Methyl 11-octadecenoate	E15	38.33	0.000817589	**	38.33	0.000382393	**	38.33	0.000382	**	G6
	Ethyl 9-octadecenoate	E16	2568.07	< 0.0001	**	2568.07	< 0.0001	**	2568.07	< 0.0001	**	G1
	Phenylmethyl 9-octadecenoate	E17	1.00	0.355917684	ns	1.00	0.421875	ns	1.00	0.421875	ns
	Methyl eicosanoate	E18	2795.60	< 0.0001	**	2795.60	< 0.0001	**	2795.60	< 0.0001	**
	Methyl docasanoate	E19	6.09	0.048624795	*	6.09	0.035967165	*	6.09	0.035967	*	G6
	Methyl tetracosanoate	E20	4330.23	< 0.0001	**	4330.23	< 0.0001	**	4330.23	< 0.0001	**	G6
	1-methylpropyl benzoate	E21	52.16	0.000357186	**	52.16	0.000160838	**	52.16	0.000161	**
	2-methylpropyl benzoate (isobutyl benzoate)	E22	7.81	0.031361859	*	55.69	0.000133566	**	16.60	0.003585	*
	Penthyl benzoate	E23	3192.57	< 0.0001	**	3192.57	< 0.0001	**	3192.57	< 0.0001	**	G1
	Diethyl 1,2-benzenedicarboxilate	E24	446.08	< 0.0001	**	446.08	< 0.0001	**	446.08	< 0.0001	**	G1

Values of compounds come from three separate determinations. * Significant differences (p < 0.05). ** Significant differences (p < 0.001). ns = non-significant differences / Los valores de los compuestos provienen de tres determinaciones distintas. * Diferencias significativas (p < 0.05). ** Diferencias significativas (p < 0,001). ns = diferencias no significativas

Table 2. Volatile compounds identified and odour description in cocoa beans and chocolates.

Tabla 2. Compuestos volátiles identificados y descripción de su olor en semillas de cacao y chocolate

Familie	Compounds	Afoackwa (2009)	Ducki et al. (2008)	Perego et al. (2004)	Counet et al. (2002)	Hashim (1197)	Hashim and Chaveron (1994)	Frauendorfer and Schieberle (2008)	Vítová et al. (2009)	Huang and Barringer (2010)	Ramli (2006)	Rodriguez-Campos et al. (2011)	Serra-Bonvehí (2005)	ID
Alkanes	3,5-Dimethyloctane		x
	2,3,5-Trimethyldecane					x								AK2
	Toluene	x			x					x
Esters	Ethyl benzoylformate	x			x
	2-(4-methyl-1-cyclohex-3-enyl)propan-2-yl formate												Herbaceous, citrus
	Methyl acetate		x									x		E1
	Ethyl acetate								x			Pineapple		E2
	Propyl acetate								x
	Butyl acetate								x			Fruit, apple, banana
	3-Methyl-1-butyl acetate					x						x
	3-Methyl-2-butyl acetate											x
	(E)Trans-3,7-Dimethyl-2,6-octadien-1-yl acetate												Rose, lavender, sweet
	2-Phenyl acetate											x
	Benzyl acetate												Floral, jasmine
	Ethyl phenylacetate										x	Fruit, sweet, honey	Sweet, honey
	2-Phenylethyl acetate	Honey, sweet			x			Flowery	x		x	Rose, honey, tobacco, flowery		E5
	Ethyl 2-methylpropanoate							Fruity
	Ethyl 2-hydroxipropanoate											Fruit
	3,7-dimethyl-6-octen-1-yl propanoatE (Propionic acid citronellol ester)					x
	Ethyl 2-methylbutanoate							Fruity
	Ethyl 3-methylbutanoate							Fruity
	Ethyl butanoate								x
	Octyl butanoate					x
	Ethyl pentanoate												Fruity, apple
	Ethyl hexanoate												Fruity, apple, banan, winelike, brandy
	Ethyl heptanoate												Winelike, brandy
	Ethyl octanoate	x			x				x				Fruity, floral, pineapple	E8
	Ethyl decanoate								x				Pear, grape, brandy
	Ethyl dodecanoate					x						Leaf, fruity, floral	Fruity, floral	E10
	Methyl tetradecanoate												Fatty
	Ethyl tetradecanoate												Waxy, soapy
	Methyl palmitate												x
	Ethyl palmitate											Waxy, mild green	Waxy, mild green
	Methyl stearate												Olily
	Ethyl stearate												Waxy
	Ethyl cis-9-octadecenoate												x
	Ethyl 9,12-octadecadienoate												x
	Ethyl benzoate	x			x								Fatty, floral, fruity
	3-methylbutyl benzoate												Balsam, sweet
	Isopentyl benzoate		x			x
	Methyl 2-hydroxybenzoate (methyl salicylate)												Caramel, sweet, bitter-almond
	Methyl phenylacetate												Sweet, honey, jasmine
	Methyl (E)-3-Phenylprop-2-enoate (methyl cinnamate)												Balsamic, strawberry
	Ethyl 3-phenylprop-2-enoate (ethyl cinnamate)	Fruity, floral (low)											Fruity, balsam, honey
Ethers	Methoxymethylcyclooctariene					x
	3–2(phenylmethoxy)phenyl					x
Furans	3-Phenylfuran	Cocoa, green, nutty			Cocoa, green, mint
	Furan-2-ylmethanol	x	x		x									F1
	Furan-2-ylmethanol (furfuryl propionate)				x								Cooked-sugar
	(Z)-2-(5-Methyl-5-vinyltetrahydro-2-furanyl)-2-propanol (linalool oxide; cis-furanoid)	Fruity, floral/flowery (low)			x								Sweet, nutty
	2-(5-Ethenyl-5-methyloxolan-2-yl)propan-2-ol (linalool oxide; trans-furanoid)												Floral, citrus, lemon, refreshing
	Furancarboxaldehyde (furfural)	Caramel-like, sweet			x								Sweet,, woody, fragant, almond	F10
	5-Methyl-2-furancarboxaldehyde (5-Methylfurfural)	x			x					x			Sweet, caramel
	5-Hydroxymethyl-2-furancarboxaldehyde												Fatty, musty, wax flowers	F13
	1-(2-Furanyl)ethanone (acetylfuran)	x			x								Sweet, balsamic, cocoa, slightly coffee
	2-Acetyl-5-methylfuran												Strong, nutty
	1(2-Furyl)butanone					x
	Dihydro-2-methyl-3(2 H)-furanone	x			x
	3,5-Dimethyldihydrofuran-2-one		x
	2,5-Dimethyl-4-hydroxy-3(2 H)furanone (Furaneol)	Caramel-like, sweet			Caramel-like, sweet			Caramel-like		x			Sweet, fruity, strawberry, hot sugar
	3-Hydroxy-4,5-dimethyl-2(5 H)-furanone							Seasoning-like
	2-Furancarboxylic acid												Odourless
	Furan-2-ylmethyl propanoate (furfuryl propionate)												Spicy, floral
Furans-S-Compounds	3-(Methylthio)propanal	Potato			Potato
	2-Methyl-3-(methyldithio)furan							Meat-like
Ketones	Propanone		x						x	x
	2-Butanone		x						x
	3-Hidroxy-2-butanone (acetoin)	x	x						x	x		Butter, cream		K2
	2-Pentanone								x			Fruit
	4-Methylcyclohexanone	x			x
	2-Heptanone	x			x				x	x
	2,6-dimethylheptanone					x
	2-Nonanone								x	x	x
	1-penten-3-one					x
	3,4,4-Trimethyl-2-cyclopenten-1-one	x			x
	1-Octen-3-one							Mushroom-like
	2,3-Butanedione	Buttery (low)	x		Buttery				x			Butter
	2,3-Pentanedione												Bitter
	Phenylethanone					x						Must, flower, almond, sweet	Floral, almond, sweet
	4-Methylphenyl methyl ketone												Fruity, floral, strong
	2-Hydroxyphenyl methyl ketone												Heavy, floral, herbaceous, sweet
	(E)-4-Phenylbut-3-en-2-one												Sweet, floral, pungent, creamy
Ketones-Lactones	γ-Nonalactone							Peach-like
	γ-Decalactone							Peach-like
	δ-Decalactone							Coconut-like		x
	δ-Octenolactone							Coconut-like
	δ-Decenolactone							Coconut-like
N-Compounds	Benzylhydrazine					x
N-Compounds-Amides	N-(2-Phenylethyl)formamide												Essencies
	2-Phenylacetamide												Phenolic odour
	N-(2-Phenylethyl)acetamide												Essencies
	Benzonitrile	x			x					x			Almond
	Indole (benzopyrrole)	x			x					x
	3-Methylindole									x
N-Compounds-Others	1,3,7-trimethyl-1 H-purine-2,6(3 H,7 H)-dione (caffeine)		x											N6
Pyran derivatives	3-Hydroxy-2-methyl-4 H-pyran-4-one (maltol)	x			x					x			Malt, roasted-nuts	P4
	2,3-Dihydro-3,5-dihydroxy-6-methyl-4 H-pyran-4-one (DDMP)		x										Roasted
	(3 R)-3,4-Dihydro-8-hydroxy-3-methyl-1 H-2-benzopyran-1-one	x	x		x
Pyrazines	Pyrazine				x								Pungent, sweet
	Methylpyrazine	Nuttry, green	x	x	Hazelnut, green	x	x						Nutty, cocoa, chocolate, roasted-nuts	PZ1
	2,5-Dimethylpyrazine	Roasted, cooked	x	x	x	x	x			x	x		Cocoa, roasted nuts	PZ2
	2,6-Dimethylpyrazine	Roasted, cooked		x		x	x			x			Nutty, coffee, green	PZ3
	2,3-Dimethylpyrazine	Cooked, nutty	x	x	Hazelnut, roasted	x	x			x	x		Caramel, cocoa
	Trimethylpyrazine	Cocoa, roasted, cooked	x	x	Cocoa, roasted, green		x	Earthy		x	x		Cocoa, roasted nuts, peanut	PZ4
	Tetramethylpyrazine	Milk-coffee, roasted	x	x	Milk coffee, mocha, roasted, green	x	x			x	x	Milk-coffee, roasted, chocolate	Chocolate, cocoa, coffee	PZ5
	Ethylpyrazine	Nutty, roasted	x		Green, ether, rum	x							Peanut-butter, musty, nutty	PZ6
	2-Ethyl-5(or 6)-methylpyrazine	Cocoa, roasted, green	x		x	x
	2-Ethyl-3-methylpyrazine	Hazelnut, roasted			x								Nutty, raw potato
	2-Ethyl-6-methylpyrazine				x						x
	5-Ethyl-2-methylpyrazine												x
	3(or 2),5-Dimethyl-2(or 3)-ethylpyrazine	x	x		Roasted, smoky, praline,rum						x			PZ8
	3,5(or 6)-Dimethyl-2-ethylpyrazine	Cocoa, praline, chocolate
	2-Ethyl-3,6(or 5)-dimethylpyrazine							Earthy			x
	2,3-Dimethyl-5-ethylpyrazine	Cocoa, chocolate												PZ7
	2,3,5-Trimethyl-6-ethylpyrazine	Candy, sweet		x										PZ9
	2,3-Diethylpyrazine												Nutty, hazelnut, cereal, meaty
	2,6-Diethylpyrazine					x
	3,5(or6)-diethyl-2-methylpyrazine				Cocoa, chocolate, rum, sweet, roasted						x			PZ11
	2,3-diethyl-5-methylpyrazine				x			Earthy		x
	2-Ethenyl-6-methylpyrazine	Roasted, smoky			Hazelnut, roasted						x
	2-isopropyl-3-methoxypyrazine				Garden peas, green, hazelnut
	2-methyl-5-isopropylpyrazine					x
	2,5(or6)-dimethyl-3-(2-methylpropyl)pyrazine				Hazelnut
	2,5-dimethyl-3-(3-methylbutyl)pyrazine				Roasted, sweet, green
	3-isobutyl-2-methoxypyrazine							Bell pepper
	Tetramethyl-2,5-dimethylpyrazine						x
Pyridines	Pyridine	x			x
	2-Methylpyridine	Caramel-like, sweet			x
	4-Ethylpyridine												x
	3-Hydroxy-2-methylpyridine												Wizened
	3-Hydroxy-6-methylpyridine												Wizened
	1-(2-Pyridinyl)-1-propanone	x			x
	3-Methoxypyridine					x
	2-Aminopyridine	x			x
Pyrroles	Pyrrole												Nutty, sweet
	2,3-Dimethyl-1 H-pyrrole	Cocoa, praline, chocolate			x
	3-Ethyl-2,5-dimethyl-1 H-pyrrole	Cocoa, coffee			Cocoa, hazelnut, coffee, roasted
	1-(1 H-Pyrrol-2-yl)ethanone (2-acetylpyrrole)		x		Cocoa, chocolate, hazelnut, roasted								Bread, walnut, licorice
	2-Acetyl-1-methylpyrrole												x
	1-(3,4-Dihydro-2 H-pyrrol-5-yl)ethanone							Popcron-like
	1 H-Pyrrole-2-carboxaldehyde	Honey, candy (low)	x		x								x	PY2
	1-(2-Furanylmethyl)-1 H-pyrrole (furfurylpyrrole)	Cocoa, roasted (low)			Roasted, chocolate, green
	1 H-Indole	Chocolate, green (low)
	3-Methylindol							Faecal
S-Compounds	Benzenethiol												Penetrating
	Dimethyl disulphide	Meaty (low)			x								Sulfurous
	Dimethyl trisulphide												Sulfurous, earthy, camphor, wizened
	Dimethyl trisulphide				Onion, cabbage, sweaty			Sulfurous		x
	4,5-Dihydro-2-methylthiazole	x			x
	4-Methyl-5-thiazolethanol												Beefy, nutty	T1
Terpenes	Alfa-pinene		x
	Beta-pinene		x

X means compounds identified without odour description / X significa compuestos identificados sin descripción de su olor

Figure 2. Principal component analysis of the variation of volatile compounds in the dark chocolate samples, (PC1 and PC2): a) score plot b) loading plot. Code of samples: origin (E = Ecuador and G = Ghana) and roasting time (R1 = 30.5 minutes; R2 = 34.5 minutes and R3 = 38.5 minutes). Identification of volatile compounds in Table 1.

Figura 2. Análisis de componentes principales de la variación de compuestos volátiles en las muestras de chocolate negro, (PC1 y PC2): a) score plot b) loading plot. Código de muestras: origen (E = Ecuador y G = Ghana) y tiempo de tostado (R1 = 30,5 minutos; R2 = 34,5 minutos y R3 = 38,5 minutos). Identificación de compuestos volátiles en la Tabla 1

Figure 3. Principal component analysis of the variation of volatile compounds in the dark chocolate samples, (PC1 and PC3): a) score plot b) loading plot. Code of samples: origin (E = Ecuador and G = Ghana) and roasting time (R1 = 30.5 minutes; R2 = 34.5 minutes and R3 = 38.5 minutes). Identification of volatile compounds in Table 1.

Figura 3. Análisis de componentes principales de la variación de compuestos volátiles en las muestras de chocolate negro, (PC1 y PC3): a) score plot b) loading plot. Código de muestras: origen (E = Ecuador y G = Ghana) y tiempo de tostado (R1 = 30,5 minutos; R2 = 34,5 minutos y R3 = 38,5 minutos). Identificación de compuestos volátiles en la Tabla 1

Figure 4. Distribution of volatile compounds in the groups established according to the position in the PC plots for each family of compounds.

Figura 4. Distribución de compuestos volátiles en los grupos establecidos según la posición en los gráficos de componentes principales (PC) para cada familia de compuestos

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