Volatile compounds of Algerian extra-virgin olive oils: Effects of cultivar and ripening stage

Figures & data

Table 1. Regression parameters of volatile compounds analysis using SPME-GC-MS.

Volatile compounds	Rt	Calibration curve	R^2	SD slope	SD intercept	SSE	Wr	LOD	LOQ
Ethanol	1.63	y = 0.029x − 0.005	0.989	1.78E−03	3.22E−03	9.00E−05	4.8 E−01–3.95	1.4 E−01	4.8 E−01
(Z)-2-Penten-1-ol	8.46	y = 0.256x + 0.121	0.957	2.72E−02	5.81E−02	3.75E−02	5.2 E−02–4.27	8.8E−03	5.2 E−02
Hexanal	10.38	y = 0.183x + 0.186	0.950	2.53E−02	1.41E−01	2.14E−01	2.3E−01–12.23	6.9E−02	2.3E−01
(E)-2-Hexenal	16.04	y = 0.387x + 0.325	0.984	2.44E−02	2.59E−01	1.17E+00	1.2E−01–25.38	1.1E−01	1.2E−01
(E)-2-Hexen-1-ol	17.35	y = 0.406x + 0.072	0.991	1.89E−02	4.02E−02	1.79E−02	3.1E−02–4.25	9.2E−03	3.1E−02
Benzaldehyde	20.82	y = 0.079x − 0.012	0.995	2.80E−03	7.31E−03	5.90E−04	4.2E−01–5.23	1.3E−01	4.2E−01
(E)-2-Heptenal	21.00	y = 0.039x − 0.003	0.997	1.02E−03	2.19E−03	5.00E−05	5.4E−01–4.30	1.6E−01	5.4E−01
6-Methyl-5-hepten-2-one	21.67	y = 0.340x + 0.009	0.997	7.98E−03	1.43E−02	3.56E−03	1.5E−01–4.30	4.4E−02	1.5E−01
(Z)-3-Hexen-1-yl acetate	22.18	y = 0.335x − 0.004	0.996	9.71E−03	1.82E−02	5.77E−03	4.5E−02–4.50	1.4E−02	4.5E−02
Hexyl acetate	22.33	y = 0.3340x − 0.005	0.966	8.60E−03	1.57E−02	4.24E−03	7.3E−03–4.35	2.2E−03	7.3E−03
p-Cymene	22.53	y = 0.301x + 0.000	0.998	6.32E−03	1.14E−02	2.24E−03	1.3E−02–4.30	3.9E−03	1.3E−02
Limonene	22.63	y = 0.303x + 0.007	0.999	4.38E−03	7.74E−03	1.04E−03	4.7E−03–4.20	1.4E−03	4.7E−03
Nonanal	24.14	y = 0.059x + 0.008	0.994	2.16E−03	4.47E−03	2.20E−04	3.7E−02–4.14	1.1E−02	3.7E−02
Phenylethyl alcohol	24.40	y = 0.029x − 0.003	0.989	2.16E−03	5.64E−03	1.50E−04	2.0E−01–5.10	1.4E−01	2.0E−01
Alloocimene (E or Z)	24.59	y = 0.052x + 0.001	0.996	1.50E−03	3.04E−03	1.00E−04	1.6E−02–4.06	4.8E−03	1.6E−02
Alloocimene (E or Z)	24.82	y = 0.023x + 0.000	0.993	9.50E−04	1.93E−03	4.00E−05	1.6E−02–4.06	4.8E−03	1.6E−02
Methyl salicylate	25.74	y = 0.016x − 0.002	0.995	5.77E−04	1.69E−03	3.00E−05	1.8E−01–5.90	3.7E−02	1.8E−01
α-Farnesene	29.09	y = 0.006x − 0.001	0.971	5.89E−04	1.21E−03	1.00E−05	7.7E−01–4.30	2.3E−01	7.7E−01

Rt, retention time (min); R², coefficient of determination; SD, standard deviation; SSE, sum of squares of errors; Wr, working ranges (mg/L); LOD, limit of detection (mg/L); LOQ, limit of quantification (mg/L).

Table 2. Volatile compounds concentration (mg/L, mean of three replicates) in eight Algerian monocultivar EVOOs.

Cultivars	Aaleh	Abani	Bouricha	Chemlal				Ferkani	Limli	Mekki	Rougette de Mitidja
MI=	3.08	2.37	2.75	3.00	4.20	5.50	6.20	2.64	2.01	3.30	2.89
Ethanol	<LOD	2.22	0.81	<LOD	8.42^a	<LOD	2.67^b	0.81	<LOD	<LOD	<LOD
1-Penten-3-one	5.38	4.97	3.53	<LOD	<LOD	<LOD	<LOD	5.23	2.67	<LOD	13.91
(Z)-2-Penten-1-ol	0.39	0.34	0.22	<LOD	<LOD	<LOD	<LOD	0.22	<LOD	0.15	<LOD
Hexanal	<LOD	0.23	3.28	3.69^a	6.04^b	8.12^c	7.06^b,c	1.32	<LOD	<LOD	3.88
(E)-2-Hexenal	2.26	0.38	14.00	10.74^a	15.83^b	9.15^a	13.97^b	<LD	26.51	13.25	15.48
(E)-2-Hexen-1-ol	<LOD	<LOD	<LOD	<LOD	2.52^a	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD
1-Hexanol	<LOD	<LOD	0.28	<LOD	<LOD	<LOD	<LOD	<LOD	0.21	<LOD	0.01
Benzaldehyde	<LOD	<LOD	0.66	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD
(E)-2-Heptenal	<LOD	<LOD	<LOD	<LOD	<LOD	3.18^a	2.36^a	<LOD	<LOD	<LOD	<LOD
6-Methyl-5-hepten-2-one	<LOD	<LOD	<LOD	0.50^a	0.75^a,b	0.99^b	1.78^c	<LOD	<LOD	<LOD	<LOD
(Z)-3-Hexen-1-yl acetate	<LOD	<LOD	0.54	1.00^a	0.88^a	0.82^a	0.84^a	0.10	0.34	0.08	0.09
Hexyl acetate	<LOD	<LOD	1.54	1.11^a	1.42^a	1.65^a	1.42^a	0.12	0.87	<LOD	0.09
p-Cymene	<LOD	<LOD	<LOD	0.06^a	0.09^a	0.10^a	0.09^a	0.01	0.03	<LOD	<LOD
Limonene	0.25	0.21	0.16	0.14^a	0.26^a,b	0.32^b	0.36^b	0.25	0.37	0.47	0.08
β-Ocimene	<LOD	<LOD	0.77	4.71^a	6.21^a	5.80^a	<LOD	<LOD	0.22	0.30	0.35
Nonanal	0.06	0.15	0.56	0.49^a	0.57^a	0.69^a,b	1.09^b	<LOD	0.52	0.23	0.35
Phenylethyl alcohol	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	0.72	<LOD	<LOD
Alloocimene (E,Z)	0.08	<LOD	0.51	3.17^a	4.51^b	4.02^a,b	3.59^a,b	<LOD	<LOD	<LOD	<LOD
Methyl salicylate	<LOD	0.35	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	<LOD	0.37	<LOD
α-Farnesene	<LOD	<LOD	<LOD	<LOD	<LOD	2.08^a	2.08^a	<LOD	<LOD	<LOD	<LOD
ΣC6 aldehydes	2.26	0.61	17.28	14.43	21.87	17.27	21.03	1.32	26.51	13.25	19.36
ΣC6 compounds	2.26	0.61	19.64	16.54	26.68	19.74	23.29	1.54	27.92	13.33	19.55
% C6 aldehydes/ΣC6 compounds	100	100	88.01	87.24	81.96	87.50	90.28	85.99	94.94	99.41	99.01
Σ volatile compounds	8.42	8.85	26.86	25.61	47.50	36.91	37.32	8.06	32.45	14.85	34.24

MI, maturity index; LOD, limit of detection (mg/L); ^a–d, statistical differences of maturity stage (p < 0.05).

Figure 1. Principal chemical group quantified (mg/L) from the volatile fraction of eight Algerian monocultivar EVOOs: Aaleh, Abani, Bouricha, Chemlal (MI = 3.00), Ferkani, Limli, Mekki, and Rougette de Mitidja.

Figure 2. Evolution of C6 aldehydes, C6 alcohols, and C6 esters (mg/L, mean of three replicates) in Chemlal EVOO at four stages of fruit maturity.

Figure 3. Principal component analysis of volatile compounds: (a) plot of component weights and (b) scatter plot of EVOOs samples: Aaleh, Abani, Bouricha, Chemlal, Ferkani, Limli, Mekki, and Rougette de Mitidja.