Volatile-Olfactory Profiles of cv. Arbequina Olive Oils Extracted without/with Olive Leaves Addition and Their Discrimination Using an Electronic Nose

Table 3

Identified volatile compounds and respective contents (mean ± standard deviation; mg of compound/kg of olive oil (as internal standard equivalents); for each oil, n = 5 olive oil bottles × 2 analytical extractions × 1 GC-MS analysis) of the studied cv. Arbequina olive oils.

Volatile compounds^#	Industrially extracted cv. Arbequina oils
	Without leaves addition (control)	With cv. Arbequina leaves	With cv. Santulhana leaves	Aroma sensory descriptor^‡	value^§
Acids
Acetic acid	1.0 ± 0.12^B	1.0 ± 0.07^B	1.9 ± 0.32^A	Sour, vinegary	<0.0001
Alcohols
(Z)-3-hexen-1-ol	0.9 ± 0.2^A	0.7 ± 0.2^A	0.3 ± 0.1^B	Apple, banana	<0.0001
(Z)-2-hexen-1-ol	0.6 ± 0.1^A	0.3 ± 0.04^B	0.2 ± 0.03^C	Green, apple, flowers, fruity, grass	<0.0001
1-hexanol	3.7 ± 0.3^A	2.3 ± 0.1^B	1.8 ± 0.1^C	Fruit, banana, soft, tomato, cut grass	<0.0001
1-octanol	0.08 ± 0.015^A	0.07 ± 0.008^A	0.02 ± 0.005^B	Rancid, musty	<0.0001
Phenylethyl alcohol	0.08 ± 0.019^A	0.08 ± 0.013^A	0.07 ± 0.013^A	Floral, sweet	0.2428
1-nonanol	0.07 ± 0.014^A	0.06 ± 0.006^B	0.01 ± 0.003^C	Rancid	<0.0001
Aldehydes
(E)-2-hexenal	35.3 ± 2.4^B	32.7 ± 1.2^B	39.2 ± 3.3^A	Green, apple-like, bitter, almonds, cut grass, bitter almond like	<0.0001
2,4-hexadienal	0.5 ± 0.1^B	0.3 ± 0.1^B	0.7 ± 0.1^A	Ripe fruity	<0.0001
Nonanal	0.9 ± 0.15^A	0.9 ± 0.11^A	0.2 ± 0.03^B	Fatty, waxy, pungent	<0.0001
Esters
(Z)-3-hexen-1-yl, acetate	14.9 ± 1.67^A	13.5 ± 0.85^AB	13.0 ± 2.07^B	Green-banana, fruity, Green, green leaves	0.0398
(Z)-2-hexen-1-yl, acetate	0.3 ± 0.04^A	0.2 ± 0.03^B	0.2 ± 0.03^C	Apple, banana, grape	<0.0001
Ethers
(Z)-2-Pentene, 1-ethoxy-4-methyl	0.1 ± 0.02^B	0.1 ± 0.02^B	0.2 ± 0.03^A	—	<0.0001
Hydrocarbons
Pentene dimer isomer I	1.3 ± 0.08^B	1.4 ± 0.08^B	2.0 ± 0.18^A	—	<0.0001
Pentene dimer isomer II	1.0 ± 0.08^B	1.0 ± 0.06^B	1.6 ± 0.16^A	—	<0.0001
Pentene dimer isomer III	2.5 ± 0.28^B	2.5 ± 0.16^B	3.7 ± 0.58^A	—	<0.0001
Dodecane	0.04 ± 0.010^A	0.01 ± 0.011^B	0.04 ± 0.036^AB	Undesirable	0.0345
Terpenes
d-limonene	0.3 ± 0.24^A	0.3 ± 0.30^A	0.3 ± 0.46^A	Greenery, fruity	0.9767
α-copaene	0.05 ± 0.008^A	0.03 ± 0.006^B	0.02 ± 0.004^C	Wood, spicy	<0.0001
β-curcumene	0.02 ± 0.005^A	0.01 ± 0.002^A	0.02 ± 0.004^A	—	0.0585
α-farnesene	0.02 ± 0.007^A	0.02 ± 0.005^A	0.01 ± 0.003^B	Soft cooking of vegetable	0.0021
ΣAcids	1.0 ± 0.1^B	1.0 ± 0.1^B	1.9 ± 0.3^A	—	<0.0001
ΣAlcohols	5.5 ± 0.5^A	3.4 ± 0.3^B	2.4 ± 0.2^C	—	<0.0001
ΣAldehydes	36.6 ± 2.5^B	33.9 ± 1.3^B	40.1 ± 3.4^A	—	<0.0001
ΣEthers	0.12 ± 0.02^B	0.09 ± 0.01^C	0.17 ± 0.03^A	—	<0.0001
ΣEsters	15.2 ± 1.7^A	13.7 ± 0.9^AB	13.2 ± 2.0^B	—	0.0317
ΣHydrocarbons	4.9 ± 0.4^B	5.0 ± 0.3^B	7.3 ± 0.9^A	—	<0.0001
ΣTerpenes	0.4 ± 0.2^A	0.4 ± 0.3^A	0.4 ± 0.5^A	—	0.9973
Σ, Total volatile compounds	63.7 ± 4.8^A	57.5 ± 2.5^B	65.5 ± 7.2^A	—	0.0050

^#Peaks identification based on mass spectra comparison with the spectrometer database of the NIST 11 Library, being set a minimum similarity of 90%. ^‡Aroma sensory descriptor found in the literature [2, 3, 38]. ^§ values for the one-way ANOVA. Different letters in the same row show statistical differences from the given mean ().