Table 3.

Retention index (RI), aroma properties and molecular origin of volatile compounds arising from oxidation of n-3 fatty acids (FA). Units of Equivalents (rightmost column) are percent of compound originating from the terminal end.

Compound	RI1	Odour descriptor	Equivalents of terminal end in fragment (%)
Acetaldehyde	812	Apple skin, fruity, green leaves, sweet, sweet burninga,b	20
Propanal	833	Sharp-irritatingc	97
2-Propanone	842	Pungent, irritatingb	0
2-Propenal	857	Irritatingb	0
Butanal	873	Burnt, irritating, green, penetrating pungent, varnishb	65
2-Butanone	890	-	45
2-Ethylfuran	940	Flowerc	100
2-Pentanone	968	Acetone, sweet fruity ketoneb	96
1-Penten-3-one	1018	Pungent, rancid green, glue, sharp fishyc	100
(E)-2-Butenal	1039	Old cheesec	100
2,3-Pentanedione	1059	Butter-likea	100
Hexanal	1080	Pungent, green, fresh grass, fattya,c	48
(E)-3-Penten-2-one	1125	-	?
(E)-2-Pentenal	1128	Pungent, glue, green, grassy, applec	100
1-Penten-3-ol	1156	Sweetc	100
3-Hexen-2-one	1214	-	91
1 -Hydroxy-2-propanone	1300	-	0
(E)-2-Penten-1-ol	1308	Greenc	100
2-Hydroxy-3-pentanone	1355	-	100
1 -Hydroxy-2-butanone	1373	-	100
Acetic acid	1450	Vinegaryd	2
(E,E)-2,4-Heptadienal	1492	Nasty, green, fatty, fatty-oily, rancid hazelnutsa,c	?
Propanoic acid	1538	Goaty, vinegar, cooked, potato-liked,e	100
5-Methyl-2(5H)-Furanone	1684	Caramel, fruity, phenolicse	?
5-Ethyl-2(5H)-Furanone	1765	-	100

- Data not found. ? No conclusive data were obtained from the present study.

¹Retention index on DB-FFAP.

^a(Triqui & Guth, 1997).

^bThe LRI and Odour Database.

^c(Genot, Meynier, & Riaublanc, 2003).

^d(Rapp & Mandery, 1986).

^e(Vazquez-Cruz, Jimenez-Garcia, Torres-Pacheco, Guzman-Maldonado, Guevara-Gonzalez, & Miranda-Lopez, 2012).