Methyl (R)-(-)-2-methylbutanoate - fruity, dairy (Boelens et. al.) = Methyl (R)-(-)-2-methylbutyrate Flavor perception threshold = 5 ppb in water (Amano et. al) Odor perception threshold (nasal) for racemic Methyl 2-methylbutanoate: 0.4 ppb in water (Blank et. al) Odor perception threshold (retronasal) for racemic Methyl 2-methylbutanoate: 0.2 ppb in water (Blank et. al) On the basis of the Odor perception threshold (nasal) for racemic and the (S)-enantiomer, we calculate that the Odor perception threshold (nasal) for Methyl (R)-(-)-2-methylbutanoate would be about ~0.5 ppb Ref: Mans H. Boelens, Harrie Boelens & Leo J. van Gemert, Perfumer & Flavorist, Vol. 18, No. 6, 1-15, 1993 and references therein; Imre Blank, Alina Sen & Werner Grosch (1992), Sensory study on the character-impact flavour compounds of dill herb (Anethum graveolens L.), Food Chem., 43, 337-343; Akira Amano, Kazuhiko Tokoro, Kenichi Uchiumi, United States Patent 5496580, Method for improving flavor of food or drink (March 5, 1996)

Methyl (S)-(+)-2-methylbutanoate - fruity, apple-like (Boelens et. al.); fruity Blank et. al) Odor perception threshold (nasal): 0.3 ppb in water (Blank et. al) Flavor perception threshold = 5 ppb in water (Amano et. al) = Methyl (S)-(+)-2-methylbutyrate Ref: Mans H. Boelens, Harrie Boelens & Leo J. van Gemert, Perfumer & Flavorist, Vol. 18, No. 6, 1-15, 1993 and references therein; Imre Blank, Alina Sen & Werner Grosch (1992), Sensory study on the character-impact flavour compounds of dill herb (Anethum graveolens L.), Food Chem., 43, 337-343; Akira Amano, Kazuhiko Tokoro, Kenichi Uchiumi, United States Patent 5496580, Method for improving flavor of food or drink (March 5, 1996)

Ionones, Irones, Damascones & Structurally Related Odorants

Acyclics (Alcohols, Esters, Acids, Aldehydes)

Lactones

Sesquiterpenoid Related Odorants