Ethyl (R)-(-)-2-methylbutanoate - fruity, caprylic; also described as (R)-(-)-ethyl 2-methylbutyrate has a first medical-phenolic note and then a fruity-sweet but unspecific note (Amano, et al.) Flavor dectection threshold = 10 ppb in water (Amano, et al.) Also described as - sweet fruity, reminiscent of apples (by GC-O; Mosandl & coworkers) = Ethyl (R)-(-)-2-methylbutyrate Ref: Mans H. Boelens, Harrie Boelens & Leo J. van Gemert, Perfumer & Flavorist, Vol. 18, No. 6, 1-15, 1993 and references therein; Akira Amano, Kazuhiko Tokoro, Kenichi Uchiumi, Method for improving flavor of food or drink, United States Patent 5496580 (March 5, 1996); See also - K Bauer, O Garbe and H Surburg, Flavors and Fragrances, in Ullmann’s Encyclopedia of industrial Chemistry, 5th Edition, Vol. A11, Weinheim, Germany VCH (1988) pp 144-246; Grüb, H., Müller, D.A., Schmidt, H.-L., Rossmann, A., Werner, R.A., Mosandl, A. and Lögtenbörger, H.-J. (2008) Quality Control, in Flavourings: Production, Composition, Applications, Regulations (eds E. Ziegler and H. Ziegler), Wiley-VCH Verlag GmbH, Weinheim, Germany; Karl, V., Dietrich, A. and Mosandl, A. (1993), Stereoisomeric flavour compounds. LXIV: The chirospecific analysis of 2-alkyl-branched flavour compounds from apple headspace extracts and their sensory evaluation. Phytochem. Anal., 4: 158–164

Ethyl (S)-(+)-2-methylbutanoate - fresh fruity, apple-like; also described as (S)-(+)-ethyl 2-methylbutyrate has an etheric, sweety, unspecific, pleasant apple note at extreme dilution (Amano, et al.) Odor threshold: 0.006 ppb in water Flavor dectection threshold = 10 ppb in water (Amano, et al.) Also described as - substantially stronger than the (R) enantiomer: sweet. fruity, full-ripe apple (by GC-O; Mosandl & coworkers) = Ethyl (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; Gary R. Takeoka, Ron G. Buttery, Robert A. Flath, Volatile constituents of Asian pear (Pyrus serotina), J. Agric. Food Chem., 1992, 40 (10), pp 1925–1929; Rychlik, M.; Schieberle, P.; Grosch, W. Compilation of Odor Thresholds, Odor Qualities and Retention Indices of Key Food Odorants; Deutsche Forschungsanstalt fuer Lebensmittelchemie: Garching, Germany, 1998; Akira Amano, Kazuhiko Tokoro, Kenichi Uchiumi, Method for improving flavor of food or drink, United States Patent 5496580 (March 5, 1996); See also - K Bauer, O Garbe and H Surburg, Flavors and Fragrances, in Ullmann’s Encyclopedia of industrial Chemistry, 5th Edition, Vol. A11, Weinheim, Germany VCH (1988) pp 144-246; Grüb, H., Müller, D.A., Schmidt, H.-L., Rossmann, A., Werner, R.A., Mosandl, A. and Lögtenbörger, H.-J. (2008) Quality Control, in Flavourings: Production, Composition, Applications, Regulations (eds E. Ziegler and H. Ziegler), Wiley-VCH Verlag GmbH, Weinheim, Germany; Karl, V., Dietrich, A. and Mosandl, A. (1993), Stereoisomeric flavour compounds. LXIV: The chirospecific analysis of 2-alkyl-branched flavour compounds from apple headspace extracts and their sensory evaluation. Phytochem. Anal., 4: 158–164

Ionones, Irones, Damascones & Structurally Related Odorants

Acyclics (Alcohols, Esters, Acids, Aldehydes)

Lactones

Sesquiterpenoid Related Odorants