Butyric and valeric acids or esters present a typical odour named "fatty acid odour" (Clarke ey al. 1991). These compounds are many times produced by microorganisms action. A compound, isovaleronitrile, with this type of odour, was detected in beet molasses alcohol (Strating, Westra, 1982).
Clarke M.A., E.J. Roberts, M.A. Godshall, X.M. Miranda, 1991, The polysaccharides of sugarbeet, C.I.T.S.
Strating J., W.M. Westra, 1982, Isovaleronitrile; a characteristic component of beet molasses alcohol, J.
Chromatogr., 244: 159-165