Volatiles Produced by Staphylococcus xylosus and Staphylococcus carnosus during Growth in Sausage Minces Part I. Collection and Identification

Aseptic model minces were inoculated with commercial samples of either Staphylococcus xylosus or Staphylococcus carnosus. Volatiles produced by the cultures were collected during growth by diffusive sampling onto adsorbent traps, identified by thermal desorption-gas chromatography-mass spectrometry and quantified by thermal desorption-gas chromatography-flame ionisation. The data were analysed by principal component analysis. The study showed that both starter cultures produced a large number of volatiles in concentrations of sensory importance. Almost all of the major volatiles resulted from amino acid degradation, suggesting that the effect of Staphylococcus starter cultures on flavour quality is much related to their ability of catabolizing amino acids. With the exception of diacetyl, acetoin and 2-methyl-1-butanol, both cultures formed the same volatiles. Diacetyl and acetoin were not produced by Staphylococcus carnosus and 2-methyl-1-butanol was not produced by Staphylococcus xylosus. The ketones, acetone, 3- and 4-methyl-2-pentanone, and the two sulphides, dimethyldisulphide and dimethyltrisulphide, were produced in higher amounts by Staphylococcus xylosus, whereas methyl-branched, shortchain aldehydes and acids were produced in higher amounts by Staphylococcus carnosus. 2-Pentanone, aromatic compounds and nitrogen-compounds were produced in similar amounts by both cultures.