Fig. 1.

Abundance of six aroma compounds, expressed as area of a specific ion (m/z), in arbitrary units, in the cultures of 28 P. freudenreichii strains of four lac/nit phenotypes (freudenreichii, shermanii, lac⁺/nit⁺ and lac⁻/nit⁻), abbreviated as F, S, P+ and P−, respectively). ctrl, control non-inoculated medium incubated under the same conditions; a–d, the production within phenotype with different letters differ significantly (P < 0.05)