Volatiles produced by Staphylococcus xylosus and Staphylococcus carnosus during growth in sausage minces: Part II. The influence of growth parameters

Aseptic model minces inoculated with commercial samples of either Staphylococcus xylosus or Staphylococcus carnosus were prepared in accordance with an experimental design investigating the effect of seven parameters: fermentation temperature, pH, salt, nitrate, glucose, ascorbate, and the access of air. Volatiles produced by the cultures were collected during growth, identified and quantified. The data were analysed by partial least squares regression. The results showed that oxygen in general had more influence on the aroma producing capacity of Staphylococcus xylosus than of Staphylococcus carnosus which was more affected by nitrate and glucose. The two strains differed mostly with regards to pH. Aroma production by both strains was strongly related to growth-either positively or negatively depending on compound. Potent aroma compounds such as methyl-branched aldehydes and acids arising from degradation of leucine, isoleucine and valine, and aromatic compounds arising from phenylalanine were produced in lower amounts when the bacteria grew well, that is, produced cell mass, whereas the opposite was the case for compounds such as sulphides and ketones.