PCA of fluorescent RAP-PCR profiles obtained from RNA extracted from defined mixed culture fermentation of pasteurized whole or skim milk treated by acidification and neutralization. WR is the whole milk reference profile; WCN is whole milk acidified with CO₂ and neutralized with NaOH; WCC is whole milk acidified with CO₂ then neutralized with Na₂CO₃; SR is pasteurized skim milk reference with no treatment; SC is pasteurized skim milk treated with CO₂; and SCA is pasteurized skim milk treated with CO₂ then neutralized by agitation. Gray shading represents the clustering of the three experimental repetitions (●) inside an ellipse which represents a confidence level of 95%. (□) Cluster’s barycenter.