Fig. 3

Raman spectroscopy analysis of the C. sakazakii wild type strain and each of the mutants. a A principal component analysis (PCA) model that was based on the Raman spectral features of the wild type strain and the mutants. b A comparison of the Raman spectral features between the wild type and mutant strains. A: wild type strains; B–I: mutants AM 2, AM 6, AM 4, AM 5, AM 7, AM 8, AM 9 and AM 10, respectively. The numbers in red indicate the decreases observed in biochemical components, and the numbers in blue indicate the increases observed in biochemical components