Fig. 4

Characterization and comparison of the metabolite profiles. PLS-DA analysis of individual samples in (a) POS mode and (b) NEG mode. The volcano plots showed the DMs of (c) SAS vs. SMS and (d) SAW vs. SAS. The key pathways in (e) SAS vs. SMS and (f) SAW vs. SAS were shown. The key pathways are labelled in terms of impact value. The larger the impact value, the more important the pathway. Only the top five pathways in (f) are labelled