Metabolomics were initially defined as the global analysis of all metabolites present in a sample (metabolomics) and the analysis of metabolic responses to drugs and diseases (metabonomics) [Nicholson et al., 1999, Fiehn 2002, Weckwerth and Morgenthal 2005]. These two definitions have an historical origin, while metabolomics has its foundations in microbial and plant sciences metabonomics origi...