A metabolite profiling approach to follow the sprouting process of mung beans (Vigna radiata)

A metabolite profiling methodology based on capillary gas chromatography/mass spectrometry (GC/MS) was employed to investigate time-dependent metabolic changes in the course of the sprouting of mung beans (Vigna radiata). Intact mung beans and sprout samples taken during the germination process were subjected to an extraction and fractionation procedure covering a broad spectrum of lipophilic (e.g. fatty acid methyl esters, hydrocarbons, fatty alcohols, sterols) and hydrophilic (e.g. sugars, acids, amino acids, amines) low molecular weight constituents. Investigation of the obtained fractions by GC resulted in the detection of more than 450 distinct peaks of which 146 were identified by means of MS. Statistical assessment of the metabolite profiling data via principal component analysis demonstrated that the metabolic changes during the sprouting of mung beans are reflected by time-dependent shifts of the scores which were comparable for two spouting processes independently conducted under the same conditions. Analysis of the loadings showed that polar metabolites were major contributors to the separation along the first principal component. The dynamic changes of single metabolites revealed significantly increased levels of monosaccharides, organic acids and amino acids and a decrease in fatty acid methyl esters in mung bean sprouts.