Cold Storage and Drying Alter Polar Metabolite Profiles in Commercial Sprouts of Eight Plant Species

The application of the gas chromatography coupled to mass spectrometry (GC-MS) has been applied for metabolite profiling in sprouts of Brassicaceae (broccoli, kale, radish), sunflower, and Fabaceae (alfalfa, clover, lentil, and mung bean). Soluble carbohydrates were quantitatively the major fraction of total polar metabolites in Brassicaceae and sunflower sprouts. The main sugars in sunflower, mung bean, and Brassicaceae sprouts were fructose and glucose, while in clover, alfalfa, and lentil sprouts, the dominant sugar was sucrose. Myo-inositol was found in the sprouts of all analyzed species, while d-chiro-inositol, epi-inositol, or scyllo-inositol, as well as d-pinitol, were present in the sprouts of some legumes. Among the amino acids in clover and alfalfa sprouts, asparagine, serine, and threonine were quantitatively dominant. During cold storage of sprouts or their drying, a decrease in the content of monosaccharides and an increase in the levels of sucrose were found. Furthermore, such conditions of sprouts storage caused an accumulation of raffinose, proline, and γ-aminobutyric acid. The reduction in the content of monosaccharides and the increase in the content of free amino acids in dried sprouts is new information. Moreover, information about the small effects of low-temperature storage and drying of sprouts on the content of cyclitols seems to be valuable.