Changes in the Soluble Carbohydrate Profile During Fenugreek (Trigonella foenum-graecum L.) Germination and in the Response of Sprouts to Desiccation and Cold Stress

Germination of fenugreek (Trigonella foenum-graecum L.) seeds causes degradation of some antinutritional compounds. At the same time, the content of dietary important compounds, including some carbohydrates, in the sprouts increases. The aim of this study was to investigate changes in the soluble carbohydrate profile during germination and growth of fenugreek sprouts in the roots, hypocotyl and cotyledons. Furthermore, we assessed the effect of cold stress and desiccation on the carbohydrate profile in the main parts of the sprouts. Gas chromatography analyses of soluble carbohydrates showed that fenugreek seeds and sprouts contained sixteen soluble carbohydrates. In dry seeds, the main saccharides were raffinose family oligosaccharides (RFOs), sucrose and d-pinitol. During fenugreek germination, the drastic decomposition of RFOs and galactosides of cyclitols occurred faster in the embryonic axis than in the cotyledons. This was accompanied by an increase in the concentrations of monosaccharides and sucrose, as well as d-pinitol and myo-inositol in the developing hypocotyl and roots. Both examined stresses increased sucrose and raffinose concentration in cotyledons and roots, but in the hypocotyl similar changes were observed only under desiccation. The process of desiccation did not affect the d-pinitol content in the cotyledons of fenugreek sprouts, slightly reduced the content in the hypocotyl, but increased its level in the roots. Applied cold stress did not affect the content of d-pinitol and myo-inositol in the cotyledons and hypocotyl of fenugreek sprouts and only slightly reduced their level in the roots. The obtained results indicate different responses of fenugreek sprout organs to vegetation conditions caused by cold and/or desiccation stress. The practically insignificant effect of cold storage and desiccation on the level of d-pinitol and myo-inositol in fenugreek sprouts is new information that will probably be important for consumers.