WATER-SOLUBLE CARBOHYDRATES IN DRIED PLANT

Within the framework of studying the fructan metabolism of wheat, seve ral comparative investigations of different preparation and extraction methods were accomplished to find the most suitable methods for quant itative determination of primary water-soluble carbohydrate contents o f plant material. Changes in sugar content of oven-dried samples were detailed. Oven-dried plant materials have significantly lower total wa ter-soluble carbohydrate content than fresh ones. The decreases were h igher in monosaccharide level than in fructan and glucan. Sucrose conc entration of dried samples was similar to fresh ones. Changes in sugar components were different, so their ratio in the fresh samples were n ot identical with the dried ones. The efficiency of extraction of solu ble carbohydrate could be increased by using boiling water as the firs t extracting solution instead of ethanol. The TLC analysis show that o ven-dried plant samples contain significantly lower amount of fructans with low degrees of polymerization (DP). The conclusion is, that neit her glucose, fructose, or oligosaccharide content, nor the DP of fruct ans of dried plant are similar to the fresh one.