The Estimation of Carbohydrates. IV.: The Presence of Free Pentoses in Plant Extracts and the Influence of other Sugars on their Estimation

Evidence is brought forward to show that free pentoses exist in the alcoholic extracts of foliage leaves of different plants. Their amount can be estimated with a fair degree of accuracy by the ordinary distillation process or by the reducing power of the purified liquor after other sugars have been fermented away. When, however, small amounts of pentose have to be estimated accurately in presence of large quantities of other sugars, it is advisable, as suggested by Kluyver, to ferment away these sugars before applying Kröber's process.