Cereal Chem 50:176 - 183.  |  VIEW ARTICLE
A Specific Method for the Determination of Pentosans in Cereals and Cereal Products.

J. Cerning and A. Guilbot. Copyright 1973 by the American Association of Cereal Chemists, Inc. 

A method for the determination of total pentosans in cereals and cereal products is described. The pentosans are converted into furfural by hydrochloric acid and separated by a steam distillation. Compared with classic distillation techniques the apparatus developed by Duffau has several advantages: The hydrolysis of the pentosans into pentoses, their transformation into furfural, and the distillation take place without direct heating of the reaction medium. Furthermore, the total acid volume and its concentration are maintained constant during the whole operation. The colorimetric determination of furfural is carried out by means of the aniline reaction. The difficulty presented by the great instability of the aniline furfural color has been resolved by the use of a buffer which leads to a stabilization of the color reaction for at least 45 min. Furfural can be determined specifically in the presence of large amounts of hydroxy methyl furfural (HMF). Uronic acids, such as glucuronic acid, do not interfere up to a concentration of 10% of total pentosans. The method is quite simple and can be employed within a wide range of concentrations. Specificity, precision, and reproducibility are equal, if not superior, to current techniques.