DETERMINATION OF SUGARS FROM NONSTARCH PO LYSACCHARIDES AS THEIR ALDONONITRILE ACETATES BY GAS-CHROMATOGRAPHY

The present paper describes a method for the determination of sugars f rom non-starch polysaccharides (NSP) by gas chromatography. This metho d consists of an enzymatic hydrolysis of starch by alpha-amylase and a successive acidic hydrolysis of the total NSP fraction. The released sugars are converted into their aldononitrile acetates by hydroxylamin e hydrochlorid, pyridine and acetic acid anhydride. The aldononitril-a cetate derivatives of the most important sugars are separated on a ver y polar capillary column coated with 100 % cyanopropylpolysiloxane wit hin only 13 minutes and quantified by flame ionization detection. Coef ficients of variation which represent the reproducibility of the metho d were below 5 % for the major sugars (glucose, xylose, arabinose, gal actose) and below 10 % for the minor sugars (rhamnose, fucose, mannose ). The method has been applied to the determination of sugars from NSP of various plant foodstuffs.