STABILIZATION OF POLYMERIC CARBOHYDRATE NITRATES FROM STUDIES ON STARCH, AMYLOSE, AMYLOPECTIN, AND GLYCOGEN

Abstract

Whole starch, amylose, amylopectin, and glycogen (polymeric carbohydrates of the α-D-glycosidic linkage type) were nitrated by nitric acid in the presence of phosphoric anhydride and stability properties of the nitrated products were studied. Crude amylose nitrate is more stable than amylopectin nitrate and the latter is less stable than the whole-starch nitrate as judged by the Bergmann–Junk test. The stability of glycogen nitrate is closely similar to that of amylopectin nitrate.Appreciable stabilization of the crude nitrates was brought about by boiling with slightly alkaline water for long periods (60–70 hours). All stabilized samples were found to possess closely similar stability properties. The Bergmann–Junk values of all examined nitrates ranged from 2.2 to 1.7 mg of nitrogen per gram sample; the latter value seems to represent the maximum stabilization which could be attained for the polymeric carbohydrate nitrates of the α-D-glycosidic linkage type. In the case of cellulose nitrate (β-D-glycosidic linkage type) Bergmann–Junk values of 1 to 1.25 mg of nitrogen were obtained.