No abstract

I948 6. Exposure of amylose to hot water brings about changes even in the portion which does not retrograde. The blue value falls and fi-amylase action is incomplete. 7. Amylopectin was not so successfully purified, but fractional precipitation with ethanol freed it slightly from amylose which had escaped the first precipitation.

The fractionation of starch by precipitation with butanol and similar alcohols, first developed by Schoch (1942), stimulated research in this field by providing the first efficient method of preparing in reasonably pure form the components, amylose and amylopectin. These names have often been applied

No abstract

The effect of various carbohydrates on the levels of amino acids excreted in the feces of rats has been studied. Potato starch, autoclaved potato starch, or dextrin each induced much greater levels of amino acids in the feces than either sucrose or glucose. The amino acids appear to be derived mainly from endogenous nitrogen. However, when rats were fed rations containing unmodified potato starch, undigested dietary protein apparently contributed a significant amount of the amino acids found in the feces. The inclusion of 10% lactose in a ration containing sucrose as the source of carbohydrate caused a statistically significant increase in the levels of lysine and histidine in the feces. The influence of lactose may be related to changes in the intestinal flora. The incorporation of ammonium salts into 9% casein diets had no significant effect on the amounts of amino acids in the feces.