Abstract
In order to clarify the machanism of digestion of amylomaize starch granules by rats, some properties of the starch remaining in the digestive tract and the activities of starch-degrading enzyme in the intestine were examined by using the animals fed on the starch granules (amylose content 49.3%). The starch granules were isolated from stomach, small intestine, cecum, large intestine and feces at various intervals after feeding. The elution patterns of the starches on a Sephadex G-50 column showed that low molecular weight components accumulated and increased gradually with progress of digestion. The iodine coloration of the starches decreased, and the λmax of the starch-iodine complex shifted to a shorter wavelength during the same process. These findings as well as of the previous studies suggest that the amorphous parts of amylomaize starch granules were preferentially degraded in the rat intestine, and the crystalline parts in the granules accumulated in the residual starch. The amylase activities in the intestine of rats fed on amylomaize starch granules were detected not only in the small intestine but in the cecum and large intestine, whereas the amylase activities in the intestine of the animals fed on normal corn starch were present mostly in the small intestine. It seems that amylomaize starch granules were digested through the whole intestine. The digestive capacity for mylomaize starch granules of the cecum contents tended to be larger than that of the small intestine contents, as compared on the same basis of amylase activity. These results suggest that the starch-degrading enzyme systems are different in these organs.
