| Abstract: | When potato starch was hydrolyzed to form Nägeli amylodextrin by 16% sulfuric acid at 30°C, only the amorphous portion of the starch granules was deteriorated. The crystallinity of Nägeli amylodextrin showing the hydrolysis ratio of 0.22 was 1.28 times as large as that of original starch. The hydrolysis process at above 45°C was given by two exponential equations. The value of acid resistance portion (Co) at 30 and 38°C was 100%, while the values at 45, 50 and 55°C were 67, 38 and 18%, respectively. The high value of Co generally showed the high acid resistance in the various starches. Sweet potato and waxy rice starches were more easily hydrolyzed than other starches, although they gave the relatively high value of Co. Thus, it was slightly more difficult for low acid resistance portion of potato starch to be hydrolyzed than for that of other starches. Moreover, that of waxy rice was easily hydrolyzed. |
