Abstract
The relations between properties of commercial sweetpotato starches (warabi-mochi flour) and particle-size distribution, mineral composition, and defatting of the starches were investigated. The results were as follows. 1) Mineral composition and limewater treatment had no effect on the pasting properties and texture of the starch gels. 2) Classified starch samples having a larger particle-size distribution showed larger breakdown and smaller setback in pasting properties, and also less firmness in their gel texture than those starch samples having a smaller particle-size distribution. 3) After defatting, the decrease in the initiation temperature of breakdown and in the ratio of setback for pasting properties was observed. Firmness of the starch gels decreased but their cohesiveness increased by defatting. These observations showed that particle-size distribution and defatting largely affect pasting properties and gel texture as a result of change in resistibility to degradation of the starch granule.
