The physicochemical properties and charteristics of sweet potato starches which were isolated from the six varieties were investigated. The shapes of starch granules which observed through photomicroscope and scanning electron microscope lucre round and polygonal, but those of the Shinmi were most polygonal, and the average diameters were in the range of 10.4∼14.2 microns. The amylose contents were between 25% and 28%, and blue values and alkali numbers were in the range of 0.29∼0.36, 7.0∼12, respectively. The swelling power and solubility patterns of the starches were negligible until 50℃, thereafter it increased rapidly and the Eunmi showed highest water binding capacity of 211.6%.
Amylogram pattern of 6% starch solutions were similar to no peak viscosity, but maximum viscosity varied widely with varieties. A significant positive correlation was observed between amylose content and average gelatinization temperature. Taste and texture of the steam cooked sweet potatoes were negatively and positively correlated with moisture and amylose contents, respectively, while those of the microwave cooked sweet potatoes were only positively correlated with amylose contents.
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