The Distribution and Pasting Properties of Starches in Fresh Sweet Potato (Ipomoea batatas Lam.) Tuber

This study focused on the distribution and pasting properties of starches in sweet potato (Ipomoea batatas L.) tuber. A fresh sweet potato tuber was cut into six equivalent parts. The extractable contents and pasting properties of starches from different parts of fresh sweet potato tuber were determined. The results showed that the extractable content of starches from the Middle section of sweet potato tuber is lower than that from the head and the end section of sweet potato tuber. The extractable content of starches from the inner-end part and the outer-Middle part of sweet potato tuber are 16.2% and 10.3% respectively. The amylose content of starches is relatively higher in the Middle section and outer layer of sweet potato tuber. The amylose content of starches from the outer-Middle part and the inner-end part of sweet potato tuber are 29.5% and 26.7% respectively. Pasting properties of starches from different parts of sweet potato tubers are different from each other. Among them, the starches from inner-end part of sweet potato tuber have the highest viscosities and a lower breakdown.