Table 4. Effect of cooking methods on amylase activity of sweetpotato storage roots.

Variety	Raw sweetpotatoes	Baking (%)	Boiling (%)	Steaming (%)
Jinyu	12.80 ± 0.66	0.48 ± 0.03 (3.75)	0.96 ± 0.10 (7.50)	0.19 ± 0.01 (1.48)
Xinxiang	4.82 ± 0.06	0.42 ± 0.08 (8.71)	0.02 ± 0.01 (0.41)	0.00 ± 0.01 (0.00)
Yuzishu263	12.64 ± 0.20	0.00 ± 0.00 (0.00)	0.16 ± 0.01 (1.27)	0.03 ± 0.00 (0.24)
Zimei	2.23 ± 0.11	0.20 ± 0.06 (8.97)	0.07 ± 0.01 (3.14)	0.41 ± 0.09 (18.38)

Note: The numbers in the table represent α-amylase activity (mg/g of Dw/5 min) of raw sweetpotatoes and those under different cooking conditions followed by the percentage of amylase activity in the cooked sweetpotatoes relative to those in raw sweetpotatoes.