Frying Technological Process of Low-Fat “Red-Heart” Sweet Potato Slices at Normal Atmospheric Pressure

The frying technological process of low-fat “Red-heart” sweet potato slices at normal atmospheric pressure was studied, and the results showed as follow: (1) The condition of color-protection is that the sweet potato slices were dipped into the solution of NaHSO₃ 0.10％ and citric acid 0.10％ for 5 minutes, then hot-water blanching at the temperature of 95～100℃ for 3 minutes. (2)Dehydration at 60℃ for 120 minutes, and then the water content of semi-finished product was controlled at about 42％ before frying. (3)Slices were freezed at -32℃ for 30 minutes. (4)The optimum frying conditions of sweet potato slices were the frying temperature at 170℃ for 1 minute, and the ratio of sweet potato slices to oil was from 1∶5 to 1∶4. After the process, the sweet potato slices were red-orange in color, crisp and fine in texture, even in bubble distribution, beautiful in external form, and fat contents were less than 15％.