Two-stage frying process for high-quality sweet-potato chips

The product fried in a two-stage (TS) frying process (1 min fried at atmospheric pressure and 2 min under vacuum) had better appearance and texture compared to the ones that were only fried under vacuum or single-stage (SS) conditions. The samples were lighter and more yellow (less compact) than the chips fried under the SS process. The atmospheric frying prior to vacuum frying helped the starch to gelatinize thus producing a better product in terms of texture, oil content, and flavor. The final oil content of the TS fried chips was 15% lower than those fried by the SS process showing that the structure of the chips formed during the process affected the oil absorption during frying.