A laboratory wet-milling process was used to determine steeping characteristic,starch yield and the purity of corn dried under different drying temperature.

The test was designed applying quadratic regression orthogonaltest and amathematic model characterizingthe relationship among the parameters includingsteeping time,temperature,concentration of SO_(2,)and starch yield was established.

With the raw material of yellow dent corn, this test applies the technology of wet-milling extraction to get pure corn starch with high starch yield and fine quality.

The starch contents and amylase activities in the roots of different genotypes of sweetpotato during whole storage period were measured.

By measuring several indexes,such as water content,starch gelatinization ratio,enzymatic hydrolyzeα-amino nitrogen content and total fat content,we obtained the change rule of these indexes in the process.

In this paper, we take starch recovery and the content of anthracene quinoanthraquinone as main aims, after studying the technology conditions of pH value, immersion time and ratio of polygonum multiflorum Thunb to immersion solution, the new technology p arameters are investigated.