In four types of RS, 33 is the most interesting one. It can produce RS 53 or increase yield of RS 33 by controlling moisture, PH, heating temperature, time, circulating times of gelatinization, freezing and drying factors, which is because the molecules reassemble to ordered crystal during retrogradation. The crystalline region prevents approach of amylase to glucoside bond and the active group of amylase combining with starch molecule, leading to resistance to enzymolysis. In general, RS is recrystallization of retrogradation starch.

　　Different deep corn processing technologies are used according to RS property. Following are introduction of RS3 processing methods and its influence factor.

　　1. RS Processing Technology

　　Hydrotherm can be classified into 5 categories according to the temperature and proportion of water and starch.

① Heat-moisture treatment is that the starch is heated under low moisture content≤35%, temperature as high as 80-160℃.

② Tough treatment is also called annealing processing in the condition of moisture＞40%, temperature lower than gelatination. 

③ Autoclave treatment is that the moisture content of starchy solution ＞40%.

④ Decompression processes a large amount in a short time without gelatinized starch particles, highly thermostable, potential in industry.

⑤ Ultrahigh pressure treatment makes the double helix of eight shape crystal reassemble, partly transforming into type 3. However, This technology will not lead to degradation of molecular weight. The starch particles gelatinize but keep its structure without dissolving out. Compared with heat gelatinized starch, it appears a different gel property.

　　In some conditions where gelatinization does not happen, starch keeps its original particle structure. Treatment under high temperature and pressure makes starch completely gelatinize. The amylose thoroughly dissolves out, beneficial for association of double helix to form resistant starch.