1. Freezing operation: Instant noodles refers to flour, buckwheat flour, macaroni, etc. as raw materials, add water, cut strips after steaming and shaping of the noodles. When the alpha noodles (boiled noodles) obtained from steaming are cooled down to 30℃ or below, they are put into the freezer, where the temperature is adjusted to -30～-40℃ in advance, so that they can be frozen. The boiled noodles are cooled sharply between 4 and 0°C, and the production of β-amylopectin is strongly excluded, and the boiled noodles are placed below 0°C. Then it was slowly frozen between -30 and -40°C over a period of 3 to 4 hours. In this temperature region, the freezing effect will be better if it is instantly and sharply chilled to -50°C with dry ice or liquid nitrogen.

2. Vacuum drying: the instant noodles obtained in the freezing operation as described above are vacuum dried in the vacuum drying room. If the noodle structure obtained in the freezing operation is microfine and the α-starch is very fixed, there is no special requirement for the conditions of vacuum drying. The usual conditions are as follows: the initial shed temperature is 80°C, and the depressurization is started at 85°C in the storage room, and as the vacuum drying proceeds the temperature rises, accompanied by a drop in the shed temperature. The final noodle temperature of 25 ℃, the library temperature of 30 ℃, the vacuum degree of 3.99Pa (absolute pressure).