Preparation method of rice noodle with low glycemic index

A preparation method of low glycemic index rice noodles, comprising the following steps:

• (a) raw material preparation:
• sieving rice starch by a 100-mesh sieve, and adding water for preparation to reach a water content of 30%-40%;
• (b) mixing and tempering:
• adding debranching enzymes and an emulsifying agent into a raw material obtained in step (a), and performing uniform mixing, wherein the debranching enzymes are pullulanase and isoamylase, a total addition amount of the debranching enzymes is 40-60 ASPU/g rice starch dry basis, a consumption ratio of the pullulanase to the isoamylase is 1:(0.5-2), the emulsifying agent is glycerin monostearate, and an addition amount of the emulsifying agent is 0.5%-1% (w/w) of the rice starch raw material;
• (c) first-step extrusion:
• conveying a mixed material obtained in step (b) into an extrusion machine to be extruded, setting four section temperatures of the extrusion machine in the extrusion to be in ranges of 45-55° C., 55-65° C., 65-75° C., and 75-95° C., respectively, and setting a screw rod rotating speed to be in a range of 80-110 rpm;
• (d) drying and crushing:
• after an extruded product obtained in step (c) is dried for 20-50 min at 70-90° C., performing crushing and sieving by a 100-mesh sieve to obtain resistant starch;
• (e) second-step extrusion:
• adding 60%-70% of rice flour, 1%-5% of salad oil, 0.1%-0.5% of citric acid, and 0.1%-0.5% of table salt into the resistant starch obtained in step (d), conveying the material into the extrusion machine to be extruded, performing extrusion and noodle discharging through the extrusion machine, and performing cutting in a die head position to obtain strip-shaped rice noodle products, wherein four section temperatures of the extrusion machine in the extrusion are set to be in ranges of 75-85° C., 85-95° C., 95-105° C., and 105-135° C., respectively, and a screw rod rotating speed is set to be in a range of 80-110 rpm;
• and
• (f) strip rubbing, shaping air drying and packaging:
• performing a strip rubbing treatment on rice noodle strips to avoid adhesion, and then performing air drying and packaging to obtain the low glycemic index rice noodles.