Problems in processing sweet potato vermicelli

First, the fans are gray in color.

Reason: sweet potato is beaten and separated and precipitated to get starch, which is usually called flour. Wool powder contains impurities, phenols, many pigments, grayish white, in which phenols are easily oxidized and browned, which are bound to blacken after being made into vermicelli.

Solution: refined starch.

The method is: add water 2x 3 times, stir, add appropriate amount of potato starch decolorizer, after about 20 minutes, then filter with 120 mesh nylon screen. After the filtrate passes through the lake for 4 hours, the clear water in the upper layer is removed, stirred with water, and then precipitated. So 3 times, the purpose of decolorization and purification can be achieved.

Second, it is difficult for fans to open more fans.

The reason: the noodles are too thin, the cooling is too slow after flour production, and the thickening is too much, which will make the noodles bond and make it difficult to open the noodles.

Solution: add water when mixing noodles, the amount of thickening should be appropriate, the total amount of water and thickening should not exceed 90 kg per 100 kg of dry starch, blow with an electric fan or blower at the powder outlet of the powder machine to accelerate cooling. When mixing noodles, alum and vegetable oil can be added at 0.3% to 0.4% of the weight of dry starch. If you produce silver powder with a diameter less than 1 mm, you should add an appropriate amount of vermicelli quality improver (powder opener).

Third, vermicelli pot soup, broken bar (no muscle strength)

Reason: usually the noodles are too thin, or the gelatinization temperature is too low and undercooked, but the poor quality of starch or excessive decolorization destroys the structure of starch, which can also lead to vermicelli without gluten strength.

Solution: in addition to moderate dry and wet dough and increase the gelatinization temperature, 10% of the dry starch weight can be mixed with pea starch to enhance gluten strength; it is best to use mung bean and pea starch when thickening. One of sodium alginate, Agar and konjac flour can also be added according to 0.3%-0.5% of the dry starch weight. The first two should be boiled and thickened, while konjac flour can be added directly when mixing noodles.

Fourth, the fans are beaded on the surface and are not smooth and clean.

Reason: the gelatinization temperature is too high, and the vermicelli shrinks unevenly after leaving the machine as expected, forming a large section and a small bead shape, which is not smooth. The dough is too dry and too little moisture aggravates this phenomenon.

Solution: reduce the temperature of the interlayer water flow in the fan machine and reduce the temperature difference before and after the fan leaves the machine. The total water content of the dough should be between 45% and 50%.

5. Vermicelli are crisp and easy to break

Reason: the flour is not ripe, the powder is not cold thoroughly after drying, too much alum is added, it is too dry and is not packed for a long time, which will lead to the crisp vermicelli and the loss in the process of storage and transportation.

Solution: in addition to taking measures for the cause, sodium pyrophosphate can be added according to 0.1% of the dry starch weight during mixing to maintain moisture, or 0.1%-0.5% salt can be added to naturally absorb moisture.