What Is a Fan Rating?

Fan is one of the common foods in China. It is a kind of silky food made from mung beans and sweet potato starch. They are often called noodles and winter noodles (mainly in Taiwan), called Korean noodles on the Korean Peninsula, and noodles on Vietnam.

1. Fans are dull

Reason: The starch obtained by beating and separating the sweet potatoes is usually called flour. Wool powder contains impurities, phenols, many pigments, and is off-white. The phenols in it are easily oxidized and browned, and they are bound to become black when made into vermicelli.

Solution: refined starch. Add 2 to 3 times of water to the flour, stir, add an appropriate amount of potato starch decolorant, and after about 20 minutes, filter through a 120 mesh nylon mesh sieve. After the filtrate was precipitated for 4 to 6 hours, the upper clear water was removed, and then water was added to stir and precipitate again. In this way 3 times, the purpose of decolorization and purification can be achieved.

2. Many fans draw, difficult to open

Reason: The noodles are too thin, the cooling speed is too slow after flouring, and too much glutinous will cause the noodles to stick together, resulting in many draws and difficult to open.

Solution: Add appropriate amount of water and coriander to the noodles. The total amount of water and mash added per 100 kg of dry starch is preferably not more than 90 kg. Use an electric fan or blower to blow at the fan outlet of the fan machine to accelerate cooling. For the production of silver silk powder with a diameter greater than 1 mm, an appropriate amount of vermicelli quality improver (opening powder) should be added.

3. Fans add muddy soup and broken bars (non-gluten)

Cause: Usually the dough is too thin, or the temperature is too low when it is gelatinized, and it is not cooked properly. In addition, poor starch quality or excessive discoloration can also lead to vermicelli soup and broken bars.

Solution: In addition to controlling the dryness and wetness of the noodles and increasing the temperature during gelatinization, the noodles can also be mixed with pea starch at 10% of the dry starch weight to enhance the strength. It is best to use mung bean and pea starch when snoring. You can also add sodium alginate agar or konjac flour at 0.3% ~ 0.5% of dry starch weight. The first two should be boiled and added as ravioli. Konjac flour can be added directly during noodle mixing.

4. Fans pilling, not smooth

Reason: The temperature was too high during gelatinization, and the fans contracted imbalanced when they got cold when they went out of the machine, forming a small rosary, large and small, not smooth. Too dry noodles and too little water can exacerbate this phenomenon.

Solution: reduce the temperature of the fan's interlayer water flow, and reduce the temperature difference before and after the fan goes out. The total moisture content of the dough should be controlled between 45% and 50%.

^[2]

It can be eaten by everyone. Pregnant women eat little or no food.

Traditional fans added during processing

China

China

Calories 338 calories per 100 grams of fans. The specific nutrient content is detailed in the table below: ^[3]

A video was circulated on the Internet. In this video, a female consumer said that fans of a certain brand could be lit with a lighter, and the sound of cracking became more and more fierce, and the woman introduced, All made of plastic , You ca nt get rid of it by sticking to the pen, good fans will break it as soon as you hit it. ^[4] This "fans are made of plastic" video has been reposted a lot, and many netizens said "Don't dare eat fans anymore" ^[4]

1. What is the truth of the matter? Will real fans burn ^[4] ?

Normal fans contain a lot of starch and protein. These organic substances can burn in the air. Therefore, we cannot distinguish between fans and plastics by whether they can burn or not. If judging only by burning, then human hair can also be burned. Isn't human hair also made of plastic?

Of course, from a realistic point of view, there are many fan production companies across the country, and the fans produced are very different. It is not ruled out that fans produced by individual companies may use some chemical additives for purposes such as beautiful colors.

In general, it is normal for fans to be able to burn ^[4] .

2. Use color reaction to identify starch in fans ^[4]

As mentioned earlier, fans contain a large amount of starch, and starch is made by the aggregation of glucose molecules. To put it more succinctly, "There is sugar in the fans, but no sugar in the plastic."

Here comes the key point: there are two types of starch, amylose and amylopectin. Amylose appears blue when meeting iodine, and purple-red when amylopectin meets iodine.

Therefore, in life, we just need to soak the fans in clean water, and then add some iodine (color is brown) used for disinfection in small household medicine boxes. It means that your fan contains starch, it must not be made of plastic. Because the general plastic is mainly polyethylene or polypropylene, these plastics do not contain starch itself, and it is impossible for this color reaction to occur ^[4] .

3. Use color reaction to identify proteins in fans ^[4]

We know that the color reaction is a more convenient detection method that depends on the naked eye to judge (there may be deviations), so we should perform multiple verifications.

Normal fans not only have starch, they also contain protein. There is no protein in plastic, so we can distinguish them by detecting proteins.

We can add a small section of fans (or plastic) to sodium hydroxide solution (2mL), shake and shake to create an alkaline reaction environment, and then add 3 to 4 drops of copper sulfate solution (blue), and shake and shake Observation phenomenon: if it is a fan, the solution will turn purple, which is caused by the protein in the fan; if it is plastic, the blue color will not change. As long as you can distinguish blue from purple, you can distinguish plastic from fans.

Of course, this method requires some chemical reagents, which is not very convenient in life, but it is a general method for detecting proteins. It is useful for us to identify fans and plastics ^[4] .

4. Summary ^[4]

In daily life, if there is no iodine in the home and chemical reagents such as sodium hydroxide and sulfuric acid, the color reaction described above will not be implemented. Then it can be identified by burning observation and smelling: fans have no pungent odor after burning, but plastic will produce oil droplets and have a pungent odor after burning. If you do have a pungent odor after burning a fan, it is recommended not to consume it.

In short, fans are organic. Generally, they are relatively dry and can definitely burn. The logic of "fans can be ignited is plastic" is very logically flawed and unbelievable. The reality is more complicated, and you can't conclude that fans are plastic just by burning. For fans produced by regular manufacturers, they can buy with confidence ^[4] .