Can starch be hydrolyzed under alkaline conditions?

No, starch is a polymer compound, which can be hydrolyzed under certain conditions, and dilute sulfuric acid can be added and heated. Starch is an important polysaccharide, which is a natural polymer compound with a relatively large molecular weight. Although it is a sugar, it has no sweetness and is a white powder that is insoluble in cold water.

In hot water, the starch granules swell, and some of the starch dissolves in the water, and the other part is suspended in the water, forming a gelatinous starch paste. After the starch enters the human body, a part of the starch is catalyzed by the amylase contained in the saliva, and the hydrolysis reaction occurs to generate maltose; The remaining starch is hydrolyzed by amylase secreted by the pancreas in the small intestine to form maltose.

Extended Materials. Advantages of hydrolyzing starch with acid:

The production is simple, the whole chemical reaction process of gradual hydrolysis of starch into glucose is only carried out in a high-pressure vessel, the hydrolysis time is short, and the equipment has a large production capacity.

If 10obe concentration starch is used, in.

20min under MPA pressure; At.

It only takes 7-10min under MPA pressure

Disadvantages: 1) Because the hydrolysis is carried out under high temperature and high pressure conditions, the equipment is required to be corrosion resistant, high temperature and high pressure resistant;

2) In the process of acid hydrolysis, in addition to the hydrolysis reaction of starch, there are still side reactions, which will reduce the utilization rate of starch;

3) The acid hydrolysis method has strict requirements for starch raw materials, uniform particle size, and starch concentration should not be too high.

In order to prove that starch "starts" to convert to glucose, that is, to prove the appearance of glucose, use silver ammonia solution, or Cu(OH)2 alkaline suspension, but it should be noted that the catalyst for starch hydrolysis is dilute sulfuric acid, so the experiment must be noted: after sampling, alkali is added to neutralize to alkaline, and then tested with the above reagents.

In order to prove that the starch is "completely hydrolyzed", that is, there is no starch, so iodine water can be used, if it does not change blue, that is, there is no starch, that is, the starch is completely hydrolyzed, at this time, it should be noted that after sampling, alkali must not be added to alkaline, because i2 itself can also react with alkali.

Lv Xiangji Scientific Research Institute: From the scientific research laboratory, it has been verified that starch needs to be hydrolyzed under acidic conditions, and so far the national high school textbooks are generally hydrolyzed under sulfuric acid!

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Lack of priority: It refers to the inability of people to distinguish between the main and the secondary.

Lost pawn to protect the rook: Originally a chess term. The latter metaphor discards the secondary and keeps the primary.

Priority: refers to the major and minor things, those that are urgent and those that can be done slowly.

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Putting the cart before the horse: Ben: tree roots; End: treetops; Place: Put. The metaphor reverses the position of priority and priority.

Loud: loud. The voice of the guest overwhelmed the voice of the host. It is a metaphor for the foreign or secondary thing occupying the place of the original or primary thing.

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