There are many, many people who have cognitive misconceptions about food additives. So, how should we treat food additives correctly?

(1) Function of food additives.

The rational use of food additives can prevent food from spoilage, maintain or enhance the nutrition of food, and improve or enrich the color, smell and taste of food.

(2) The necessity of using food additives.

In fact, it is more dangerous not to use preservatives, because spoiled food often causes food poisoning. In addition, preservatives can not only prevent food deterioration, but also kill toxic microorganisms such as Aspergillus, which is undoubtedly beneficial to human health.

(3) Safe dosage of food additives.

The amount of food additives without any toxic effect or adverse effect on health is expressed by the daily intake per kilogram (mg), referring to

GB 2760-2011 National Food Safety Standard for Use of Food Additives.

(4) Do not use toxic additives.

"NaHSO2 · CH2O · 2H2O" is sodium formaldehyde bisulfite, also known as NaHSO2 · CH2O · 2H2O. It is prepared by reacting zinc powder with sulfur dioxide to generate low sulfite, etc., and then reacting with formaldehyde, concentrating in a vacuum evaporator, condensing into blocks. "Diaobai" is white lump or crystalline powder, soluble in water. It is relatively stable at normal temperature, and can decompose sulfite at high temperature. It has strong reducibility, so it has bleaching effect. It starts to decompose into harmful substances at above 80 ℃. The chemical equation of the reaction is:

6NaHSO2·CH2O·2H2O + 3H2O = 4NaHSO3 + 2HCOONa + HCOOH + 2H2O + 3CH3OH

It is decomposed into formaldehyde at 110 ℃, and the reaction equation is:

NaHSO2 ˙ CH2O = NaHSO2 + CH2O

NaHSO2 + H2O =NaHSO3 + 2「H」

It can cause fever, headache, fatigue, anorexia, etc. If the one-time consumption dose reaches 10g, life will be in danger. "Hanging white block" is mainly used in the printing and dyeing industry as a dye catching agent and reducing agent. Its bleaching and anti-corrosion effects are more obvious.