Several Categories of Chemicals

Food additives refer to a natural or synthetic chemical substance added to improve the sensory properties (color, fragrance, taste) of food and food quality. In adult food, some additives can be added in accordance with my country’s sanitary standards, but in infant food, the use should be strictly controlled. The detoxification and protection mechanisms in infants and young children are poor, which can easily cause the accumulation of a large number of chemical substances. 

The World Health Organization and other countries have stipulated that no food additives should be added to infant foods, and the addition of saccharin, pigments, and flavors should also be restricted as much as possible in children’s foods. Wait. Especially in infant foods under 12 weeks of age, such as infant formulas, cereal products, etc., should be completely free of food additives.

A catalyst refers to a substance that can change the reaction speed in a chemical reaction, but its composition and quality remain unchanged after the reaction. The catalyst that accelerates the reaction is called a positive catalyst, and the one that slows down is called a negative catalyst or retarder. Generally speaking, the catalyst refers to the positive catalyst. Such catalysts are used more in industry, especially in the organic chemical industry, and are of great significance, such as the production of sulfuric acid by contact method, synthesis of ammonia, the hydrolysis of esters and polysaccharides, and the hydrogenation of fats and oils. The commonly used catalysts mainly include metals, metal oxides and inorganic acids. If the catalyst is a solid, the reactant is a gas, forming a heterogeneous catalytic reaction. This catalyst is sometimes called a catalyst or contact agent. The catalyst is generally selective, it can only accelerate a certain reaction or a certain type of reaction. 

However, for some reactions, multiple catalysts can be used. For example, platinum, palladium, and nickel are often used for hydrogenation reactions, which should be carefully selected. In catalytic reactions, substances other than catalysts, called promoters, are often added to enhance the catalytic effect of the catalyst. For example, iron is a catalyst for the synthesis of ammonia industry, adding a small amount of potassium oxide and alumina can enhance the catalytic effect of iron. The composition and weight of the catalyst and the co-catalyst remain unchanged before and after the reaction. The above are all inorganic catalysts. Enzymes are proteins and are very important organic catalysts.

Flavors and fragrances refer to substances with aromatic odors. Most of the cakes and biscuits can use spices and flavors to improve or enhance the aroma and fragrance. These flavors and spices are called flavoring agents or flavoring agents. Spices can be divided into natural flavors and artificial flavors according to different sources. Natural flavors also include animal and plant flavors. Plant flavors are mainly used in food production. Artificial fragrances are compounds obtained from raw materials such as petrochemical products and coal tar products through synthetic reactions. Essence is a compound perfume made by mixing several or dozens of perfumes with diluents. Strictly speaking, spices generally refer to raw materials used as flavor components and are rarely directly used in food. Flavor is an important raw material used directly to increase the flavor of food.

Organic raw materials are petrochemical industries that use petroleum and natural gas as raw materials, and use grain fermentation to produce alcohol or solvents. The raw material gas after coal gasification and the coal tar recovered by dry distillation are produced or fractionated to produce various organic chemical products. In our country’s organic chemical industry, the route of generating acetylene from calcium carbide from coal, the route of synthesizing methanol and formaldehyde by coal gasification, the route of recovering benzene, naphthalene and anthracene from coal tar, and the route of producing alcohol by fermentation and distillation with grain as raw material were developed first.

In general, raw materials are the raw materials of medicines. Only when they are processed into pharmaceutical preparations can they become medicines for clinical application. Therefore, the medicines we usually eat are finished medicines after processing.

Dyestuffs refer to organic substances that can color fibers and other materials firmly. There are many types of dyes, which can be divided into natural dyes (such as vegetable dyes, animal dyes, mineral dyes, etc.) and synthetic dyes (or artificial dyes) according to their sources. According to the molecular structure, it can be divided into azo dyes, anthraquinone dyes, phthalocyanine dyes, arylmethane dyes, nitro dyes and so on. According to the application method, it is divided into acid dyes, basic dyes, sulfur dyes, reactive dyes, disperse dyes, direct dyes, etc. Dyes have colors, but colored substances are not necessarily dyes. The dye must have a chromophore and an auxiliary chromophore. The dye in the ink should also have water-soluble groups such as sulfonic acid groups. 

Pigment is a kind of colored, black, white or fluorescent granular organic or inorganic solid. It does not dissolve in water, oil or other application media, but can be uniformly dispersed, and is not affected by the physical and chemical effects of the media during the entire dispersion process, and still retains its unique crystal or particle structure.

Inorganic salt is a general term for salts of inorganic compounds, and is a nutrient essential for the reasonable nutrition of humans and animals. Most of them exist in a combined form in food, and they are often dissociated into inorganic salt ions in body fluids, and a small amount (especially trace elements) are also combined with protein.