Glycerin (E422)

Glycerin is a colorless, sweet-tasting syrupy liquid that is widely used in the food industry. Products containing it are labeled E422.

E422 is added to foods to thicken, control moisture levels or stabilize them if they contain a mixture of water and oil. It is mainly used in processed foods and sweets and is generally considered safe in many countries.

Glycerin was first synthesized in the late 18th century. It was used in the pharmaceutical and chemical industries, in the manufacture of paper and explosives. Later, it began to be added to various cosmetics, believing that this substance is very beneficial for the skin. However, during recent studies, it was found that glycerin dries the epidermis, and not only softens it.

In the 1980s, the scope of glycerin, which had already begun to be used as a food additive E422, expanded significantly. The fact is that 100 stabilizing properties of this substance were discovered, which, among other things, is able to give a special density to various products. Not surprisingly, E422 can be found in confectionery today, especially if they contain creams. It is added to alcoholic and non-alcoholic drinks, in which, for various reasons, regular sugar cannot be used.

Types of glycerin

Natural and synthetic glycerols are chemically identical, differing only in the purity of the substance and the scope of application.

When oil is distilled, propylene is stripped off as an overhead. Glycerin is obtained by adding chlorine to a propylene molecule and then hydrolyzing the resulting trichloropropane. Synthetic glycerin is used in biotechnology and pharmaceuticals due to its purity, which is 99.7%.

Natural glycerin is obtained from soap production and from biodiesel. Hydrolysis of vegetable or animal lipids with sodium hydroxide yields a fatty acid and glycerol. Until recently, this process caused the largest production of natural glycerol.

Recent interest in biodiesel has created a market surplus for the substance. Biodiesel is prepared by adding methanol to a source of oil, or fat. The fatty acid part of the molecule is esterified to biodiesel, and glycerol is formed as a by-product. The crude material is distilled and purified to a possible purity of 99.5% with ion exchange resins. Research today is focused on using lipids from algae or bacteria to produce biodiesel and glycerol.

Use in the food industry

Dairy products, including cheese, yogurt, milk powder, cream are among the potential sources of glycerol. You can also find this nutritional supplement in condensed milk, whey products, pudding and milk drinks. Processed meats, soy products, processed seafood, dried eggs, canned eggs, and egg desserts may also contain this additive.

Vegetables and fruits do not usually contain glycerin unless they are processed. Some examples of foods that may contain E422 include:

  • dried vegetables;
  • canned vegetables;
  • processed fruits;
  • precooked vegetables;
  • sauces containing vegetables.
  • alcoholic beverages;
  • sauces, vinegar, mustard, condiments;
  • nut butter;
  • candy.

Effects on the human body

A small amount of vegetable glycerin used in foods is unlikely to cause side effects. However, it is classified as a sugar alcohol and in turn can have a laxative effect when consumed in large amounts. Thus, it can lead to diarrhea, excessive urination, and dehydration when consumed in excess. Because of this effect, glycerin suppositories are used to relieve constipation. Less serious side effects that can occur when consuming large amounts of vegetable glycerin include nausea, vomiting, and headache. Some less common side effects that require immediate medical attention include confusion and abnormal heart rhythms. But they are extremely unlikely for the small amounts that are commonly used in foods, as they are very rarely seen even at medicinal doses.


Medical applications

Glycerin is often used in medicine, and is the main ingredient in some pharmaceutical preparations. Used to treat eye disorders caused by increased intraocular pressure such as glaucoma. It can also be used to relieve pressure in the eye before and after eye surgery, or during an eye exam.

Intravenous glycerol preparations may be used to treat raised intracranial pressure. It draws fluid from the tissues into the body into the bloodstream and also acts as a diuretic, preventing the kidneys from reabsorbing water. These actions dehydrate tissues while reducing blood volume, thereby reducing intracranial pressure.

It is the main component of nitroglycerin. Better known for its explosive properties, nitroglycerin is also used to treat angina (a painful condition caused by narrowing of the blood vessels in the heart). Nitroglycerin, taken orally, acts as a vasodilator, quickly opening the blood vessels in the body to allow more blood flow and oxygen perfusion to the heart.

It also works as an emollient and lubricant in cases of constipation. A suppository inserted into the rectum melts at body temperature. Glycerin then causes water to be drawn into the colon and rectum, softening the stool and lubricating the intestines, allowing stool to move more easily through the intestines.

Due to its emollient, solvent, sweetening and moisturizing properties, E422 is often used as an ingredient in other pharmaceutical preparations. It is used in tinctures and elixirs such as theophylline, which is used to treat asthma. It is also used in ointments and creams to prevent them from drying out and can act as a preservative.

Glycerin is a viscous organic alcohol with a sweet taste. Used in cosmetics, food, industry, medicine and pharmaceuticals.

Because glycerin is highly hygroscopic, it is added to foods to retain moisture. Its flavor makes it an excellent sweetener because it has a low glycemic index. In soaps and cosmetics, it serves as a lubricant and moisturizer. Thanks to all these useful properties and relative safety, it is very widely used in various types of industry.