What is Benzoic Acid

Have you ever seen a title like this: "Red dates failed to meet the standards, and the preservative-benzoic acid was detected"

You must have seen similar news reports or self-media titles. What is your first reaction? Is it that red dates can no longer be eaten? Or, what else can we eat?

The national standard stipulates that benzoic acid shall not be added to dried fruits, and benzoic acid was indeed detected in red dates. However, this is not artificially added, nor is it caused by fertilizers and pesticides, but the background content. This means that benzoic acid is produced by the jujube itself.

When the jujube is still green, it basically does not contain benzoic acid. But as the nutrients in the jujube accumulate, it slowly matures and turns red, and the benzoic acid will gradually increase from zero to something. After harvesting the red dates, they need to be dried. Whether you dry them naturally, sun-dry them, or bake them, the content of benzoic acid will increase in this process. Of course, the benzoic acid content of jujubes of different varieties and regions varies greatly.

For example, benzoic acid can be found in various berries (blueberries, raspberries, raspberries, grapes, currants, figs, grapes, strawberries, kiwis, blackberries, cherries, guava, etc.), potatoes, soybeans, fermented black beans, various grains, various nuts, as well as yogurt and cheese. It exists naturally.

Plants usually have phenylalanine, which is gradually converted into benzoic acid under the catalysis of enzymes. This is a normal metabolite of plants. Of course, the mainstream opinion is that benzoic acid is a self-protection ability evolved by plants to resist fungi and insect pests.

Because benzoic acid is common in the plant kingdom, animals that eat plants also have benzoic acid in their bodies, such as milk, various dairy products (fermented yogurt and aged cheese have higher benzoic acid content), royal jelly, animal viscera, and muscles. Let's put it this way, if you and I go for testing, it is normal to find that there is benzoic acid in the body.

So how did benzoic acid come from as a food additive? This starts with another name for benzoic acid, benzoic acid.

Benzoin is a resin secreted by some plants of the Styracaceae family (the resin that flows out after the bark of the benzoin tree is separated). It is actually a very common Chinese medicine. There are about 25%-35% benzoic acid in benzoin resin. In the origin of benzoin, Sumatra Island and Indochina Peninsula, it has a long history of use. It has been used to treat various wounds and oral ulcers since ancient times... The principle is to use the high content of benzoic acid in benzoin.

The mechanism of benzoic acid's antiseptic effect, in simple terms, is that it can pass through the cell membrane of microorganisms, interfere with the absorption of amino acids, and neutralize the alkali in the cells to inhibit respiration to achieve the antiseptic effect.

Later, benzoin was introduced to Europe during the Roman period. In the process of gradual use, Europeans began to make benzoin tincture (similar to Chinese medicinal wine). Later, in 1556, Nostradamus discovered a needle-shaped crystal when distilling benzoin, and benzoic acid came into being.

More than 200 years later, in 1832, Liebig determined the structure of benzoic acid. Since then, benzoic acid has been widely used in food preservation. Then, because benzoic acid has poor solubility in cold water, it reacts with NaOH to form the sodium salt of benzoic acid, sodium benzoate.

After the discovery of benzoic acid, people began to try to synthesize it, but the effect was not good. For a long time, benzoic acid needed to be extracted from benzoin, which was expensive. It was not until the 1960s that people could produce a large amount of cheap benzoic acid for food use.