Benzoic acid, also known as benzoic acid, has an odorless or slightly benzoin odor and is widely used as a food preservative. It naturally exists in cranberries, prunes, cinnamon, and cloves. It is an aromatic acid and can also be added as a spice. The undissociated acid has antibacterial activity, and the best activity is in the range of pH 2.5-4.0.
With reference to the quality index of sodium benzoate specified in the national standard GB 1902-94,
Chemical formula: C6H5COOH
Benzoic acid preservatives act on their undissociated molecules. Undissociated benzoic acid has strong lipophilicity and is easy to pass through the cell membrane and enter the cell, interfering with the permeability of the cell membrane of microorganisms such as molds and bacteria, and hindering the cell membrane’s resistance to amino acids. Absorb and enter the benzoic acid molecules in the cell, acidify the alkali storage in the cell, inhibit the activity of the respiratory enzyme system in the microbial cell, and thus play a preservative role.
Benzoic acid is a broad-spectrum antimicrobial agent, which has a good effect on yeast, mold and some bacteria. It has an inhibitory effect on various bacteria within the maximum allowable use range and pH value below 4.5.
Applications and Limits:
Benzoic acid and sodium benzoate are widely used as preservatives in food processing and preservation, but are limited in some foods in some countries. Because in food, benzoic acid can play a role in the free state, so the effect is better in strong acid food. Benzoic acid is generally used in carbonated drinks, soy sauce, sauces, candied fruit and fruit and vegetable beverages. Benzoic acid can be used together with para-hydroxybenzoic acid esters in soy sauce and beverages for synergy. Benzoic acid and sodium benzoate are often used to preserve highly acidic fruits, jams, beverage syrups and other acidic foods.
Benzoic acid and sodium benzoate are generally limited to foods with higher protein content. The effect of sodium benzoate on microorganisms is the same as that of benzoic acid, but because it is a sodium salt, to obtain the same bactericidal effect as benzoic acid, the required addition amount is 1.2 times that of benzoic acid.
According to the United States FAO regulations, benzoic acid and sodium benzoate can be used for quick-frozen fish sticks, fish pieces, and fish filling products, but meat products are not included in the scope of use. In addition, in the countries listed above where benzoic acid and sodium benzoate are permitted, these two additives are not recommended as preservatives for meat products.
The acute toxicity of sodium benzoate is less, and the maximum non-effect dose (MNL) of animals is 500mg/kg body weight. However, it can be converted into highly toxic benzoic acid in the acidic environment of the human intestinal tract. Ingestion of benzoic acid and its sodium salt in mice can cause weight loss, diarrhea, bleeding, paralysis and even death. The toxicity of benzoic acid is achieved by changing the permeability of the cell membrane, inhibiting the absorption of amino acids by the cell membrane, and inhibiting the activity of enzymes such as lipase through the cell membrane, thereby hindering the synthesis of ATP.