Benzoic acid is a preservative derived from benzene, an aromatic hydrocarbon which at room temperature appears as a colorless liquid that evaporates very quickly in the air.
Benzoic acid, in nature, is found in free or combined form; it can be obtained from natural sources, in fact for example it is present in benzoin (see photo), in balsam of Peru and Tolù , in other balsams, in plums , in yogurt , but in practice it is produced by chemical synthesis starting from anhydride phthalic.
On the market, almost all benzoic acid is converted into phenol and caprolactam, compounds used in the plastics industry.
Benzoic acid and its salts are used as food preservatives to combat the action of yeasts and bacteria in foods with acidic pH; they are usually used in flavored soft drinks, alcoholic beverages, canned fish, jams, most fruits, especially blueberries , mushrooms, cinnamon , cloves and some dairy products.
At the concentrations used, there appears to be no health side effects; however, it may happen that in predisposed subjects, benzoic acid and benzoates can trigger allergic reactions .
Their use in various products is limited, because if present in high concentrations they produce a bitter taste.
The salts of benzoic acid are:
- E211 SODIUMBENZOATE → this preservative derives from E210. Thanks to its great solubility, 200 times higher than that of benzoic acid, it is one of the major antimicrobial agents used in food and drinks; however it turns out to be harmful, therefore its concentration in the products must be at most 0.1%. Recent studies have shown that it can cause negative effects on the liver and brain ; it can also cause skin rashes , asthma and anaphylactic shock . Frequent consumption of foods containing this preservative is not recommended.
- E212 POTASSIUMBENZOATE → this preservative comes from E210. It has the function of blocking the growth of mold , some bacteria and the fermentation of products. Its maximum effectiveness is found in products with a low pH, ie lower than 4.5, therefore it is present in acidic foods and drinks such as fruit juices , carbonated drinks and pickles.
Potassium benzoate, together with ascorbic acid ( vitamin C ), can form benzene, a known carcinogenic compound.
- E213 CALCIUMBENCH
ADI DOSE (for benzoic acid and its salts): 5 mg for each kg of body weight .