Corrosion Prevention Food Additives Sodium Benzoate Industrial 532-32-1 Cas No

Food Additives Sodium Benzoate for Corrosion Prevention and Stability in Industrial Products

Sodium benzoate, The organic compound is the sodium salt of benzoic acid. The chemical formula is C7H5O2Na, with a molar mass of 144.10 g/mol and a density of 1.44 g/cm3. Sodium benzoate is a white particle or crystalline powder with no odor or a slight benzoin smell. It is highly soluble in water, and its aqueous solution is slightly alkaline. It is slightly soluble in ethanol, glycerol, and methanol, and when exposed to air, it absorbs moisture. Reacting with acid will precipitate benzoic acid, reacting with carbonate will generate bubbles, and it can also react with alkali and vitamin C. There are two methods for preparing sodium benzoate in industry: benzoic acid method and toluene method. Sodium benzoate is commonly used as a preservative, corrosion inhibitor, etc., and is widely used in water treatment, food, medicine, and other fields.  
Specifically, corrosion inhibitors are commonly used in the field of water treatment to protect ferrous metals, but they need to be used in combination with other water treatment agents; The food industry is often used for preservation and preservation, inhibiting microbial growth, maintaining food flavor and nutrition; In the pharmaceutical field, it is often used as a preservative, such as syrup, eye drops, etc., to prevent microbial contamination; In the industrial field, it is often used for corrosion prevention and stability, and is used in industrial products such as coatings and plastics.
In addition, benzoic acid and its salts are broad-spectrum antimicrobial agents, but their antibacterial effectiveness depends on the pH value of the food. As the acidity of the medium increases, its bactericidal and bacteriostatic effects increase, but it loses its bactericidal and bacteriostatic effects in alkaline media. The optimal pH value for its anti-corrosion is 2.5-4.0.

Food preservation field
Sodium benzoate belongs to acidic preservatives and has no bactericidal or bacteriostatic effect in alkaline media. Its optimal pH for corrosion prevention is 2.5-4.0. Sodium benzoate is commonly used to preserve highly acidic fruits, berries, fruit juices, jams, beverage syrups, and other acidic foods, and can be used in conjunction with low-temperature sterilization methods to complement each other. The general method of use is to dissolve sodium benzoate in an appropriate amount of water, then add it to food and stir evenly.
(1) Beverages: Widely used in acidic beverages such as carbonated drinks, fruit juice, functional drinks, flavored water, and iced tea. Sodium benzoate can effectively prevent microbial contamination, allowing beverages to maintain a longer shelf life in acidic environments.
(2) Jam and jelly: Sodium benzoate is used to extend the shelf life of jam and jelly, prevent mold growth, especially when they need to be stored for a longer period of time after opening.
(3) Pickled foods: such as pickled cucumbers, kimchi, and chili peppers, sodium benzoate can effectively prevent excessive fermentation of lactic acid bacteria and other microorganisms in the food.
(4) Seasoning: Sodium benzoate can ensure that acidic seasonings such as soy sauce, tomato sauce, salad dressing, and chili sauce do not spoil during long-term storage.
(5) Baked goods: Sodium benzoate is also used in some baked goods, such as packaging cakes, pies, and fillings, to prevent products from spoiling due to microorganisms.
Sodium benzoate is widely used as a preservative in food processing and preservation, but is limited in use in some countries in certain foods. Due to its ability to function in a free state in food, benzoic acid is more effective in strong acid foods. Benzoic acid is generally used in carbonated beverages, soy sauce, sauces, candied fruits, and fruit and vegetable drinks. Benzoic acid can be used together with parabens in soy sauce and beverages to enhance efficiency. Benzoic acid and sodium benzoate are commonly used to preserve high acid fruits, jams, beverage syrups, and other acidic foods. They can be used in combination for low-temperature sterilization and have a synergistic effect.
Sodium benzoate is generally limited to foods with high protein content. Sodium benzoate has the same effect on microorganisms as benzoic acid. However, as a sodium salt, to achieve the same bactericidal effect as benzoic acid, the required amount of addition is 1.2 times that of benzoic acid.
Industrial applications
The application of sodium benzoate in the industrial field includes as a corrosion inhibitor, lubricant additive, and rust inhibitor:
Corrosion inhibitor: used in coolant and antifreeze to prevent corrosion of metal surfaces.
Lubricating oil and rust inhibitor: As additives, they play a role in preventing oxidation and rust prevention.

Water treatment field
Sodium benzoate can form a loose anodic corrosion inhibitor film on ferrous metals, which can bind with nitrite to protect the ferrous metals. When used as a corrosion inhibitor in the field of water treatment, it has good corrosion inhibition effect under slightly acidic conditions and almost no anti-corrosion effect under alkaline conditions. Usually, sodium benzoate is converted into an effective form of benzoic acid during use. Often used in combination with other water treatment agents, it has a synergistic effect on the main agent. The corrosion inhibition effect is not high when used alone, with a corrosion inhibition rate of only 20.9% at 500 mg/L. When used in combination with sodium gluconate at the same total dosage, the corrosion inhibition rate is 93.7%