Sodium benzoate is a moderately effective bacteriostatic and fungistatic agent at a pH of 5 or less. It is more water soluble than benzoic acid, but anti-microbial activity is dependent on dissociation to the free acid.
Sodium benzoate remain important in the preservation of mayonnaise and mayonnaise-containing delicatessen products, which as oil in water emulsion, are more susceptible to microbial attack.
Fruit pulp of acid fruit products can be protected by additional of 0.1% to 0.3% of sodium benzoate against mold attack and fermentation.
Sodium benzoate can be used in concentrations of up to 0.1% in the United Sates, whereas other countries allow concentrations as high as 0.25%.
Antispoilage agent: sodium benzoate