Benzoic  acid and salts: These are mainly used  to protect foods against yeasts and moulds.  They  are not  very  effective against bacteria and have to  be  used in combination with sulphur dioxide  in foods prone  to spoilage  by bacteria. Benzoic acid is used in squashes, hit  syrups, cordials,  juices, jams, marmalades, preserves, sweetened ready-to-serve  beverages, pickles,  chutneys,  sauces,  tomato puree and  paste and  fat  spread. Its effectiveness increases with  the lowering of  pH and  is most effective below of pH  4.5.