ISO 6632:1981

Fruits, vegetables and derived products — Determination of volatile acidity

The method consists in acidifying a test portion with tartaric acid, entraining the volatile acids by steam distillation and titrating the distillate with standard volumetric sodium hydroxide solution in the presence of phenolphthalein as an indicator. The method is applicable to all fresh products, to products preserved without chemical preservatives, and to products to which sulphur dioxide has been added.