Validation of an automated spectrophotometric method to dose SO2 in vinegar

Sulfur dioxide and sulfites are considered allergens, and their levels in food are regulated by law. The method used to dose free and total sulfites in vinegar is the Ripper method which consists of a direct titration with iodine using starch as an indicator. The Ripper method involves long and elaborate processes, requires excellent operator skills, and has long analysis times. This work validated an enzymatic method performed by an automatized spectroscopic apparatus. Method linearity, applicability range, minimum detection limit, the limit of quantification, and repeatability were demonstrated. Therefore, the enzymatic method performed by an automatized spectroscopic apparatus can be used to detect SO2 in vinegar.