Vitamin C Determination by Indophenol Method

Vitamin C is an essential nutrient in the diet, but is easily reduced or destroyed by exposure to heat and oxygen during processing, packaging, and storage of food. The official method of analysis for Vitamin C determination of juices is the 2, 6-dichloroindophenol titrimetric method (AOAC Method 967.21). While this method is not official for other types of food products, it is sometimes used as a rapid, quality control test for a variety of food products, rather than the more time-consuming microfluorometric method (AOAC Method 984.26). In this laboratory exercise, the Vitamin C content of various orange juice products is determined using the titration method with the indicator dye 2, 6-dichloroindophenol.