Sample preparation for vitamin C analysis of pigmented orange juices

A method is described for preparing samples of pigmented orange juices for vitamin C analysis. The method consists in the selective separation of anthocyanins present in juices using reverse-phase C 18 resin prior to titration of depigmented juice with 2,6-dichlorophenolindophenol. Pigmented and blond orange juices were analysed and the results were compared to HPLC analysis of the same juices.