Vitamin C content of commercial orange juices: an analytical project

It has become customary at this University for the first year, nonchemistry major students, to conduct a survey involving the analysis of a consumer item and to perform a detailed statistical evaluation of the results. The project for 1975 occupied four 3 l/2-hr laboratory sessions and involved a study of the magnitude and stability of the ascorbic acid content of commercial orange juices. This study had two aims: firstly to confirm that newly purchased juice contained sufficient ascorbic acid to meet government standards (at present 40 mg/100 ml of juice), and secondly to establish the rate of aerial oxidation of this ascorbic acid when the juice was stored in a refrigerator. Students were interested in ascertaining if the juice represented a,suitable source of Vitamin C after one or two weeks of storage.