Determining the Differences in Vitamin C Content Between Conventional, Organic, Frozen, and Canned Oranges

This experiment was designed to compare the amounts of vitamin C (ascorbic acid) in organic oranges, conventionally grown oranges, canned oranges, and frozen concentrate orange juice. In order to test for vitamin C, a chemical indicator is needed, which signifies the presence of ascorbic acid by a color change reaction. A titration was carried out to administer the orange juice in small amounts to the indicator solution, 2,6-Dichlorophenolindophenol, allowing the exact measurement of the amount of orange juice needed to produce a complete color change. The data from the titrations was first analyzed using two t-tests, which showed that a significant difference in vitamin C content was found in the organic and conventional oranges, and also between the canned and frozen oranges. Finally, all of the data was analyzed with an ANOVA test of significance, which confirmed that there was a significant difference in vitamin C content between all four types of oranges.

Research Done By:

Kelly Salis
Lakeview High School

Allyson Zelinski
Lakeview High School