Determination of Ascorbic Acid in Commercial Fruit Juices Using an Iodometric Titration Method


  • Youngsub Lee


In this observational study, the relative quantity of ascorbic acid present in fruit (apple, orange,
cranberry, and grape) juices was determined using an analysis of redox titration involving an iodometric
method. The titration was conducted three times per each treatment and the identification of the
endpoint in titration was determined using starch as a visual indicator. In our result, apple juice (4.8 mg /
10 mL) had the highest amount of vitamin C present followed by orange juice (4.0 mg / 10 mL), grape
juice (2.2 mg / 10 mL), and (2.0 21mg / 10 mL) cranberry juice. As this experiment was conducted at
home-setting, we propose that there are many sources of error and need of improvement. Therefore, it
is recommended that for the future studies to conduct this experiment in a laboratory setting with
access to precise measurement equipment. No hypothesis was stated for this observational research.