MEASUREMENTS OF VITAMIN C CONCENTRATION IN VARIOUS FRUIT JUICES (ORANGE, WATERMELON, PINEAPPLE, BANANA AND LEMON) USING IODINE SOLUTION TITRATION
Abstract
ABSTRACT
This study investigates the vitamin C concentrations in different fruit juices, specifically orange,
watermelon, pineapple, banana, and lemon, utilizing iodine solution titration as an analytical
method. The process involved extracting fresh juice samples, diluting them with distilled water,
and conducting redox titrations using iodine solution and starch as an indicator to detect the
endpoint of the reaction. The results demonstrated significant variations in vitamin C content
among the juices tested. Orange juice exhibited the highest concentration of vitamin C (49.3
mg/100 mL), reflecting its strong genetic predisposition as a citrus fruit to store ascorbic acid.
This was followed by watermelon (12. I mg/100 mL), lemon (12.0 mg/100 mL), banana (9.8 mg/100
mL), and pineapple (8.0 mg/100 mL). These diferences were attributed to the unique physiological
and genetic characteristics of each fruit, as well as environmental factors such as growth
conditions, ripening stages, and post-harvest handling. Citrus fruits, particularly orange and
lemon, displayed significantly higher vitamin C levels due to their evolutionary adaptations for
nutrient preservation and oxidative stress protection. Non-citrus fruits like watermelon, pineapple,
and banana showed lower concentrations, likely due to their focus on other nutrients and their
higher water content, which dilutes the vitamin C levels. The study underscores the reliability and
practicality of iodine solution titration as a low-cost and accessible method for determining
ascorbic acid concentration. To enhance the accuracy and applicability of this analytical
approach, the study recommends standardizing titration protocols across laboratories,
incorporating advanced techniques such as high-performance liquid chromatography (HPLC) for
validation, and investigating the effects offactors such as pH, temperature, and storage conditions
on vitamin C degradation. These findings provide valuable insights into the nutritional profiles of
fruit juices and reinforce the importance of citrus fruits as a primary dietary source of vitamin C.
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