Effect of Temperature and Initial Moisture Content on the Chemical Stability and Color Change of Various Forms of Vitamin C

Vitamin C is a widely used food ingredient, and its stability is both important and sensitive to environmental conditions. To monitor chemical and color stability, samples were prepared with varying water contents (0–50 mol water/mol solid) and stored at temperatures (22–60°C) for up to eight weeks. Three common methods (UV/Vis spectroscopy, high performance liquid chromatography, and 2,6-dichloroindophenol titration) were used to monitor chemical stability. Color changes were documented using Hunter colorimeter analysis. Both temperature and moisture content had a significant effect on chemical stability. Browning occurred faster than chemical degradation, and kinetic models were developed for both chemical degradation and color change.