Stabilization effects of polyphosphoric acid for the decomposition of enriched vitamin C in the soft drinks containing food color, and its inhibiting effects for the decolorization of food color by the vitamin C were studied at pH 2.5-6.0. In the presence of polyphosphoric acid (0.1%, final concentration), the decomposition of vitamin C and decolorization of food color in the soft drinks were not observed at pH 2.5-3.0,even by heating at 90℃ for 30 min., storing at 20℃ for 10 days, or exposure to sun light for 2 days.
