Stabilization of Red Beet Pigments with Isoascorbic Acid

Isoascorbic acid was investigated as a stabilizer for red beet pigments. Sterilized samples of red beet juice containing 0.05–1.0% isoascorbic acid, with the pH adjusted to 3, 5, or 7, were stored under artificial light or in darkness at 25°C or at 5°C. The best pigment preservation was obtained with 0.1% added isoascorbic acid. After 30 days storage at 25°C, samples at pH 5 containing 0.1% isoascorbit acid retained 52% (under light) and 65% (in darkness) of the red beet pigments, whereas the controls faded to yellow within 6 days under the same conditions.