EFFECT OF SWEETENING AGENTS ON THE LIGHT-STABILITY OF AQUEOUS-SOLUTIONS OF L-ASCORBIC-ACID

Aqueous solutions of L-ascorbic acid were irradiated with simulated sunlight in the presence of mannitol, sorbitol, sucrose, dextrose and 'Canderel', and the residual L-ascorbic acid was measured spectroscopically. The photostability of L-ascorbic acid was enhanced by all of the sweetening agents at 5% w/v concentration. However, the addition of stoichiometric amounts of hydrogen peroxide to provide a source of hydroxyl radicals and 2,2'-azobis(2-amidopropane) to provide hydroperoxyl radicals resulted in diminished stability of L-ascorbic acid solutions. The possibility of the diminished stability of the L-ascorbic acid solutions being due to the action of hydroperoxyl radicals in the presence of hydroxyl radical scavengers is discussed.