Reaction of nitrite with ascorbic acid and its significant role in nitrite-cured food.

The decrease in concentration of free nitrite in an aqueous reaction solution made by mixing nitrite and ascorbic acid was studied. This decrease resulted information of a reaction product which transferred NO to ferricytochrome c to form ferrocytochrome c nitroso compound. From the solution containing the reaction product, nitrite could be regenerated spontaneously and suddenly by physical agitation. Oxygen was apparently not necessary for regeneration nitrite from the reaction solution. It does not seem that the regeneration of nitrite was responsible for a bimolecular dismutation of nitrosoascorbic acid in a reverse direction proposed by Fox and Thomson (Biochemistry2, 465; 1963). Heating of the reaction solution at less than 100°C resulted in a loss of nitrite from the solution, which was greater with increasing concentration of ascorbic acid. The reaction product formed between nitrite and ascorbic acid is probably responsible not only for nitrosation reactions, but also for the loss of nitrite observed during curing of meat.