Degradation kinetics of vitamin B12 in model systems of different pH and extrapolation to carrot and lime juices

Fortification has been universally recommended to control the increasing prevalence of deficiency of vitamin B-12. Liquid food systems could be a suitable medium for this fortification. The present work was undertaken to evaluate the effect of pH and storage temperature on the kinetic behavior of vitamin B-12 degradation during storage in model aqueous systems at pH 2, 4, 6, 8, 10, and two model fruit juices. Vitamin B-12 degraded rapidly at pH 2 with half life (t(1/2)) of 8 days at 37 degrees C. The maximum stability of Vitamin B-12 was at pH 6/4 degrees C. Lime and carrot juices gave t(1/2) of 4 and 99 days, respectively, at 37 degrees C. Following the Arrhenius model, the activation energies for model systems ranged from 10.29 to 41.94 kJ mol(-1). The results indicated that pH and storage temperature influenced the kinetic degradation of vitamin B-12. Carrot juice was more suitable for vitamin B-12 fortification.