Study of vitamin C degradation in acerola pulp during ohmic and conventional heat treatment
This work presents a study regarding total vitamin C and ascorbic acid degradation in acerola pulp during thermal treatment by ohmic and conventional heating. For the ohmic heating technology, the ascorbic acid degradation ranged from 3.08 to 10.63%. The applied voltage and the solids content of the pulp significantly influenced the degradation of the compounds. The voltage gradient had a positive effect, i.e., an increase in the voltage gradient lead to an increase in the AA degradation. The total vitamin C degradation ranged from 2.0 to 5.1%. The vitamin C degradation was influenced only by the linear and the quadratic effects of the voltage.
Ohmic heating, when performed with low voltage gradients, exhibited vitamin C and ascorbic acid degradation similar to conventional heating. However, high voltage gradients increased the degradation of both vitamin C and ascorbic acid. This behavior may be explained by the increase of electrochemical reactions when using high voltage gradients, which can adversely affect the ascorbic acid and catalyze the degradation pathways in the presence of oxygen.