Table 5 presents the AA/DHA ratios for unpasteurized and
pasteurized samples. As can be seen, after pasteurization, the AA/
DHA ratio changed; experiments conducted with lower voltages
achieved AA/DHA ratios closer to those of the non-pasteurized
samples than those conducted with higher voltages. The first
oxidation reaction (conversion of AA to DHA) probably happened
faster than the subsequent reaction, which converts DHA into DCG,
a compound that has no biological activity. This result indicates that,
during heat treatment, more AAwas oxidized to DHA than DHA was
oxidized to DCG. As the compound DHA does exhibit biological
activity, the total vitamin C degradationwas lower than the ascorbic
acid degradation. However, it is noteworthy that only AA has antioxidant
activity and DHA is a pro-oxidant