The inactivation rate constants of the indole glucosinolates
are significantly higher (P < 0.01) than that of the
aliphatic glucosinolates for temperatures 6110 C. As
can be concluded from Fig. 4 the differences in degradation
rates between the two structurally different groups
of glucosinolates is reduced at higher temperatures. At
120 C both indole and aliphatic glucosinolates have
very similar degradation rates, with the exception of
progoitrin and gluconapin that have significantly lower
degradation rates at this temperature. The indole glucosinolates
comprise only a small part (8%) of the total
glucosinolates level measured in red cabbage. 4-Hydroxyglucobrassicin
and 4-methoxyglucobrassicin were
determined to be the most thermolabile glucosinolates
studied, and glucobrassicin also showed a significant
degradation. These indole glucosinolates showed higher
degradation rates than the aliphatic glucosinolates identified
in this study.