When cabbage is left undisturbed in the garden, its mustard oils,
which are attached to sugar molecules, simply remain unnoticed. But when
garden pests nibble cabbage leaves, these oils are indeed put to use.
When plant cells are broken, the oils are separated from the sugar
molecules by an enzyme and released as a very bitter compound. It's a
clever defense mechanism for the cabbage plant to discourage hungry
foragers.
Of course, slivering or dicing cabbage to make coleslaw also
ruptures plant cell walls, so the same reaction is triggered. At first,
any bitterness may seem pleasantly tangy as the salad's dressing mellows
cabbage flavors. After a while, however, the released mustard oils
definitely become more noticeable and pungent.
Coleslaw is appealing in both its crunch and tang. It's at its best,
however, when made shortly before it's eaten. So try to use only the
amount you think will get eaten.
Good wishes,
Anne and Sue