What it is
E200 (sorbic acid) is a natural-identical preservative, originally extracted from rowan berries; commercial production today is synthetic from ketene and crotonaldehyde.
Why it matters
Widely used in cheese, baked goods, dried fruit, soft drinks, and wine to inhibit moulds and yeasts.
What to do
Always vegan. The related potassium and calcium sorbates (E202, E203) are also vegan.