The Gros Michel banana had a higher concentration of isoamyl acetate - aka banana oil - than the Cavendish banana we eat today. But that's just one component of the natural banana flavor. Runts - and most other banana flavored candy - are flavored with synthetic isoamyl acetate derived from petroleum. Here's the weird part: artificial banana flavoring was popularized in the USA about 10 years before actual bananas were first imported. Candy makers associated the isoamyl acetate flavor with bananas in the USA, so it was kind of exotic for the time. In Britain, it was pears, because there was already a tradition there of making pear-flavored candies.