Peppermint oil is the most common mint oil used in flavouring. It is used in sweets, toothpaste,  and liqueurs.

It is made by steam distilling the plant before flowering.

There are two main varieties, Mentha piperita and Mentha arvensis(cornmint)

Piperita is grown in North America and is the main oil used in toothpastes etc. There are numerous growing areas and all these areas produce slightly different oils. Cineol and menthofuran are unique to piperita.

Mentha Arvensis is grown in India and China and is the main source of natural menthol and a cheaper blending oil.

The oils are distilled immediately after harvesting and redistilled after if there are defects in the original distillation. Hence double and triple distilled oils. The distillation removes the tops and tails of the oil giving a cleaner aroma profile.

Spearmint oil is mostly used in toothpastes, blended with menthol, peppermint oil and anethol.

It is to a much lesser extent used is chewing gums and sweets.

The main component is l carvone but it is only a contributor not the total flavour.