Cooling flavors

Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (Cinnamomum camphora), a large evergreen tree found in East Asia; and in the kapur tree (Dryobalanops sp.), a tall timber tree from South East Asia. It also occurs in some other related trees in the laurel family, notably Ocotea usambarensis. Rosemary leaves (Rosmarinus officinalis) contain 0.05 to 0.5% camphor, while camphorweed (Heterotheca) contains some 5%. A major source of camphor in Asia is camphor basil (the parent of African blue

Menthol is a monoterpenoid organic compound that occurs naturally in the oils of certain plants in the mint family, such as corn mint and peppermint. It is a white or clear waxy crystalline substance that is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is (−)-menthol, which is assigned the (1R,2S,5R) configuration.

Eucalyptol (also called cineole) is a monoterpenoid colorless liquid, and a bicyclic ether. It has a fresh camphor-like odor and a spicy, cooling taste. It is insoluble in water, but miscible with organic solvents. Eucalyptol makes up about 70–90% of eucalyptus oil. Eucalyptol forms crystalline adducts with hydrohalic acids, o-cresol, resorcinol, and phosphoric acid. Formation of these adducts is useful for purification.

Menthone is a chemical compound of the monoterpene class of naturally occurring organic compounds found in a number of essential oils, one that presents with minty flavor. It is a specific pair of stereoisomers of the four possible such isomers for the chemical structure, 2-isopropyl-5-methylcyclohexanone. Of those, the stereoisoomer '''l-menthone'—formally, the (2S,5R)-trans'' isomer of that structure, as shown at right—is the most abundant in nature. Menthone is structurally related to menthol, which has a secondary alcohol (>C-OH) in place of the carbon-oxygen double bond (carbonyl group) p

Pulegone is a naturally occurring organic compound obtained from the essential oils of a variety of plants such as Nepeta cataria (catnip), Mentha piperita, and pennyroyal. It is classified as a monoterpenoid, which means that it is an oxidized derivative of a terpene, a large class of naturally occurring C10 hydrocarbons.

Cubebol is a natural sesquiterpene alcohol first identified in cubeb oil. It is also found in basil. It was patented as a cooling agent in 2001 by Firmenich, an international flavor company. The taste of cubebol is cooling and refreshing. The patent describes application of cubebol as a refreshing agent in various products, ranging from chewing gum to sorbets, drinks, toothpaste, and gelatin-based confectioneries.

Menthoxypropanediol (also known as Cooling agent 10 [tradename of Takasago]), is a synthetic derivative of menthol. While the cooling strength of 3-(l-menthoxy)propane-1,2-diol is accepted as being about 20–25% that of menthol, it is also noted that "in a Vaseline ointment, 3-(l-menthoxy)propane-1,2-diol shows a cool feeling 2.0 to 2.5 times stronger than that of l-menthol". It is used in various cosmetic chemical concoctions.

Icilin (AG-3-5) is a synthetic super-agonist of the transient receptor potential M8 (TRPM8) ion channel. Although structurally not related to menthol, it produces an extreme sensation of cold, both in humans and animals. It is almost 200 times more potent than menthol, and 2.5 times more efficacious. Despite their similar effects, icilin activates the TRPM8 receptor in a different way than menthol does. Icilin has been shown to be effective in the treatment of pruritus in an experimental model of itch. It is now used as a research tool for the study of TRP channels, although despite its high p