Nootkatone

Nootkatone is the sesquiterpene ketone behind grapefruit’s unmistakable woody-citrus perfume, one of the key aroma compounds that make the fruit smell like itself. It occurs naturally in grapefruit peel oil and also turns up in vetiver, cypress, and Alaskan yellow cedar. Flavourists prize it for authentic grapefruit character in beverages, confectionery, and chewing gum, effective at very low doses, and it has found a second career as a naturally derived insect repellent and acaricide. Supply once depended on extracting valencene from orange-processing by-products and oxidizing it, but fermentation-based biotechnology now produces it more sustainably for clean-label formulations.