The relative positions of the double bond and the ketone group in unsaturated aliphatic ketones have an important, and frequently overriding, effect on the aroma of these fascinating ingredients. Many ketones with the double bond in the 3 position and the ketone group in the 2 position possess extremely attractive combinations of fruity and nutty characters. 3-Nonen-2-one (FEMA# 3955, CAS# 14309-57-0) is an especially useful example because it can be used in such a wide range of diverse flavor types. The character is strong and nutty, with distinct fruity notes that are reminiscent of peaches, melons and avocados.
Two other closely related chemicals have similar odor profiles to this ingredient but the fruit characters are both subtly unique. 3-Octen-2-one (FEMA# 3416, CAS# 14309-57-0; CAS#1669-44-9) possesses a similar complex aroma of nuts and fruit, with a slight emphasis on an attractive, fruity blue cheese character. Meanwhile, 3-Decen- 2-one (FEMA# 3532, CAS# 10519-33-2) is also nutty but the attendant fruity note shades slightly more toward citrus.
The dose rates given throughout this article are the levels suggested for use in flavors that are intended to be dosed at 0.05% in a ready-to-drink beverage or in a simple bouillon.