Lactone
Lactones contribute to the flavor profile of whiskeys and other beverages aged in oak barrels.
Lactones contribute significantly to the flavor of fruit, and of unfermented and fermented dairy products,[9] and are therefore used as flavors and fragrances.[3] Some examples are γ-decalactone (4-decanolide), which has a characteristic peach flavor;[9] δ-decalactone (5-decanolide), which has a creamy coconut/peach flavour; γ-dodecalactone (4-dodecanolide), which also has a coconut/fruity flavor,[9] a description which also fits γ-octalactone (4-octanolide),[10] although it also has a herbaceous character;[9] γ-nonalactone, which has an intense coconut flavor of this series, despite not occurring in coconut,[11] and γ-undecalactone.
Macrocyclic lactones (cyclopentadecanolide, 15-pentadec-11/12-enolide) have odors similar to macrocyclic ketones of animal origin (muscone, civetone), but they can be prepared more easily, for example, by depolymerization of the corresponding linear polyesters. Replacement of a methylene unit by oxygen barely affects the odor of these compounds, and oxalactones with 15 – 17-membered rings are produced in addition to cyclopentadecanolide (e. g., 12-oxa-16-hexadecanolide).[3]