Cassis and Green Tea: Spontaneous Release of Natural Aroma Compounds from β-Alkylthioalkanones

In depth headspace analysis of the slow degradation of beta-alkylthioalkanones in ambient air led to the discovery of a novel delta-cleavage pathway, by which beta-mercaptoketones are released. Since beta-mercaptoketones are potent natural aroma compounds occurring in many fruits, herbs and flowers, the discovery of an enzyme-independent molecular precursor for this class of high-impact molecules is of practical importance. Moreover, the formation of beta-diketones and aldehydes by concomitant oxidation at the alpha-sulfur-position enhances the versatility of this class of aroma precursors. A mechanistic model is proposed which suggests that the oxidative degradation occurs through a novel Pummerer-type rearrangement of initially formed persulfoxides.

Automated summary

In-depth headspace analysis of the slow degradation of beta-alkylthioalkanones in ambient air revealed a novel delta-cleavage pathway, leading to the release of potent natural aroma compounds known as beta-mercaptoketones. The discovery of an enzyme-independent molecular precursor for these high-impact molecules is of practical importance, as it enhances the versatility of aroma precursors through the formation of beta-diketones and aldehydes. A proposed mechanistic model suggests that the oxidative degradation occurs through a unique Pummerer-type rearrangement of initially formed persulfoxides.