Abstract: The invention provides a process for producing gamma-lactones useful for incorporation in flavorings and fragrances, wherein a micro-organism which is acceptable for making food grade products and which does not metabolize gamma-lactones, is cultured aerobically in a culture medium containing as the substrate a hydroxy fatty acid having an even number 4 of carbon atoms between the carboxyl group and the carbon atom carrying the hydroxy group. The preferred micro-organism is a Saccharomyces cerevisiae, Debaromyces hansenii or Candida boidinii species. The gamma-hydroxy-alkanoic acid reaction product of the process is lactonized either in the fermentation broth or after separation therefrom. Especially suitable are 12-hydroxy fatty acids such as ricinoleic acid. The hydroxy fatty acid may be added either pure or as the mixture obtained by hydrolysis of an ester thereof. Enzymatic hydrolysis of such ester may be done in situ in the fermentation broth.

Abstract: The invention provides a process for producing delta-lactones useful for incorporation in flavourings and fragrances, wherein a micro-organism which is preferably acceptable for making "food grade" products and which does not metabolize delta-lactones, is cultured aerobically in a culture medium containing as the substrate, an 11-hydroxy fatty acid having an odd number .gtoreq.5 of carbon atoms between the carboxyl group and the carbon atom carrying the hydroxy group. The preferred micro-organism is a Saccharomyces cerevisiae species. The delta-hydroxy-alkanoic acid reaction product of the process is lactonized either in the fermentation broth or after separation therefrom. Especially suitable is 11-hydroxy palmitic acid. The hydroxy fatty acid may be added either pure or as the mixture obtained by hydrolysis of an ester thereof. Enzymatic hydrolysis of such ester may be done in situ in the fermentation broth.