Chemo-enzymatic synthesis of [alpha]-terpineol thioacetate and thiol derivatives and their use as flavouring compounds

• Published in: Yeast (Chichester, England) Vol. 32; no. 1; p. 115
• Main Authors: Bel-Rhlid, Rachid, Fleury Rey, Yvette, Welti, Dieter, Fumeaux, René, Moine, Deborah
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.01.2015
• ISSN: 0749-503X; 1097-0061
• DOI: 10.1002/yea.3056

Reaction of (R,S)-[alpha]-terpineol with thioacetic acid in food-grade n-hexane resulted into two [alpha]-terpineol thioacetate derivatives with the same molecular weight. After 5h of reaction time, (R,S)-[alpha]-terpineol was completely transformed and the mixture analysed by different chromatographic techniques. The aroma character of the [alpha]-terpineol thioacetates was described as exotic, sweet, blackcurrant, roasted and sulphury. Of eight lipases and two esterases assayed, only non-immobilized pig liver esterase (PLE) hydrolysed [alpha]-terpineol thioacetates into the corresponding [alpha]-terpineol thiols. When reactions were performed in 0.2m phosphate buffer at pH8.0 and 30°C with non-immobilized PLE, [alpha]-terpineol thiols were produced in an optimal yield of 88% after 24h of reaction time. The aroma character of [alpha]-terpineol thiols was described as green, exotic and fresh grapefruit. Flavouring powders were prepared by freeze-drying the [alpha]-terpineol thioacetates and [alpha]-terpineol thiols in the presence of maltodextrine. Preliminary applications showed that these flavouring preparations could be used to improve the flavour quality of lighter cooked notes and tropical fruit aromas. Copyright © 2014 John Wiley & Sons, Ltd.