Chemo-enzymatic synthesis of α-terpineol thioacetate and thiol derivatives and their use as flavouring compounds.
Reaction of (R,S)-α-terpineol with thioacetic acid in food-grade n-hexane resulted into two α-terpineol thioacetate derivatives with the same molecular weight. After 5 h of reaction time, (R,S)-α-terpineol was completely transformed and the mixture analysed by different chromatographic techniques. The aroma character of the α-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 α-terpineol thioacetates into the corresponding α-terpineol thiols. When reactions were performed in 0.2 m phosphate buffer at pH 8.0 and 30 °C with non-immobilized PLE, α-terpineol thiols were produced in an optimal yield of 88% after 24 h of reaction time. The aroma character of α-terpineol thiols was described as green, exotic and fresh grapefruit. Flavouring powders were prepared by freeze-drying the α-terpineol thioacetates and α-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.
Nestlé Research Centre, Nestec Ltd, Lausanne, Switzerland.
Rachid
R
Bel-Rhlid
Yvette
Y
Fleury Rey
Dieter
D
Welti
René
R
Fumeaux
Deborah
D
Moine
D000818:Animals; D002175:Candida / Q000201:enzymology; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes / Q000138:chemical synthesis* / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry; D005421:Flavoring Agents / Q000138:chemical synthesis* / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry*; D007536:Isomerism; D008049:Lipase / Q000737:chemistry*; D015394:Molecular Structure; D039821:Monoterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013552:Swine
D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes; D004800:Enzymes, Immobilized; D005421:Flavoring Agents; D005656:Fungal Proteins; D039821:Monoterpenes; D013438:Sulfhydryl Compounds; C016775:alpha-terpineol; D008049:Lipase; C005732:thioacetic acid
esterase; flavor; lipase; thioacetates; thiols; α-terpineol