Enzymatic lipophilization of d-borneol extracted from Cinnamomum camphora chvar. Borneol seed

Borneol esters have attracted increasing interest due to their potential application in the food industry. In this study, the extraction of d -borneol from Cinnamomum camphora chvar. borneol seed was carried out via steam distillation to gain highly purified d -borneol (99.66%). The lipase-catalyzed lipophilization of extracted d -borneol with oleic acid was performed in a solvent-free system. The influences of lipase type, substrate molar ratio, lipase loading, reaction temperature and reaction time on d -bornyl oleate yield were evaluated. Among four kinds of commercial lipases screened for their esterification efficiency, CRL (lipase from Candida rugose ) displayed the highest catalytic activity in the synthesis of d -bornyl oleate. The yield of more than 95% was obtained under the optimal conditions: substrate molar ratio 1:2 ( d -borneol/oleic acid), lipase loading 8%, reaction temperature 45 °C, reaction time 48 h. The structural identification of d -borneol and product d -bornyl oleate was performed by gas chromatography mass spectrometry (GC-MS) and proton nuclear magnetic resonance spectroscopy ( 1 H NMR). The results showed that the product was confirmed to be d -bornyl oleate and the purity of which was 97.51%. This study will pave the way for d -borneol and its esters application in food industry.