2Department of Food Engineering

URI - Campus de Erechim

Av. Sete de Setembro, 1621

Erechim, RS, 99700 - 000, Brazil

Phone: (54)5209000

Fax: (54)5209090

E-mail: odebora@uricer.edu.br

Limonene, a -pinene and b -pinene are low-priced monoterpenes and are precursors of many flavours and fragrances. Monoterpenes as substrates of microbial transformations have led to a great variety of oxyfunctionalized compounds. Terpenes and their oxygenated derivatives are extensively used by aroma industries. Consumer preference for flavours and fragrances of natural origin, over their synthetic counterparts, has increased the demand for "natural" products. Bioconversion or biotransformation can be used to convert monoterpene precursors into the more valuable "natural" flavours and fragrances. In this context, the main objective of this work was to investigate the biotransformation of (-)a -pinene, (-)b -pinene and D-limonene by Aspergillus niger ATCC 9642. The culture conditions involved, concentration of co-solvent (EtOH) and substrate applied and the sequential addition of substrates were investigated. Adaptation of the pre-cultures with small amounts of substrate was also studied. The experiments were performed in conical flasks with liquid cultures. The strain of A. niger was able to convert only (-)b -pinene to a -terpineol as sole product. The optimum conversion of (-)b -pinene to a -terpineol was obtained when the substrate was applied as a diluted solution in EtOH and when sequential addition of substrate was used.