| 摘要 |
A method for preparation of smoke extract from wood tar for flavouring and colouring of food products is disclosed. The smoke extract is with the present method produced by means of supercritical extraction of fractions of the wood tar. The extractions solvent, such as carbon dioxide, has very good properties of entraining and resolving the required fractions of the wood tar, and it is relatively simple to separate the resolved components in the retrieving process, as the different components have different solubility at different supercritical and subcritical conditions. Thus, a smoke extract containing less than 10 ppb (parts per billion) of benzo (a) pyrene and less than 20 ppb of benzo (a) athracene may be obtained. In one embodiment, the wood tar is subject to a separation process prior to the supercritical extraction to remove a substantial part of the unwanted components. |
