METHOD FOR DIRECT OBTAINING OF SMOKE LIQUIDS

摘要

A method for direct obtaining of benzo(a)pyrene-free liquid smoke by oxidative pyrolysis of wood or other lignocellulosic biomass in an externally heated flow reactor in superheated water vapour medium in the presence of a limited amount of air is proposed. The vapours and gases of wood thermal degradation formed as a result of restricted combustion and heating are oxidized, and the characteristic composition of curing smoke components (acids, phenols, carbonyl compounds) is formed, which imparts the typical aroma, flavour and resistance against the lipid oxidation during smoking or treatment with liquid smoke to the treated food-stuffs. To present the formation of carcinogenic polycyclic aromatic hydrocarbon substances, it is recommended to perform the oxidative pyrolysis in the superheated water vapour medium, which improves the heat transfer from the gaseous phase to the solid one and prevents the heating up of the wood carbonaceous residue above 350-400oc, the evaporation of polycyclic aromatic hydrocarbons and getting of carcinogenic substances, e.g. benzo(a)pyrene in the condensates. The presence of the surplus water vapour enhances the condensation of smoke components and produces liquid smoke directly without processing of the primary smoke condensate and dilution. The liquid smoke does not contain benzo(a)pyrene.