Characterisation of volatile compounds in a smoke flavouring from rice husk

An aqueous smoke flavouring from rice husk was obtained on a laboratory scale. The volatile compounds were isolated by simultaneous steam distillation–solvent extraction and its identification and quantitative composition was studied by GC–MS and GC–FID. A total of 93 compounds were isolated and 86 of them were positively identified. Major compounds (more than 5% GC area) were 2-furfural, phenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, and 2,6-dimethoxyphenol. Application of aroma extract dilution analysis on the volatile fraction revealed that 2-methoxyphenol, 4-methyl-2-methoxyphenol, 2,6-dimethoxyphenol, 2-furfural, 2-acetylfuran, 3-methyl-1,2-cyclopentanedione, acetic acid, 5-methyl-2-furfural, 4-(2-propenyl)-2-methoxyphenol, 4-methyl-2,6-dimethoxyphenol, phenol, 2,6-dimethylphenol, 4-ethyl-2-methoxyphenol, 2-methylphenol were the most odour-active compounds.