Deodorization of fish sauce by continuous-flow extraction with microbubbles of supercritical carbon dioxide

Volatiles were removed from fish sauce by continuous-flow extraction with microbubbles of supercritical carbon dioxide. The extraction was done at 35 degreesC and CO2/sample flow ratio of 0.14 and 0.29 under pressures of 10 to 30 MPa. After the treatment at a CO2/sample flow ratio, 0.29 at 10 MPa, remaining percentage ((the concentration in treated sample/that in untreated one) x 100) was 5.2% trimethylamine, 8.0% S-methyl ethanethioate 30% dimethyldisulfide, 55 to 61% aliphatic aldehydes, and 25 to 42% carboxylic acids. The increase in CO2 flow rate improved the extraction efficiency significantly but no effect of pressure was observed. The odor intensities of treated samples were between 1/4 and 1/8 of the untreated fish sauce.