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 °C and CO 2 /sample flow ratio of 0.14 and 0.29 under pressures of 10 to 30 MPa. After the treatment at a CO 2 /sample flow ratio, 0.29 at 10 MPa, remaining percentage ((the concentration in treated sample/that in untreated one) × 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 CO 2 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.