Deodorization of Fish Sauce by Continuous‐Flow Extraction with Microbubbles of Supercritical Carbon Dioxide

Abstract

ABSTRACT: 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.