Flavour retention and removal of dissolved carbon dioxide in the solution treated with low-pressure carbon dioxide microbubbles

Abstract

Pressurized carbon dioxide (CO2) is a promising technique for inactivating enzymes and microorganisms in food, although there are no discussion about handling of residual CO2. Therefore, the effect of cooling temperature and nitrogen (N2) gas flow on removing dissolved carbon dioxide (CO2) were investigated as means of retaining the flavour components in a model solution containing sake flavour treated with low-pressure CO2 microbubbles (MBCO2). The residual ratios of ethyl acetate, isobutyl alcohol and isoamyl alcohol in the model solution were largely uninfluenced by adding MBCO2 to the mixing vessel. However, isoamyl acetate, isobutyl acetate and ethyl caproate were significantly lost by heating to 65 °C, although these component loss could be prevented by cooling to below 20, 10 and 5 °C, respectively. Furthermore, even if dissolved CO2 in model solution treated with MBCO2 was removed by N2 gas flow, the flavour components levels were comparable to those before degassing. These results suggested that N2 gas flow with a Y-branch after cooling below 5 °C was a promising method for removing dissolved CO2.