Experimental Measurements and Thermodynamic Modeling of CO2 Solubility at High Pressure in Model Apple Juices

Abstract

High pressure carbon dioxide (HPCD) treatment can be used for the pasteurization of liquid foods. Solubility of CO2 in the liquid affects microbial inactivation. Measurement and prediction of CO2 solubility in a real or model system are of industrial relevance since the knowledge of the solubility limits will avoid the use of excess CO2. An experimental apparatus was set up to measure CO2 solubility in ternary mixtures of water−CO2−glucose and water−CO2−malic acid and in a quaternary mixture of water−CO2−malic acid−glucose at different concentrations of malic acid (0.01 and 2.68 g in 100 g of solution, corresponding to 7.5 × 10−5 and 0.02 mols in 100 mols of solution) and of glucose (4 and 12 g in 100 g of solution, corresponding to 0.02 and 0.07 mols in 100 mols of solution). CO2 solubility was also measured in a more complex solution of water−malic acid−ascorbic acid−pectin−glucose−sucrose, based on apple juice composition and in a commercial apple juice. The range of pressure tested was between 7.5 and...