The present invention relates to a process of preparing a liquid foodstuff, comprising treating at least one juice and/or one extract having a Brix of more than 10°, with carbohydrate oxidase and catalase at a temperature between −10° C. and +15° C. to obtain a substrate mixture, and dispersing oxygen or an oxygen-containing gas in the substrate mixture, without keeping the pH>；3.5 before or during the treatment by addition of buffering substances or basic substances, to obtain a liquid foodstuff, wherein the final pH is lower than 3.5； and wherein the flow rate of the gas is adjusted according to the following equation: (0.001/x) to (0.02/x) L gas/L substrate mixture/min, with x being the content of oxygen by volume in the gas.
