Résumé :
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Freeze concentration is a relatively new method for removing water from aqueous solutions, e.g. coffee, tea, fruit juices and milk. It offers several advantages in product quality, aroma retention and product yields. The basic principle is cooling the solution to temperatures below its freezing point to produce ice crystals which can then be removed. The freeze concentration technique studied used a unique system of removing the ice crystals, leaving a solution with an increased total solids content. Experiments performed in a single-stage freeze concentration pilot plant with skim milk, whole milk and a diacetyl-containing liquid showed that concentration of the solids content up to 36, 38 and 49%, respectively, was possible. The product quality was good and the aroma retention in the diacetyl-containing liquid was high (99.5%). Product losses were relatively low (
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