Samples of mannitol's aqueous solution at various contents of dissolved oxygen were frozen with he help of ultrasound and the ice crystals size distributions were measured by optical microscopy. Increasing the oxygen content led to a fair decreasing of the average crystals size and an increasing of the homogeneity of the size of crystals within the sample. The average size appeared simply as inversely proportional to the oxygen content in the initial liquid solution. (C) 2014 Elsevier B.V. All rights reserved.