DOI: 10.1094/CC-82-0251 |  VIEW ARTICLE

Ice in Prefermented Frozen Bread Dough—An Investigation Based on Calorimetry and Microscopy.

A. Baier-Schenk (1), S. Handschin (1), and B. Conde-Petit (1,2). (1) Laboratory of Food Chemistry and Technology, Institute of Food Science and Nutrition, Swiss Federal Institute of Technology (ETH) Zurich, Switzerland. (2) Corresponding author: <beatrice.conde@ilw.agrl.ethz.ch> Cereal Chem. 82(3):251-255. Accepted January 31, 2005. Copyright 2005 AACC International, Inc.

The amount, morphology, and distribution of ice in prefermented frozen bread dough were investigated by differential scanning calorimetry (DSC) and cryoscanning electron microscopy (cryo-SEM). Bread dough was frozen after proofing, stored frozen at –22 ± 3°C and analyzed without previous thawing. At constant storage conditions, the ice fraction amounted to 53% of the total water and remained constant even over a period of 56 days. Unlike other frozen food foams, ice crystals were observed in the gas pores of the dough. Ice crystals were already present at 1 hr after freezing. Crystal growth and rounding off by recrystallization was observed after 1 day of frozen storage. After 149 days, crystal size reached several 100 µm. It is concluded that growth of ice crystals leads to a redistribution of water in the dough mix in the form of ice, which in turn affects the properties of polymeric compounds in dough and reduces the baking performance of prefermented frozen doughs.