113 Use of response surface methodology to determine optimum processing conditions for frozen wheat bread dough.

S. Kenny (1,2), H. Grau (1,2), K. Wehrle (1,2), C. M. O’BRIEN (1,2), and E. K. Arendt (2). (1) National Food Biotechnology Centre and (2) Department of Food Science and Technology, University College Cork, National University of Ireland.

Processing conditions have a considerable effect on the quality of frozen dough. In this study we used response surface methodology to examine the effects of processing conditions on frozen dough quality (1). A central composite design was used to evaluate the effects of final dough temperature, rest time and thaw time. The wheat bread formulation used included 2% salt, 2% dry yeast, 3% shortening, 100 ppm ascorbic acid and 0.5% DATEM (diacetyl tartaric acid esters of monoglycerides), all based on % flour weight. Dough temperature was varied from 15 to 30 C and rest time was varied from 0 to 45 min. Thawing was carried out using a dough conditioning programme and thaw time was varied from 6 to 15 hours. Responses measured were proof time, specific volume and texture attributes measured with the texture analyser including hardness, gumminess and chewiness. Dough temperature had the greatest effect on proof time, loaf volume and bread texture. Proof time decreased, loaf volume increased and hardness, gumminess and chewiness values decreased with increasing dough temperature. The response surface design was used to predict processing conditions to give an optimum product with low proof time, producing bread with high specific volume, and low hardness, gumminess and chewiness values. Optimum processing conditions were final dough temperature 28 C, 29 min rest time and 14 hr thaw time.