University of Tehran Press Iranian Journal of Biosystem Engineering 2008-4803 45 1 2014 05 22 Effect of Pre-fermentation and Freezing Temperature of Sangak Dough on the Yeast Activity and Sangak Bread Volume Effect of Pre-fermentation and Freezing Temperature of Sangak Dough on the Yeast Activity and Sangak Bread Volume 81 87 51294 10.22059/ijbse.2014.51294 FA Sayyed Vahid Ayati corresponding author Naser Hamdami Second Author Journal Article 2013 04 06 In this study the impact of freezing rate and degree of pre-fermentation on Sangak frozen dough and its bread was assessed. The pre-fermentation was between zero and 120 min and the corresponding secondly fermentation was between 120 and 0 min, respectively, to obtain total fermentation time of 120 min. The pre-fermentation dough was formed in flat shape and frozen under -20, -25 and -30 °C. It was followed by one day storage at -18 °C. After storage period a second fermentation (in some case there was no second fermentation) was done and in order to finish the fermented dough was baked. Sangak frozen dough quality was assessed by measuring yeast survival and gassing power after thawing. Characteristics of frozen dough bread were evaluated by measuring density after baking. Results showed that viability of yeast initially increased and then decreased by increasing freezing rate, so that at -25 °C the most viability was observed. The maximum yeast viability was observed at short pre-fermentation (30 min). A direct relationship was observed between gassing power and yeast viability. The lowest bread density was obtained with the highest freezing rate and with the short pre-fermentation time. In this study the impact of freezing rate and degree of pre-fermentation on Sangak frozen dough and its bread was assessed. The pre-fermentation was between zero and 120 min and the corresponding secondly fermentation was between 120 and 0 min, respectively, to obtain total fermentation time of 120 min. The pre-fermentation dough was formed in flat shape and frozen under -20, -25 and -30 °C. It was followed by one day storage at -18 °C. After storage period a second fermentation (in some case there was no second fermentation) was done and in order to finish the fermented dough was baked. Sangak frozen dough quality was assessed by measuring yeast survival and gassing power after thawing. Characteristics of frozen dough bread were evaluated by measuring density after baking. Results showed that viability of yeast initially increased and then decreased by increasing freezing rate, so that at -25 °C the most viability was observed. The maximum yeast viability was observed at short pre-fermentation (30 min). A direct relationship was observed between gassing power and yeast viability. The lowest bread density was obtained with the highest freezing rate and with the short pre-fermentation time. https://ijbse.ut.ac.ir/article_51294_8075d0ac9c83695b1fdb13dd4d81147b.pdf