Freeze-thaw stability of prefermented frozen lean wheat doughs: effect of flour quality and fermentation time

The effects of fermentation time and flour quality on the baking quality of prefermented frozen wheat doughs were studied. The doughs were baked from six different flours and fermented optimally (40 min) and less than optimally (25 min) before freezing. After frozen storage (1-14 days), the baking quality was evaluated and the structure of the doughs was studied by microscopic and rheological methods. Fermentation time had a dramatic effect on the freezing and thawing stability of the doughs. With one-day storage, the loaf volumes were, on average, 20% greater after shorter than after longer fermentation time. Moreover, with interrupted fermentation the change in loaf volume due to freezing was almost independent of flour quality. Microstructural and rheological studies showed that the reason for these improvements was a thicker gluten network and greater amount of small gas bubbles. However, the interrupted fermentation did not reduce the deterioration of loaf volumes during longer storage times. The most significant decrease (11% of the fresh volume) occurred during the first week but continued during the second week of frozen storage (up to 15% of the fresh volume).