1. Effect of Storage Period on Survival of Freeze Tolerant Yeast and on the Rheological Properties of Frozen Dough
- Author
-
Sadako Takasaki and Keiko Karasawa
- Subjects
Torulaspora delbrueckii ,Rheology ,biology ,Survival ratio ,digestive, oral, and skin physiology ,fungi ,food and beverages ,Frozen storage ,Food science ,biology.organism_classification ,Saccharomyces ,Yeast - Abstract
The survival of yeast in frozen dough in several stages in the baking process up to 10 weeks of frozen storage and the rheological properties of thawed dough were determined to clarify the causes of bread deterioration during long storage. Torulaspora delbrueckii was used as a freeze tolerant yeast and Saccharomyces cereuisiae as a freeze sensitive yeast. The survival yeast counts were constant in several steps of the breadmaking process before baking in non-frozen and frozen dough with both types of yeasts. The frozen dough using T. delbrueckii retained constant survival yeast counts for 10 weeks, but there was a decrease in the fermentative ability per yeast cell during longer storage. With white bread dough using T. delbrueckii, the fermentative ability gradually decreased, and with sweet bread dough, it decreased quickly from 4 weeks on. The survival counts of yeast on S. cereuisiae were 30% for white bread dough after 1 week storage and 70% for sweet bread dough. The changes in the rheological properties started immediately after freezing and the adhesiveness of thawed dough increased with the length of the storage period in every case regardless of the survival ratio of yeast cells. The long storage of frozen dough with T. delbrueckii has a negative effect on the quality of bread and appliable storage period is under 3 weeks. more...
- Published
- 1992
- Full Text
- View/download PDF