Cryoresistance of Baker's yeast Saccharomyces cerevisiae in frozen dough : contribution of cellular trehalose

Cereal Chem. 72(6):609-615 The effects of freezing on gas production of two baker's yeast strains then examined by following the changes in yeast trehalose content in (A and B) were studied in dough. A specific parameter, the mean volume dough. Cryoresistance was not directly correlated with the initial amount (volm), obtained from the area under the gassing curve was shown to be of trehalose in the yeast nor with the level still present in the dough at the best expression of overall yeast dynamics during fermentation. the time of freezing. However, when the trehalose level dropped below Assessing the specific freeze-thaw and frozen storage resistances of 5%, the delayed frozen storage resistance was clearly lowered. A 4-5% yeasts showed that strain B was particularly cryoresistant. Immediate trehalose content at freezing appeared to be sufficient to prevent yeast freeze-thaw resistance of both yeasts was unaffected by 1 or 2 hr of from indirect chilling injury during frozen storage. A higher quantity of prefermentation before freezing, which is not the case for frozen storage cellular trehalose does not contribute to further cryoresistance. resistance. The possible cryoprotective role of cellular trehalose was