Water-Holding Capacity of HPMC and Its Antifreeze Effect on Baker's Yeast Cells

Abstract:

In order to study water holding capacity of HPMCand its antifreeze effectonbaker's yeast cells，the method of DSC was used to measure the antifreeze active of HPMC and other cryoprotectants. HPMC was used into frozen dough to detect the frozen watercontent after 45 d. Finally，the yeast cellsviability（η） in samples with different cryoprotectants was investigated in different frozen days and concentration. The experimental results showed that the AF of HPMC changes with its degree of substitution and polymerization，up to 9.82，has a significant advantage than Glutamate and Trehalose，which were 5.99 and 3.98. After being frozen for 45d，the frozen water in the dough with 1% HPMC decreased to 51.3% compared with the 65.2% of control samples. The yeast cellsviability（η） decreased quickly in the first 6d，and was stable after 8d，but the η was increased from 23.2% to 55.5% by adding 1% of HPMC，and η was increasing by theincreasing concentration of HPMC from 0 to 1%.