12. Effect of Eutectic Temperature on Freeze-Thaw pamage of Yeast

Abstract

The viability of Saccharomyces cerevisiae suspended in NaCl solution decreased markedly when the suspension was frozen to the temperature to form a eutectic mixture, whereas the suspension in CaCl_2 gave good survival of the cells. The difference between two groups of compounds, which involve NaCl and CaCl_2, respectively, on the freeze-thaw damage was studied. The viability of yeast cells decreased markedly when the formation of eutectic mixture was completed between about -10 and -40℃ in the solution of each compound. On the other hand, it hardly decreased when the formation of eutectic mixture was not completed in the range. These results suggest that compounds which had eutectic temperature in this range will give lower survival of yeast cells in the freezing process.