The apparent rate constants of freeze inactivation (KF) at different storage temperatures for various salts were calculated. Comparisons were then made among salts with relation to storage temperature and ionic strength of unfrozen salt solutions. For three kinds of sulfates with high eutectic points,hardly any change occured in relation to the storage temperature and ionic strength. The reason was thought to be the weaker action of sulfates to protein denaturation. The K
F values of six kinds of salts (namely NH
4Cl, NaNO
3, Mg(NO
3)
3, BaCl
2, CaCl
2 and MgCl
2 ) were highest in the temperature range of - 6~-14 °C. The extent of denaturation in the K
F value differed for each salt,although,no relationship was found between maximum KF value and eutectic point. A possible explanation for the above results relates to the amount and ionic strength of unfrozen salt solution. The log K
F increased with an increase in ionic strength,and reached a maximum at about 0.9 due to the effect of salt concentration. However,above an ionic strength of 0.9, the log K
F decreased with an increase in ionic strength due to the decrease of unfrozen salt solution.
抄録全体を表示