- 期刊
高温殺菌的理論－Ball氏的Z值與Arrhenius方程式的關係
Death of bacteria at elevated temperature-Ball's Z value and the Arrhenius equation
摘要
細菌的存在是造成食品腐壞的重要因素，食品能否保存全賴殺菌適當或否。Charm說在高溫殺菌時所畫的對數殘存曲線（Iogarithmic survival curve）可以由化學動力學導出。Balla曾以Z值討論罐頭食品中微生物對熱的抵抗性。Johnson認爲Z值僅在某狭隘的溫度範圍內，可以適用。而Kempe指出Z值與賦活能（activation energy）△Ha間有矛盾之處。本文特以數學方法根據化學動力學方程式，針對Kempe的意見，導出Z值與Arrhenius方程式的關係。
關鍵字
無資料並列摘要
Bacteria can be killed in many ways, which are treatments with chemical poisons, extreme cold, heat, very high pressure, desication, ultrasonic waves and ionizing radiations, etc. In recent years, there are many bacterologists interesting in heat sterilization. Ball's Z value has been used to predict the time for the sterilization of canned foods. Although Kempe mentioned in his discussion that the contradiction between Z value and activation energies is not adequately recognized, Johnson has told that the Z value is useful for the narrow temperatere ranges. Such a kind of view was also discussed by Charm. The writers were stimulated by Kempe's discussion m and worked on the mathematical derivation of the relation between Z value and activation energies or Anhenius equation with the help of Physics Department. Thus a correlation was established by the writers mathematically both from kinetic approach and the definitions of decimal reduetion time (D) and Z value (see Eqs. 1, 2. 10, 11); it was learned that, unless the temperature ranges for inactivation of bacterial spores is narrow enough, the Z value is not a constant but agrees with a fraction of Arrhenius equation, the reciprocal of △Ha/2.3RT^2 or d log K/2.3dT (see Eqs. 16, 18); 1/Z=d log K/2.3dT=△Ha/2.3RT^2 In pure chemistry, if t he temperature is higher, 1/Z or d log K/2.3dT will becomes smaller. This may be responsible for the contradiction between Z value and its prediction in flash sterilization discussed by Kempe in the same article that the Z value method indicating the longest time as much as 35 folds at 310°F.