After sterilization by high pressure steam sterilizer china, the pH value of the medium will drop by 0.2 to 0.3 units. The direction and magnitude of pH change of culture medium after sterilization are affected by many factors. When the medium contains a single component and contains high or high concentrations of substances, the pH value after autoclaving changes greatly.

Autoclaving often decomposes the sucrose water in the medium into monosaccharides, thereby changing the osmotic pressure of the medium. In the range of 8%-20% sucrose, the medium after autoclaving increased by about 0.43 times. The iron in the medium will catalyze the hydrolysis of sucrose during autoclaving, which will decompose 15% to 25% of the sucrose water into glucose and fructose. When the medium value is less than 5.5, the amount of hydrolysis is more. When 0.1% activated carbon is added to the medium, the hydrolysis of sucrose under high pressure is greatly enhanced. When 1% activated carbon is added, the hydrolysis rate of sucrose can reach 5%.