THE SIGNIFICATION OF STERILIZATION VALUES OF UHT-HEATING OF MILK

Since the beginning of the 1990's the sterilization value F0 (F-value) , which depends on the destruction of spores of Clostridium botulinum, has been used for evaluating the microbiological efficiency of steril ization processes. In 1980 milk-specific F-values based on the chemica l changes of the content of milk ingredients were used to evaluate the UHT process for the first time. All ingredients of milk, which follow a linear reduction- or formation-curve in a half-logarithm temperatur e-time-diagram as a result of UHT-heat treatment, could be used to cal culate the various different F-values. Systematic investigations for n umerous milk ingredients have shown that this is indeed the case. Beca use the destruction curves for microorganism are steeper than those fo r chemical reactions of milk ingredients, it is possible to optimize U HT-processes in respect of necessary microbiological destruction and m inimum change of the product. The basics for calculating sterilization values and for evaluating the dimension of microbiological destructio n and chemical change of milk ingredients will be discussed in this re view.