The effect of high pressure homogenization on microorganisms in milk

Milk is a highly consumed product worldwide mainly because of nutrient content, but this rich composition associated to pH and water activity makes the milk an ideal medium for microbial growth. The thermal process is usually applied to guarantee microbial stability of milk, however, the heat promotes undesirable changes in the milk sensory and nutritional characteristics. Therefore, recent researchers have developed alternative non-thermal methods to obtain safe milk. High pressure homogenization (HPH) is based upon common milk homogenization processes, though it uses 10-15 times higher pressures, which makes the process able to promotes microbiological reduction. This review evaluated the application of HPH into fluid milk processing for microbiological reduction and also how the process condition (i.e. pressure, inlet temperature) and milk composition can affect the efficacy of this new process.