Analytical assessment of the intensity of heat treatment of milk and dairy products
Sabrina P. van den Oever, Helmut K. Mayer
Abstract
Adequate heat treatment of raw milk is required to guarantee microbiological safety, but there is a huge variation in the heat load of different categories of heat-treated milk due to different thermal treatment temperatures when using different processes. However, uncontrolled "over-processing” of milk leads to certain undesirable losses of nutritional and organoleptic quality. To evaluate the actual intensity of heating, numerous analytical tools have been established to determine several associated time‐temperature integrators. Enzymes are appropriate indicators for the assessment of lower heat treatment; higher heat load can be evaluated using indicators such as β-lactoglobulin, α-lactalbumin, lactulose, furosine, and hydroxymethylfurfural. Analytical methods are mainly based on photometric/fluorimetric methods for determination of enzymatic activity, and high-performance liquid chromatography for β-lactoglobulin, α-lactalbumin, lactulose, furosine, and hydroxymethylfurfural. Capillary electrophoresis and other analytical tools (e.g., gas chromatography, infrared methods) are also appropriate to evaluate the intensity of heat treatment of milk and dairy products.