The fluorimetric FAST method, a simple tool for the optimization of microwave pasteurization of milk.

The effect of microwave pasteurization of cow's milk on its nutritional quality was examined by the FAST method (Fluorescence of Advanced Maillard products and Soluble Tryptophan). Raw milk samples were submitted to different laboratory scale in batch microwave treatments using a central composite experimental design based on specific power and treatment time. The FAST index and bacterial count were monitored to assess protein denaturation, modification by the Maillard reaction and pasteurization efficiency, respectively. High discrimination between samples indicated that the FAST method is a potent tool for estimating the deterioration of the milk quality during experimental microwave treatment. Thus, the FAST index can be effectively used as the continuous response in experimental designs set up and to maximize information economically. In short, the FAST method allows us to retain the rapidity of experimental design while providing the advantages of convenience and low cost.