Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The aim of this study was the methodological use of experimental planning for the optimization of microwave vacuum drying of enzymes using alpha-amylase as a model. A factorial in star design-was used to optimize the microwave vacuum-drying process, and the variables were power output and vacuum pressure. The material dehydrated by this technique was analyzed with regard to its enzymatic activity, water activity, and moisture content. Response surface methodology was used to estimate the main effects of vacuum pressure and power on the enzymatic and water activities. The experimental in star design revealed that microwave vacuum drying is influenced mainly by power. The dehydrated product showed high enzymatic activity and low water activity.291518281835Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [99/12379-5, 01/00571-0]