Glucosinolates (GSs) are secondary metabolites of Brassica vegetables that are associated with health benefits. The concentrations of these compounds are strongly affected by processing of the vegetables. During thermal treatment of Brassicaceae, such as domestic cooking, different mechanisms affecting the content of GSs can take place and were modeled in the present study: Lysis of plant cells and compartments, leaching of GSs into the cooking water and thermal degradation of GSs in both the intact vegetable tissue and the cooking water. These mechanisms were described mathematically and the model parameters for broccoli, Brussels sprouts, red cabbage and white cabbage were estimated based on experimental results. Differences between the thermostability of the same GSs originating from different Brassicaceae could be detected, as well as differences between the thermostability of the same GSs in the vegetable matrix compared to that in the cooking water. Industrial relevance: This mathematical model and the estimated parameters can be used to simulate the different glucosinolate contents in prepared foods considering the processing method. This will be a very useful tool for food research and industry to make predictions about the nutritional quality of foods and to optimize their health related quality attributes.