Modelling the fate of glucosinolates during thermal processing of Brassica vegetables

Glucosinolates are secondary metabolites of Brassica vegetables that have been associated with health benefits. The concentrations of these compounds are strongly affected by processing of the vegetables. Various mechanisms are responsible for these changes: Lysis of plant cells and compartments, diffusion and leaching of glucosinolates and myrosinase (a plant enzyme able to hydrolyze glucosinolates) into the cooking water, enzymatic hydrolysis of glucosinolates, inactivation of myrosinase and thermal degradation of glucosinolates. This publication presents a dynamic mathematical model that includes these mechanisms with their estimated parameters and the effect of temperature on them.Simulations made by the model for several process conditions show losses of glucosinolates as a consequence of domestic boiling of 69%, microwaving of 8%, industrial blanching of 37% and by industrial sterilization of 82%.The model can assist in adapting the processing conditions like the time–temperature profile and the vegetable–water ratio to optimize industrial and domestic processing of Brassica vegetables in terms of health benefits. In addition this model can help to add the effect of vegetable preparation practices on the quantitative glucosinolate intake in epidemiological studies.

► A mathematical model of glucosinolate losses during thermal processing is described.
► Glucosinolate losses from Brussels sprouts during various processes are predicted.
► Losses were higher during cooking than during microwaving or blanching.
► The model can improve epidemiological studies by providing realistic intake levels.
► The model can be used to improve industrial processes in terms of health aspects.