A simulation model of an integrated blancher/cooler machine to optimize the blanching process has been developed. The model determines the thermal treatment that, assuring the quality of the product by means of the enzyme inactivation, minimizes its specific costs. The model also simulates the loss of a significant quality factor for many of the vegetables: the ascorbic acid. The loss of this vitamin was taken as indicator of the intensity of the thermal treatment. The use of recycled water was also studied. With this model, specific energy consumption, loss of vitamin C, enzyme inactivation and blanching capacity can be determined as a function of design variables, such as the number of zones in the preheating, blanching and cooling sections, the water flow rate and the characteristics of the thermal treatment to be applied to the product. (C) 2003 Elsevier Science Ltd. All rights reserved.