Because of the high quality demanded by consumers, the study of French fries manufacture considering the product as an homogeneous system does not provide enough information on main compositional and volumetric changes occurring during potato processing. Attending to recent food quality and safety requirements, the SAFES methodology has been developed to precisely describe and quantify changes taking place throughout the operations involved in food processing. Considering different phases, components and aggregation states present in the food and applying the knowledge about its structure and the interactions between its components, those properties directly connected to food quality and safety can be defined. In the present study, the application of SAFES methodology to French fries manufacture has been proved to be a useful tool to describe some textural attributes from quantitative changes in water and oil content, as well as in volume and starch aggregation state. Studying the French fries manufacture process by applying the SAFES methodology also showed the need of additional information in certain areas of knowledge, as it could be the inactivation rate of enzymes that catalyse oxidation and the extraction rate of reducing carbohydrates during the blanching step. Apart from the experimental data and the mathematical models found in the bibliography, several hypotheses were formulated in relation to the amount of water retained by starch granules after the blanching process and the crust formation and development during the deep frying step. Information on water vapour retention by the crust layer at the end of the deep frying process was also considered, as it is directly connected with French fries quality after cooling. (C) 2007 Elsevier Ltd. All rights reserved.