Application of SAFES (systematic approach to food engineering systems) methodology to apple candying

Abstract

The application of a vacuum pulse for a specified time before long term osmotic dehydration has been proposed to obtain candied fruits at mild temperatures, thus maintaining the characteristic attributes of fresh fruits. Information about main changes involved in apple candying by long term pulsed vacuum osmotic dehydration is missed by applying traditional methods of modelling foods and processes. A new systematic approach to food engineering systems (SAFES) methodology has been recently developed and applied to predict quality and safety attributes from compositional and volumetric changes taking part throughout food processing. Identification and quantification of main components, phases and aggregation states at different stages of changes in which the process can be divided into would be required. Apart from experimental data and data found in references, several hypotheses related to water and soluble solids flow were also formulated for this purpose. The application of SAFES methodology to the apple candying process highlights the usefulness of this tool in making evident that different mechanisms are involved in the process in a coupled way. Indeed, not only osmotic, but also pseudo-difusional and hydrodynamic mechanisms were responsible for compositional and volumetric changes occurring during apple candying to a different extend, depending on the concrete stage of the process. As a result, it should be necessary to analyse the process in different steps in order to avoid a confused knowledge of it.